Inertial measurement unit

An inertial measurement unit includes: a sensor unit having at least one inertial sensor; a display unit performing a display based on detection information from the inertial sensor; and a mode changeover switch. The mode changeover switch changes a display mode of the display unit.

The present application is based on, and claims priority from JP Application Serial Number 2019-178184, filed Sep. 30, 2019, the disclosure of which is hereby incorporated by reference herein in its entirety.

BACKGROUND

1. Technical Field

The present disclosure relates to an inertial measurement unit and the like.

2. Related Art

Recently, with the increasing precision of manufacturing devices and measuring devices or the like, vibration measurement to improve the efficiency and yield of production processes has become more important. Therefore, simplified device vibration measurement and ambient vibration measurement are desired. For example, JP-A-2016-205868 discloses a vibration monitoring device in which a vibration detection unit detects a vibration, using a vibration sensor, and wirelessly transmits vibration data acquired by the detection, and in which a vibration monitor receives the transmitted vibration data and displays the vibration data at a display unit. In this vibration monitoring device, the vibration detection unit detects a vibration of a device and an ambient vibration, and the detected vibration data can be displayed at the display unit of the vibration monitor provided separately from the vibration detection unit.

Using an inertial measurement unit having an inertial sensor such as an acceleration sensor or angular velocity sensor enables the monitoring of the state of a device or the monitoring of the ambient state as described above. However, when using the technique of displaying the result of the measurement by the inertial measurement unit at the display unit provided separately from the inertial measurement unit, as in JP-A-2016-205868, the user needs to check the result of the measurement by looking at the display unit provided separately from the inertial measurement unit. This makes the checking work complicated for the user. Also, since the content of information to be displayed at the display unit based on the detection information from the inertial sensor varies depending on the user using the inertial measurement unit, various demands about the display form of the display information need to be met.

SUMMARY

An aspect of the present disclosure relates to an inertial measurement unit including: a sensor unit having at least one inertial sensor; a display unit performing a display based on detection information from the inertial sensor; and a mode changeover switch. The mode changeover switch changes a display mode of the display unit.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

An embodiment will now be described. The embodiment described below does not unduly limit the contents described in the appended claims. Not all the components described in the embodiment are essential components.

1. Inertial Measurement Unit

FIG. 1is a perspective view showing a configuration example of an inertial measurement unit10according to this embodiment. The inertial measurement unit (IMU)10includes a sensor unit20. The inertial measurement unit10can also include fixing members11,12,13, a substrate40, a base150, and a protection plate160. InFIG. 1, a direction from the inertial measurement unit10toward an installation surface2for the inertial measurement unit10is defined as a direction DR1, and a direction orthogonal to DR1is defined as a direction DR2. The direction DR1is a direction orthogonal to the installation surface2and, for example, orthogonal to a main surface of the sensor unit20. The main surface is a top surface or bottom surface of the sensor unit20and, for example, a surface orthogonal to a lateral surface. A direction DR3is a direction orthogonal to the direction DR1and the direction DR2. Directions DR4, DR5, DR6are the opposite directions of the directions DR1, DR2, DR3, respectively. The directions DR1, DR2, DR3, DR4, DR5, DR6are a first direction, a second direction, a third direction, a fourth direction, a fifth direction, and a sixth direction, respectively.

The sensor unit20includes at least one inertial sensor. The inertial sensor is a physical quantity sensor detecting physical quantity information. Specifically, as described later with reference toFIGS. 15, 16, and 17, the sensor unit20includes at least one acceleration sensor, as at least one inertial sensor. Alternatively, the sensor unit20includes at least one acceleration sensor and at least one angular velocity sensor, as at least one inertial sensor. The angular velocity sensor is, for example, a gyro sensor. The inertial sensor is not limited to the acceleration sensor or the angular velocity sensor and may be any sensor configured to detect information about inertia by any detection technique. The inertial sensor may be a physical quantity sensor configured to detect a physical quantity equivalent to an acceleration or angular velocity. The inertial sensor may be, for example, a physical quantity sensor configured to detect a physical quantity such as a velocity or angular acceleration. The sensor unit20includes a case24. For example, the sensor unit20includes a sensor substrate210provided with at least one inertial sensor, and the case24accommodating the sensor substrate210, as shown inFIGS. 15 to 17, described later. The case24is formed of an electrically conductive member such as a metal and is provided with the sensor substrate210in an accommodation space inside the case24.

The substrate40is provided with at least one of a processing unit50and a display unit60. InFIG. 1, both of the processing unit50and the display unit60are provided at the substrate40. However, for example, only the processing unit50may be provided at the substrate40, or only the display unit60may be provided at the substrate40. The substrate40is a circuit board, for example, a printed circuit board where a metal wiring is formed. The substrate40is, for example, a rigid substrate.

The processing unit50performs processing based on detection information from the inertial sensor of the sensor unit20. The processing unit50is a processing circuit and can be implemented by a processor such as an MPU or CPU. Alternatively, the processing unit50may be implemented by an ASIC (application-specific integrated circuit) by automatic placement and routing of a gate array or the like. For example, the processing unit50is electrically coupled to the inertial sensor of the sensor unit20via a connector or the like, as described later. The detection information from the inertial sensor is inputted to the processing unit50via the connector or the like. The detection information is, for example, acceleration information, angular velocity information, or information based on these pieces of information. The processing unit50performs various kinds of processing based on the detection information from the inertial sensor. For example, the processing unit50performs processing to process the detection information. For example, the processing unit50performs processing to process the detection information into information that is appropriate as display information to be displayed at the display unit60or at a display unit70shown inFIG. 2, described later. The processing unit50also performs analysis processing to analyze the detection information. For example, the processing unit50performs analysis processing to analyze a vibration, tilt, or attitude or the like of a measuring target, based on the detection information from the inertial sensor. For example, the processing unit50performs FFT analysis (Fast Fourier Transform analysis) and thus analyzes a frequency component of vibration information or the like, as the analysis processing.

The display unit60inFIG. 1and the display unit inFIG. 2perform a display based on the detection information from the inertial sensor of the sensor unit20. For example, when the inertial measurement unit10has the processing unit50and the display units60,70, the processing unit50performs processing based on the detection information from the inertial sensor, and the display units60,70performs a display based on the result of the processing by the processing unit50. For example, display information based on the result of the processing on the detection information by the processing unit50is displayed at the display units60,70. For example, when the processing unit50performs processing to process the detection information, the display units60,70display display information corresponding to the processed detection information. When the processing unit50performs analysis processing to analyze the detection information, the display units60,70display display information corresponding to the result of the analysis. For example, inFIG. 1, the display unit60, which is a display device, has light-emitting element groups62,64. The light-emitting element of the light-emitting element groups62,64is an element converting an electrical signal into a light signal and can be implemented by a semiconductor element such as a light-emitting diode (LED). Alternatively, the light-emitting element may be implemented by other elements than the semiconductor element. InFIG. 2, the display unit70, which is a display module, has a display panel72. The display panel72is, for example, an organic EL panel, liquid crystal panel or the like.

The substrate40is also provided with a mode changeover switch80, a reset switch82, and a measurement start switch84. The substrate40is also provided with a wireless communication unit90and an antenna unit92. These switches and the wireless communication unit90and the like will be described in detail later.

The substrate40is also provided with an interface unit100. The interface unit100performs wired communicates with outside. For example, the interface unit100implements a communication interface such as UART (universal asynchronous receiver/transmitter), GPIO (general-purpose input/output), or SPI (serial peripheral interface). The UART is an asynchronous serial communication interface. The GPIO is a general-purpose communication interface whose operation can be controlled by the user at the time of execution. The SPI is an interface communicating via three or four signal lines including a serial clock signal line, a serial data signal line and the like. The substrate40is also provided with an interface unit101implementing a JTAG or similar communication interface.

The substrate40is also provided with memories102,103,104. The memory102is, for example, a non-volatile memory and is implemented, for example, by an EEPROM (electrically erasable programmable read-only memory) where data is electrically erasable, or an OTP (one time programmable) memory using a FAMOS (floating-gate avalanche injection MOS) or the like. The memories103,104are, for example, SRAMs temporarily storing data. The substrate40is also provided with a power interface106. External power is supplied to the inertial measurement unit10via the power interface106.

The inertial measurement unit10includes the base150. The base150is a member for installing the inertial measurement unit10at the installation surface2. For example, the sensor unit20is provided between the base150and the substrate40, and the base150is fixed to the sensor unit20by the fixing members11,12,13, which are at least one fixing member. For example, the base150is provided between the sensor unit20and the installation surface2. The installation surface2is, for example, a surface of a device such as a manufacturing device or a measuring device, or a floor surface where the device is installed. The base150has a recess154at a bottom surface, which is the surface facing the installation surface2. In cases such as where the inertial measurement unit10is installed at the installation surface2via a double-sided adhesive tape, the provision of such a recess154can make it easier to strip off the double-sided adhesive tape. The sensor unit20is provided in contact with the top surface of the base150.

The protection plate160is a member for protecting the substrate40. The substrate40is provided between the sensor unit20and the protection plate160. Thus, the components installed at the substrate40such as the processing unit50, the display unit60, and the wireless communication unit90can be protected using the protection plate160. For example, the protection plate160, which is a first protection plate, is a transparent or semitransparent plate-like member and can be implemented, for example, by a resin plate of acryl or the like. The protection plate160may be formed of other materials than acryl. The protection plate160may be, for example, a resin plate of ABS or PET, or may be formed of other materials than resin.

The inertial measurement unit10includes at least one fixing member removably fixing the sensor unit20and the substrate40together. Specifically, inFIG. 1, the inertial measurement unit10includes the fixing members11,12,13as at least one fixing member. Although the three fixing members11,12,13are provided inFIG. 1, the number of fixing members may be two or fewer, or four or more. InFIG. 1, columnar members are provided as the fixing members11,12,13. That is, the fixing members11,12,13are columnar members having the longitudinal direction thereof along the direction DR1. As described later, the columnar members are provided in such a way as to penetrate holes in the sensor unit20, the substrate40and the like.

FIG. 2shows another configuration example of the inertial measurement unit10. InFIG. 2, a substrate48is provided in addition to the configuration shown inFIG. 1. The substrate48is provided with the display unit70having the display panel72. The display panel72, which is an organic EL panel or liquid crystal panel, performs a display based on the detection information from the sensor unit20. For example, the processing unit50provided at the substrate40, which is a first substrate, performs analysis processing to analyze a vibration or the like of a measuring target such as a device or floor surface, based on the detection information from the inertial sensor of the sensor unit20. The display unit70provided at the substrate48, which is a second substrate, displays information about the result of the analysis processing. For example, the display unit70displays information about the result of analysis such as FFT on the vibration of the measuring target. The display unit70displays, for example, information about a peak frequency or peak value of the vibration.

InFIG. 2, a protection plate170is provided in addition to the protection plate160. The protection plate170is, for example, a protection member for the substrate48. For example, the substrate48is provided between the protection plate160and the protection plate170. Thus, the protection plate170and the like installed at the substrate48can be protected using the protection plate170. For example, the protection plate170, which is a second protection plate, is a transparent or semitransparent plate-like member and can be implemented, for example, by a resin plate of acryl or the like. The protection plate170as the second protection plate may be formed of other materials than acryl and may be formed of other materials than resin, similarly to the protection plate160as the first protection plate. In this way, inFIG. 2, the substrate48is provided between the protection plate160and the protection plate170, and the substrate40is provided between the sensor unit20and the protection plate160.

The protection plate170is provided with a window174. At the position of this window174, the display unit70installed at the substrate48is arranged. This enables the user to view the information displayed at the display unit70, via the window174.

FIG. 3is an exploded perspective view of the inertial measurement unit10. As shown inFIG. 3, the sensor unit20is provided with a plurality of holes21,22,23, and the substrate40is provided with a plurality of holes41,42,43. As the fixing members11,12,13, which are columnar members, fit into the plurality of holes41,42,43provided in the substrate40and the plurality of holes21,22,23provided in the sensor unit20, the sensor unit20and the substrate40are removably fixed together. Specifically, the fixing members11,12,13are provided in such a way as to penetrate the holes41,42,43in the substrate40and the holes21,22,23in the sensor unit20. Also, the base150is provided with holes151,152,153. As the fixing members11,12,13, which are columnar members, fit into the holes151,152,153provided in the base150, the base150is fixed to the sensor unit20. Also, the protection plate160is provided with a plurality of holes161,162,163and the protection plate170is provided with a plurality of holes171,172,173. As the fixing members11,12,13fit into the holes161,162,163and the holes171,172,173, the protection plates160,170are removably fixed together.

For example, the fixing members11,12,13, which are columnar members, are screw members. That is, the fixing members11,12,13are male screws threaded on the outer circumference. The holes151,152,153in the base150are female screws threaded on the inner circumference. Thus, the distal ends of the fixing members11,12,13, which are screw members, can be screwed into the holes151,152,153in the base150. This enables the fixing of the sensor unit20, the substrate40, the protection plates160,170and the like to the base150. The holes21,22,23in the sensor unit20, the holes161,162,163in the protection plate160, and the holes171,172,173in the protection plate170are not threaded on the inner circumference. However, a modified embodiment where these holes are threaded can be employed as well.

As shown inFIG. 3, spacers14,15,16are provided at positions corresponding to the holes41,42,43in the substrate40. Also, spacers17,18,19are provided at positions corresponding to the holes161,162,163in the protection plate160. When fixing, the fixing members11,12,13penetrate the holes in these spacers14,15,16,17,18,19. Providing such spacers14,15,16,17,18,19enables provision of a space between the substrate40and the protection plate160and between the protection plate160and the protection plate170.

Also, a modified embodiment where the holes in the spacers14,15,16,17,18,19are formed as female screws threaded on the inner circumference can be employed as well. As shown inFIG. 3, the substrate48can be installed as supported by the substrate40using a support part44. The protection plate160is provided with a slit164. As the support part44is installed in such a way as to penetrate the slit164, the protection plate160is arranged between the substrate40and the substrate48.

FIG. 4is a side view of the inertial measurement unit10.FIG. 5is a bottom view. As shown inFIG. 4, the sensor unit20is provided between the base150and the substrate40. The substrate40is provided between the sensor unit20and the protection plate160. The substrate is provided between the protection plate160and the protection plate170. As described with reference toFIG. 3, the fixing members11,12,13, which are columnar members, are provided in such a way as to fit into the holes provided in each of the base150, the sensor unit20, the substrate40, the protection plate160, the substrate48, and the protection plate170. Thus, these members can be removably fixed.

As shown inFIGS. 4 and 5, the base150has fixing parts156,157at the bottom surface thereof facing the installation surface2. The fixing parts156,157are magnets, that is, magnetic bodies. The fixing parts156,157are attached to the bottom surface of the base150, for example, with a screw. Thus, the fixing parts156,157can be removably attached to the base150. For example, the fixing parts156,157are cubic. The bottom surfaces of the fixing parts156,157come into contact with the installation surface2. As such fixing parts156,157, which are magnets, are provided at the bottom surface of the base150, the inertial measurement unit10can be easily installed, for example, at a metal surface or the like of a device by the magnetic force of the magnets.

FIG. 6is a plan view of the protection plate160. As shown inFIG. 6, the protection plate160is provided with the holes161,162,163to be penetrated by the fixing members11,12,13, which are columnar members. The protection plate160is also provided with the slit164to be penetrated by the support part44for supporting the substrate48. InFIG. 6, the protection plate160is shown as a transparent plate-like member.

FIG. 7is a plan view of the protection plate170. As shown inFIG. 7, the protection plate170is provided with the holes171,172,173to be penetrated by the fixing members11,12,13. The screw heads of the fixing members11,12,13, which are screw members, are located above the holes171,172,173, as shown inFIG. 3. The protection plate170is also provided with the window174so that the user can view the display unit70below. The protection plate170is also provided with windows175,176so that the user can view the light-emitting element groups62,64of the display unit60below. InFIG. 7, the protection plate170is shown as a semitransparent plate-like member colored in a predetermined color such as blue. On the protection plate170, letters for explaining the functions of switches, described later, and letters for notifying the content of display information at the light-emitting element groups62,64, are written.

FIG. 8is a plan view of the display unit70. The display unit70has the display panel72. A signal line for transmitting a drive signal for the display panel72is electrically coupled to a coupling terminal in the display unit70from the substrate40below, via the support part44and the substrate48. This coupling terminal is provided, for example, on the right side of the display panel72as viewed inFIG. 8.

As described above, the inertial measurement unit10according to this embodiment includes: the sensor unit20having at least one inertial sensor; the substrate40provided with at least one of the processing unit50performing processing based on detection information from the inertial sensor and the display unit60performing a display based on the detection information; and at least one fixing member11,12,13removably fixing the sensor unit20and the substrate40together.

In the inertial measurement unit10according to this embodiment, the processing unit50provided at the substrate40can execute processing based on detection information from the inertial sensor of the sensor unit20, and the display unit60provided at the substrate40can perform a display based on the detection information. InFIG. 1, the display unit60having the light-emitting element groups62,64is provided at the substrate40. However, the display unit70having the display panel72may be provided at the substrate40, as shown inFIG. 2.

In this embodiment, the sensor unit20and the substrate40are removably fixed together using the fixing members11,12,13, as shown inFIG. 3. For example, the sensor unit20and the substrate40are fixed together in a freely removable manner. Thus, the type of the sensor unit20and the type of the substrate40incorporated into the inertial measurement unit10can be freely changed. For example, the sensor unit20having an acceleration sensor can be incorporated into the inertial measurement unit10, or the sensor unit20having both of an acceleration sensor and an angular velocity sensor, or the like, can be incorporated into the inertial measurement unit10. Alternatively, the substrate40provided only with the processing unit50can be incorporated into the inertial measurement unit10, or the substrate40provided only with the display unit60can be incorporated into the inertial measurement unit10. Also, the substrate40provided with both of the processing unit50and the display unit60, or the like, can be incorporated into the inertial measurement unit10. Thus, various demands by the user using the inertial measurement unit10can be met and the extensibility of the inertial measurement unit10can be improved. Also, the inertial measurement unit10can be installed at the installation surface2in the state where the sensor unit20and the substrate40are firmly fixed together via the fixing members11,12,13. Therefore, a situation where an unwanted vibration or the like due to resonance or the like is transmitted to the inertial measurement unit10and adversely affects the measurement by the inertial measurement unit10can be restrained. Thus, the inertial measurement unit10in which extensibility can be improved while deterioration in the accuracy of measurement is restrained can be provided.

For example, according to the related art, the sensor unit20itself is used as the inertial measurement unit10, and the detection information from the inertial sensor of the sensor unit20is outputted from a connector26shown inFIGS. 15 to 17, described later. For example, acceleration information and angular velocity information detected by the inertial sensor are outputted directly as the detection information. However, handling the detection information from the inertial sensor is difficult and needs expertise, and therefore has the problem of poor user-friendliness. In this case, a technique such as coupling a PC (personal computer) to the connector26of the sensor unit20, then using the PC to perform various kinds of processing such as analysis processing on the detection information, and displaying the result of the analysis at the display unit, may be employed. However, in this technique, the PC needs to be coupled to the sensor unit20to perform various kinds of work. Therefore, the technique has a problem in that the work becomes complicated and that the scale of the measuring system increases.

In contrast, in this embodiment, the sensor unit20and the substrate40are fixed together via the fixing members11,12,13, thus forming the inertial measurement unit10. Therefore, processing such as analysis processing on detection information from the inertial sensor of the sensor unit20can be performed using the processing unit50provided at the substrate40, and a display based on the detection information can be performed using the display unit60provided at the substrate40. For example, there is no need to couple a PC to the inertial measurement unit10to perform processing based on detection information or to perform a display based on the detection information. Therefore, user-friendliness can be improved. That is, simply installing the inertial measurement unit10to a measuring target enables processing based on detection information or a display based on the detection information. For example, when the measuring target is a device such as a manufacturing device or measuring device, or a floor surface where the device is installed, the inertial measurement unit10is installed on the installation surface2that is a surface of the device or the floor surface. Then, the processing unit50executes processing to analyze a vibration of the device or the floor surface. Information about the result of the processing can be outputted to outside via the wireless communication unit90and the interface unit100, or the result of the analysis can be displayed at the display unit60. Thus, the state of the measuring target can be monitored by a highly portable, low-cost and small-scale system.

For example, for a user who needs only acceleration information, the inertial measurement unit10in which the sensor unit20provided with an acceleration sensor as an inertial sensor and the substrate40are fixed together via the fixing members11,12,13is provided. For a user who need both of acceleration information and angular velocity information, the inertial measurement unit10in which the sensor unit20provided with both of an acceleration sensor and an angular velocity sensor as an inertial sensor and the substrate40are fixed together via the fixing members11,12,13is provided. For a user who wants the display unit70having the display panel72, the inertial measurement unit10in which the sensor unit20, the substrate40, and the substrate48provided with the display unit70are fixed together via the fixing members11,12,13, as shown inFIG. 2, is provided. In this way, the inertial measurement unit10meeting various demands by the user can be provided and the extensibility of the inertial measurement unit10can be increased. Also, since the inertial measurement unit10in which the sensor unit20and the substrate40are firmly fixed together via the fixing members11,12,13can be provided, it is advantageous in that deterioration in the accuracy of the result of measurement by the inertial measurement unit10due to an unwanted vibration or the like such as resonance can be restrained.

InFIGS. 1 and 2, both of the processing unit50and the display unit60are provided at the substrate40. However, at least one of the processing unit50and the display unit60may be provided at the substrate40. For example, when the processing unit50is not provided at the substrate40, processing based on detection information may be performed, for example, using a processing unit212, described later, provided in the sensor unit20. Alternatively, the processing unit50may be provided at the substrate48located above the substrate40. The display unit60may be provided at the substrate48instead of at the substrate40. Alternatively, the display unit60using a light-emitting element may not be provided as a display unit in the inertial measurement unit10. The display unit70having the display panel72may be provided at the substrate40.

In this embodiment, as shown inFIG. 3, the inertial measurement unit10includes a plurality of columnar members as the fixing members11,12,13. As the fixing members11,12,13, which are the plurality columnar members, fit into the plurality of holes41,42,43provided in the substrate40and the plurality of holes21,22,23provided in the sensor unit20, the sensor unit20and the substrate40are removably fixed together. Thus, various combinations of sensor unit20and substrate40can be freely attached or removed from each other and removable fixing of the sensor unit20and the substrate40can be realized. For example, replacing the sensor unit20with a sensor unit of a different type and inserting the fixing members11,12,13into the holes21,22,23in the sensor unit can change the type of the sensor unit20. Also, replacing the substrate40with a substrate of a different type and inserting the fixing members11,12,13into the holes41,42,43in the substrate can change the type of the substrate40. Thus, sensor units20and substrates40of various types can be provided as option parts for the user, and the extensibility of the inertial measurement unit10can be significantly improved.

For example, the fixing members11,12,13, which are a plurality of columnar members, are screw members. For example, the fixing members11,12,13are male screws threaded on the outer circumference. Using screw members as the fixing members11,12,13in this way enables screw-fixing with the screw members. Therefore, the sensor unit20, the substrate40and the like can be fixed firmly and stably. Thus, deterioration in the accuracy of the result of measurement by the inertial measurement unit10due to an unwanted vibration or the like caused by resonance or the like can be restrained further. Also, the work of attaching the sensor unit20, the substrate40and the like becomes easier and work efficiency or the like is improved.

The inertial measurement unit10also includes the base150for installing the inertial measurement unit10at the installation surface2. The sensor unit20is provided between the base150and the substrate40. The base150is fixed to the sensor unit20via at least one fixing member11,12,13. For example, the base150is a member serving as a base stand for installing the inertial measurement unit10at the installation surface2. As the bottom surface or the like of the base150comes into contact with the installation surface2, the inertial measurement unit10is installed on the installation surface2. The installation surface2is, for example, a surface of a device such as a manufacturing device or measuring device, or a floor surface or the like where the device is installed. The installation surface2is a surface of a measuring target. The sensor unit20is fixed by the fixing members11,12,13in such a way as to be held between the substrate40and the base150. Such fixing can restrain deterioration in the accuracy of detection of the inertial sensor of the sensor unit20due to a vibration or the like caused by resonance or the like. Even when the bottom surface of the sensor unit20does not have a suitable shape for installation on the installation surface2, the bottom surface of the base150instead of the bottom surface of the sensor unit20can be attached to the installation surface2, and this enables table installation of the inertial measurement unit10. For example, stable installation can be achieved regardless of the shape and type of the sensor unit20, and detection errors or the like due to wobbly installation can be prevented.

As shown inFIGS. 4 and 5, the base150has the fixing parts156,157, which are magnets, on the surface facing the installation surface2. That is, the fixing parts156,157for fixing the inertial measurement unit10to the installation surface2are provided at the bottom surface of the base150. These fixing parts156,157are magnets. For example, the fixing parts156,157are cubic magnets. Thus, the bottom surfaces of the fixing parts156,157are attracted to a metal surface or the like of a device, as the installation surface2, by the magnetic force of the magnets. Therefore, simply bringing the bottom surfaces of the fixing parts156,157into contact with the installation surface2enables the inertial measurement unit10to be fixed and installed at the installation surface2by the magnets. This makes it easier for the user to carry out installation work and can improve work efficiency.

AlthoughFIGS. 4 and 5show an example where the number of the fixing parts156,157is two, the number of fixing parts is not limited to this and may be, for example, three or more. The base150itself or a part of the base150may be a magnet.

As shown inFIGS. 4 and 5, the base150has the recess154on the surface facing the installation surface2. That is, the bottom surface, which is the surface facing the installation surface2, of the base150has the recess154recessed in the direction DR4, which is the opposite direction of the direction DR1. In cases such as where the inertial measurement unit10is installed at the installation surface2via a double-sided adhesive tape, the provision of such a recess154can make it easier to strip off the double-sided adhesive tape. That is, in this embodiment, the inertial measurement unit10can be installed at the installation surface2, using a double-sided adhesive tape instead of using the fixing parts156,157. Specifically, one side of the double-sided adhesive tape is attached to the bottom surface of the base150, and the other side of the double-sided adhesive tape is attached to the installation surface2. Thus, the inertial measurement unit10can be installed at the installation surface2by simple work and can be installed at the installation surface2even when, for example, the installation surface2is not a metal surface. In this case, after measurement is finished and the inertial measurement unit10is removed from the installation surface2, the double-sided adhesive tape needs to be stripped off from the bottom surface of the base150. In this regard, the provision of the recess154at the bottom surface of the base150enables the user as a worker to insert a finger or the like into this recess154and thus easily strip off the double-sided adhesive tape from the bottom surface of the base150. The inertial measurement unit10can also be installed via a screw as well as the magnets and the double-sided adhesive tape.

As shown inFIGS. 1 and 2, the substrate40is provided with the wireless communication unit90wirelessly transmitting information based on detection information from the inertial sensor. For example, a wireless communication IC that is the wireless communication unit90is provided at the substrate40. The wireless communication unit90transmits the information based on the detection information from the inertial sensor, to outside. For example, when the processing unit50performs processing such as analysis processing based on the detection information from the inertial sensor, the wireless communication unit90transmits information about the result of the processing, to outside. Alternatively, the wireless communication unit90may transmit the detection information itself from the inertial sensor, to outside. Thus, the information based on the detection information from the inertial sensor can be wirelessly transmitted to an external device, even without coupling the inertial measurement unit10and the external device together via a wire. For example, the information based on the detection information detected by the inertial sensor can be transmitted to the external device, using the wireless communication unit90, in the state where the inertial measurement unit10remains installed at the installation surface2. Therefore, improved convenience or the like can be achieved.

The substrate40is also provided with the interface unit100for wired communication with outside. For example, the interface unit100communicates with outside by such a communication interface format as UART, GPIO or SPI. For example, the interface unit100transmits information based on detection information from the inertial sensor, to an external device. The provision of such an interface unit100can meet various demands by the user with respect to the communication interface. For example, UART can be converted to RS-232C so as to couple the inertial measurement unit10to various devices. Also, UART can be converted to Ethernet (trademark registered). Moreover, the inertial measurement unit10can be coupled to an SD (trademark registered) card slot device, using SPI. Thus, user-friendliness can be improved.

The substrate40is also provided with at least one of the mode changeover switch80for changing the mode of the inertial measurement unit10, the reset switch82for resetting the inertial measurement unit10, and the measurement start switch84for starting measurement by the inertial measurement unit10. InFIGS. 1 and 2, all of these switches are provided. However, in this embodiment, at least one of these switches may be provided. As such various switches are provided, the user can operate each of these switches to cause the inertial measurement unit10to carry out various operations. This can make the measuring work simpler and more efficient. When the user operates the mode changeover switch80, the inertial measurement unit10switches between various modes. Specifically, the display mode in the display units60,70is changed. When the user operates the reset switch82, the inertial measurement unit10becomes reset. When the user operates the measurement start switch84, the inertial measurement unit10starts measurement. The measurement start switch84also functions as a measurement end switch. For example, when the user presses the measurement start switch84before starting measurement, the inertial measurement unit10shifts into a state monitoring mode and starts measurement. Then, when the user presses measurement start switch84again, the state monitoring mode ends. The measurement start switch84also functions as a teach switch, as described later.

The inertial measurement unit10also includes the protection plate160. The substrate40is provided between the sensor unit20and the protection plate160. For example, the protection plate160is arranged above the substrate40, that is, in the direction DR4from the substrate40, via a gap space formed by the spacers14,15,16. Thus, a dustproof function by the protection plate160can be realized. Also, the protection plate160, as a protection member, can prevent an unwanted impact from being applied to the components arranged at the substrate40, such as the processing unit50, the display unit60, and the wireless communication unit90. Also, for example, inFIG. 1, the user can hold the inertial measurement unit10in a hand with its palm in contact with the top surface of the protection plate160and thus install the inertial measurement unit10at the installation surface2. The provision of the protection plate160makes it easier for the user to manually hold the inertial measurement unit10and thus makes the installation work easier and more efficient.

The inertial measurement unit10includes, as a substrate, the substrate40as the first substrate, and the substrate48as the second substrate, as shown inFIG. 2. The substrate40as the first substrate is provided with the processing unit50. The substrate48as the second substrate is provided with the display unit70having the display panel72. Thus, for example, processing based on detection information from the inertial sensor of the sensor unit20is executed by the processing unit50provided at the substrate40, and information about the result of the processing can be displayed on the display panel72of the display unit70provided at the substrate48. That is, the information based on the detection information can be displayed on the display panel72. The display panel72is formed of an organic EL panel or liquid crystal panel and therefore can perform a more detailed and advanced display of information than when a light-emitting element is used. For example, numbers and letters about a measured value can be displayed and more precise and advanced changeover processing about the display mode can be implemented. Thus, user-friendliness can be improved. Also, a modified embodiment where the display unit70having the display panel72is provided at the substrate40can be employed.

The inertial measurement unit10also includes the protection plate160as the first protection plate, and the protection plate170as the second protection plate. The substrate40is provided between the sensor unit20and the protection plate160. The substrate48is provided between the protection plate160and the protection plate170. For example, as shown inFIG. 3, the protection plate170is arranged above the protection plate160, that is, in the direction DR4from the protection plate160, via a gap space formed by the spacers17,18,19provided at the holes161,162,163in the protection plate160. The substrate48is arranged in this gap space. Thus, the protection plate160can protect the components provided at the substrate40. For example, the components provided at the substrate40, such as the processing unit50, the wireless communication unit90, and the display unit60, can be protected. The protection plate170can protect the components provided at the substrate48. For example, the components provided at the substrate48, such as the display unit70, can be protected. Thus, damage or the like to the components of the inertial measurement unit10, for example, due to a touch by the user, can be effectively prevented.

The substrate40is also provided with the display unit60having the light-emitting element groups62,64. That is, the display unit60formed of the light-emitting element groups62,64such as LEDs is provided. Thus, the display of information based on detection information from the inertial sensor of the sensor unit20can be implemented via an indication operation based on light emission of the light-emitting elements of the light-emitting element groups62,64. For example, information about whether the result of measurement satisfies a determination criterion or not, or the like, can be sufficiently communicated via light emission of the light-emitting elements. The light-emitting elements are available at a lower cost than the display panel72and therefore can achieve cost reduction or the like of the inertial measurement unit10.

In this embodiment, the user holds the inertial measurement unit10in such a way that the bottom surface of the inertial measurement unit10comes into contact with the installation surface2, then installs the inertial measurement unit10, using a double-sided adhesive tape, magnet, screw or the like, and carries out measurement with the inertial measurement unit10. In this case, it is desired that, when measuring with the inertial measurement unit10, the user can easily carry out operations such as mode setting and measurement start instruction for the inertial measurement unit10. Thus, in this embodiment, the inertial measurement unit10is provided with various switches such as the mode changeover switch80, the reset switch82, and the measurement start switch84, as shown inFIG. 9. The mode changeover switch80is a switch for changing the mode of the inertial measurement unit10and specifically a switch for changing the display mode of the display unit70. For example, the mode changeover switch80is a switch for changing the mode of display information. The reset switch82is a switch for resetting the inertial measurement unit10. Pressing the reset switch82initializes the inertial measurement unit10. The measurement start switch84is a switch for starting measurement by the inertial measurement unit10. The measurement start switch84also functions as a switch for ending measurement by the inertial measurement unit10. When long-pressed, the measurement start switch84functions as a teach switch for giving an instruction to store measurement criteria information for inertial measurement into a memory. Also, the mode changeover switch80, when long-pressed, functions as a switch for saving measurement log data. A slide switch86is a switch for selecting wireless communication and a communication interface.

The display unit70performs a display based on detection information from the inertial sensor of the sensor unit20. For example, inFIG. 9, the display unit70shows that a measured vibration satisfies VC-B of VC (vibration criteria), which are ambient vibration criteria. The display unit70also shows information about vibration displacement. In this embodiment, the display mode of the display unit70changes via the mode changeover switch80. For example, inFIG. 10, the display unit70shows a result of determination based on the VC standard. For example, the display unit70shows the result of determination that a measured vibration satisfies VC-B. That is, in a first display mode inFIG. 10, the result of determination based on a first determination criterion is displayed. Meanwhile, inFIG. 11, the display unit70shows a result of measurement based on a determination criterion set by the user. For example, the display unit70shows the result of determination that what percentage of a threshold set by the user is reached. That is, in a second display mode inFIG. 11, the result of determination based on a second determination criterion is displayed. For example, pressing the mode changeover switch80results in the first display mode inFIG. 10or the second display mode inFIG. 11.

Also, the unit of information displayed based on detection information from the inertial sensor changes via the mode changeover switch80. That is, the display mode changes in terms of unit via the mode changeover switch80. For example, inFIG. 10, the unit of vibration displacement, μm, is shown. Specifically, a peak frequency of vibration displacement and the vibration displacement at the peak frequency are shown. Pressing the mode changeover switch80changes the display of the unit to a display of the unit of vibration velocity, mm/s, or a display of the unit of vibration acceleration, Gal. Specifically, pressing the mode changeover switch80results in a display of a peak frequency of vibration velocity and the vibration velocity at the peak frequency, or a display of a peak frequency of vibration acceleration and the vibration acceleration at the peak frequency. For example, the result of determination based on VC is displayed at the beginning, and every time the mode changeover switch80is pressed, the display mode sequentially changes to the display of vibration acceleration and peak frequency thereof, the display of vibration velocity and peak frequency thereof, the display of vibration displacement and peak frequency thereof, and the display of the measured value in percentage terms to the threshold set by the user.

VC, which are ambient vibration criteria, define VC-A, VC-B, VC-C, VC-D, VC-E and the like. Showing which of these is satisfied enables the user to easily grasp the vibration level of an ambient vibration or the like. The threshold set by the user is stored, for example, into the memory102inFIG. 1, which is a non-volatile memory, for example, based on the setup by the user. Alternatively, a threshold may be set via the teach switch, described later.

As shown inFIG. 9, the mode changeover switch80has a moving part81. The moving part81is implemented, for example, by a push-button. It is now assumed that the direction from the inertial measurement unit10toward the installation surface2is defined as DR1and that a direction orthogonal to the direction DR1is defined as DR2. The direction DR1is a first direction. The direction DR2is a second direction. The direction DR2is, for example, a direction along the main surface, that is, the top surface of the sensor unit20and the main surface, that is, the top surface of the substrate40, and for example, along the shorter sides of the sensor unit20and the substrate40. In this case, the moving part81is movable in the direction DR2. That is, the push-button as the moving part81is movable and can be pressed along a directions indicated by A1inFIG. 9. The movement of the moving part81of the mode changeover switch80gives an instruction to change the display mode of the display unit70. That is, pressing the push-button as the moving part81results in the change in the display mode described with reference toFIGS. 10 and 11.

The moving part81of the mode changeover switch80, when not pressed, protrudes from a side of the sensor unit20as viewed in a plan view in the direction DR1. For example, inFIG. 9, a side SD1is a first shorter side of the substrate40, and a side SD2is a second shorter side opposite the side SD1. A side SD3is a first longer side of the substrate40, and a side SD4is a second longer side opposite the side SD3. The mode changeover switch80is arranged on the side SD3, which is a longer side of the substrate40. The reset switch82and the measurement start switch84, too, are arranged on the side SD3. That is, the mode changeover switch80, the reset switch82, and the measurement start switch84are arrayed along the side SD3. The moving part81of the mode changeover switch80, when not pressed, protrudes from the side SD3of the substrate40and also protrudes from the side of the sensor unit20corresponding to the side SD3of the substrate40, as viewed in a plan view. That is, when not pressed, the push-button as the moving part81protrudes from the side SD3. Thus, for example, when the user holds the inertial measurement unit10with the palm in contact with the top surface thereof, the user can press the moving part81, for example, using a finger of the hand. Therefore, while holding the inertial measurement unit10, the user can press the push-button as the moving part81of the mode changeover switch80with a finger of the hand and thus can easily change the display mode of the display unit70. For example, the user can attach the bottom surface of the inertial measurement unit10to the installation surface2and operate the mode changeover switch80with a hand's finger. Therefore, user-friendliness can be improved.

The reset switch82similarly has a moving part83. The moving part83can be pressed along directions indicated by A2inFIG. 9. However, the moving part83, when not pressed, does not protrude from the side SD3of the substrate40and does not protrude from the side of the sensor unit20and the side of the protection plate160corresponding to the side SD3, either. That is, since pressing the moving part83of the reset switch82initializes the inertial measurement unit10, the moving part83does not protrude from the side SD3. Thus, the user can be prevented from making an erroneous operation such as making a reset operation by mistake.

The measurement start switch84similarly has a moving part85movable in the direction DR2. The movement of the moving part85of the measurement start switch84gives an instruction to start measurement by the inertial measurement unit10. That is, a push-button that is the moving part85can be moved and pressed along directions indicated by A3inFIG. 9. Pressing the push-button as the moving part85starts measurement by the inertial measurement unit10. Then, pressing the push-button as the moving part85again after the measurement is started ends the measurement. That is, the measurement start switch84also functions as a measurement end switch.

The moving part85of the measurement start switch84, when not pressed, protrudes from the side SD3of the substrate40and protrudes from the side of the sensor unit20corresponding to the side SD3, as viewed in a plan view. That is, when not pressed, the push-button as the moving part85protrudes from the side SD3. Thus, for example, when the user holds the inertial measurement unit10with the palm in contact with the top surface thereof, the user can press the moving part85, for example, using a finger of the hand. Therefore, while holding the inertial measurement unit10, the user can press the push-button as the moving part85of the measurement start switch84with a finger of the hand and thus can easily start measurement. Therefore, user-friendliness can be improved.

In this embodiment, the measurement start switch84also functions as a teach switch, which is a switch for giving an instruction to store measurement criteria information for inertial measurement into the memory102. That is, the measurement start switch84functions as a teach switch for causing the inertial measurement unit10to learn measurement criteria information. Specifically, for example, a long press on the measurement start switch84by the user causes the measurement start switch84to functions as a teach switch. When the measurement start switch84functions as a teach switch, the teach switch has the moving part85movable in the direction DR2and the movement of the moving part85of the teach switch gives an instruction to store measurement criteria information into the memory102. Specifically, a long press on the measurement start switch84causes the inertial measurement unit10to shift to a learning mode, which is a teach mode. Then, the inertial measurement unit10performs measurement for learning during a predetermined learning period. Based on an average value or the like of measured values measured during the learning period, a threshold that serves as measurement criteria information is found. The threshold is stored as measurement criteria information into the memory102, which is a non-volatile memory. In actual measurement by the inertial measurement unit10, determination processing is performed using the threshold as the measurement criteria information, and the result of the determination is displayed at the display unit70. For example, the display as shown inFIG. 11is performed.

As described above, the inertial measurement unit10according to this embodiment includes the sensor unit20having at least one inertial sensor, the display unit70performing a display based on detection information from the inertial sensor, and the mode changeover switch80. The display mode of the display unit70changes via the mode changeover switch80. For example, the changeover of the display mode as described with reference toFIGS. 10 and 11is carried out. For example, the mode of display information at the display unit70is changed.

In the inertial measurement unit10of such a configuration, the display unit70provided in the inertial measurement unit10can perform a display based on detection information from the inertial sensor of the sensor unit. For example, simply installing the inertial measurement unit10on a measurement target enables the display unit70to display information based on detection information. Therefore, there is no need to couple the inertial measurement unit10to a PC and cause the display unit of the PC to perform a display based on detection information. Thus, the work of checking the result of measurement can be simplified and user-friendliness can be improved. When the user operates the mode changeover switch80provided in the inertial measurement unit10, the display mode of the display unit70changes. Specifically, as described with reference toFIGS. 10 and 11, when the user operates the mode changeover switch80, a change of the display mode takes place, such as displaying the result of determination about measurement at the display unit70, based on a different determination criterion, or changing the unit of information displayed at the display unit70. The simple operation of operating the mode changeover switch80can change the display mode of the display unit70in various forms. Thus, various demands about the display form of the result of measurement can be met and user-friendliness can be improved further.

In the inertial measurement unit10having the configuration described with reference toFIG. 9, the mode changeover switch80need not necessarily be provided at the substrate40and may be provided, for example, at other substrates than the substrate40. For example, the mode changeover switch80may be provided at the substrate48, where the display unit70is provided, instead of the substrate40, where the processing unit50or the like is provided. Alternatively, various modified embodiments, for example, installing the mode changeover switch80at the top surface of the sensor unit20, can be employed.

As shown inFIG. 9, the mode changeover switch80has the moving part81movable in the direction DR2, which is orthogonal to the direction DR1from the inertial measurement unit10toward the installation surface2. The movement of the moving part81of the mode changeover switch80gives an instruction to change the display mode of the display unit70. Thus, for example, the user can hold the inertial measurement unit10with the palm in contact with the top surface thereof and can move the moving part81in the direction DR2parallel to the top surface of the inertial measurement unit10, thus giving an instruction to change the display mode of the display unit70. Therefore, the user can give an instruction to change the display mode by a simple operation and can cause the display unit70to display information based on detection information from the inertial sensor, in a display mode desired by the user.

The moving part81of the mode changeover switch80, when not pressed, protrudes from a side of the sensor unit20as viewed in a plan view along the direction DR1. Thus, for example, when the user holds the inertial measurement unit10with the palm in contact with the top surface thereof, the moving part81of the mode changeover switch80is in a protruding state when not pressed. Therefore, while holding the inertial measurement unit10, the user can press the protruding moving part81, for example, with a finger of the hand, thus causing the display mode of the display unit70to change. The simple operation of pressing the moving part81protruding in a direction parallel to the top surface of the sensor unit20when not pressed, changes the display mode of the display unit70. Thus, user-friendliness can be improved.

The inertial measurement unit10also includes the measurement start switch84for starting measurement by the inertial measurement unit10. As such a measurement start switch84is provided, processing of giving a command to start measurement via a PC or the like is not needed. When wishing to start measurement, the user can start measurement by the inertial measurement unit10by the simple operation of pressing the measurement start switch84.

The measurement start switch84has the moving part85movable in the direction DR2, which is orthogonal to the direction DR1toward the installation surface2. The movement of the moving part85of the measurement start switch84gives an instruction to start measurement by the inertial measurement unit10. Thus, for example, the user can hold the inertial measurement unit10with the palm in contact with the top surface thereof and can move the moving part85in the direction DR2parallel to the top surface, thus giving an instruction to start measurement by the inertial measurement unit10. Therefore, the user can give an instruction to start measurement by the inertial measurement unit10by a simple operation at a timing desired by the user.

The inertial measurement unit10also includes the memory102and the teach switch for giving an instruction to store measurement criteria information for inertial measurement into the memory102. InFIG. 9, for example, the measurement start switch84is also used as the teach switch. When the measurement start switch84is long-pressed, the leaning mode sets in and a threshold as the measurement criteria information for inertial measurement is stored into the memory102. Then, for example, the processing unit50performs determination processing about measurement based on the threshold as the determination criterion, or the display unit70displays the result of the determination about measurement based on the threshold as the determination criterion. Thus, the inertial measurement unit10can be made to learn measurement criteria information corresponding to the state of a device as a measuring target or the ambient state, and can perform measurement using the measurement criteria information.

The teach switch, also used as the measurement start switch84, has the moving part85movable in the direction DR2. The movement of the moving part85of the teach switch gives an instruction to store measurement criteria information into the memory102. Thus, for example, the user can hold the inertial measurement unit10with the palm in contact with the top surface thereof and can move the moving part85in the direction DR2parallel to the top surface, thus giving an instruction to store measurement criteria information into the memory102. Therefore, the user can cause the inertial measurement unit10to learn measurement criteria information during a period when the user wants the inertial measurement unit10to learn the measurement criteria information.

The inertial measurement unit10also includes the substrate40provided with the mode changeover switch80. For example, the mode changeover switch80is provided at the substrate40where the processing unit50or the display unit60or the like is provided. For example, the mode changeover switch80is mounted at the substrate40arranged parallel to the top surface of the sensor unit20. Thus, the mode changeover switch80can be mounted in a compact form in the inertial measurement unit10. Particularly, making the direction of movement of the moving part81of the mode changeover switch80parallel to the surface of the substrate40enables the mode changeover switch80to be mounted compactly.

As described with reference toFIGS. 1 and 2or the like, the inertial measurement unit10includes at least one fixing member11,12,13for removably fixing the sensor unit20and the substrate40together. That is, the sensor unit20having the inertial sensor, and the substrate40provided with the mode changeover switch80, are removably fixed together via the fixing members11,12,13. Thus, the type of the sensor unit20and the type of the substrate40incorporated in the inertial measurement unit10can be freely changed, and the extensibility of the inertial measurement unit10can be improved. The inertial measurement unit10can be installed at the installation surface2in the state where the sensor unit20and the substrate40are fixed together via the fixing members11,12,13. Therefore, a situation where an unwanted vibration or the like due to resonance or the like is transmitted to the inertial measurement unit10and adversely affects the measurement can be restrained.

Also, the inertial measurement unit10includes the substrate40as the first substrate, and the substrate48as the second substrate. The mode changeover switch80is provided at the substrate40. The display unit70is provided at the substrate48. The substrate40is provided between the sensor unit20and the substrate48. Thus, when the mode changeover switch80provided at the substrate40is operated, the display mode of the display unit70provided at the substrate48changes. The mode changeover switch80is provided at the substrate40provided between the sensor unit20and the substrate48and therefore is arranged, for example, near the center in the direction of the height of the inertial measurement unit10. Therefore, the operability of the mode changeover switch80can be improved. Meanwhile, the display unit70is provided at the substrate48arranged above the substrate40, that is, in the direction DR4from the substrate40, and therefore can be arranged at a position visible to the user.

In the first display mode, the display unit70displays the result of determination based on the first determination criterion, as the result of determination in determination processing based on detection information. In the second display mode, the display unit70displays the result of determination based on the second determination criterion. For example, in the first display mode, the display unit70displays the result of determination as shown inFIG. 10, and in the second display mode, the display unit70displays the result of determination as shown inFIG. 11. Thus, the display mode can be switched between the first display mode, in which the result of determination based on the first determination criterion is displayed, and the second display mode, in which the result of determination based on the second determination criterion is displayed, via the mode changeover switch80. Therefore, as the user operates the mode changeover switch80, the result of determination about measurement is displayed at the display unit70, based on different determination criteria. This enables presentation of the result of determination based on various determination criteria to the user.

In this case, the first determination criterion is a determination criterion of VC (vibration criteria) and the second determination criterion is a determination criterion set by the user. For example, in the first display mode, the result of determination is displayed based on the determination criterion of VC as the first determination criterion, as shown inFIG. 10. For example, which of VC-A, VC-B, VC-C, VC-D, VC-E and the like as indicators of ambient vibration criteria is satisfied by a vibration measured by the inertial measurement unit10is displayed. Meanwhile, in the second display mode, the result of determination is displayed based on the determination criterion set by the user, as shown inFIG. 11. For example, what degree of the determination criterion set by the user is reached by the result of measurement by the inertial measurement unit10is displayed. For example, when the determination criterion set by the user is a threshold, what proportion of the threshold is reached by the measured value is displayed. Thus, the display mode can be switched between the first display mode, in which the result of determination based on the VC determination criterion is displayed, and the second display mode, in which the result of determination based on the determination criterion set by the user is displayed, via the mode changeover switch80. When the display unit60formed of the light-emitting element groups62,64is used, which of VC-A, VC-B, VC-C, VC-D, VC-E and the like is satisfied is displayed using the light-emitting element group62, as clear fromFIG. 7. Also, for example, which of L (low), M (middle), and H (high) the peak value is, is displayed using the light-emitting element group64. That is, one of the light-emitting elements corresponding to the positions of L, M, H emits light, thus displaying which of the low level, the middle level, and the high level the peak value is. “A” inFIG. 7represents an alarm state. When the light-emitting element corresponding to the position of “A” emits light, the user is notified that the alarm state has set in, such as where the measured value exceeds the threshold.

The mode changeover switch80also changes the unit of information displayed based on detection information. For example, in the case of measuring a vibration, the unit of the displayed measured value changes to the unit of vibration displacement (μm), the unit of vibration velocity (mm/s), and the unit of vibration acceleration (Gal) or the like, in response to an operation on the mode changeover switch80, as shown inFIG. 10. Thus, in response to the operation on the mode changeover switch80, the measured value can be displayed in various units to the user. Therefore, user-friendliness can be improved.

The inertial measurement unit10includes the processing unit50performing processing based on detection information. The processing unit50performs analysis processing on vibration information of a detection target. The display unit70displays information about the result of the analysis processing. The display unit60similarly displays information about the result of the analysis processing. For example, the processing unit50performs analysis processing such as FFT analysis on vibration information, based on detection information from the inertial sensor of the sensor unit20. The display unit70displays, for example, a peak frequency of vibration, vibration displacement at the peak frequency, vibration velocity, or vibration acceleration or the like, as the information about the result of the analysis processing. Thus, even when detection information from the inertial sensor is difficult for the user to handle, the processing unit50performs analysis processing on this detection information and the display unit70displays information about the result of the analysis processing, enabling the user to easily grasp the vibration state of the detection target.

3. Wireless Communication Unit, Antenna Unit

The inertial measurement unit10according to this embodiment is provided with the wireless communication unit90for wirelessly transmitting, to outside, information based on detection information from the inertial sensor of the sensor unit20, and the antenna unit92coupled to the wireless communication unit90. The wireless communication unit90is, for example, a device performing near-field wireless communication such as Bluetooth (trademark registered, hereinafter simply referred to as BT) and is implemented by a wireless communication IC, which is an integrated circuit device, or the like. The wireless communication performed by the wireless communication unit90is not limited to BT and may be near-field wireless communication of another type such as ZigBee or Wi-SUN or may be Wi-Fi (trademark registered) wireless communication. Meanwhile, as described with reference toFIGS. 15 to 17later, the sensor unit20includes the sensor substrate210provided with the inertial sensor, and the electrically conductive case24accommodating the sensor substrate210. The case24includes, for example, a container220and a lid222. The sensor substrate210is accommodated in an accommodation space formed by the container220and the lid222. InFIG. 15, acceleration sensors30X,30Y,30Z are provided as the inertial sensor at the sensor substrate210. The acceleration sensors30X,30Y,30Z detect information about an acceleration in directions along an X-axis, a Y-axis, and a Z-axis, respectively, as detection information. InFIGS. 16 and 17, an acceleration sensor32and angular velocity sensors34X,34Y,34Z are provided as the inertial sensor at the sensor substrate210. The acceleration sensor32detects information about an acceleration in directions along the X-axis, the Y-axis, and the Z-axis, as detection information. The angular velocity sensors34X,34Y,34Z detect information about an angular velocity about the X-axis, the Y-axis, and the Z-axis, respectively, as detection information.

InFIGS. 15 to 17, the case24is formed of an electrically conductive material such as a metal. Since the sensor substrate210where the inertial sensor is installed is thus accommodated in the electrically conductive case24, adverse effects of external electromagnetic waves or the like on the inertial sensor can be reduced. For example, when the electrically conductive case24is not provided, external electromagnetic waves or the like may cause the problem of drift in the detection information from the inertial sensor. However, providing the inertial sensor in the electrically conductive case24can restrain the occurrence of such a problem.

Meanwhile, it has been found that the sensitivity of the antenna unit92drops when such an electrically conductive case24is located near the antenna unit92. For example, the antenna unit92is implemented by an inductor of a metal wiring formed at the substrate. For example, when the inductor of the metal wiring of the antenna unit92is located directly above the electrically conductive case24, the sensitivity of the antenna unit92drops significantly.

Thus, in this embodiment, as shown inFIG. 12, when the direction from the inertial measurement unit10toward the installation surface2is defined as DR1, the antenna unit92is provided in such a way as to protrude from a side of the case24of the sensor unit20, as viewed in a plan view in the direction DR1. For example, inFIG. 12, the substrate40has sides SD1, SD2as shorter sides opposite each other, and sides SD3, SD4as longer sides opposite each other. The direction from the side SD1toward the side SD2is DR3. The opposite direction of DR3is DR6. The direction from the side SD3toward the side SD4is DR2. The opposite direction of DR2is DR5. The antenna unit92protrudes from the side SD1, which is a shorter side of the substrate40. The antenna unit92also protrudes from the side of the sensor unit20corresponding to the side SD1. Specifically, the antenna unit92is provided in such a way as to protrude in the direction DR6from the side SD1.

Thus, for example, the antenna unit92is not located directly above the electrically conductive case24of the sensor unit20. Specifically, the inductor of the metal wiring of the antenna unit92is not located directly above the electrically conductive case24. Therefore, the drop in the sensitivity of the antenna unit92due to the electrically conductive case24can be restrained. That is, when the antenna unit92is provided in the direction DR3from the side SD1inFIG. 12, the presence of the electrically conductive case24causes a drop in the sensitivity of the antenna unit92. However, when the antenna unit92is provided in the direction DR6from the side SD1as shown inFIG. 12, the electrically conducive case24is not present directly below the antenna unit92and the sensitivity of the antenna unit92can be improved accordingly.

As described above, the inertial measurement unit10according to this embodiment includes the sensor unit20having at least one inertial sensor, the wireless communication unit90wirelessly transmitting information based on detection information from the inertial sensor, and the antenna unit92coupled to the wireless communication unit90. Providing the wireless communication unit90and the antenna unit92in this way enables wireless transmission of information based on detection information from the inertial sensor, to outside. Thus, the information based on the detection information can be transmitted to an external device, for example, even without coupling the inertial measurement unit10to the external device. Therefore, user-friendliness can be improved.

The sensor unit20includes the inertial sensor, the sensor substrate210provided with the inertial sensor, and the electrically conductive case24accommodating the sensor substrate210. That is, inFIG. 15, the sensor substrate210provided with the acceleration sensors30X,30Y,30Z as the inertial sensor is accommodated in the case24. InFIGS. 16 and 17, the sensor substrate210provided with the acceleration sensor32and the angular velocity sensors34X,34Y,34Z as the inertial sensor is accommodated in the case24. Thus, the inertial sensor is accommodated in the electrically conductive case24and therefore deterioration in the accuracy of detection information from the inertial sensor due to external electromagnetic waves or the like can be restrained.

As shown inFIG. 12, in the inertial measurement unit10according to this embodiment, the antenna unit92is provided in such a way as to protrude from a side of the case24, as viewed in a plan view in the direction DR1toward the installation surface2. That is, the antenna unit92protrudes from the side SD1of the substrate40and also protrudes from the side of the case24below corresponding to the side SD1. Thus, the drop in the sensitivity of the antenna unit92due to the electrically conductive case24can be restrained. Therefore, both of restraint on the deterioration in the accuracy of detection of the inertial sensor by accommodating the inertial sensor in the electrically conductive case24and improvement in the sensitivity of the antenna unit92can be achieved.

In the inertial measurement unit10having the configuration described with reference toFIG. 12, the wireless communication unit90and the antenna unit92need not necessarily be provided at the substrate40and may be provided, for example, at other substrates than the substrate40. For example, the wireless communication unit90and the antenna unit92may be provided at the substrate48, where the display unit70is provided, instead of the substrate40, where the processing unit50or the like is provided. Alternatively, various modified embodiments, for example, installing the wireless communication unit90and the antenna unit92at the top surface of the sensor unit20, can be employed.

The inertial measurement unit10has the substrate40provided with the wireless communication unit90, and the protection plate160. As described with reference toFIGS. 1 and 2, the substrate40is provided between the sensor unit20and the protection plate160. As shown inFIG. 12, the antenna unit92does not protrude from the protection plate160, as viewed in a plan view in the direction DR1. That is, the antenna unit92protrudes in the direction DR6from the side SD1of the substrate40and the corresponding side of the sensor unit20but does not protrude in the direction DR6from the corresponding side of the protection plate160. For example, the electrically conductive case24of the sensor unit20is not present below the antenna unit92, whereas the protection plate160is provided above the antenna unit92in such a way as to cover the antenna unit92. Providing the antenna unit92in such a way as not to protrude from the protection plate160as viewed in a plan view and providing the protection plate160in such a way as to cover the antenna unit92can prevent a situation such as where an unwanted impact is applied to the antenna unit92. For example, a situation where a finger of the user's hand or the like accidentally touches the antenna unit92and causes damage or the like to the antenna unit92, can be restrained. Therefore, the sensitivity of the antenna unit92can be improved by providing the antenna unit92in such a way as to protrude from the electrically conductive case24as viewed in a plan view, and the antenna unit92can be protected from an external impact by providing the antenna unit92in such a way as not to protrude from the protection plate160as viewed in a plan view.

The inertial measurement unit10includes the substrate40provided with the wireless communication unit90. The antenna unit92is provided in such a way as to protrude from the side SD1, which is a shorter side of the substrate40. Specifically, a communication substrate94is installed at the substrate40, where the processing unit50or the like is provided. The wireless communication unit90and the antenna unit92are provided at the communication substrate94. That is, a wireless communication IC as the wireless communication unit90is installed at the communication substrate94, and an inductor of a metal wiring is formed at a substrate part protruding from the side SD1of the substrate40, of the communication substrate94, thus forming the antenna unit92. The substrate part where the wireless communication unit90is installed and the substrate part where the antenna unit92is formed may be formed as a single substrate or may be formed as separate substrates. Providing the antenna unit92in such a way as to protrude from the side SD1of the substrate40in this way can reduce the risk of an unwanted impact being applied to the antenna unit92. For example, a situation such as where a finger of the user's hand touches the antenna unit92and applies an unwanted impact to the antenna unit92when the user holds the inertial measurement unit10on the two longer sides with the palm in contact with the top surface thereof, can be restrained.

As shown inFIG. 12, the wireless communication unit90is provided at the side SD1, which is a shorter side of the substrate40. Specifically, the wireless communication unit90is arranged along the side SD1in the direction DR3from the side SD1. The antenna unit92coupled to the wireless communication unit90is provided in such a way as to protrude in the direction DR6from the side SD1. Thus, the antenna unit92can be electrically coupled via a short path to the wireless communication unit90arranged at the side SD1of the substrate40, and the sensitivity of the antenna unit92can be improved by making the antenna unit92protrude from the side SD1. Therefore, the wireless communication unit90and the antenna unit92can be installed in a compact form at the substrate40, and improvement in the sensitivity of the antenna unit92can be achieved.

The inertial measurement unit10includes the substrate40provided with the wireless communication unit90, and the processing unit50provided at the substrate40and performing processing based on detection information from the inertial sensor of the sensor unit20. The wireless communication unit90transmits the information processed by the processing unit50. For example, when the processing unit50performs processing to process detection information from the inertial sensor, the wireless communication unit90wirelessly transmits, for example, the processed detection information to outside. When the processing unit50performs analysis processing on detection information from the inertial sensor, the wireless communication unit90transmits, for example, information about the result of the analysis processing to outside. Thus, instead of detection information from the inertial sensor itself, information resulting from predetermined processing performed on the detection information by the processing unit50can be wirelessly transmitted to outside by the wireless communication unit90. Therefore, an external device of the inertial measurement unit10need not perform the processing performed by the processing unit50of the inertial measurement unit10, and reduction in processing load and cost reduction or the like of the measuring system including the inertial measurement unit10can be achieved.

The handling of the detection information from the inertial sensor is difficult and needs expertise and therefore has the problem of poor user-friendliness. However, as the inertial measurement unit10transmits the information processed by the processing unit50, information that is easy for the user to handle can be transmitted and therefore user-friendliness can be improved.

As shown inFIG. 12, in the inertial measurement unit10according to this embodiment, the antenna unit92is provided in such a way as to protrude from the side SD1of the substrate, and the processing unit50is provided between the wireless communication unit90and the side SD2opposite the side SD1. The side SD1is the first shorter side. The side SD2is the second shorter side. For example, when the direction from the side SD1toward the side SD2of the substrate40is DR3and the opposite direction of the direction DR3is DR6, the antenna unit92is provided in the direction DR6from the wireless communication unit90in such a way as to protrude from the side SD1of the substrate40. The wireless communication unit90is provided in the direction DR3from the antenna unit92. The processing unit50is provided in the direction DR3from the wireless communication unit90. Thus, the antenna unit92, the wireless communication unit90, and the processing unit50can be efficiently arranged along the direction from the side SD1, which is a shorter side of the substrate40, toward the opposite side SD2. For example, the antenna unit92, the wireless communication unit90, and the processing unit50can be arrayed in this order along the direction from the side SD3to the side SD4, which is a longer-side direction of the substrate40. Thus, the efficiency of installation of circuit components at the substrate40can be improved.

The inertial measurement unit10includes the interface unit100for wired communication of data with outside. The interface unit100is arranged at the side SD2, which is a shorter side of the substrate. Specifically, the interface unit100is arranged along the side SD2in the direction DR6from the side SD2. The interface unit100is, for example, a circuit implementing a communication interface of UART, GPI, or SPI or the like. The provision of such an interface unit100enables transmission of information based on detection information from the inertial sensor to an external device and acceptance of a command from the external device, via a broadly used wired communication interface of UART, GPI, or SPI or the like. Since the interface unit100is provided at the side SD2of the substrate40, the antenna unit92, the wireless communication unit90, the processing unit50, and the interface unit100can be efficiently arranged along the longer-side direction of the substrate40. Thus, the efficiency of installation of circuit components at the substrate40can be improved.

As shown inFIG. 12, at least one of the mode changeover switch80, the reset switch82, and the measurement start switch84is provided at the side SD3, which is a longer side of the substrate40. Thus, the wireless communication unit90, the processing unit50, and the interface unit100can be arranged, using an area between the side SD1and the side SD2, which are the shorter sides of the substrate40, and the mode changeover switch80, the reset switch82, and the measurement start switch84can be arranged, using an area along the side SD3, which is a longer side of the substrate40. Therefore, an efficient installation layout can be achieved. Also, the inertial measurement unit10includes at least one fixing member11,12,13for removably fixing the sensor unit20and the substrate40, where the wireless communication unit90or the like is provided. Thus, as described above, the extensibility of the inertial measurement unit10can be improved, and a situation where an unwanted vibration or the like due to resonance or the like is transmitted to the inertial measurement unit10and adversely affects measurement can be restrained.

As shown inFIG. 13, in the inertial measurement unit10according to this embodiment, the sensor unit20has the sensor-side connector26at the surface facing the substrate40. That is, the connector26is provided at the top surface of the sensor unit20. The substrate40has a substrate-side connector46coupled to the sensor-side connector26, at the surface facing the sensor unit20. That is, the connector46is provided at the bottom surface of the substrate40. The connector46of the substrate40is electrically coupled to the connector26of the sensor unit20. Specifically, in the state where the sensor unit20and the substrate40are fixed together via the fixing members11,12,13, as shown inFIGS. 1 and 2, the connector26of the sensor unit20and the connector46of the substrate40are electrically coupled together. Thus, detection information from the inertial sensor of the sensor unit20can be communicated to the substrate40via the connectors26,46. The processing unit50provided at the substrate40can perform processing based on the detection information from the inertial sensor. The display unit60provided at the substrate40can perform a display based on the detection information from the inertial sensor. The connector26is, for example, a male connector formed of a plurality of pin terminals. The connector46is, for example, a female connector to which a male connector can be coupled.

FIG. 14is a state transition diagram explaining an operation of the inertial measurement unit10according to this embodiment. When the inertial measurement unit10is supplied with electric power and starts up, the inertial measurement unit10first shifts to the state of initialization processing. When it is detected that BT (Bluetooth (trademark registered)) is enabled, based on selection via the slide switch86, the inertial measurement unit10performs BT setup and then returns to the state of initialization processing on completion of the setup. When BT is enabled, wireless communication is disabled. Meanwhile, when a shift to a light display operation is detected, based on selection via the slide switch86, the inertial measurement unit10shifts to a light display mode. In the light display mode, the interface unit100shifts into a GPIO output mode, enabling light display via PATLITE (trademark registered) or the like using the inertial measurement unit10.

When BT being enabled or a shift to the light display mode is not selected via the slide switch86, the inertial measurement unit10assumes that a shift to a standby operation is detected, and therefore shifts to a standby mode. When learning is requested in the standby mode, for example, by a long press on the measurement start switch84or by a command, the inertial measurement unit10shifts to a learning mode and performs learning processing. In the learning mode, for example, a predetermined light-emitting element in the display unit60flashes on and off, or for example, the letters of “LEARNING” are displayed at the display unit70, thus notifying the user that learning is underway. Then, measurement is performed during a learning period in the learning mode. Based on the result of the measurement during the learning period, a measurement threshold as measurement criteria information for inertial measurement is found. The threshold thus found is stored into the memory102, which is a non-volatile memory. On completion of the learning processing, the inertial measurement unit10returns to the standby mode. When setup is requested in the standby mode, for example, by a command given from an external device or the like, the inertial measurement unit10performs various kinds of setup processing about the inertial measurement unit10. On completion of the setup, the inertial measurement unit10returns to the standby mode.

Also, when a request to start state monitoring is made in the standby mode by a press on the measurement start switch84, the inertial measurement unit10shifts to a state monitoring mode. In the state monitoring mode, the display unit60and the display unit70display the result of measurement. At this time, a press on the mode changeover switch80changes the display mode. Also, for example, when the measured value exceeds the threshold in the state monitoring mode, the inertial measurement unit10shifts to an alarm state and, for example, a light-emitting element for alarm in the display unit60flashes on and off. As the inertial measurement unit10shifts to the alarm state, log data is saved. When a request to stop state monitoring is made in the state monitoring mode or in the alarm state, for example, by another press on the measurement start switch84, the inertial measurement unit10returns to the standby mode.

In the inertial measurement unit10according to this embodiment as described above, the user first installs the inertial measurement unit10at a device or floor surface and presses the measurement start switch84. For example, the user holds the inertial measurement unit10with the palm in contact with the top surface of the inertial measurement unit10and presses the measurement start switch84, using a finger of the hand or the like. To cause the inertial measurement unit10to learn a threshold, the user long-presses the measurement start switch84, which causes the inertial measurement unit10to learn a measurement threshold. The user then presses the measurement start switch84. After pressing the measurement start switch84, the user waits for a predetermined measurement time. For example, the measurement time is a duration of 5 to 10 seconds. The length of the measurement time can be set. As the measurement time ends, a display via the LED as the light-emitting element in the display unit60or a display on the display panel72of the display unit70notifies the user of the result of the measurement. At this time, the user can switch between various display modes by pressing the mode changeover switch80. By pressing the measurement start switch84again, the user can stop the state monitoring mode and shift the inertial measurement unit10to the standby mode. In this way, with the inertial measurement unit10according to this embodiment, the user can carry out measurement by a simple operation. Since the display units60,70display information based on detection information from the inertial sensor, the user can check the result of measurement via the display of information that is easy to understand, and this can improve convenience. The user can also check the result of measurement in various display modes by operating the mode changeover switch80. Also, since the inertial measurement unit10is provided with the wireless communication unit90and the antenna unit92, the inertial measurement unit10can wirelessly transmit information based on detection information from the inertial sensor, to an external device. In this case, since the antenna unit92is provided in such a way as to protrude from the main surface of the case24of the sensor unit20, wireless communication can be performed with high antenna sensitivity.

4. Sensor Unit

FIG. 15shows a first configuration example of the sensor unit20.FIG. 15is an exploded perspective view of the sensor unit20. The sensor unit20shown inFIG. 15includes the sensor substrate210provided with at least one acceleration sensor as at least one inertial sensor, and the case24accommodating the sensor substrate210. InFIG. 15, the acceleration sensors30X,30Y,30Z detecting an acceleration in directions along the X-axis, the Y-axis, and the Z-axis, respectively, are provided at the sensor substrate210, as at least one acceleration sensor. The acceleration sensors30X,30Y,30Z are installed at the sensor substrate210in such a way that the main surfaces of the acceleration sensors30X,30Y,30Z are orthogonal to the X-axis, the Y-axis, and the Z-axis, respectively. The acceleration sensors30X,30Y,30Z are, for example, acceleration sensors using a quartz crystal vibrator and can detect an acceleration with higher accuracy than a MEMS (micro-electromechanical systems) acceleration sensor. Thus, a vibration or the like of a device or floor surface can be detected with high accuracy. InFIG. 15, the three acceleration sensors30X,30Y,30Z for detecting an acceleration on the three axes are provided at the sensor substrate210. However, various modified embodiments can be employed, such as providing one acceleration sensor for detecting an acceleration on one axis at the sensor substrate210, or providing two acceleration sensors for detecting an acceleration on two axes at the sensor substrate210.

Also, the processing unit212implemented by an ASIC, microcomputer or the like is provided at the sensor substrate210. For example, the processing unit212of the sensor unit20may execute a part or all of the processing carried out by the processing unit50of the inertial measurement unit10. At a second surface, that is, the back side of a first surface, which is the main surface of the sensor substrate210where the acceleration sensors30X,30Y,30Z are provided, the connector26formed of a plurality of connector terminals is provided. As described with reference toFIG. 13, the connector26of the sensor unit20is coupled to the connector46at the back side of the substrate40in the inertial measurement unit10.

The case24is formed of an electrically conductive material such as a metal and has the container220and the lid222. The sensor substrate210is accommodated in the accommodation space formed by the container220and the lid222. The container220and the lid222are fixed together and airtightly sealed by a fixing member such as a screw. A sealing member224as a buffer member is provided between the lid222and the sensor substrate210.

FIGS. 16 and 17show a second configuration example of the sensor unit20.FIG. 16is an exploded perspective view of the sensor unit20.FIG. 17is a plan view of the sensor substrate210. The sensor unit20shown inFIGS. 16 and 17includes the sensor substrate210provided with at least one acceleration sensor and at least one angular velocity sensor, as at least one inertial sensor, and the case24accommodating the sensor substrate210. InFIGS. 16 and 17, the acceleration sensor32detecting an acceleration in directions along the X-axis, the Y-axis, and the Z-axis is provided at the sensor substrate210, as at least one acceleration sensor. Inside the acceleration sensor32, a sensor element detecting an acceleration in the X-axis direction and the Y-axis direction and a sensor element detecting an acceleration in the Z-axis direction are provided. These sensor elements are, for example, MEMS sensor elements. Also, various modified embodiments can be employed, such as providing individual acceleration sensors for the X-axis, the Y-axis, and the Z-axis, respectively, or providing an acceleration sensor for two axes or one axis of the X-axis, the Y-axis, and the Z-axis, at the sensor substrate210. InFIGS. 16 and 17, the angular velocity sensors34X,34Y,34Z detecting an angular velocity about the X-axis, the Y-axis, and the Z-axis, respectively, are provided as at least one angular velocity sensor. The angular velocity sensors34X,34Y,34Z are installed at the sensor substrate210in such a way that the main surfaces of the angular velocity sensors34X,34Y,34Z are orthogonal to the X-axis, the Y-axis, and the Z-axis, respectively. The angular velocity sensors34X,34Y,34Z are, for example, gyro sensors detecting an angular velocity, using a quartz crystal vibrator. Providing not only an acceleration sensor but also an angular velocity sensor at the sensor substrate210in this way enables not only detection of a vibration or the like but also detection of a tilt, attitude change and the like of a target object. InFIGS. 16 and 17, the three angular velocity sensors34X,34Y,34Z for detecting an angular velocity about the three axes are provided at the sensor substrate210. However, various modified embodiments can be employed, such as providing one angular velocity sensor for detecting an angular velocity about one axis at the sensor substrate210, or providing two angular velocity sensors for detecting an angular velocity about two axes at the sensor substrate210.

As shown inFIG. 17, at the first surface, which is the main surface of the sensor substrate210where the acceleration sensor32or the like is provided, the connector26formed of a plurality of connector terminals is provided. As described with reference toFIG. 13, the connector26of the sensor unit20is coupled to the connector46at the back side of the substrate40in the inertial measurement unit10. At the second surface, which is the back side of the sensor substrate210, a processing unit, not illustrated, implemented by an ASIC, microcomputer or the like is provided. For example, the processing unit of the sensor unit20may execute a part or all of the processing carried out by the processing unit50of the inertial measurement unit10.

The case24is formed of an electrically conductive material such as a metal and has the container220and the lid222. The sensor substrate210is accommodated in the accommodation space formed by the container220and the lid222. The container220and the lid222are fixed together and airtightly sealed by a fixing member such as a screw. The sealing member224as a buffer member is provided between the lid222and the sensor substrate210.

As described above, the inertial measurement unit according to this embodiment includes: a sensor unit having at least one inertial sensor; a display unit performing a display based on detection information from the inertial sensor; and a mode changeover switch. The mode changeover switch changes a display mode of the display unit.

According to this embodiment, the display unit provided in the inertial measurement unit can perform a display based on detection information from the inertial sensor of the sensor unit. Therefore, the work of checking the result of measurement can be simplified. Also, since the display mode of the display unit can be changed by operating the mode changeover switch, various demands about the display form of the result of measurement can be met.

In the embodiment, when a direction from the inertial measurement unit toward an installation surface for the inertial measurement unit is defined as a first direction and a direction orthogonal to the first direction is defined as a second direction, the mode changeover switch may have a moving part movable in the second direction. A movement of the moving part of the mode changeover switch may give an instruction to change the display mode of the display unit.

Thus, the user can give an instruction to change the display mode by a simple operation of moving the moving part of the mode changeover switch in the second direction, which is orthogonal to the first direction from the inertial measurement unit toward the installation surface.

In the embodiment, the moving part of the mode changeover switch, when not pressed, may protrude from a side of the sensor unit as viewed in a plan view in the first direction.

Thus, the display mode of the display unit is changed by a simple operation of pressing the moving part of the mode changeover switch protruding from the side of the sensor unit when not pressed. Therefore, user-friendliness can be improved.

In the embodiment, the inertial measurement unit may include a measurement start switch for starting measurement by the inertial measurement unit.

Thus, measurement by the inertial measurement unit can be started by a simple operation of operating the measurement start switch. Therefore, user-friendliness can be improved.

In the embodiment, when a direction from the inertial measurement unit toward an installation surface for the inertial measurement unit is defined as a first direction and a direction orthogonal to the first direction is defined as a second direction, the measurement start switch may have a moving part movable in the second direction. A movement of the moving part of the measurement start switch may give an instruction to start measurement by the inertial measurement unit.

Thus, the user can give an instruction to start measurement by the inertial measurement unit by a simple operation of moving the moving part of the measurement start switch in the second direction, which is orthogonal to the first direction from the inertial measurement unit toward the installation surface.

In the embodiment, the inertial measurement unit may include a memory, and a teach switch for giving an instruction to store measurement criteria information for inertial measurement into the memory.

Thus, the inertial measurement unit can be made to learn measurement criteria information corresponding to a measurement target, and measurement using the measurement criteria information can be realized.

In the embodiment, when a direction from the inertial measurement unit toward an installation surface for the inertial measurement unit is defined as a first direction and a direction orthogonal to the first direction is defined as a second direction, the teach switch may have a moving part movable in the second direction. A movement of the moving part of the teach switch may give an instruction to store the measurement criteria information into the memory.

Thus, the user can give an instruction to store measurement criteria information into the memory by a simple operation of moving the moving part of the teach switch in the second direction, which is orthogonal to the first direction from the inertial measurement unit toward the installation surface.

In the embodiment, the inertial measurement unit may include a substrate where the mode changeover switch is provided.

Thus, the mode changeover switch can be installed in a compact form in the inertial measurement unit.

In the embodiment, the inertial measurement unit may include at least one fixing member removably fixing the sensor unit and the substrate together.

Thus, the sensor unit and the substrate incorporated in the inertial measurement unit can be freely changed and the extensibility of the inertial measurement unit ca be improved.

In the embodiment, the inertial measurement unit may include a first substrate and a second substrate, as the substrate. The mode changeover switch may be provided at the first substrate. The display unit may be provided at the second substrate. The first substrate may be provided between the sensor unit and the second substrate.

Thus, when the mode changeover switch provided at the first substrate is operated, the display mode of the display unit provided at the second substrate changes. Since the mode changeover switch is provided at the first substrate provided between the sensor unit and the second substrate, the operability of the mode changeover switch can be improved.

In the embodiment, the display unit may display, in a first display mode, a result of determination based on a first determination criterion, and in a second display mode, a result of determination based on a second determination criterion, as a result of determination based on the detection information.

Thus, as the user operates the mode changeover switch, the result of determination about measurement is displayed at the display unit, based on different determination criteria. The result of determination based on various determination criteria can be presented to the user.

In the embodiment, the first determination criterion may be a determination criterion of VC (vibration criteria), and the second determination criterion may be a determination criterion set by a user.

Thus, the display mode can be switched between the first display mode, in which the result of determination based on the VC determination criterion is displayed, and the second display mode, in which the result of determination based on the determination criterion set by the user is displayed, via the mode changeover switch.

In the embodiment, a unit of information displayed based on the detection information may be changed via the mode changeover switch.

Thus, the measured value can be displayed in various units to the user via the operation of the mode changeover switch. Therefore, user-friendliness can be improved.

In the embodiment, the inertial measurement unit may include a processing unit performing processing based on the detection information. The processing unit may perform analysis processing on vibration information about a detection target. The display unit may display information about a result of the analysis processing.

Thus, as the processing unit performs analysis processing on detection information from the inertial sensor and the display unit displays information about the result of the analysis processing, the user can easily grasp the vibration state of the detection target.

In the embodiment, the sensor unit may include a sensor substrate provided with at least one acceleration sensor as the at least one inertial sensor, and a case accommodating the sensor substrate.

Thus, the display unit provided in the inertial measurement unit can perform a display based on detection information from the acceleration sensor provided at the sensor substrate of the sensor unit. Therefore, the work of checking the result of measurement can be simplified.

In the embodiment, the sensor unit may include a sensor substrate provided with at least one acceleration sensor and at least one angular velocity sensor, as the at least one inertial sensor, and a case accommodating the sensor substrate.

Thus, the display unit provided in the inertial measurement unit can perform a display based on detection information from the acceleration sensor and the angular velocity sensor provided at the sensor substrate of the sensor unit. Therefore, the work of checking the result of measurement can be simplified.

The embodiment has been described above in detail. However, a person skilled in the art will readily understand that various modifications can be made without substantially departing from the new matters and effects of the present disclosure. Therefore, such modifications are understood as included in the scope of the present disclosure. For example, a term described along with a different term having a broader meaning or the same meaning, at least once in the specification or drawings, can be replaced with the different term in any part of the specification or drawings. Any combination of the embodiment and the modifications is included in the scope of the present disclosure. The configuration, operation and the like of the inertial measurement unit are not limited those described in the embodiment and can be carried out with various modifications.