Patent Description:
A work robot that includes a robot arm including a plurality of arm members is known in the related art. <CIT> discloses, for example, a funnel-shaped suction member having an opening for sucking in external air and holding a workpiece by suction, in which a conductive wire for detecting breakage due to disconnection is provided around the opening.

Document <CIT> discloses a method of judging a defect of a component suction nozzle. The method has: detecting a center position of the nozzle, rotating the nozzle a predetermined angle, detecting the center position of the nozzle, detecting a shift amount between the center positions of the nozzle, and determining whether a deviation of the nozzle is good or defective based on the shift amount and a predetermined value.

Document <CIT> discloses a vacuum gripping device having a suction cup that has an elastically deformable conductive track and an electric processing circuit connected thereto. The electric processing circuit periodically measures a resistance of the conductive track and compares the measured resistance values and their evolution with reference data stored therein in order to detect a local reduction of the suction cup, such as a tearing of the suction cup or excessive abrasion of an edge of the suction cup.

However, the above-described related art has a problem that it is not versatile because it is necessary to manufacture a dedicated suction portion.

An aspect of the present invention has been made in view of such circumstances, and an object of the present invention is to provide a suction apparatus capable of easily determining deterioration of a suction portion.

In order to solve the above-described problem, the present invention employs the following configurations.

A deterioration determination apparatus according to an aspect of the present disclosure includes: an information obtainment unit configured to obtain information on deformation of a plurality of regions of a suction portion, which suction portion is configured to hold an object by suction with negative pressure, in a state in which the suction portion does not hold an object by suction; and a deterioration determination unit configured to calculate a ratio of the deformation of the plurality of regions of the suction portion based on the information on the deformation of the plurality of regions of the suction portion in a state in which the suction portion does not hold an object by suction, and determine whether or not the suction portion has deteriorated, depending on that ratio.

A deterioration determination method according to an aspect of the present disclosure includes: an information obtainment step of obtaining information on deformation of a plurality of regions of a suction portion, which suction portion is configured to hold an object by suction with negative pressure, in a state in which the suction portion does not hold an object by suction; and a deterioration determination step of calculating a ratio of the deformation of the plurality of regions of the suction portion based on the information on the deformation of the plurality of regions of the suction portion in a state in which the suction portion does not hold an object by suction, and determining whether or not the suction portion has deteriorated, depending on that ratio.

According to an embodiment of the present invention, it is possible to provide a suction apparatus capable of easily determining whether or not a suction portion has deteriorated.

Hereinafter, an embodiment according to one aspect of the present invention (hereinafter, also referred to as "the present embodiment") will be described with reference to the drawings.

<FIG> shows an example of a configuration of a suction apparatus <NUM> according to the present embodiment. The suction apparatus <NUM> can be used as a mobile robot for conveying an object.

As shown in <FIG>, the suction apparatus <NUM> includes: a sensor assembly <NUM>; a suction portion <NUM> configured to hold an object by suction with negative pressure; a shaft <NUM> that supports the suction portion <NUM> and includes an air passage; and a tube <NUM> connected to the air passage.

The sensor assembly <NUM> is attachable to the suction apparatus <NUM>, and includes a body <NUM>, one or more proximity sensors <NUM>, and a fixture <NUM>.

The suction portion <NUM> may be worn and deformed, or cracked, due to a change over time. The proximity sensor <NUM> measures deformation of the suction portion <NUM>. A deterioration determination apparatus <NUM> according to the present embodiment shown in <FIG> determines whether or not the suction portion <NUM> has deteriorated, depending on the deformation of the suction portion <NUM> in the state in which the suction portion <NUM> does not hold an object by suction.

<FIG> shows an example of the configuration of the suction apparatus <NUM>. <FIG> shows an example of the sensor assembly <NUM> in a cross-sectional view taken along line A-A of <FIG>.

As shown in <FIG>, the suction apparatus <NUM> includes: the sensor assembly <NUM>; the suction portion <NUM> configured to hold an object by suction with negative pressure; the shaft <NUM> that supports the suction portion <NUM> and includes an air passage, and the tube <NUM> connected to the air passage. Examples of the suction portion <NUM> include a suction pad that holds an object by suction with negative pressure.

The sensor assembly <NUM> is attachable to the suction apparatus <NUM>, and includes the body <NUM>, one or more proximity sensors <NUM>, and the fixture <NUM>. A space through which the shaft <NUM> passes is formed in the body <NUM>. The proximity sensor <NUM> is disposed on the body <NUM>, and detects that the suction portion <NUM> is deformed by negative pressure. The fixture <NUM> includes a fixed portion <NUM> that is fixed to the shaft <NUM>, and a support portion <NUM> that supports the body <NUM>.

The proximity sensor <NUM> may be a sensor capable of measuring a distance to an object at a short distance, or a senser capable of detecting that an object has approached to a certain distance. Examples of a detection method of the proximity sensor <NUM> include a capacitive method, an optical method, an electromagnetic induction method, and an acoustic method such as a sound wave method or an ultrasonic method. Also, examples of the capacitive sensor include a self-capacitive sensor and a mutual capacitive sensor. The one or more proximity sensors provided in the sensor assembly may be of the same type, or may be of different types. Instead of the proximity sensor <NUM> included in the sensor assembly <NUM>, the suction portion <NUM> may also be provided with a strain sensor that detects strain in one or more regions of the suction portion <NUM>.

The sensor assembly <NUM> is attachable to the shaft <NUM> of the suction apparatus <NUM> that supports the suction portion <NUM> and has the air passage, and the proximity sensor <NUM> can be disposed on the suction portion <NUM>. The proximity sensor <NUM> measures the amount of deformation of the suction portion <NUM> that is deformed by negative pressure.

In the example of <FIG>, the suction apparatus <NUM> includes the sensor assembly <NUM>, the suction portion (suction pad) <NUM>, and the shaft <NUM>. An air passage for sucking in air is provided in the shaft <NUM>. The air passage is connected to the suction portion <NUM> and the tube <NUM>. The shaft <NUM> and a vacuum pump that generates negative pressure may be connected through the tube <NUM>. The suction portion <NUM> of the suction apparatus <NUM> may be grounded.

Because the suction portion <NUM> is disposed on one end side of the shaft <NUM>, the sensor assembly <NUM> is preferably attached to the shaft <NUM> on other end side of the shaft <NUM>, for example. However, in order to accurately detect the deformation of the suction portion <NUM>, the body <NUM> is preferably disposed at a position close to the suction portion <NUM>, for example.

The support portion <NUM> of the fixture <NUM> extends from the fixed portion <NUM> toward the suction portion <NUM>. The body <NUM> is disposed on a suction portion <NUM> side relative to the fixed portion <NUM>, using the support portion <NUM>. With this configuration, it is possible to fix the fixture <NUM> to the other end side (the opposite side to the suction portion <NUM>) of the shaft <NUM>, and to dispose the sensor assembly <NUM> at a position close to the suction portion <NUM>.

A space <NUM> (not shown) through which the shaft <NUM> of the suction apparatus <NUM> passes is formed in the body <NUM>. The space <NUM> may be a hole, or a notch. The main body <NUM> is not in contact with the shaft <NUM>, for example. The body <NUM> may have a circular shape, a quadrangular shape, or an elliptical shape. In addition, the space <NUM> may have a circular shape, a quadrangular shape, or an elliptical shape. The body <NUM> and a controller such as a programmable logic controller (PLC) or the deterioration determination apparatus <NUM> may be connected through a sensor wiring <NUM>.

In the example of a suction apparatus 1a in <FIG>, the proximity sensor <NUM> is disposed on the main body <NUM> along the circumferential direction of the space <NUM> (the shaft <NUM>). In the example of a suction apparatus 1b in <FIG>, a plurality of the proximity sensors <NUM> are disposed on the body <NUM> along the circumferential direction of the space <NUM> (the shaft <NUM>). In the example of a suction apparatus 1c in <FIG>, a plurality of the proximity sensors <NUM> are disposed on the body <NUM> along the circumferential direction and the radial direction with respect to the space <NUM> (the shaft <NUM>). In the example of a suction apparatus 1d in <FIG>, the space <NUM> has a quadrangular shape, and the proximity sensor <NUM> is disposed on the body <NUM> having a quadrangular outer shape. In the example of a suction apparatus 1e in <FIG>, the space <NUM> has a circular shape, and the proximity sensor <NUM> is disposed on the body <NUM> having a quadrangular outer shape. In the example of a suction apparatus If in <FIG>, the proximity sensor <NUM> is disposed on a quadrangular body <NUM> in which the space <NUM> has a circular shape. In the example of a suction apparatus <NUM> in <FIG>, the proximity sensor <NUM> is disposed on an elliptical body <NUM> in which the space <NUM> has an elliptical shape. In the example of a suction apparatus <NUM> in <FIG>, a plurality of the proximity sensors <NUM>, which are sensor chips, are disposed on the body <NUM> along the circumferential direction of the space <NUM> (the shaft <NUM>). In the example of a suction apparatus 1i in <FIG>, a plurality of the proximity sensors <NUM> are disposed on the body <NUM> along the circumferential direction and the radial direction with respect to the space <NUM> (the shaft <NUM>).

<FIG> illustrates an example of the configuration of the sensor assembly <NUM>. In the example <NUM> shown in <FIG>, the sensor assembly <NUM> includes the main body <NUM> shown in the example of the suction apparatus 1a shown in <FIG>. The proximity sensor <NUM> provided in the body <NUM> can measure the amount of displacement of the suction portion <NUM>. The proximity sensor <NUM> is disposed above the suction portion <NUM>. In the example <NUM> shown in <FIG>, the sensor assembly <NUM> includes the main body <NUM> shown in the example of the suction apparatus 1c shown in <FIG>. The plurality of proximity sensors <NUM> are disposed on the body <NUM> along the radial direction with respect to the shaft <NUM>. With this configuration, the sensor assembly <NUM> can individually detect displacement at a plurality of positions in the radial direction of the suction portion <NUM>. In the example <NUM> shown in <FIG>, the sensor assembly <NUM> includes the main body shown in the example of the suction apparatus 1i shown in <FIG>. The plurality of proximity sensors <NUM> are disposed on the body <NUM>, along the circumferential direction and the radial direction with respect to the shaft <NUM>. When the sensor assembly <NUM> includes the body <NUM> of the examples of the suction apparatuses 1c or 1i shown in <FIG>, then a plurality of proximity sensors <NUM> are disposed in a circle covering the suction portion <NUM>. With this configuration, it is possible to select an appropriate proximity sensor, according to the size of the body. The example <NUM> shown in <FIG> shows a state in which the suction portion <NUM> has been worn off compared to the example <NUM> shown in <FIG>. The proximity sensors <NUM> disposed on the radially outer side detect a region on the radially outer side of the suction portion <NUM> in a normal state as in the example <NUM> shown in <FIG>, but cannot detect the region on the radially outer side of the suction portion <NUM> in a worn state (deteriorated state) as in the example <NUM> shown in <FIG>.

<FIG> shows examples of shapes of a normal state and deteriorated states of the suction portion <NUM>. The example <NUM> shown in <FIG> shows the shape of the suction portion <NUM> in a normal state, which is unused. The example <NUM> shown in <FIG> shows the shape of the suction portion <NUM> in which a part of the distal end portion of the suction portion <NUM> shown in the example <NUM> in <FIG> is worn or deformed due to deterioration. The example <NUM> shown in <FIG> shows a shape of the suction portion <NUM> in a state in which the distal end portion of the suction portion <NUM> in the example <NUM> shown in <FIG> is worn, and deformed as a whole due to deterioration. The example <NUM> shown in <FIG> shows a shape of the suction portion <NUM> in a state in which there is a crack in the suction portion <NUM> of the example <NUM> shown in <FIG>. The proximity sensor <NUM> outputs different sensor values in the normal state shown in the example <NUM> in <FIG> and in the deteriorated states shown in the examples <NUM> to <NUM> in <FIG>. When the distance between the proximity sensor <NUM> and the suction portion <NUM> changes due to deterioration, the sensor value that is output from the proximity sensor <NUM> changes. Also, when the electrostatic capacitance of the suction portion <NUM> changes due to wear, the sensor value output from the capacitive proximity sensor <NUM> changes. When a crack occurs in the measurement region of the proximity sensor <NUM> in the suction portion <NUM>, the distance from the proximity sensor <NUM> to the measurement region may change, and thus the sensor value output from the proximity sensor <NUM> may change. Instead of the proximity sensor <NUM>, a strain sensor may also be attached to the surface of the suction portion <NUM>. The strain sensor outputs a sensor value that corresponds to the deformation of the suction portion <NUM>. Accordingly, in the deteriorated states shown in examples <NUM> to <NUM> in <FIG>, the sensor value output from the strain sensor changes in accordance with the deformation of the suction portion <NUM>.

Next, an example of a hardware configuration of the suction system <NUM> including the deterioration determination apparatus according to the present embodiment will be described with reference to <FIG>.

<FIG> is a block diagram schematically showing an example of the configuration of the suction system <NUM> according to the present embodiment. In the example of <FIG>, the suction system <NUM> according to the present embodiment includes a suction apparatus <NUM>, a controller <NUM>, a deterioration determination apparatus <NUM>, a display unit <NUM>, and a sound output unit <NUM>. In the present embodiment, the suction apparatus <NUM> may be a fixed suction apparatus that is fixed at a predetermined position, or may also be a movable suction apparatus including an automated guided vehicle.

The suction apparatus <NUM> includes a manipulator unit <NUM>, a suction portion <NUM>, a vacuum pump <NUM>, a proximity sensor <NUM>, a pressure sensor <NUM>, a flow rate sensor <NUM>, and a microphone <NUM>.

The manipulator unit <NUM> is driven together with the suction portion <NUM>, under control of the controller <NUM>. The manipulator unit <NUM> is, for example, an articulated robot arm having one or a plurality of joints.

When the suction portion <NUM> is positioned at a work position by driving of the manipulator unit <NUM>, the suction portion <NUM> holds an object by suction with negative pressure that corresponds to the driving amount of the vacuum pump <NUM>. The suction portion <NUM> is elastically deformed by negative pressure, and is brought into intimate contact with an object. In this manner, the suction portion <NUM> holds the object.

The vacuum pump <NUM> generates negative pressure that corresponds to the driving amount, and provides the generated negative pressure to the suction portion <NUM>. Here, an example in which the suction apparatus <NUM> in the suction system <NUM> includes the vacuum pump <NUM> is described. However, in the present embodiment, the suction apparatus <NUM> in the suction system <NUM> does not necessarily have to include the vacuum pump <NUM>, and for example, the vacuum pump <NUM> may also be provided outside the suction apparatus <NUM> and the suction system <NUM>. Also with this configuration, the controller <NUM> controls the driving amount of the vacuum pump <NUM>, so that the same effect as in the above-described example can be achieved.

The pressure sensor <NUM> measures pressure P inside the suction portion <NUM> in which negative pressure is generated using the vacuum pump <NUM>, and outputs information indicating the pressure P to the information obtainment unit <NUM>.

The flow rate sensor <NUM> is disposed with respect to, for example, the tube <NUM>, measures a flow rate of air flowing through the tube <NUM>, and outputs information indicating the flow rate to the information obtainment unit <NUM>.

The microphone <NUM> is disposed near the tube <NUM>, and measures sound generated due to flow of air. Examples of the sound include a sound generated when an object is held by suction with the suction portion <NUM> and air flowing into the air passage from a portion between the object and the suction portion <NUM> is blocked, and a sound generated due to air flowing through the tube. The sound measured by the microphone <NUM> varies depending on the flow rate of air. The microphone <NUM> outputs information on the measured sound to the information obtainment unit <NUM>, as sound data.

The controller <NUM> includes, for example, a central processing unit (CPU), and a random access memory (RAM) or a read only memory (ROM), and performs control in response to an information process. In addition, the controller <NUM> controls the manipulator unit <NUM>. In this manner, the controller <NUM> moves the suction portion <NUM> through the manipulator unit <NUM>. Specifically, the controller <NUM> drives the manipulator unit <NUM> so that the suction portion <NUM> is positioned at a work position where the suction portion <NUM> can hold an object by suction. Also, the controller <NUM> may also operate the manipulator unit <NUM> so that the angle of the suction portion <NUM> with respect to the object reaches a predetermined angle, after the suction portion <NUM> is positioned at the work position. In this manner, the position of the suction portion <NUM> can be finely adjusted to a more suitable position. Furthermore, the controller <NUM> controls the vacuum pump <NUM>. In this manner, the controller <NUM> drives the vacuum pump <NUM>, and causes the suction portion <NUM> to hold an object by suction. The controller <NUM> outputs, to the deterioration determination apparatus <NUM>, information on the mass of an object to be held by suction and information whether or not the suction portion <NUM> is currently holding an object by suction.

In the present embodiment, an example is described in which the controller <NUM> included in the suction system <NUM> is provided outside the suction apparatus <NUM> and the deterioration determination apparatus <NUM>. However, the present invention is not limited to the above configuration, and for example, the suction apparatus <NUM> may also include the controller <NUM>, or the deterioration determination apparatus <NUM> may also include the controller <NUM>.

The suction apparatus <NUM> may be configured to be operated by a battery, or may also be configured to be supplied with electric power from the outside of the suction apparatus <NUM> through a power cord.

The deterioration determination apparatus <NUM> includes an information obtainment unit <NUM>, a deterioration determination unit <NUM>, a storage unit <NUM>, a lifetime prediction unit <NUM>, and a notification control unit <NUM>.

The information obtainment unit <NUM> obtains information on deformation of a plurality of regions of the suction portion <NUM>. In this manner, the deterioration determination apparatus <NUM> can strictly determine a deteriorated region of the suction portion <NUM>. The information obtainment unit <NUM> obtains, for example, data indicating the deformation amount of the suction portion <NUM> from the proximity sensor <NUM>, and specifies the deformation amount of the suction portion <NUM>. Also, the information obtainment unit <NUM> obtains, from the pressure sensor <NUM>, information indicating pressure. The information obtainment unit <NUM> obtains, from the flow rate sensor <NUM>, information indicating the flow rate of air flowing through the tube <NUM>. The information obtainment unit <NUM> obtains sound data from the microphone <NUM>. Furthermore, the information obtainment unit <NUM> obtains, from the controller <NUM>, information indicating whether or not the suction portion <NUM> is currently holding an object by suction. The information obtainment unit <NUM> outputs, to the deterioration determination unit <NUM>, the information indicating the deformation amount, the information indicating the pressure, the information indicating the flow rate of air, the sound data, and the information indicating whether or not the suction portion <NUM> is currently holding an object by suction.

The information obtainment unit <NUM> outputs, to the controller <NUM>, deformation data such as deformation amount, deformation speed, or deformation acceleration of the suction portion <NUM>.

According to the invention, the deterioration unit <NUM> calculates a ratio of the deformation of a plurality of regions of the suction portion <NUM> in the state in which the suction portion <NUM> does not hold an object by suction, based on information on deformation of the plurality of regions of the suction portion <NUM>. When a metal piece or the like is attached to a partial region of the suction portion <NUM>, a deviation occurs in the sensor values of the proximity sensors <NUM>, even when the suction portion <NUM> is in a normal state. When the sensor values of the proximity sensors <NUM> are deviated even when the suction portion <NUM> is in a normal state, the deterioration determination unit <NUM> may also calculate a ratio that is corrected by the sensor value obtained when the suction portion <NUM> is in a normal state.

Specifically, a case where the ratio is calculated from the sensor values obtained from the three proximity sensors <NUM> will be described. The sensor values of the three proximity sensors <NUM> in the normal state are referred to as values d1o, d2o, and d3o, and the sensor values of the three proximity sensors <NUM> for determining deterioration are referred to as values d1, d2, and d3. The deterioration determination unit <NUM> may determine whether or not the suction portion <NUM> has deteriorated, according to whether or not d1/d1o:d2/d2o:d3/d3o is within a normal range. When (d2/d2o)/(d1/d1o) is within a predetermined range and (d3/d3o)/(d1/d1o) is within a predetermined range, for example, the deterioration determination unit <NUM> may determine that the ratio of d1/d1o:d2/d2o:d3/d3o is within a normal range.

Alternatively, more simply, when d2/d1 is within a predetermined range and d3/d1 is within a predetermined range, the deterioration determination unit <NUM> may also determine that the deformation ratio dl:d2:d3 of each region is within a normal range.

The deterioration determination unit <NUM> determines whether or not the suction portion <NUM> has deteriorated, depending on the calculated ratio. The deterioration determination unit <NUM> determines whether or not the suction portion <NUM> has deteriorated, depending on whether or not the calculated ratio is within a normal range that has been set for a plurality of regions of the suction portion <NUM>. The normal range may be a range including a ratio that has been set in advance as a ratio indicating that the suction portion is normal, or a range including a ratio when the suction portion is in an initial state.

By calculating the ratio of deformation of a plurality of regions of the suction portion <NUM> in the state in which the suction portion <NUM> does not hold an object by suction, and determining whether or not the suction portion has deteriorated according to the calculated ratio, it is possible to accurately determine whether or not the suction portion <NUM> has deteriorated, even if the sensor values fluctuate due to the influence of the environment such as temperature.

The deterioration determination unit <NUM> outputs, to the controller <NUM>, a signal whether or not to continue the operation. When it is determined that the suction portion <NUM> has not deteriorated, the deterioration determination unit <NUM> outputs, to the controller <NUM>, a signal for continuing the operation. When it is determined that the suction portion <NUM> has deteriorated, the deterioration determination unit <NUM> outputs, to the controller <NUM>, a signal for stopping the operation.

The storage unit <NUM> stores information on deformation of the one or more regions of the suction portion <NUM> obtained by the deterioration determination unit <NUM> from the information obtainment unit <NUM>, the date and time when deformation is measured, and a result of the determination performed by the deterioration determination unit <NUM>. The storage unit <NUM> is, for example, an auxiliary storage device such as a hard disk drive or a solid state drive.

The lifetime prediction unit <NUM> obtains, from the storage unit <NUM>, time-series information in a predetermined period indicating deformation of the one or more regions of the suction portion <NUM> in the state in which the suction portion <NUM> does not hold an object by suction. The lifetime prediction unit <NUM> predicts the lifetime of the suction portion <NUM> from a temporal change in the deformation of the one or more regions of the suction portion <NUM> in the state in which the suction portion <NUM> does not hold an object by suction.

The lifetime prediction unit <NUM> outputs, to the controller <NUM>, a signal indicating whether or not to continue the operation, depending on the predicted lifetime of the suction portion <NUM>. The lifetime prediction unit <NUM> may output, to the controller <NUM>, a signal for stopping the operation when the suction portion <NUM> reaches the end of its lifetime, or may also output, to the controller <NUM>, a signal for stopping the operation before a predetermined period from the end of the lifetime of the suction portion <NUM>. When the lifetime prediction unit <NUM> predicts that, for example, the end of lifetime will be reached when the suction portion <NUM> holds an object by suction <NUM> more times and stops the operation at <NUM> suctions before the end of lifetime, the lifetime prediction unit <NUM> may also output, to the controller <NUM>, a signal for stopping the operation when the suction portion <NUM> holds an object by suction another <NUM> times.

When the deterioration determination unit <NUM> determines that the suction portion <NUM> has deteriorated, the notification control unit <NUM> may notify at least one of the display unit <NUM> and the sound output unit <NUM> that the suction portion <NUM> has deteriorated. The notification control unit <NUM> may cause, for example, for notifying deterioration of the suction portion <NUM>, the display unit <NUM> to emit light of a predetermined color or display an image for notifying deterioration of the suction portion <NUM>, or may also cause the sound output unit <NUM> to output a predetermined sound for notifying deterioration of the suction portion <NUM>.

The notification control unit <NUM> may also notify at least one of the display unit <NUM> and the sound output unit <NUM> that the lifetime of the suction portion <NUM> predicted by the lifetime prediction unit <NUM> is close to its end. The notification control unit <NUM> may also notify, for example, at least one of the display unit <NUM> and the sound output unit <NUM> that the suction portion <NUM> will reach the end of its lifetime after a predetermined period has elapsed, at a point in time before the predetermined period. Specifically, for example, the notification control unit <NUM> may also cause the display unit <NUM> to emit light of a predetermined color or display an image, for notifying that the suction portion <NUM> will reach the end of its lifetime after a predetermined period has elapsed. Alternatively, the notification control unit <NUM> may also cause the sound output unit <NUM> to output a predetermined sound, for notifying that the suction portion <NUM> will reach the end of its lifetime after a predetermined period has elapsed. The predetermined period is not limited to a specific period, but is, for example, one month.

The display unit <NUM> displays light or an image, in accordance with an instruction transmitted from the notification control unit <NUM>. The display unit <NUM> is not limited to a specific device as long as it emits light or displays an image, and examples of the display unit <NUM> include a lamp or a display.

The sound output unit <NUM> outputs sound, in accordance with an instruction transmitted from the notification control unit <NUM>. Examples of the sound include a buzzer sound, for example. The sound output unit <NUM> is not limited to a specific device as long as it outputs sound, and examples of the sound output unit <NUM> include a speaker.

Next, an operation example of the suction system <NUM> will be described with reference to <FIG> and <FIG>. The operation procedure described below is merely an example, and may be changed to the extent possible.

<FIG> is a flow chart showing how the suction system <NUM>, not part of the scope of protection, operates.

First, in step S11, the controller <NUM> included in the suction apparatus <NUM> controls the vacuum pump <NUM> so as not to generate negative pressure, thereby stopping suction. By stopping suction, the vibration of the suction portion <NUM> can be reduced, and thus the deterioration of the suction portion <NUM> can be detected more accurately. The proximity sensor <NUM> can detect deformation of one or more regions of the suction portion <NUM> in a state in which the suction portion <NUM> does not hold an object by suction. A signal indicating that the suction portion <NUM> is not holding an object by suction is input from the controller <NUM> to the information obtainment unit <NUM>. In this step, it is also possible that suction is not stopped, as long as the suction portion <NUM> is not holding an object by suction.

Next, in step S12 (information obtainment step), the information obtainment unit <NUM> included in the deterioration determination apparatus <NUM> obtains, from the proximity sensor <NUM>, information on the deformation of the one or more regions of the suction portion <NUM> in the state in which the suction portion <NUM> does not hold an object by suction.

Next, in step S14 (deterioration determination step), the deterioration determination unit <NUM> included in the deterioration determination apparatus <NUM> determines whether or not the suction portion <NUM> has deteriorated, in accordance with the deformation of the one or more regions of the suction portion <NUM> in the state in which the suction portion <NUM> does not hold an object by suction.

In step S14, the deterioration determination unit <NUM> determines whether or not the suction portion <NUM> has deteriorated, depending on whether or not the deformation of the one or more regions of the suction portion <NUM> in the state in which the suction portion <NUM> does not hold an object by suction is within a normal range that is set for the one or more regions of the suction portion <NUM>.

In step S14, when the deformation of the one or more region of the suction portion <NUM> in the state in which the suction portion <NUM> does not hold an object by suction is within a normal range, the deterioration determination unit <NUM> determines that the suction portion <NUM> has not deteriorated, that is to say, the deterioration determination unit <NUM> determines that the suction portion <NUM> is in a normal condition. In step S14, when the deformation of the one or more regions of the suction portion <NUM> is outside the normal range, the deterioration determination unit <NUM> determines that the suction portion <NUM> has deteriorated.

When the deterioration determination unit <NUM> determines that the suction portion <NUM> has not deteriorated (YES in step S14), the process proceeds to step S15. In contrast, when the deterioration determination unit <NUM> determines that the suction portion <NUM> has deteriorated (NO in step S14), the process proceeds to step S18.

Next, in step S15, the controller <NUM> included in the suction apparatus <NUM> causes the vacuum pump <NUM> to generate negative pressure that corresponds to the driving amount. In this manner, the vacuum pump <NUM> causes the suction portion <NUM> to hold an object by suction. A signal indicating that the suction portion <NUM> is holding an object by suction is input from the controller <NUM> to the information obtainment unit <NUM>.

Next, in step S16, the information obtainment unit <NUM> included in the deterioration determination apparatus <NUM> obtains, from the pressure sensor <NUM>, the internal pressure of the suction portion <NUM> currently holding the object by suction. In step S16, the information obtainment unit <NUM> may also obtain, from the flow rate sensor <NUM>, the flow rate of air flowing through the tube <NUM>, instead of obtaining the pressure. Alternatively, the information obtainment unit <NUM> may also obtain, from the microphone <NUM>, the sound generated due to the flow of air.

Next, in step S17, the deterioration determination unit <NUM> determines whether or not the suction portion <NUM> has deteriorated, depending on the pressure obtained in step S16.

In step S17, the deterioration determination unit <NUM> determines whether or not the suction portion <NUM> is in an abnormal condition, according to whether or not the pressure obtained in step S16 is within a normal range that is set for the suction portion <NUM>. Examples of an abnormal condition in the suction portion <NUM> include not only deterioration, but also a state in which dust or the like is sandwiched between the suction portion <NUM> and an object.

In step S17, when the pressure obtained in step S16 is within the normal range, the deterioration determination unit <NUM> determines that the suction portion <NUM> is not in an abnormal condition. In contrast, in step S17, when the pressure obtained in step S16 is outside the normal range, the deterioration determination unit <NUM> determines that the suction portion <NUM> is in an abnormal condition. When a crack occurs in the suction portion <NUM>, for example, air flows into the suction portion <NUM>, and thus the decrease in pressure is reduced. Similarly, when the suction portion <NUM> is deformed due to deterioration, the suction portion <NUM> does not come into intimate contact with an object, and air may flow into the suction portion <NUM>. Also, when dust or the like is sandwiched between the suction portion <NUM> and an object, the suction portion <NUM> does not come into intimate contact with the object, and air may flow into the suction portion <NUM>.

When the deterioration determination unit <NUM> determines that the suction portion <NUM> is not in an abnormal condition (YES in step S17), the deterioration determination unit <NUM> ends the deterioration determination process. In contrast, when the deterioration determination unit <NUM> determines that the suction portion <NUM> is in an abnormal condition (NO in step S17), the process proceeds to step S19.

In step S17, when the information obtainment unit <NUM> obtains the flow rate of air instead of pressure in step S16, the deterioration determination unit <NUM> may also determine whether the suction portion <NUM> is in an abnormal condition, according to the flow rate. Similarly, when the information obtainment unit <NUM> obtains sound instead of pressure in step S16, the deterioration determination unit <NUM> may also determine whether the suction portion <NUM> is in an abnormal condition, according to the sound. When air flows into the suction portion <NUM>, for example, the flow rate of air or the sound increases due to the flow of air. In order to determine whether or not the suction portion <NUM> is in an abnormal condition, the suction system <NUM> may include any one of the pressure sensor <NUM>, the flow rate sensor <NUM>, and the microphone <NUM> (the other two devices may be omitted).

Next, in step S18, when the deterioration determination unit <NUM> determines that the suction portion <NUM> has deteriorated, the notification control unit <NUM> notifies at least one of the display unit <NUM> and the sound output unit <NUM> that the suction portion <NUM> has deteriorated.

In step S19, when the deterioration determination unit <NUM> determines that the suction portion <NUM> is in an abnormal condition, the notification control unit <NUM> notifies at least one of the display unit <NUM> and the sound output unit <NUM> that the suction portion <NUM> is in an abnormal condition.

According to the above-described operation example, by detecting deformation of one or more regions of the suction portion <NUM> in the state in which the suction portion <NUM> does not hold an object by suction, it is possible to detect how much the suction portion <NUM> has deteriorated, based on the degree of deformation of the suction portion <NUM>. As a result, it is possible to determine whether or not the suction portion <NUM> has deteriorated, in accordance with the degree of deformation of the suction portion <NUM>.

<FIG> is a flow chart showing how a suction system according to an embodiment of the present invention operates. Steps S11, S12, and S15 to S18 are as described in "operation example <NUM>", and thus only different points will be described.

Next, in step S22 (information obtainment step), the information obtainment unit <NUM> included in the deterioration determination apparatus <NUM> obtains, from the proximity sensor <NUM>, information on deformation of a plurality of regions of the suction portion <NUM> in the state in which the suction portion <NUM> does not hold an object by suction.

In step S23 (deterioration determination step), the deterioration determination unit <NUM> calculates a ratio of the deformation of the plurality of regions of the suction portion <NUM>, based on the information on deformation of the plurality of regions of the suction portion <NUM> in the state in which the suction portion <NUM> does not hold an object by suction.

In step S24 (deterioration determination step), the deterioration determination unit <NUM> determines whether or not the suction portion <NUM> has deteriorated, depending on the calculated ratio.

In step S24, the deterioration determination unit <NUM> determines whether or not the suction portion <NUM> has deteriorated, depending on whether or not the calculated ratio is within a normal range that has been set for the plurality of regions of the suction portion <NUM>.

In step S24, when the calculated ratio is within a normal range, the deterioration determination unit <NUM> determines that the suction portion <NUM> has not deteriorated. In contrast, in step S24, when the calculated ratio is outside the normal range, the deterioration determination unit <NUM> determines that the suction portion <NUM> has deteriorated.

When the deterioration determination unit <NUM> determines that the suction portion <NUM> has not deteriorated (YES in step S24), the process proceeds to step S15. In contrast, when the deterioration determination unit <NUM> determines that the suction portion <NUM> has deteriorated (NO in step S24), the process proceeds to step S18.

According to the above-described operation example, it is possible to strictly determine a deteriorated region of the suction portion <NUM>, by obtaining information on deformation of a plurality of regions of the suction portion <NUM> in a state in which the suction portion <NUM> does not hold an object by suction. Furthermore, by calculating the ratio of deformation of the plurality of regions of the suction portion <NUM>, and determining whether or not the suction portion <NUM> has deteriorated according to the calculated ratio, it is possible to accurately determine whether or not the suction portion <NUM> has deteriorated, even if the sensor value fluctuates due to the influence of the environment such as temperature.

The lifetime prediction unit <NUM> obtains, from the storage unit <NUM>, information on deformation of one or more regions of the suction portion <NUM> in a state in which the suction portion <NUM> does not hold an object by suction, and predicts the lifetime of the suction portion <NUM> based on a temporal change in deformation of the one or more regions. The lifetime prediction unit <NUM> can predict the lifetime of the suction portion <NUM>, based on a temporal change of a sensor value due to deformation caused by deterioration or due to wear.

<FIG> shows the relationship between the elapsed time from the start of use of the suction portion <NUM> and sensor values. The lifetime prediction unit <NUM> obtains, for example, from the storage unit <NUM>, sensor values measured by the proximity sensor <NUM> from the start of use of the suction portion <NUM> to the time point ti. The lifetime prediction unit <NUM> obtains a curve indicating a predicted change of sensor values, based on the obtained sensor values from the start of use of the suction portion <NUM> to the time point ti. The lifetime prediction unit <NUM> obtains, for example, a curve indicating the predicted change of sensor values using the sensor values in a predetermined period up to time point ti. The lifetime prediction unit <NUM> can predict the replacement time te from the intersection of the obtained curve and the threshold value in the normal range.

When the suction apparatus <NUM> includes a plurality of proximity sensors <NUM>, the lifetime prediction unit <NUM> may also predict the lifetime of the suction portion <NUM> using a total value or an average value of sensor output values of the proximity sensors <NUM>, or the number of proximity sensors <NUM> whose outputs are ON. Here, the fact that the output of a proximity sensor <NUM> is ON means that an object is present within a certain distance.

According to the operation example described above, it is possible to replace the suction portion <NUM> at an appropriate time by predicting the lifetime of the suction portion <NUM>. Furthermore, because the maintenance schedule can be determined before an abnormality occurs in the suction portion <NUM>, it is possible to avoid an unexpected stop of the production line.

Control blocks (in particular, the information obtainment unit <NUM>, the deterioration determination unit <NUM>, the lifetime prediction unit <NUM>, and the notification control unit <NUM>) included in the deterioration determination apparatus <NUM> may be implemented by a logic circuit (hardware) formed in an integrated circuit (IC chip) or the like, or may also be implemented by software.

Claim 1:
A deterioration determination apparatus (<NUM>), comprising:
an information obtainment unit (<NUM>) configured to obtain information on deformation of a plurality of regions of a suction portion (<NUM>), which suction portion (<NUM>) is configured to hold an object by suction with negative pressure, in a state in which the suction portion (<NUM>) does not hold an object by suction; and
a deterioration determination unit (<NUM>) configured to:
calculate a ratio of the deformation of the plurality of regions of the suction portion (<NUM>) based on the information on the deformation of the plurality of regions of the suction portion (<NUM>) in a state in which the suction portion (<NUM>) does not hold an object by suction, and
determine whether or not the suction portion (<NUM>) has deteriorated, depending on that ratio.