Patent Description:
In order to perform driving support of the vehicle, a sensor unit for detecting information of an outside area of the vehicle is mounted on the vehicle body. <CIT> discloses a radar as such a sensor unit. The radar is disposed in a lamp chamber of a lamp device for illuminating the outside area of the vehicle. That is, the radar is covered with a cover that defines the lamp chamber and allows passage of the illumination light. The cover forms a part of an outer surface of the vehicle, and allows passage of the sensing light for the radar to detect information of the outside area.

As used herein, the term "driving support" means control processing that at least partially performs at least one of driving operation (steering operation, acceleration, deceleration, etc.), monitoring of a driving environment, and backup of driving operation. That is, the term "driving support" means not only the partial driving support such as braking function for collision avoidance and assisting function for lane-keeping, but also a full self-driving operation.

Further examples of previously known sensor systems are derivable from <CIT>, <CIT>, <CIT> as well as <CIT>.

It is demanded to suppress degradation in the information detecting capability of the sensor unit covered by the cover forming a part of the outer surface of the vehicle.

In order to meet the demand described above, the present invention discloses a sensor system according to independent claim <NUM>. Distinct embodiments are derivable from the dependent claims.

For example, a first illustrative aspect of the presently disclosed subject matter provides a sensor system adapted to be installed in a vehicle, comprising:.

The distribution of the strain generated in the cover is not uniform, but the modes of strain detected at the same location exhibit the same displacement tendency. Accordingly, the detected results repeatedly obtained by the same displacement sensor exhibit the same tendency. However, the adhesion of foreign substance to the cover causes a change in the distribution of the strain of the cover. Accordingly, the result detected by the same displacement sensor also changes. That is, it is possible to detect the foreign substance adhering to the cover by monitoring the change in the result detected by the displacement sensor.

If a foreign substance adheres to a portion of the cover located on the traveling path of the light used by the sensor unit for detecting information, the sensor unit may be obstructed from detecting the information of the outside area of the vehicle. However, since the adhesion of such a foreign substance is detected by the displacement sensor configured as described above, it is possible to perform appropriate treatment according to the detected result. Accordingly, it is possible to suppress degradation in the information detecting capability by the sensor unit covered by the cover forming a part of the outer surface of the vehicle.

As the displacement sensor, for example, at least one of a strain gauge, an acceleration sensor, and an optical fiber sensor may be used.

In particular, in a case where the optical fiber sensor is used as the displacement sensor, it is possible to arrange the optical fiber sensor on the cover with higher degree of freedom because the optical fiber is light and flexible. In addition, since the optical fiber is very thin, even if it is disposed on the surface of the cover, the appearance or the design of the cover is less influenced. In addition, a plurality of strain sensing points can be set in a single optical fiber. Accordingly, it is possible to enhance the degree of freedom in designing the sensor system for suppressing the degradation of the information detecting capability of the sensor unit.

In particular, in a case where an acceleration sensor is used as the displacement sensor, the sensor system may include an actuator for vibrating the cover.

According to such a configuration, by actively vibrating the cover, it is possible to make the change of the vibration mode detected by the acceleration sensor more remarkable. Accordingly, the influence of noise can be suppressed, so that the detection accuracy of the foreign substance requiring removal can be enhanced. Accordingly, the effect of suppressing degradation in the information detecting capability by the sensor unit covered by the cover forming a part of the outer surface of the vehicle is further enhanced.

The sensor system according to the first illustrative aspect may be configured such that the displacement sensor is disposed in an peripheral portion of the cover.

The peripheral portion of the cover is likely to cause a significant change in the rigidity or flexibility of the cover. In such a position, strain is likely to occur. Accordingly, by disposing the displacement sensor at the peripheral portion of the cover, it is possible to enhance the detection sensitivity of the strain. Accordingly, the effect of suppressing degradation in the information detecting capability by the sensor unit covered by the cover forming a part of the outer surface of the vehicle is further enhanced.

The sensor system according to the first illustrative aspect may be configured such that the displacement sensor is disposed in a portion where a thickness of the cover changes.

The portion where the thickness of the cover changes is likely to cause a significant change in the rigidity or flexibility of the cover. In such a position, strain is likely to occur. Accordingly, by disposing the displacement sensor in such a portion, it is possible to enhance the detection sensitivity of the strain. Accordingly, the effect of suppressing degradation in the information detecting capability by the sensor unit covered by the cover forming a part of the outer surface of the vehicle is further enhanced.

The sensor system according to the first illustrative aspect may be configured so as to further comprise a nozzle configured to spray liquid, and such that the processor is configured to cause the nozzle to spray the liquid toward the cover in a case where adhesion of the foreign substance is detected.

According to such a configuration, it is possible to automate the treatment for removing the foreign substance adhering to the cover. Accordingly, the effect of suppressing degradation in the information detecting capability by the sensor unit covered by the cover forming a part of the outer surface of the vehicle is enhanced.

The sensor system according to the first illustrative aspect may be configured so as to further comprise a nozzle configured to spray liquid, and such that the processor is configured to specify a position in the cover to which the foreign substance adheres, and to cause the nozzle to spray the liquid toward the position.

According to such a configuration, since the liquid is more accurately sprayed onto the foreign substance adhering to the light passage area, it is possible to increase the possibility of removing the foreign substance. Accordingly, the effect of suppressing degradation in the information detecting capability by the sensor unit covered by the cover forming a part of the outer surface of the vehicle is further enhanced.

In order to meet the demand described above, a second illustrative aspect of the presently disclosed subject matter provides a sensor system adapted to be installed in a vehicle, comprising:.

If a foreign substance adheres to a portion of the cover located on the traveling path of the light used by the sensor unit for detecting information, the sensor unit may be obstructed from detecting the information of the outside area of the vehicle. However, according to the configuration as described above, it is possible to promote the separation or removal of the adhered foreign substance by the vibration of the cover itself excited by the ultrasonic actuator. Accordingly, it is possible to suppress degradation in the information detecting capability by the sensor unit covered by the cover forming a part of the outer surface of the vehicle.

The sensor system according to the second illustrative aspect may be configured so as to further comprise a nozzle configured to spray liquid toward the cover.

According to such a configuration, a so-called ultrasonic cleaning effect by the liquid sprayed from the nozzle can be obtained, so that separation or removal of the foreign substance adhering to the cover can be further promoted.

The sensor system according to each of the first and second illustrative aspects may be configured so as to further comprise a lamp unit configured to emit illumination light to the outside area of the vehicle, and such that the cover is configured to allow passage of the illumination light.

Because of the function of supplying illumination light to the outside area of the vehicle, the lamp unit is generally disposed in a place in the vehicle where there are few obstructions. By disposing also the sensor unit in such a place, it is possible to efficiently obtain information of the outside area of the vehicle.

In order to meet the demand described above, a third illustrative aspect of the presently disclosed subject matter provides a sensor system adapted to be installed in a vehicle, comprising:.

In order to meet the demand described above, a fourth illustrative aspect of the presently disclosed subject matter provides a sensor system adapted to be installed in a vehicle, comprising:.

In order to meet the demand described above, a fifth illustrative aspect of the presently disclosed subject matter provides a sensor system adapted to be installed in a vehicle, comprising:.

The camera according to each of the third to fifth illustrative aspects is not a device for acquiring an image of the outside area of the vehicle (strictly speaking, an image of an area outer than the outer face of the cover) but is a device for acquiring an image of the light passage area of the cover located on the traveling path of light used by the sensor unit for detecting information. Accordingly, at least a portion of the focal plane of the camera overlaps the light passage area. In addition, since it is prioritized to arrange the camera such that at least a portion of the focal plane overlaps the light passage area, an optical axis of the camera may extend in a direction different from a reference sensing direction of the sensor unit.

If the foreign substance adheres to the light passage area, the sensor unit may be obstructed from detecting the information of the outside area of the vehicle. However, since the adhesion of such a foreign substance is detected by the camera configured as described above, it is possible to perform appropriate treatment according to the detected result. Accordingly, it is possible to suppress degradation in the information detecting capability by the sensor unit covered by the cover forming a part of the outer surface of the vehicle.

Since the detection of the foreign substance adhering to the light passage area by the LiDAR sensor unit is relatively difficult, the detection of the foreign substance through the acquisition of the image of the area by the camera is more advantageous in combination with the LiDAR sensor unit.

The sensor system according to each of the third to fifth illustrative aspects may be configured so as to further comprise a nozzle configured to spray liquid, and such that the processor is configured to cause the nozzle to spray the liquid toward the light passage area in a case where adhesion of the foreign substance is detected.

According to such a configuration, it is possible to automate the treatment for removing the foreign substance adhering to the light passage area. Accordingly, the effect of suppressing degradation in the information detecting capability by the sensor unit covered by the cover forming a part of the outer surface of the vehicle is enhanced.

The sensor system according to each of the third to fifth illustrative aspects may be configured so as to further comprise a nozzle configured to spray liquid, and such that the processor is configured to specify a position where the foreign substance adheres, and to cause the nozzle to spray the liquid toward the position.

The sensor system according to each of the third to fifth illustrative aspects may be configured such that the camera comprises: an image pickup element; a resin lens configured to form an image on the image pickup element; and a circuit board supporting the image pickup element and the resin lens.

According to such a configuration, since the space occupied by the camera can be considerably reduced, it is possible to arrange the camera for acquiring the image of the light passage area with higher degree of freedom. Accordingly, it is possible to make easier to suppress degradation in the information detecting capability by the sensor unit covered by the cover forming a part of the outer surface of the vehicle.

The sensor system according to each of the third to fifth illustrative aspects may be configured so as to further comprise a lamp unit configured to emit illumination light to the outside area of the vehicle, and such that the cover is configured to allow passage of the illumination light.

As used herein, the term "light" means not only visible light but also an electromagnetic wave having an arbitrary wavelength such as ultraviolet light, infrared light, microwave, millimeter wave, or the like.

As used herein, the term "sensor unit" means a constituent unit of a component that can be distributed by itself as a single unit while providing a desired information detecting function.

As used herein, the term "lamp unit" means a constituent unit of a component that can be distributed by itself as a single unit while providing a desired lighting function.

Examples of embodiments will be described below in detail with reference to the accompanying drawings.

Configurations of a sensor system according to the third, fourth and fifth embodiment are not part of the invention and are therefore not covered by the appended claims.

In each of the drawings used in the following descriptions, the scale is appropriately changed in order to make each of the members have a recognizable size.

In the accompanying drawings, an arrow F represents a forward direction of the illustrated structure. An arrow B represents a rearward direction of the illustrated structure. An arrow U represents an upward direction of the illustrated structure. An arrow D represents a downward direction of the illustrated structure. An arrow L represents a leftward direction of the illustrated structure. An arrow R represents a rightward direction of the illustrated structure. The terms "left" and "right" used in the following descriptions represent the left-right directions as viewed from the driver's seat.

<FIG> schematically illustrates a configuration of a sensor system <NUM> according to a first embodiment. The sensor system <NUM> is installed in a vehicle <NUM> illustrated in <FIG>. The shape of the vehicle body of the vehicle <NUM> is a mere example.

The sensor system <NUM> includes a housing <NUM> and a cover <NUM>. The housing <NUM> defines an accommodation chamber <NUM> together with the cover <NUM>.

The sensor system <NUM> includes a LiDAR sensor unit <NUM>. The LiDAR sensor unit <NUM> is disposed in the accommodation chamber <NUM>. The cover <NUM> forms a part of the outer face of the vehicle <NUM> so as to cover the LiDAR sensor unit <NUM>.

As illustrated in <FIG>, the LiDAR sensor unit <NUM> has a configuration for emitting sensing light 14a toward a sensing area outside the vehicle <NUM>, and a configuration for detecting returned light (not illustrated) as a result of the sensing light 14a being reflected by an object existing in the sensing area. As the sensing light 14a, for example, infrared light having a wavelength of <NUM> can be used.

The LiDAR sensor unit <NUM> can obtain the distance to the object associated with the returned light, for example, based on the time period from the time when the sensing light 14a is emitted in a certain direction to the time when the returned light is detected. In addition, by accumulating such distance data in association with the sensing position, it is possible to obtain information as to the shape of the object associated with the returned light. Additionally or alternatively, information as to an attribute such as the material of the object associated with the returned light can be acquired based on the difference in waveforms of the emitted light and the returned light. That is, the LiDAR sensor unit <NUM> is a device for detecting information of an outside area of the vehicle <NUM> using light.

The sensing light 14a and the returned light pass through a light passage area 12a in the cover <NUM>. In other words, the cover <NUM> is formed of a material that allows passage of at least the sensing light 14a and the returned light.

The sensor system <NUM> includes a strain gauge <NUM>. The strain gauge <NUM> is disposed on the cover <NUM>. More specifically, the strain gauge <NUM> is disposed at a position other than the light passage area 12a of the cover <NUM>. The strain gauge <NUM> is a device for detecting strain of the cover <NUM> at a position where it is disposed. The strain gauge <NUM> is an example of a displacement sensor. As illustrated in <FIG>, the strain gauge <NUM> is configured to output a strain signal S11 corresponding to the detected strain. The detection of the strained state is performed, for example, for a period of <NUM> milliseconds every second.

The sensor system <NUM> may include a plurality of strain gauges <NUM>. In the example illustrated in <FIG>, three strain gauges <NUM> are disposed. By disposing more strain gauges <NUM>, the distribution of the strain generated in the cover <NUM> can be detected with higher resolution.

The sensor system <NUM> includes a control device <NUM>. The control device <NUM> includes an input interface <NUM> and a processor <NUM>. The control device <NUM> may be disposed in the accommodation chamber <NUM> or may be supported by the housing <NUM> outside the accommodation chamber <NUM>. Alternatively, the control device <NUM> may be disposed at an appropriate position in the vehicle <NUM> distant from the housing <NUM>.

The input interface <NUM> receives the strain signal S11 outputted from the strain gauge <NUM>. The processor <NUM> is configured to detect a foreign substance adhering to the cover <NUM> based on the strain signal S11. Examples of the foreign substance include raindrops, snow chips, sludge, and carcasses of insects. As required, the input interface <NUM> may include a signal processing circuit that converts the strain signal S11 into a form suitable for processing performed by the processor <NUM>.

<FIG> illustrates an example of a flow of processing performed by the processor <NUM>. Based on the strain signal S11, the processor <NUM> creates a data set D11, which is illustrated by way of example in <FIG> (STEP1). The data set D11 represents the temporal change of the magnitude ε of the strain within one detecting period. That is, the data set D11 includes n data pairs represented by (ε1, t1) to (εn, tn) (n is an integer of <NUM> or more). t1 to tn represent time points included in the detecting period. The interval between the time points tn-<NUM> and tn corresponds to the sampling cycle.

As illustrated in <FIG>, the control device <NUM> includes a storage <NUM>. The storage <NUM> can be implemented by an appropriate rewritable semiconductor memory. As illustrated in <FIG>, the processor <NUM> determines whether or not the data set D11 created in the past based on the above technique is stored in the storage <NUM> (STEP2).

If the data set D11 created in the past is not stored in the storage <NUM> (N in STEP2), the processor <NUM> stores the data set D11 created in STEP1 in the storage <NUM> (STEP3). The processing returns to STEP1.

When the data set D11 created in the past is stored in the storage <NUM> (Y in STEP2), the processor <NUM> compares the data set D11 created in STEP1 with the data set D11 stored in the storage <NUM> (STEP4).

For example, the processor <NUM> compares each of the data pairs (ε1, t1) to (εn, tn) in the data set D11 created in STEP1 with a corresponding one of the data pairs (ε1, t1) to (εn, tn) in the data set D11 stored in the storage <NUM>.

The distribution of the strain generated in the cover <NUM> is not uniform, but the temporal change of the strain detected at the same position tends to be the same. Accordingly, the detected results repeatedly obtained by the same strain gauge <NUM> exhibit the same tendency. However, the adhesion of the foreign substance to the cover <NUM> causes a change in the distribution of the strain of the cover <NUM>. Accordingly, even based on the strain signal S11 outputted from the same strain gauge <NUM>, at least one of the values ε1 to εn related to the magnitude of the strain included in the data set D11 changes. In <FIG>, a data set D11 in a case where a foreign substance adheres is exemplified with dashed lines.

When a significant change is observed in at least one of the values ε1 to εn related to the magnitude of the strain, it is highly likely that a foreign substance is adhered to the cover <NUM>. Based on the comparison result between the data sets D11, the processor <NUM> determines whether or not a foreign substance is adhered to the cover <NUM> (STEP5).

If no significant change is observed in at least one of the values ε1 to εn related to the magnitude of the strain, the processor <NUM> determines that no foreign substance is adhered to the cover <NUM> (N in STEP5). In this case, the data set D11 created in STEP1 is newly stored in the storage <NUM> (STEP3). Thereafter, the processing returns to STEP1. The data set D11 stored in the storage <NUM> will be subjected to comparison with the data set D11 to be created next time.

If a significant change is observed in at least one of the values ε1 to εn related to the magnitude of the strain, the processor <NUM> determines that a foreign substance is adhered to the cover <NUM> (Y in STEP5). In this case, the processor <NUM> creates a detection signal S12 indicating the adhesion of the foreign substance (STEP6).

It should be noted that by configuring the processor <NUM> so as to determine that a foreign substance is adhered when the number of pieces of data for which a significant change in the magnitude of strain is recognized exceeds a prescribed threshold value, the influence of noise can be suppressed, so that the detection accuracy of the foreign substance requiring removal can be enhanced.

Based on the strain signal S11, the processor <NUM> may create a data set D12, which is illustrated by way of example in <FIG>. The data set D12 represents a frequency spectrum of the strain signal S11 acquired in one detecting period. The frequency spectrum is obtained by performing Fourier transform or the like on the strain signal S11. That is, the data set D12 includes n data pairs represented by (p1, f1) to (pn, fn) (n is an integer of <NUM> or more). p1 to pn indicate spectral intensities. f1 to fn represent frequencies included in the spectrum. The interval between the frequencies fn-<NUM> and fn corresponds to the resolution of the Fourier transform.

In this case, the processor <NUM> determines whether or not the data set D12 created in the past based on the above technique is stored in the storage <NUM> (STEP2).

If the data set D12 created in the past is not stored in the storage <NUM> (N in STEP2), the processor <NUM> stores the data set D12 created in STEP1 in the storage <NUM> (STEP3). Thereafter, the processing returns to STEP1.

If the data set D12 created in the past is stored in the storage <NUM> (Y in STEP2), the processor <NUM> compares the data set D12 created in STEP1 with the data set D12 stored in the storage <NUM> (STEP4).

For example, the processor <NUM> compares each of the data pairs (p1, f1) to (pn, fn) in the data set D12 created in STEP1 with a corresponding one of the data pairs (p1, f1) to (pn, fn) in the data set D12 stored in the storage <NUM>.

The distribution of the strain generated in the cover <NUM> is not uniform, but the temporal change of the strain detected at the same position tends to be the same. Accordingly, the detected results repeatedly obtained by the same strain gauge <NUM> exhibit the same tendency. However, the adhesion of the foreign substance to the cover <NUM> causes a change in the distribution of the strain of the cover <NUM>. Accordingly, even based on the strain signal S11 outputted from the same strain gauge <NUM>, at least one of the values p1 to pn related to the spectral intensities included in the data set D12 changes.

In <FIG>, a data set D12 in a case where a foreign substance adheres is exemplified with dashed lines. In this example, only the spectral intensity at a frequency exhibiting a remarkable peak changes. However, the frequency exhibiting a remarkable peak may be shifted, and both a change in spectral intensity and a shift in frequency may occur.

When a significant change is observed in at least one of the values p1 to pn related to the spectral intensity, it is highly likely that a foreign substance is adhered to the cover <NUM>. Based on the comparison result between the data sets D12, the processor <NUM> determines whether or not a foreign substance is adhered to the cover <NUM> (STEP5).

If no significant change is observed in at least one of the values p1 to pn related to the spectral intensity, the processor <NUM> determines that no foreign substance is adhered to the cover <NUM> (N in STEP5). In this case, the data set D12 created in STEP1 is newly stored in the storage <NUM> (STEP3). Thereafter, the processing returns to STEP1. The data set D12 stored in the storage <NUM> will be subjected to comparison with the data set D12 to be created next time.

If a significant change is observed in at least one of the values p1 to pn related to the spectral intensity, the processor <NUM> determines that a foreign substance is adhered to the cover <NUM> (Y in STEP5). In this case, the processor <NUM> creates a detection signal S12 indicating the adhesion of the foreign substance (STEP6).

It should be noted that by configuring the processor <NUM> so as to determine that a foreign substance is adhered when the number of pieces of data for which a significant change in the spectral intensity is recognized exceeds a prescribed threshold value, the influence of noise can be suppressed, so that the detection accuracy of the foreign substance requiring removal can be enhanced.

As illustrated in <FIG>, the control device <NUM> includes an output interface <NUM>. The processor <NUM> causes the output interface <NUM> to output the detection signal S12. The detection signal S12 may be transmitted to another control device in the vehicle <NUM>. For example, the other control device may notify the occupant of the vehicle <NUM> that a foreign substance is adhered to the cover <NUM>, based on the detection signal S12. Notifications may be made through at least one of a visual manner, an audible manner and a haptic manner.

The occupant who has received the notification can take an appropriate response. For example, the sensor system <NUM> may include a nozzle <NUM> that sprays liquid toward the cover <NUM>. Examples of the liquid include water, hot water, and a cleaning liquid. The occupant may perform an operation of causing the nozzle <NUM> to spray liquid. As a result, it is possible to remove the foreign substance adhering to the cover <NUM>.

If a foreign substance adheres to the light passage area 12a located on the traveling paths of the sensing light 14a and the returned light of the LiDAR sensor unit <NUM>,the LiDAR sensor unit <NUM> may be obstructed from detecting the information of the outside area of the vehicle <NUM>. However, since the adhesion of such a foreign substance is detected by the strain gauge <NUM> configured as described above, it is possible to perform appropriate treatment according to the detected result. Accordingly, it is possible to suppress degradation in the information detecting capability of the LiDAR sensor unit <NUM> covered by the cover <NUM> forming a part of the outer face of the vehicle <NUM>.

As illustrated in <FIG>, the detection signal S12 created by the processor <NUM> may be used to operate the nozzle <NUM> described above. That is, when a foreign substance adhering to the cover <NUM> is detected, the processor <NUM> can cause the nozzle <NUM> to spray liquid toward the cover <NUM>.

According to such a configuration, it is possible to automate the treatment for removing the foreign substance adhering to the cover <NUM>. Accordingly, it is possible to improve the effect of suppressing the degradation of the information detecting capability of the LiDAR sensor unit <NUM> covered by the cover <NUM> forming a part of the outer face of the vehicle <NUM>.

The data set D11 or the data set D12 may include information as to the location of the strain gauge <NUM> that has outputted the strain signal S11 as the generator. Accordingly, the processor <NUM> may specify the position of the foreign substance on the cover <NUM> based on the locational information of the strain gauge <NUM> from which the significant strain is detected. On the other hand, as illustrated in <FIG>, the nozzle <NUM> may include a mechanism capable of adjusting the spraying direction of the liquid. In this case, the processor <NUM> may configure the detection signal S12 so as to cause the nozzle <NUM> to spray the liquid toward the position of the detected foreign substance.

According to such a configuration, since the liquid is more accurately sprayed onto the foreign substance adhering to the cover <NUM>, it is possible to increase the possibility of removing the foreign substance. Accordingly, the degradation of the information detecting capability of the LiDAR sensor unit <NUM> covered by the cover <NUM> forming a part of the outer face of the vehicle <NUM> is further suppressed.

As illustrated in <FIG>, the strain gauge <NUM> is preferably disposed on a peripheral portion 12b of the cover <NUM>. As used herein, the term "peripheral portion of the cover" means a portion where a significant change occurs in the rigidity or flexibility of the cover. The cover <NUM> is coupled to the housing <NUM> at the peripheral portion 12b. Therefore, the peripheral portion 12b of the cover <NUM> has higher rigidity or lower flexibility than a non-peripheral portion 12c of the cover <NUM>. In such a position where a significant change occurs in the rigidity or the flexibility, strain is likely to occur. Accordingly, by disposing the strain gauge <NUM> in the peripheral portion 12b, it is possible to enhance the detection sensitivity of the strain. Accordingly, the degradation of the information detecting capability of the LiDAR sensor unit <NUM> covered by the cover <NUM> forming a part of the outer face of the vehicle <NUM> is further suppressed.

Alternatively, as illustrated in <FIG>, a thickness changing portion 12d in which the thickness of the cover <NUM> changes can be formed. In this case, it is preferable that the strain gauge <NUM> is disposed in the thickness changing portion 12d. In the thickness changing portion 12d, there is a change in the rigidity or flexibility of the cover <NUM>. In such a position, strain is likely to occur. Accordingly, by disposing the strain gauge <NUM> in the thickness changing portion 12d, it is possible to enhance the detection sensitivity of the strain. Accordingly, the degradation of the information detecting capability of the LiDAR sensor unit <NUM> covered by the cover <NUM> forming a part of the outer face of the vehicle <NUM> is further suppressed.

As illustrated in <FIG>, the sensor system <NUM> may include a lamp unit <NUM>. The lamp unit <NUM> is a device for emitting illumination light to the outside area of the vehicle <NUM>. Examples of the lamp unit <NUM> include a headlamp unit, a clearance lamp unit, a direction indicator lamp unit, a fog lamp unit, and a rear combination lamp unit.

The lamp unit <NUM> is disposed in the accommodation chamber <NUM>. Accordingly, the lamp unit <NUM> is covered by the cover <NUM>. The cover <NUM> also allows passage of the illumination light emitted from the lamp unit <NUM>. In this case, the cover <NUM> is formed of a material that is also transparent to visible light.

Because of the function of supplying illumination light to the outside area of the vehicle <NUM>, the lamp unit <NUM> is generally disposed in a place in the vehicle <NUM> where there are few obstructions. By disposing also the LiDAR sensor unit <NUM> in such a place, it is possible to efficiently obtain information of the outside area of the vehicle <NUM>.

The processor <NUM> capable of performing the above-described processing may be provided as a general-purpose microprocessor operating in cooperation with a general-purpose memory, or may be provided as part of a dedicated integrated circuit device. Examples of the general-purpose microprocessor include a CPU, an MPU, and a GPU. Examples of the general-purpose memory include a RAM and a ROM. A rewritable general-purpose memory may serve the function of the storage <NUM>. Examples of the dedicated integrated circuit element include a microcontroller, an ASIC, and an FPGA. The processor <NUM> and the storage <NUM> may be provided as separate devices or may be packaged in a single device.

<FIG> schematically illustrates a configuration of a sensor system <NUM> according to a second embodiment. Components that are substantially the same as those of the sensor system <NUM> according to the first embodiment are assigned with the same reference symbols, and repetitive descriptions for those will be omitted. The sensor system <NUM> is installed in the vehicle <NUM> illustrated in <FIG>.

The sensor system <NUM> includes an acceleration sensor <NUM>. The acceleration sensor <NUM> is disposed on the cover <NUM>. More specifically, the acceleration sensor <NUM> is disposed at a position other than the light passage area 12a of the cover <NUM>. The acceleration sensor <NUM> is a device for detecting vibration of the cover <NUM> at a position where the acceleration sensor <NUM> is disposed. The acceleration sensor <NUM> is an example of the displacement sensor. The acceleration sensor <NUM> is configured to output a vibration signal S21 corresponding to the detected vibration. The detection of the vibration is performed, for example, for a period of <NUM> milliseconds every second.

The sensor system <NUM> may include a plurality of acceleration sensors <NUM>. In the example illustrated in <FIG>, three acceleration sensors <NUM> are disposed. By disposing more acceleration sensors <NUM>, the distribution of the vibrations generated in the cover <NUM> can be detected with higher resolution.

The sensor system <NUM> includes a control device <NUM>. The control device <NUM> includes an input interface <NUM> and a processor <NUM>. The control device <NUM> may be disposed in the accommodation chamber <NUM>, or may be supported by the housing <NUM> outside the accommodation chamber <NUM>. Alternatively, the control device <NUM> may be disposed at an appropriate position in the vehicle <NUM> distant from the housing <NUM>.

The input interface <NUM> receives the vibration signal S21 outputted from the acceleration sensor <NUM>. The processor <NUM> is configured to detect a foreign substance adhering to the cover <NUM> based on the vibration signal S21. Examples of the foreign substance include raindrops, snow chips, sludge, and carcasses of insects. As required, the input interface <NUM> may include a signal processing circuit that converts the vibration signal S21 into a form suitable for processing performed by the processor <NUM>.

Referring to <FIG>, a flow of processing performed by the processor <NUM> will be described. Based on the vibration signal S21, the processor <NUM> creates a data set D21, which is illustrated by way of example in <FIG> (STEP1). The processor <NUM> first creates a frequency spectrum of the vibration signal S21. The frequency spectrum is obtained by performing Fourier transform or the like on the vibration signal S21. Subsequently, the processor <NUM> specifies the resonance frequency fr based on the created frequency spectrum. That is, the data set D21 includes a data pair represented by (pr, fr). pr represents a spectral intensity at the resonance frequency fr.

As illustrated in <FIG>, the control device <NUM> includes a storage <NUM>. The storage <NUM> can be implemented by an appropriate rewritable semiconductor memory. Subsequently, the processor <NUM> determines whether or not the data set D21 created in the past based on the above technique is stored in the storage <NUM> (STEP2).

If the data set D21 created in the past is not stored in the storage <NUM> (N in STEP2), the processor <NUM> stores the data set D21 created in STEP1 in the storage <NUM> (STEP3). Thereafter, the processing returns to STEP1.

If the data set D21 created in the past is stored in the storage <NUM> (Y in STEP2), the processor <NUM> compares the data set D21 created in STEP <NUM> with the data set D21 stored in the storage <NUM> (STEP4).

Specifically, the processor <NUM> compares the data pair (pr, fr) in the data set D21 created in STEP1 with the data pair (pr, fr) in the data set D21 stored in the storage <NUM>.

Although the distribution of the vibrations generated in the cover <NUM> is not uniform, the vibrations detected at the same position exhibit the same tendency. Accordingly, the detected results repeatedly obtained by the same acceleration sensor <NUM> exhibit the same tendency. However, when the weight of the cover <NUM> changes due to the adhesion of the foreign substance, the distribution of vibrations in the cover <NUM> changes. Accordingly, even based on the vibration signal S21 outputted from the same acceleration sensor <NUM>, at least one of the spectral intensity p and the resonance frequency fr included in the data set D21 changes.

In <FIG>, a data set D21 in a case where a foreign substance adheres is exemplified with dashed lines. In this example, the resonance frequency fr changes. Also in <FIG>, a data set D21 in a case where a foreign substance adheres is exemplified with dashed lines. In the example illustrated in <FIG>, the spectral intensity pr changes. In the example illustrated in <FIG>, both the spectral intensity pr and the resonance frequency fr change.

When a significant change is observed in at least one of the spectral intensity pr and the resonance frequency fr, it is highly likely that a foreign substance is adhered to the cover <NUM>. Based on the comparison result between the data sets D21, the processor <NUM> determines whether or not a foreign substance is adhered to the cover <NUM> (STEP5).

If no significant change is observed in at least one of the spectral intensity pr and the resonance frequency fr, the processor <NUM> determines that no foreign substance is adhered to the cover <NUM> (N in STEP5). In this case, the data set D21 created in STEP1 is newly stored in the storage <NUM> (STEP3). Thereafter, the processing returns to STEP1. The data set D21 stored in the storage <NUM> is subjected to comparison with the data set D21 to be created next time.

If a significant change is observed in at least one of the spectral intensity pr and the resonance frequency fr, the processor <NUM> determines that a foreign substance is adhered to the cover <NUM> (Y in STEP5). In this case, the processor <NUM> creates a detection signal S22 indicating the adhesion of the foreign substance (STEP6).

In order to detect the adhesion of the foreign substance, the processor <NUM> may detect the adhesion of the foreign substance to the cover <NUM> using the technique described with reference to <FIG>. That is, the data set D21 may include n data pairs represented by (p1, f1) to (pn, fn) constituting the frequency spectrum (n is an integer of <NUM> or more).

In this case, the processor <NUM> compares each of the data pairs (p1, f1) to (pn, fn) in the data set D21 created in STEP1 with a corresponding one of the data pairs (p1, f1) to (pn, fn) in the data set D21 stored in the storage <NUM>. If a significant change is observed in at least one of the values p1 to pn related to the spectral intensity, the processor <NUM> determines that a foreign substance is adhered to the cover <NUM>. It should be noted that by configuring the processor <NUM> so as to determine that a foreign substance is adhered when the number of pieces of data for which a significant change in the spectral intensity is recognized exceeds a prescribed threshold value, the influence of noise can be suppressed, so that the detection accuracy of the foreign substance requiring removal can be enhanced.

As illustrated in <FIG>, the control device <NUM> includes an output interface <NUM>. The processor <NUM> causes the output interface <NUM> to output the detection signal S22. The detection signal S22 may be transmitted to another control device in the vehicle <NUM>. For example, the other control device may notify the occupant of the vehicle <NUM> that a foreign substance is adhered to the cover <NUM>, based on the detection signal S22. Notifications may be made through at least one of a visual manner, an audible manner and a haptic manner.

If a foreign substance adheres to the light passage area 12a located on the traveling paths of the sensing light 14a and the returned light of the LiDAR sensor unit <NUM>,the LiDAR sensor unit <NUM> may be obstructed from detecting the information of the outside area of the vehicle <NUM>. However, since the adhesion of such a foreign substance is detected by the acceleration sensor <NUM> configured as described above, it is possible to perform appropriate treatment according to the detected result. Accordingly, it is possible to suppress degradation in the information detecting capability of the LiDAR sensor unit <NUM> covered by the cover <NUM> forming a part of the outer face of the vehicle <NUM>.

As illustrated in <FIG>, the detection signal S22 created by the processor <NUM> may be used to operate the nozzle <NUM> described above. That is, when a foreign substance adhering to the cover <NUM> is detected, the processor <NUM> can cause the nozzle <NUM> to spray liquid toward the cover <NUM>.

The data set D21 may include information as to the location of the acceleration sensor <NUM> that has outputted the vibration signal S21 as the generator. Accordingly, the processor <NUM> may specify the position of the foreign substance on the cover <NUM> based on the locational information of the acceleration sensor <NUM> that detected a significant change in the natural vibration. On the other hand, as illustrated in <FIG>, the nozzle <NUM> may include a mechanism capable of adjusting the spraying direction of the liquid. In this case, the processor <NUM> may configure the detection signal S22 so as to cause the nozzle <NUM> to spray the liquid toward the position of the detected foreign substance.

As illustrated in <FIG>, the sensor system <NUM> may include an actuator <NUM>. The actuator <NUM> is a device for vibrating the cover <NUM>. The actuator <NUM> may be implemented by a piezoelectric element, a voice coil, an ultrasonic actuator, or the like. The processor <NUM> may create a control signal S23 for controlling the operation of the actuator <NUM>. The control signal S23 is inputted to the actuator <NUM> via the output interface <NUM>. The actuator <NUM> preferably operates to excite natural vibrations in the cover <NUM>.

According to such a configuration, by actively vibrating the cover <NUM>, it is possible to make the change of the vibration mode detected by the acceleration sensor <NUM> more remarkable. Accordingly, the influence of noise can be suppressed, so that the detection accuracy of the foreign substance requiring removal can be enhanced. Accordingly, the degradation of the information detecting capability of the LiDAR sensor unit <NUM> covered by the cover <NUM> forming a part of the outer face of the vehicle <NUM> is further suppressed.

As illustrated in <FIG>, it is preferable that the acceleration sensor <NUM> is disposed on the peripheral portion 12b of the cover <NUM>. The cover <NUM> is coupled to the housing <NUM> at the peripheral portion 12b. Therefore, the peripheral portion 12b of the cover <NUM> has higher rigidity or lower flexibility than a non-peripheral portion 12c of the cover <NUM>. In such a position where a significant change occurs in the rigidity or the flexibility, a change in the vibration mode is likely to occur. Accordingly, by disposing the acceleration sensor <NUM> in the peripheral portion 12b, it is possible to enhance the detection sensitivity of the change in the vibration mode. Accordingly, the degradation of the information detecting capability of the LiDAR sensor unit <NUM> covered by the cover <NUM> forming a part of the outer face of the vehicle <NUM> is further suppressed.

Alternatively, as illustrated in <FIG>, a thickness changing portion 12d in which the thickness of the cover <NUM> changes can be formed. In this case, it is preferable that the acceleration sensor <NUM> is disposed in the thickness changing portion 12d. In the thickness changing portion 12d, there is a change in the rigidity or flexibility of the cover <NUM>. In such a position, a change in the vibration mode is likely to occur. Accordingly, by disposing the acceleration sensor <NUM> in the thickness changing portion 12d, it is possible to enhance the detection sensitivity of the change in the vibration mode. Accordingly, the degradation of the information detecting capability of the LiDAR sensor unit <NUM> covered by the cover <NUM> forming a part of the outer face of the vehicle <NUM> is further suppressed.

As illustrated in <FIG>, the sensor system <NUM> may include a lamp unit <NUM>. Because of the function of supplying illumination light to the outside area of the vehicle <NUM>, the lamp unit <NUM> is generally disposed in a place in the vehicle <NUM> where there are few obstructions. By disposing also the LiDAR sensor unit <NUM> in such a place, it is possible to efficiently obtain information of the outside area of the vehicle <NUM>.

<FIG> schematically illustrates a configuration of a sensor system <NUM> according to a third embodiment. Components that are substantially the same as those of the sensor system <NUM> according to the first embodiment are assigned with the same reference symbols, and repetitive descriptions for those will be omitted. The sensor system <NUM> is installed in the vehicle <NUM> illustrated in <FIG>.

The sensor system <NUM> includes an optical fiber sensor <NUM> and a control device <NUM>. The optical fiber sensor <NUM> includes an optical fiber <NUM> and a detection interface <NUM>.

The optical fiber sensor <NUM> is a device for detecting strain of the cover <NUM> at a position where the optical fiber <NUM> is disposed. The optical fiber sensor <NUM> is an example of the displacement sensor. The optical fiber sensor <NUM> may adopt a method of detecting reflected light generated by an FBG (Fiber Bragg Grating) formed in the optical fiber <NUM>, a method of detecting Rayleigh scattered light or Brillouin scattered light generated by glass particles forming the optical fiber <NUM>, or the like. Since the configuration itself of the optical fiber sensor according to each method is well known, detailed descriptions thereof will be omitted.

The optical fiber <NUM> is disposed on the cover <NUM>. More specifically, the optical fiber <NUM> is disposed at a position other than the light passage area 12a of the cover <NUM>. The optical fiber <NUM> is bonded or deposited on an outer face of the cover <NUM>. The outer diameter of the optical fiber <NUM> is, for example, <NUM> to <NUM>. The optical fiber sensor <NUM> may include a plurality of optical fibers <NUM>. In the example illustrated in <FIG>, three optical fibers <NUM> are disposed. By disposing more optical fibers <NUM>, the distribution of the strain generated in the cover <NUM> can be detected with higher resolution.

The detection interface <NUM> may constitute a part of the control device <NUM>. The control device <NUM> may be disposed in the accommodation chamber <NUM> or may be supported by the housing <NUM> outside the accommodation chamber <NUM>. Alternatively, the control device <NUM> may be disposed at an appropriate position in the vehicle <NUM> distant from the housing <NUM>.

The detection interface <NUM> includes a wavelength-variable laser light source. The wavelength of the light emitted from the wavelength-variable laser light source may be variable, for example, in the range of <NUM> to <NUM>. The light emitted from the wavelength-variable laser light source is incident on the optical fiber <NUM>.

The detection interface <NUM> includes a photodetector. The light incident on the optical fiber <NUM> propagates through the optical fiber <NUM> while generating reflected light by the FBG, returned light such as Rayleigh scattered light and Brillouin scattered light. The returned light is detected by a photodetector. The photodetector outputs a detection signal S31 corresponding to the intensity and the wavelength of the returned light.

The control device <NUM> includes a processor <NUM>. The processor <NUM> is configured to detect a foreign substance adhering to the cover <NUM> based on the detection signal S31. Examples of the foreign substance include raindrops, snow chips, sludge, and carcasses of insects. As required, the detection interface <NUM> may include a signal processing circuit that converts the detection signal S31 into a form suitable for processing performed by the processor <NUM>.

Referring to <FIG>, a flow of processing performed by the processor <NUM> will be described. Based on the detection signal S31, the processor <NUM> creates a data set D31 illustrated as an example in <FIG> (STEP1). The processor <NUM> first creates a frequency spectrum of the detection signal S31. The frequency spectrum is obtained by performing Fourier transform or the like on the detection signal S31. Subsequently, the processor <NUM> specifies the resonance frequency fr based on the created frequency spectrum. That is, the data set D31 includes a data pair represented by (pr, fr). pr represents a spectral intensity at the resonance frequency fr.

As illustrated in <FIG>, the control device <NUM> includes a storage <NUM>. The storage <NUM> can be implemented by an appropriate rewritable semiconductor memory. Subsequently, the processor <NUM> determines whether or not the data set D31 created in the past based on the above technique is stored in the storage <NUM> (STEP2).

If the data set D31 created in the past is not stored in the storage <NUM> (N in STEP2), the processor <NUM> stores the data set D31 created in STEP1 in the storage <NUM> (STEP3). Thereafter, the processing returns to STEP1.

If the data set D31 created in the past is stored in the storage <NUM> (Y in STEP2), the processor <NUM> compares the data set D31 created in STEP1 with the data set D31 stored in the storage <NUM> (STEP4).

Specifically, the processor <NUM> compares the data pair (pr, fr) in the data set D31 created in STEP1 with the data pair (pr, fr) in the data set D31 stored in the storage <NUM>.

Although the distribution of the vibrations generated in the cover <NUM> is not uniform, the strains detected at the same position exhibit the same tendency. Accordingly, the detected results repeatedly obtained by the returned light from the same optical fiber <NUM> exhibit the same tendency. However, when a foreign substance adheres to the cover <NUM>, the distribution of the strain of the cover <NUM> changes, so that the optical fiber <NUM> disposed on the surface of the cover <NUM> is also strained. When strain is generated in the optical fiber <NUM>, at least one of the intensity and the wavelength of the returned light is changed. Accordingly, even based on the detection signal S31 corresponding to the returned light from the same optical fiber <NUM>, at least one of the spectral intensity p and the resonance frequency fr included in the data set D31 changes.

In <FIG>, a data set D31 in a case where a foreign substance adheres is exemplified with dashed lines. In this example, the resonance frequency fr changes. Also in the example illustrated in <FIG>, the data set D31 in a case where a foreign substance adheres is exemplified with dashed lines. In the example illustrated in <FIG>, the spectral intensity pr changes. In the example illustrated in <FIG>, both the spectral intensity pr and the resonance frequency fr change.

When a significant change is observed in at least one of the spectral intensity pr and the resonance frequency fr, it is highly likely that a foreign substance is adhered to the cover <NUM>. Based on the comparison result between the data sets D31, the processor <NUM> determines whether or not a foreign substance is adhered to the cover <NUM> (STEP5).

If no significant change is observed in at least one of the spectral intensity pr and the resonance frequency fr, the processor <NUM> determines that no foreign substance is adhered to the cover <NUM> (N in STEP5). In this case, the data set D31 created in STEP1 is newly stored in the storage <NUM> (STEP3). Thereafter, the processing returns to STEP1. The data set D31 stored in the storage <NUM> is subjected to comparison with the data set D21 to be created next time.

If a significant change is observed in at least one of the spectral intensity pr and the resonance frequency fr, the processor <NUM> determines that a foreign substance is adhered to the cover <NUM> (Y in STEP5). In this case, the processor <NUM> creates a detection signal S32 indicating the adhesion of the foreign substance (STEP6).

In order to detect the adhesion of the foreign substance, the processor <NUM> may detect the adhesion of the foreign substance to the cover <NUM> using the technique described with reference to <FIG>. That is, the data set D31 may include n data pairs represented by (p1, f1) to (pn, fn) constituting the frequency spectrum (n is an integer of <NUM> or more).

In this case, the processor <NUM> compares each of the data pairs (p1, f1) to (pn, fn) in the data set D31 created in STEP1 with a corresponding one of the data pairs (p1, f1) to (pn, fn) in the data set D31 stored in the storage <NUM>. If a significant change is observed in at least one of the values p1 to pn related to the spectral intensity, the processor <NUM> determines that a foreign substance is adhered to the cover <NUM>. It should be noted that by configuring the processor <NUM> so as to determine that a foreign substance is adhered when the number of pieces of data for which a significant change in the spectral intensity is recognized exceeds a prescribed threshold value, the influence of noise can be suppressed, so that the detection accuracy of the foreign substance requiring removal can be enhanced.

As illustrated in <FIG>, the control device <NUM> includes an output interface <NUM>. The processor <NUM> causes the output interface <NUM> to output the detection signal S32. The detection signal S32 may be transmitted to another control device in the vehicle <NUM>. For example, the other control device may notify the occupant of the vehicle <NUM> that a foreign substance is adhered to the cover <NUM>, based on the detection signal S32. Notifications may be made through at least one of a visual manner, an audible manner and a haptic manner.

If a foreign substance adheres to the light passage area 12a located on the traveling paths of the sensing light 14a and the returned light of the LiDAR sensor unit <NUM>,the LiDAR sensor unit <NUM> may be obstructed from detecting the information of the outside area of the vehicle <NUM>. However, since the adhesion of such a foreign substance is detected by the optical fiber sensor <NUM> configured as described above, it is possible to perform appropriate treatment according to the detected result. Accordingly, it is possible to suppress degradation in the information detecting capability of the LiDAR sensor unit <NUM> covered by the cover <NUM> forming a part of the outer face of the vehicle <NUM>.

In particular, since the optical fiber <NUM> is light and flexible, the optical fiber <NUM> can be arranged on the cover <NUM> with a high degree of freedom. In addition, since the optical fiber <NUM> is very thin, even if it is disposed on the surface of the cover <NUM>, the appearance or the design of the cover <NUM> is less influenced. In addition, a plurality of strain sensing points can be set in a single optical fiber <NUM>. Accordingly, it is possible to enhance the degree of freedom in designing the sensor system <NUM> for suppressing the deterioration of the information detecting capability of the LiDAR sensor unit <NUM>.

As illustrated in <FIG>, the detection signal S32 created by the processor <NUM> may be used to operate the nozzle <NUM> described above. That is, when a foreign substance adhering to the cover <NUM> is detected, the processor <NUM> can cause the nozzle <NUM> to spray liquid toward the cover <NUM>.

The data set D31 may include information as to the location of the optical fiber <NUM> that has outputted returned light for generating the detection signal S31. In a case where a plurality of sensing points are provided in one optical fiber <NUM>, the data set D31 may also include information as to the position of each sensing point. Accordingly, the processor <NUM> may specify the position of the foreign substance on the cover <NUM> based on the locational information of the optical fiber <NUM> from which the significant strain is detected.

On the other hand, as illustrated in <FIG>, the nozzle <NUM> may include a mechanism capable of adjusting the spraying direction of the liquid. In this case, the processor <NUM> may configure the detection signal S32 so as to cause the nozzle <NUM> to spray the liquid toward the position of the detected foreign substance.

As illustrated in <FIG>, the optical fiber <NUM> is preferably disposed in the peripheral portion 12b of the cover <NUM>. The optical fiber <NUM> is an example of a part of the displacement sensor. The cover <NUM> is coupled to the housing <NUM> at the peripheral portion 12b. Therefore, the peripheral portion 12b of the cover <NUM> has higher rigidity or lower flexibility than a non-peripheral portion 12c of the cover <NUM>. In such a position where a significant change occurs in the rigidity or the flexibility, strain is likely to occur. Accordingly, by disposing the optical fiber <NUM> in the peripheral portion 12b, it is possible to enhance the detection sensitivity of the strain. Accordingly, the degradation of the information detecting capability of the LiDAR sensor unit <NUM> covered by the cover <NUM> forming a part of the outer face of the vehicle <NUM> is further suppressed.

Alternatively, as illustrated in <FIG>, a thickness changing portion 12d in which the thickness of the cover <NUM> changes can be formed. In this case, it is preferable that the optical fiber <NUM> is disposed in the thickness changing portion 12d. In the thickness changing portion 12d, there is a change in the rigidity or flexibility of the cover <NUM>. In such a position, strain is likely to occur. Accordingly, by disposing the optical fiber <NUM> in the thickness changing portion 12d, it is possible to enhance the detection sensitivity of the strain. Accordingly, the degradation of the information detecting capability of the LiDAR sensor unit <NUM> covered by the cover <NUM> forming a part of the outer face of the vehicle <NUM> is further suppressed.

<FIG> schematically illustrates a configuration of a sensor system <NUM> according to a fourth embodiment. Components that are substantially the same as those of the sensor system <NUM> according to the first embodiment are assigned with the same reference symbols, and repetitive descriptions for those will be omitted. The sensor system <NUM> is installed in the vehicle <NUM> illustrated in <FIG>.

The sensor system <NUM> includes an ultrasonic actuator <NUM>. The ultrasonic actuator <NUM> is a device that vibrates at a frequency in an ultrasonic band to excite natural vibration in the cover <NUM>.

The sensor system <NUM> includes a control device <NUM>. The control device <NUM> includes a processor <NUM> and an output interface <NUM>. The processor <NUM> may create a control signal S41 for controlling the operation of the ultrasonic actuator <NUM>. The control signal S41 is inputted to the ultrasonic actuator <NUM> via the output interface <NUM>.

If a foreign substance adheres to the light passage area 12a located on the traveling paths of the sensing light 14a and the returned light of the LiDAR sensor unit <NUM>,the LiDAR sensor unit <NUM> may be obstructed from detecting the information of the outside area of the vehicle <NUM>. Examples of the foreign substance include raindrops, snow chips, sludge, and carcasses of insects. However, according to the configuration as described above, it is possible to promote the separation or removal of the adhered foreign substance by the vibrations of the cover <NUM> itself excited by the ultrasonic actuator <NUM>. Accordingly, it is possible to suppress degradation in the information detecting capability of the LiDAR sensor unit <NUM> covered by the cover <NUM> forming a part of the outer face of the vehicle <NUM>.

The sensor system <NUM> may include a nozzle <NUM> that sprays liquid toward the cover <NUM>. Examples of the liquid include water, hot water, and a cleaning liquid. In this case, the processor <NUM> causes the output interface <NUM> to output a control signal S42 for causing the nozzle <NUM> to spray the liquid. The spraying of the liquid may be performed before the vibrations are excited in the cover <NUM> with the ultrasonic actuator <NUM>, or may be performed while the vibrations are excited.

According to such a configuration, a so-called ultrasonic cleaning effect by the liquid sprayed from the nozzle <NUM> can be obtained, so that separation or removal of the foreign substance adhering to the cover <NUM> can be further promoted.

The processor <NUM> capable of performing the above-described processing may be provided as a general-purpose microprocessor operating in cooperation with a general-purpose memory, or may be provided as part of a dedicated integrated circuit device. Examples of the general-purpose microprocessor include a CPU, an MPU, and a GPU. Examples of the general-purpose memory include a RAM and a ROM. Examples of the dedicated integrated circuit element include a microcontroller, an ASIC, and an FPGA.

<FIG> schematically illustrates an example of a configuration of a sensor system <NUM> according to a fifth embodiment. Components that are substantially the same as those of the sensor system <NUM> according to the first embodiment are assigned with the same reference symbols, and repetitive descriptions for those will be omitted. The sensor system <NUM> is installed in the vehicle <NUM> illustrated in <FIG>.

The sensor system <NUM> includes a camera <NUM>. The camera <NUM> is disposed in the accommodation chamber <NUM>. Accordingly, the camera <NUM> is also covered by the cover <NUM>.

The camera <NUM> is a device for acquiring an image of the light passage area 12a in the cover <NUM>. That is, the camera <NUM> is disposed such that the light passage area 12a is located in the field of view represented as the area between the pair of chain lines 55a. The camera <NUM> is configured to output an image signal S51 corresponding to the acquired image. The acquisition of the image is repeated, for example, every second.

<FIG> illustrates an example of an image I1 that can be reproduced based on the image signal S51. The image I1 includes a plurality of pixels P1 to Pn (n is an integer of <NUM> or more). The image I1 includes an image of the light passage area 12a in the cover <NUM>. In this example, the foreign substances O1 and O2 adhere to the light passage area 12a. Examples of the foreign substance include raindrops, snow chips, sludge, and carcasses of insects.

As illustrated in <FIG>, the sensor system <NUM> includes a control device <NUM>. The control device <NUM> includes an input interface <NUM> and a processor <NUM>. The control device <NUM> may be disposed in the accommodation chamber <NUM> or may be supported by the housing <NUM> outside the accommodation chamber <NUM>. Alternatively, the control device <NUM> may be disposed at an appropriate position in the vehicle <NUM> distant from the housing <NUM>.

The input interface <NUM> receives the image signal S51 outputted from the camera <NUM>. The processor <NUM> is configured to detect a foreign substance adhering to the light passage area 12a of the cover <NUM> based on the image signal S51. As required, the input interface <NUM> may include a signal processing circuit that converts the image signal S51 into a form suitable for processing performed by the processor <NUM>.

Referring to <FIG>, a flow of processing performed by the processor <NUM> will be described. The processor <NUM> creates a data set D51 illustrated in <FIG> based on the image signal S51 (STEP1). Specifically, the processor <NUM> creates the data set D51 including the pixel data PD1 to PDn by applying the binarization processing to each of the pixels P1 to Pn. Accordingly, the plurality of pixel data PD1 to PDn correspond to the plurality of pixels P1 to Pn in the one-by-one manner.

Each of the pixels P1 to Pn includes locational information and brightness information (received light intensity information) in the image I1. When the brightness of a certain pixel Pm is greater than a prescribed threshold value, the processor <NUM> creates pixel data PDm having a brightness value of "<NUM>". m is an integer arbitrarily selected from <NUM> to n. When the brightness of a certain pixel Pm is no greater than the prescribed threshold value, the processor <NUM> creates pixel data PDm having a brightness value of "<NUM>". Accordingly, each of the pixel data PD1 to PDn has a brightness value of "<NUM>" or "<NUM>" in addition to the locational information in the image I1.

In the example illustrated in <FIG>, the pixel data having the brightness value "<NUM>" is represented by a white rectangle, and the pixel data having the brightness value "<NUM>" is represented by a hatched rectangle. It is understood that the pixel data at the position corresponding to the foreign substance O1 or O2 in the image I1 has the brightness value "<NUM>".

As illustrated in <FIG>, the control device <NUM> includes a storage <NUM>. As illustrated in <FIG>, the processor <NUM> determines whether or not the data set D51 created in the past based on the above technique is stored in the storage <NUM> (STEP2).

If the data set D51 created in the past is not stored in the storage <NUM> (N in STEP2), the processor <NUM> stores the data set D51 created in STEP1 in the storage <NUM> (STEP3). The processing returns to STEP1.

If the data set D51 created in the past is stored in the storage <NUM> (Y in STEP2), the processor <NUM> compares the data set D51 created in STEP <NUM> with the data set D51 stored in the storage <NUM> (STEP4).

Specifically, it is determined whether or not the brightness value changes from "<NUM>" to "<NUM>" for each of the pixel data PD1 to PDn. When such a change occurs in a certain pixel data PDm, it is highly likely that a foreign substance is adhered to a position corresponding to the pixel data PDm. Based on the comparison, the processor <NUM> determines whether or not a foreign substance is adhered to the light passage area 12a of the cover <NUM> (STEP5).

If the brightness value has not changed from "<NUM>" to "<NUM>" in any of the pixel data PD1 to PDn, the processor <NUM> determines that no foreign substance adheres to the light passage area 12a of the cover <NUM> (N in STEP5). In this case, the data set D51 created in STEP1 is newly stored in the storage <NUM> (STEP3). Thereafter, the processing returns to STEP1. The data set D51 stored in the storage <NUM> is subjected to comparison with the data set D51 to be created next time.

If the brightness value changes from "<NUM>" to "<NUM>" in at least one of the plurality of pixel data PD1 to PDn, the processor <NUM> determines that a foreign substance is adhered to the light passage area 12a of the cover <NUM> (Y in STEP5). In this case, the processor <NUM> creates a detection signal S52 indicating the adhesion of the foreign substance (STEP6).

It should be noted that by configuring the processor <NUM> so as to determine that a foreign substance is adhered when the number of pixels whose brightness value is changed from "<NUM>" to "<NUM>" exceeds a prescribed threshold value, it is possible to avoid detecting a minute foreign substance that would not obstruct the information detection, and to enhance the detection accuracy of a foreign substance that needs to be removed.

As illustrated in <FIG>, the control device <NUM> includes an output interface <NUM>. The processor <NUM> causes the output interface <NUM> to output the detection signal S52. The detection signal S52 may be transmitted to another control device in the vehicle <NUM>. For example, the other control device may notify the occupant of the vehicle <NUM> that a foreign substance is adhered to the light passage area 12a of the cover <NUM>, based on the detection signal S52. Notifications may be made through at least one of a visual manner, an audible manner and a haptic manner.

The occupant who has received the notification can take an appropriate response. For example, the sensor system <NUM> may include a nozzle <NUM> that sprays liquid toward the cover <NUM>. Examples of the liquid include water, hot water, and a cleaning liquid. The occupant may perform an operation of causing the nozzle <NUM> to spray liquid. As a result, it is possible to remove the foreign substance adhering to the light passage area 12a.

The camera <NUM> according to the present embodiment is not a device for acquiring an image of the outside area of the vehicle <NUM> (strictly speaking, an image of an area outer than the outer face of the cover <NUM>), but is a device for acquiring an image of the light passage area 12a located on the traveling paths of the sensing light 14a of the LiDAR sensor unit <NUM> and the returned light. Accordingly, at least a portion of a focal plane 55b of the camera <NUM> overlaps the light passage area 12a. In addition, since it is prioritized to arrange the camera <NUM> such that at least a portion of the focal plane 55b overlaps the light passage area 12a, an optical axis 55c of the camera <NUM> may extend in a direction different from a reference sensing direction 14b of the LiDAR sensor unit <NUM>, as illustrated in <FIG>.

If a foreign substance adheres to the light passage area 12a located on the traveling paths of the sensing light 14a and the returned light of the LiDAR sensor unit <NUM>,the LiDAR sensor unit <NUM> may be obstructed from detecting the information of the outside area of the vehicle <NUM>. However, since the adhesion of such a foreign substance is detected by the camera <NUM> configured as described above, it is possible to perform appropriate treatment according to the detected result. Accordingly, it is possible to suppress degradation in the information detecting capability of the LiDAR sensor unit <NUM> covered by the cover <NUM> forming a part of the outer face of the vehicle <NUM>.

The LiDAR sensor unit <NUM> may be replaced with an appropriate sensor unit that uses light to detect information of the outside area of the vehicle <NUM>. Examples of such a sensor unit include a camera unit using visible light, a TOF (Time of Flight) camera unit using infrared light, and a radar unit using millimeter waves. However, since the detection of the foreign substance adhering to the light passage area 12a with the LiDAR sensor unit <NUM> is relatively difficult, the detection of the foreign substance through the acquisition of the image of the light passage area 12a with the camera <NUM> is more advantageous in combination with the LiDAR sensor unit <NUM>.

As illustrated in <FIG>, the detection signal S52 created by the processor <NUM> may be used to operate the nozzle <NUM> described above. That is, when a foreign substance adhering to the light passage area 12a of the cover <NUM> is detected, the processor <NUM> can cause the nozzle <NUM> to spray a liquid toward the light passage area 12a.

According to such a configuration, it is possible to automate the treatment for removing the foreign substance adhering to the light passage area 12a. Accordingly, it is possible to improve the effect of suppressing the degradation of the information detecting capability of the LiDAR sensor unit <NUM> covered by the cover <NUM> forming a part of the outer face of the vehicle <NUM>.

As described above, each of the pixel data PD1 to PDn included in the data set D51 has information corresponding to the location in the light passage area 12a. Accordingly, the processor <NUM> can also specify the position of the foreign substance in the light passage area 12a based on the locational information held by the pixel data whose brightness value has changed from "<NUM>" to "<NUM>". On the other hand, as illustrated in <FIG>, the nozzle <NUM> may include a mechanism capable of adjusting the spraying direction of the liquid. In this case, the processor <NUM> may configure the detection signal S52 so as to cause the nozzle <NUM> to spray the liquid toward the position of the detected foreign substance.

According to such a configuration, since the liquid is more accurately sprayed onto the foreign substance adhering to the light passage area 12a, it is possible to increase the possibility of removing the foreign substance. Accordingly, the degradation of the information detecting capability of the LiDAR sensor unit <NUM> covered by the cover <NUM> forming a part of the outer face of the vehicle <NUM> is further suppressed.

As illustrated in <FIG>, the camera <NUM> may be realized as a micro camera module including an image pickup element <NUM>, a resin lens <NUM>, and a circuit board <NUM>. Examples of the image pickup element <NUM> include a CCD image sensor and a CMOS image sensor. The resin lens <NUM> is a lens for forming an image on the image pickup element <NUM>. From the viewpoint of enlarging the field of view, it is preferable to use a wide-angle lens as the resin lens <NUM>. The circuit board <NUM> supports the image pickup element <NUM> and the resin lens <NUM>. The signal line for outputting the image signal S51 is electrically connected to the image pickup element <NUM> via the circuit board <NUM>.

According to such a configuration, since the space occupied by the camera <NUM> in the accommodation chamber <NUM> can be considerably reduced, it is possible to arrange the camera <NUM> for acquiring the image of the light passage area 12a with higher degree of freedom. Accordingly, it is possible to make easier to suppress degradation in the information detecting capability of the LiDAR sensor unit <NUM> covered by the cover <NUM> forming a part of the outer face of the vehicle <NUM>.

The processor <NUM> capable of performing the above-described processing may be provided by a general-purpose microprocessor operating in cooperation with a general-purpose memory, or may be provided as part of a dedicated integrated circuit device. Examples of the general-purpose microprocessor include a CPU, an MPU, and a GPU. Examples of the general-purpose memory include a RAM and a ROM. Examples of the dedicated integrated circuit element include a microcontroller, an ASIC, and an FPGA. The processor <NUM> and the storage <NUM> may be provided as separate devices or may be packaged in a single device.

In the present embodiment, an image of the light passage area 12a in the cover <NUM> is acquired by the single camera <NUM>. However, as illustrated in <FIG>, it is possible to employ a configuration in which an arbitrary portion in the light passage area 12a is included in any of the fields of view of a plurality of cameras <NUM>.

The above embodiments are mere examples for facilitating understanding of the gist of the presently disclosed invention. The configuration according to each of the above embodiments can be appropriately modified, improved, or combined without departing from the scope of the presently disclosed subject matter, as defined in the appended claims.

Claim 1:
A sensor system (<NUM>) adapted to be installed in a vehicle (<NUM>), comprising:
a sensor unit (<NUM>) configured to detect information of an outside area of the vehicle (<NUM>) with light;
a cover (<NUM>) covering the sensor unit (<NUM>) so as to allow passage of the light while forming a part of an outer surface of the vehicle (<NUM>);
a displacement sensor disposed on the cover (<NUM>);
characterized in that
the displacement sensor is configured to output a signal corresponding to displacement of the cover (<NUM>); and
a processor (<NUM>) configured to detect a foreign substance adhered to the cover (<NUM>) based on a change in the signal.