JP6684244B2 - Obstacle detection sensor dirt determination device and dirt determination method - Google Patents

Description

  The present invention relates to a technique for determining stains on a sensor of a work machine, and more particularly to a technique for determining the presence or absence of stains attached to an obstacle detection sensor that detects an obstacle around a work machine.

  A moving body such as a vehicle is equipped with a radar that detects an obstacle around the vehicle, and there is a technique for determining whether or not the radar is dirty. As a prior art for reducing erroneous determinations in determination, Japanese Patent Application Laid-Open No. 2006-242242 discloses a radar determination device that includes a determination unit that executes radar detection processing, condition determination processing, and radar stain determination processing. The presence of dirt is estimated based on the fact that an obstacle cannot be detected for a predetermined time, and in the condition determination processing, information on various sensors / various ECUs connected to the ACC control ECU is input to determine the moisture condition, In the radar dirt determination process, if the presence of dirt is estimated by the radar detection process, if the water condition and the area condition are not satisfied, the radar dirt determination process does not determine an abnormality and counts the time of the radar detection process. Is reset (abstract excerpt) ”, a radar determination device is disclosed.

JP, 2010-91386, A

  The technique disclosed in Patent Document 1 is premised on that a moving body travels in an urban area, and in an environment in which an obstacle cannot be detected, the detection condition is relaxed and frequent warnings are suppressed. Geographic conditions of the environment that cannot be detected include, for example, a straight road with no sign.

  Work machines represented by dump trucks are used in mines and the like. Then, it is used on a transportation route laid on a vast land. This corresponds to the undetectable geographical condition of Patent Document 1 above. Therefore, if the technique disclosed in Patent Document 1 is used to detect the contamination of the obstacle detection sensor of such a work machine, the warning is always suppressed. Therefore, there is a demand for a determination technique suitable for the working environment of a work machine such as a mine.

  The present invention has been made in view of the above circumstances, and an object thereof is to reduce erroneous determination in determining the presence or absence of dirt on an obstacle detection sensor of a work machine that reciprocates in a vast and monotonous environment such as a mine. To provide.

  The present invention relates to a dirt determination device for an obstacle detection sensor in a work machine equipped with an obstacle detection sensor and a vehicle body information detection sensor, the obstacle detected from information on the obstacle detected by the obstacle detection sensor. An obstacle number acquisition unit that acquires the number of obstacles, a vehicle body information storage unit that stores the vehicle body information obtained by the vehicle body information detection sensor, and the obstacle detection sensor using the number of obstacles and the vehicle body information And a stain determination unit that determines the presence or absence of stains, wherein the stain determination unit uses the number of obstacles and calculates an undetected period in which the number of detected obstacles is a predetermined number or less. If the calculated undetected period is equal to or greater than a predetermined value, the vehicle speed and the steering amount in the vehicle body information are used, and the traveling distance of the working machine and the steering amount greater than or equal to the predetermined amount continue during the undetected period. Provided is a dirt determination device for an obstacle detection sensor, which calculates a steering continuation period that is a period of time, and determines that dirt is present when the traveling distance satisfies at least one of a predetermined value and a steering continuation period that is at least a predetermined value. To do.

  ADVANTAGE OF THE INVENTION According to this invention, an erroneous determination can be reduced in the determination of the presence or absence of dirt of the obstacle detection sensor of the working machine which reciprocates in a vast and monotonous environment such as a mine. Problems, configurations, and effects other than those described above will be clarified by the following description of the embodiments.

It is a left side view of the dump truck of the embodiment of the present invention. It is a functional block diagram of a controller of a dump truck of an embodiment of the present invention. It is a flow chart of dirt judgment processing of an embodiment of the present invention. It is a flow chart of a modification of dirt determination processing of an embodiment of the present invention. It is a flow chart of a modification of dirt determination processing of an embodiment of the present invention. It is a flow chart of a modification of dirt determination processing of an embodiment of the present invention.

  Embodiments according to the present invention will be described below with reference to the drawings. Hereinafter, in the present specification, components having the same function will be denoted by the same reference symbols unless otherwise specified, and repetitive description will be omitted. Hereinafter, the dump truck 100 will be described as an example of the work machine.

  The dump truck 100 of the present embodiment is a sensor that detects the presence or absence of dirt on an obstacle detection sensor that is mounted on itself and that detects the detection result of the obstacle detection sensor and various vehicle body information of the host vehicle. A determination function is provided that makes an accurate determination using the vehicle body information acquired in.

  Prior to a detailed description of the determination function, a dump truck 100 equipped with these sensors will be described. FIG. 1 is a left side view of a dump truck 100 of this embodiment.

  As shown in FIG. 1, the dump truck 100 according to the present embodiment includes a frame 110, a front wheel 104, a rear wheel 105, a frame 110 mounted on the front wheel 104 and the rear wheel 105 via a suspension 109, and a frame 110. And a vessel 114 movably supported via a hoist cylinder 119. A cab (driver's cab) 113 is mounted on the front part of the frame 110. An obstacle detection sensor 121 that detects an obstacle ahead is installed on the front surface of the dump truck 100. Hereinafter, in the present embodiment, the radar 121 will be described as an example of the obstacle detection sensor 121.

  The radar 121 is a sensor that recognizes an obstacle around the dump truck 100, and obstructs the distance (relative distance) from the radar 121 to the obstacle and the relative speed between the obstacle and the host vehicle (dump truck 100). Output as product information. The radar 121 obtains obstacle information by transmitting a transmission wave such as a light wave or a millimeter wave and receiving a reflected wave reflected by the obstacle.

  The output of the radar 121 is, for example, a device that controls so as to keep the distance between the dump truck 100 and the preceding vehicle constant, or a warning or braking control when the distance between the dump truck 100 and the preceding vehicle becomes equal to or less than a certain value. It is used for devices that perform. Therefore, high accuracy is required for the output of the radar 121. However, since the surface of the radar 121 or its protective cover is exposed to the outside, raindrops, mud and the like are likely to adhere. If the surface of the radar 121 or the like is contaminated by these, the detection accuracy is reduced. Therefore, it is desired to accurately determine whether the radar 121 is dirty.

  The dump truck 100 also includes a controller 200 that controls the operation of each unit of the dump truck 100. In the present embodiment, the controller 200 further realizes the function of a stain determination device that determines the presence or absence of stains on the radar 121. Hereinafter, details of the configuration of the controller 200 according to the present embodiment that implements the dirt determination function will be described with reference to FIG.

  FIG. 2 is a functional block diagram of a configuration that realizes the dirt determination function of the controller 200 of the present embodiment. As shown in the figure, the controller 200 of this embodiment includes an obstacle number acquisition unit 210, a vehicle body information storage unit 220, and a stain determination unit 230.

  Although not shown, the controller 200 includes, for example, a CPU (Central Processing Unit) that performs various calculations, a ROM (Read Only Memory) that stores a program for executing calculations by the CPU, an HDD (Hard Disk Drive), and the like. It is composed of hardware including a storage device and a RAM (Random Access Memory) serving as a work area when the CPU executes a program.

  In such a hardware configuration, the program stored in the ROM, the HDD, or the recording medium such as an optical disk (not shown) is read out to the RAM and operates under the control of the CPU, so that the program (software) and the hardware Cooperate with each other to form a functional block that realizes the function of the controller 200. Further, the vehicle body information storage unit 220 is built in a storage device, a RAM, or the like.

  Further, all or some of the functions of the controller 200 may be realized by hardware such as an ASIC (Application Specific Integrated Circuit) and an FPGA (field-programmable gate array). Moreover, each function of the controller 200 may be realized by a circuit such as a comparator, a differentiating circuit, and an adding circuit.

  Hereinafter, the details of each unit that constitutes the controller 200 will be described.

  The obstacle number acquisition unit 210 acquires the number of obstacles within the detection range of the radar 121 for a predetermined period based on the obstacle information received from the radar 121, and the acquired information is sent to the dirt determination unit 230 each time it is acquired. Output. The predetermined period is, for example, a period in which the radar 121 scans the entire detection range once. Hereinafter, it is called a scanning period.

  The vehicle body information storage unit 220 includes outputs from various sensors (vehicle body information detection sensors) 120 that are included in the dump truck 100 and that detect vehicle body information of the dump truck 100 as vehicle body information at the reception time of each vehicle body information detection sensor 120. Correspond and save. Note that the vehicle body information may be stored according to an instruction from the dirt determination unit 230, as will be described later.

  In the present embodiment, the dump truck 100 includes, as the vehicle body information detection sensor 120, a vehicle speed sensor 122 that detects the speed of the front wheels 104 and the rear wheels 105 as a wheel speed (vehicle speed), and a steering angle sensor 123 that detects a steering angle. A suspension pressure sensor 124 that detects a suspension pressure, an acceleration sensor 125 that detects an acceleration of the dump truck 100, a torque value sensor 126 that detects a torque value, and the like. The vehicle body information storage unit 220 stores the outputs from these sensors as vehicle body information.

  The dump truck 100 may further include a load amount measurement sensor that measures the load amount of the vessel 114, a slope measurement sensor that measures the slope of the road surface on which the dump truck 100 travels, and the like.

  The dirt determination unit 230 uses the number of obstacles received from the obstacle number acquisition unit 210 for each scanning period and the vehicle body information stored in the vehicle body information storage unit 220 to determine whether the radar 121 is soiled. . When it is determined that there is dirt, a signal indicating that is output.

  In the present embodiment, the dirt determination unit 230 determines that the number of detected obstacles is equal to or less than a predetermined threshold value for a predetermined time or more, the traveling distance of the dump truck 100 during that time is a predetermined value or more, and If the period in which the steering amount is equal to or greater than the predetermined value is equal to or longer than the predetermined value, it is determined that the dirt is present. Hereinafter, a state in which the number of obstacles is less than or equal to a predetermined threshold value is called an undetected state.

  Hereinafter, the stain determination process of the stain determination unit 230 of the present embodiment will be described according to the processing flow of FIG. Here, a case will be described as an example where the determination is continued during the operation of the dump truck 100 unless it is determined that there is dirt.

  First, the dirt determination unit 230 determines whether or not it is in the undetected state (step S1101). Here, it is determined whether or not the number of obstacles transmitted from the obstacle number acquisition unit 210 is less than a predetermined threshold value. If it is less than the threshold value, it is determined that the state has not been detected.

  In step S1101, if not in the undetected state (S1101 / No), the reception of the next number of obstacles is waited for. This is because the radar 121 is able to detect an obstacle and therefore determines that there is no dirt.

  On the other hand, when it is determined in step S1101 that the undetected state has occurred (S1101 / Yes), the stain determination unit 230 determines whether the undetected state continues for a predetermined time or longer. Note that, hereinafter, the duration of the undetected state is referred to as the undetected period. Therefore, the dirt determination unit 230 first starts counting the undetected period (step S1102). Further, at this time, the dirt determination unit 230 stores the vehicle body information subsequently received from the vehicle body information detection sensor 120 in the vehicle body information storage unit 220 in association with the reception time.

  Then, for each scanning period, the number of obstacles is received from the obstacle number acquisition unit 210, and it is determined whether or not it is in the undetected state (step S1103). Then, if it is not in the undetected state (S1103 / No), the value of the undetected period is reset (step S1109), the process returns to step S1101 and waits for the reception of the next number. In addition, in step S1109, the vehicle body information storage unit 220 is also deleted.

  On the other hand, in the undetected state (S1103 / Yes), the undetected period is counted up (step S1104). Here, in order to determine whether or not it is in the undetected state for each scanning period, for example, the scanning period is added to the undetected period at that time.

  Then, it is determined whether or not the undetected period after the count-up is equal to or greater than a predetermined threshold for determination (step S1105). If it is less than the threshold value (S1105 / No), the process returns to step S1103 to repeat the process. In addition, hereinafter, the threshold value used at this time is referred to as a determination period.

  If the undetected period continues for the determination period or more, there is a possibility that the radar 121 has not been detected despite the presence of dirt and obstacles. Therefore, the dirt determination unit 230 shifts to the determination of the next condition.

  When the undetected period is equal to or longer than the determination period (S1105 / Yes), the stain determination unit 230 determines whether or not the traveling distance of the dump truck 100 during that period is equal to or greater than a predetermined threshold value (step S1106).

  The threshold used at this time is hereinafter referred to as a distance threshold. The distance threshold is set in advance to a distance sufficient for the dump truck 100 to detect an obstacle.

  For example, when the dump truck 100 is stopped or is moving at a low speed, there is a possibility of staying in an environment without obstacles for a determination period or longer. To eliminate such a possibility, the traveling distance is determined.

  The traveling distance is calculated using the vehicle speed stored in the vehicle body information storage unit 220. The vehicle speed is an output value of the vehicle speed sensor 122. For example, the dirt determination unit 230 calculates the traveling distance by integrating the vehicle speed during the undetected period.

  When the calculated traveling distance is less than the distance threshold (S1106 / No), the dirt determination unit 230 determines that dirt is not necessarily present, returns to step S1103, and repeats the processing after the radar scanning time has elapsed.

  On the other hand, when the calculated traveling distance is greater than or equal to the distance threshold (S1106 / Yes), the undetected state continues despite traveling for a predetermined distance or longer. That is, there is a possibility that the radar 121 has not been detected even though it has dirt and obstacles. In this case, the dirt determination unit 230 shifts to the determination using the steering amount.

  In the present embodiment, the dirt determination unit 230 determines whether or not the time during which the steering amount equal to or greater than a predetermined threshold continues is equal to or greater than a predetermined period (threshold) (step S1107).

  Note that, hereinafter, the time during which the steering amount that is equal to or greater than the predetermined threshold value continues is referred to as the steering continuation period. The threshold value used for the determination is set in advance according to the environment in which the dump truck 100 travels. For example, a value that can be used to determine whether or not the vehicle is traveling on a curve is set. Further, the threshold value used for determining the period is called a steering period threshold value.

  In an environment such as a mine, since there are no signs or buildings around, there is a high possibility that there will be no obstacles while traveling on a curved road. That is, the dump truck 100 may travel in an environment without obstacles during the undetected period. This is to eliminate such a situation. On the contrary, on the curve, the radar 121 detects a road shoulder or the like at the end of the traveling road as an obstacle. If the obstacle is not detected even though the vehicle is traveling on such a curved road, there is a high possibility that the radar 121 is dirty.

  The dirt determination unit 230 calculates the steering duration period by using the output value of the steering angle sensor 123 among the output values of the vehicle body information detection sensors 120 stored in the vehicle body information storage unit 220.

  When the calculated steering continuation period is less than the steering period threshold value (S1107 / No), the dirt determination unit 230 determines that dirt is not necessarily found, returns to step S1103, and repeats the processing after the radar scanning time has elapsed. .

  On the other hand, when the calculated steering duration is equal to or longer than the steering duration threshold value (S1107 / Yes), it is determined that the radar 121 is dirty (step S1108), and the process ends. This is because, in this case, the dump truck 100 is running in a situation where there is a high possibility of detecting an obstacle, but the undetected period continues.

  When the dirt determination unit 230 determines that the radar 121 has dirt, the result is output to the outside. The output destination is, for example, as shown in FIG. 2, an output device 130 for notifying the user of the result, a brake control device 140, a cleaning control device 150, or the like.

  The output device 130 receives the notification of the result and presents the fact that the radar 121 is dirty to the user by displaying or outputting the sound. For example, the output device 130 includes a display and / or a speaker. The control unit of the output device 130 receives the notification of the result, displays a warning on the display, and outputs a warning sound from the speaker. The output device 130 is provided in the cab 113, for example.

  The brake control device 140 controls driving of the brake. The brake control device 140 receives the notification of the result and performs control such as applying a brake. The brake control device 140 is, for example, one function of the controller 200.

  The cleaning control device 150 controls the cleaning device of the radar 121 included in the dump truck 100. The cleaning device is, for example, a wiper for the radar 121 or a washer fluid ejector. Upon receiving the notification of the result, the cleaning control device 150 moves the wiper or ejects the washer liquid, for example. The cleaning control device 150 may be configured as one function of the controller 200, or may be configured as a separate device that receives a drive signal from the controller 200 and operates.

  As described above, the controller 200 of the present embodiment includes the obstacle number acquisition unit 210 that acquires the number of detected obstacles from the information of the obstacles detected by the radar 121, the steering amount and the vehicle speed of the dump truck 100. A vehicle body information storage unit 220 that stores the vehicle body information as a vehicle body information, and a stain determination unit 230 that determines the presence or absence of stains on the radar 121 using the number of obstacles and vehicle body information. Then, the dirt determination unit 230 uses the number of obstacles and the vehicle body information to calculate an undetected period in which the number of detected obstacles is a predetermined number or less. Then, when the undetected period continues for a predetermined period or more, a steering continuation period that is a period during which the traveling distance of the dump truck 100 and the steering amount of a predetermined amount or more during the undetected period are calculated. Then, when the calculated traveling distance is equal to or greater than a predetermined value and the calculated steering continuation period is equal to or greater than the predetermined value, it is determined that the dirt is present.

  As described above, in the present embodiment, not only the undetected period but also the traveling distance, the steering amount, and the like are considered, and if all of these conditions are satisfied, it is determined that the radar 121 is dirty. Therefore, according to the present embodiment, as described above, the dump truck 100 is used for a specific period, such as stopping for a predetermined time or moving at a low speed, and / or a vast place such as a mine without any sign. In such a usage environment unique to the dump truck 100, it is possible to reduce erroneous determination and accurately determine whether the radar 121 is dirty.

  In the above embodiment, the undetected period, the traveling distance, and the steering amount are used to reduce erroneous determination that the radar 121 is excessively soiled. However, by using these conditions, it is possible to reduce the erroneous determination that the radar 121 is clean. An example of the flow of processing in this case is shown in FIG.

  In this processing, the flow up to the determination of the traveling distance (step S1106) is the same as the above processing flow. Here, when it is determined that the traveling distance is equal to or greater than the distance threshold (S1106 / Yes), it is determined that there is dirt (step S1108), and the process ends.

  On the other hand, here, when it is determined that the traveling distance is less than the distance threshold (S1106 / No), that is, when there is a possibility that the radar 121 is clean, the steering continuation period is determined (step S1111).

  Then, if the steering duration is less than the steering duration threshold value (S1111 / No), it is determined that there is no stain at this point, the process returns to step S1103, and the processing is repeated after the radar scanning time has elapsed. On the other hand, if the steering duration is equal to or longer than the steering duration threshold value (S1111 / Yes), the process proceeds to step S1108, that is, it is determined that there is dirt.

  In this case, even if the traveling distance is short, if the steering duration is equal to or longer than the steering duration threshold, the obstacle is not detected although the possibility of detecting the obstacle is high. Therefore, the dirt determination unit 230 determines that the radar 121 is likely to be dirty. As a result, it is possible to reduce an erroneous determination that there is no dirt even though the radar 121 is dirty.

  Further, the determination condition used to reduce the erroneous determination is not limited to the above. For example, the period during which the vehicle travels on a flat ground, the change in the load amount, the condition of the traveling path, and the like may be considered.

  For example, a processing flow in the case of considering all of these conditions will be described with reference to FIG. Here, as an example, description will be made assuming that the determination is made in the order of the period during which the vehicle travels on a flat surface, the change in the load amount, and the state of the traveling path. The determination order is not limited to this. Also, not all conditions need be used.

  In the above process flow, in step S1107, when the steering duration is equal to or longer than the steering duration threshold value (S1107 / Yes), the stain determination unit 230 determines whether the flatland duration duration is equal to or greater than a predetermined threshold value as the next condition. Yes (step S1201). In addition, the flatland continuation period is a period in which the vehicle is traveling on a flatland where the low gradient value continues and on a downward slope. The threshold value used for determining the period is called a flatland period threshold value.

  On an uphill road where a high gradient value continues, the detection surface of the radar 121 faces the information. For this reason, the detection area is also upward and far. Therefore, it is unlikely that the radar 121 detects an obstacle. In this case, the orientation of the detection surface of the radar 121 is inappropriate even if the vehicle is continuously traveling for a predetermined traveling distance for a non-detection period with a steering amount of a predetermined steering amount or more. There is a possibility that the obstacle cannot be detected.

  On the other hand, on a flat road or a downhill running road where a low gradient value continues, the radar 121 is highly likely to detect the shoulder or the ground at the end of the running road as an obstacle. Therefore, when the dump truck 100 travels a predetermined traveling distance for a non-detection period, the steering amount of a predetermined amount or more continues for a predetermined period, and the flatland continuation period is a predetermined period or more, despite an obstacle, There is a high possibility that it has not been detected.

  The dirt determination unit 230 uses, for example, the output value of the acceleration sensor 125 and the output value of the torque value sensor 126 among the output values from the vehicle body information detection sensors 120 stored in the vehicle body information storage unit 220, Calculate the slope value.

  The gradient value is calculated, for example, from the force acting on the dump truck 100 generated by each of the vehicle body acceleration and the gravitational acceleration in the horizontal direction detected by the acceleration sensor 125, and the output value of the torque value sensor 126.

  When the vehicle body information detection sensor 120 includes a gradient value measuring sensor, the output value of the gradient value measuring sensor may be used as it is.

  When the calculated flatland duration is less than the flatland period threshold value (S1201 / No), the dirt determination unit 230 determines that it is not necessarily dirty, returns to step S1103, and repeats the processing after the radar scanning time has elapsed.

  On the other hand, when the calculated flatland duration is equal to or greater than the flatland period threshold value (S1201 / Yes), the dirt determination unit 230 determines that the change amount of the load amount during the undetected period is equal to or greater than the predetermined threshold value as the next condition. It is determined whether or not (step S1202). The threshold value used here is called a loading threshold value. The loading amount threshold value is set in advance in consideration of the loading amount of the vessel 114.

  A change in the load capacity of the dump truck 100 occurs at a loading place where the dump truck 100 loads dirt or the like, or at a dumping place where the dump truck 100 unloads dirt and the like. At the loading site, earth and mountains that are being excavated for loading on the dump truck 100 and shovels for loading are used as obstacles at the dumping site, such as earth and sand after dumping and dozers that smooth the sand and sand after dumping. It is likely to be detected.

  Therefore, when the change amount of the load amount is equal to or more than the load amount threshold value, there is a high possibility that the dump truck 100 is in either the loading field or the dumping field. In this case, there is a high possibility that an obstacle will be detected.

  The dirt determination unit 230 uses the output value of the suspension pressure sensor 124 among the output values of the sensors stored in the vehicle body information storage unit 220 to make the main determination.

  For example, the dirt determination unit 230 calculates the load on the front wheel 104 and the rear wheel 105 from the suspension pressure at each reception time, and calculates the weight of the object loaded on the vessel 114. Then, the difference from the weight at the last reception time is calculated, and the change amount of the load amount is calculated. Then, the maximum value of the change amount of the load amount during the undetected period is specified, and the maximum value is compared with the load amount threshold value.

  In addition, also in the calculation of the load amount, when the load amount measurement sensor is provided as the vehicle body information detection sensor 120, the output value of the load amount measurement sensor may be used as it is.

  When the maximum value of the change amount of the load amount during the undetected period is less than the load amount threshold value (S1202 / No), the dirt determination unit 230 determines that dirt is not necessarily present and returns to step S1103 to perform radar scanning. The process is repeated after a lapse of time.

  On the other hand, when the maximum value of the change amount of the load amount is equal to or more than the load amount threshold value (S1202 / Yes), the dirt determination unit 230 determines the duration of the uneven road (uneven road duration) as a next condition in advance. It is determined whether or not the threshold is equal to or more than the threshold (step S1203).

  The larger the unevenness of the surface of the traveling path, the easier the radar 121 can detect the ground. That is, it is easy to detect an obstacle. If the obstacle is not detected even though the vehicle has been traveling on such a road surface for a predetermined period of time or more, it is highly possible that the radar 121 is contaminated.

  The dirt determination unit 230 uses the output of the suspension pressure sensor 124 among the output values of the vehicle body information detection sensors 120 stored in the vehicle body information storage unit 220 to make the main determination.

  The larger the unevenness of the ground, the larger the change in the load applied to the axles of the front wheels 104 and the rear wheels 105. Along with this, the amount of change in suspension pressure also increases. Therefore, if the situation in which the amount of change in suspension pressure exceeds a predetermined threshold value continues for a certain period of time, it can be determined that the vehicle is traveling in a section with large surface irregularities.

  The threshold used here is called the suspension pressure threshold. In addition, the threshold value used for determining the period is referred to as an uneven period threshold value. The suspension pressure threshold value and the unevenness period threshold value are set in advance in consideration of the traveling environment of the dump truck 100.

  When the calculated uneven road duration is less than the uneven time threshold (S1203 / No), the dirt determination unit 230 determines that dirt is not necessarily found, returns to step S1103, and repeats the processing after the radar scanning time elapses. .

  On the other hand, if the calculated uneven road duration is equal to or larger than the uneven road threshold value (S1203 / Yes), it is determined that the radar 121 is dirty (step S1108), and the process ends.

  Even when these conditions are taken into consideration, similarly to the steering duration, each condition may be configured to determine the next condition when it is determined that there is no stain. FIG. 6 shows the flow of processing by the stain determination unit 230 in this case.

  In the above process flow, in step S1107, when the steering duration is less than the steering duration threshold (S1107 / No), the dirt determination unit 230 determines whether the flatland duration is equal to or greater than a predetermined threshold as the next condition. Yes (step S1211).

  If the flatland duration is equal to or greater than the flatland period threshold value (S1211 / Yes), it is determined that there is dirt (step S1108), and the process ends.

  On the other hand, when the flatland duration period is less than the flatland period threshold value (S1211 / No), it is determined whether or not the amount of change in the load amount during the undetected period is equal to or greater than the load amount threshold value (step S1212).

  When the change amount of the load amount is equal to or more than the load amount threshold value (S1212 / Yes), it is determined that there is dirt (step S1108), and the process ends.

  On the other hand, when the change amount of the loading amount is less than the loading amount threshold value (S1212 / No), it is determined whether the uneven road duration is equal to or longer than the uneven road period threshold value (step S1213).

  Then, if the uneven road duration is less than the uneven road period threshold (S1213 / Yes), it is determined that there is dirt (step S1108), and the process ends. On the other hand, if the uneven road duration is equal to or greater than the uneven road period threshold value (S1213 / No), the process returns to step S1103 to repeat the process after the radar scanning time has elapsed.

  Furthermore, by considering conditions such as the slope of the traveling road, changes in the load capacity, and the unevenness of the traveling road, the presence or absence of dirt on the radar 121 can be detected with higher accuracy in the usage mode and usage environment unique to the dump truck 100. You can judge.

  When these plural conditions are further used for the judgment, the judgment order of each condition does not matter. Further, not all the conditions need be used for the determination. Further, depending on the condition, it may be used when it is determined that there is stain under the previously determined condition, or when it is determined that there is no stain, or different.

  Although the dump truck 100 is described as an example of the work machine in the above-described embodiment, the work machine is not limited to the dump truck 100. The above-described embodiment is a vast and monotonous mine such as a transportation vehicle other than a dump truck, for example, a general large truck, another self-propelled machine capable of carrying luggage, a wheel loader, a grader, an excavator, a dozer, etc. It is applicable to any vehicle used in the workplace such as.

  Further, in the above embodiment, the radar 121 that uses the transmitted wave and the reflected wave as the obstacle detection sensor has been described as an example, but the present invention is not limited to this. For example, it may be a plurality of vehicle-mounted cameras or the like. When a vehicle-mounted camera is used as the obstacle detection sensor, the number of obstacles is detected by an existing method such as pattern matching. In addition, the distance to the obstacle is calculated by an existing method using, for example, the difference between the images acquired by the two vehicle-mounted cameras.

  It should be noted that the present invention is not limited to the above-described embodiment, and various modifications are included. For example, the above-described embodiments have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those including all the configurations described.

  100: dump truck, 104: front wheel, 105: rear wheel, 109: suspension, 110: frame, 113: cab, 114: vessel, 119: hoist cylinder, 120: vehicle body information detection sensor, 121: obstacle detection sensor, 121 : Radar, 122: vehicle speed sensor, 123: steering angle sensor, 124: suspension pressure sensor, 125: acceleration sensor, 126: torque value sensor, 130: output device, 140: brake control device, 150: cleaning control device, 200: Controller, 210: obstacle number acquisition unit, 220: vehicle body information storage unit, 230: determination unit

Claims (5)

A dirt determination device for an obstacle detection sensor in a work machine equipped with an obstacle detection sensor and a vehicle body information detection sensor,
From the information of the obstacle detected by the obstacle detection sensor, an obstacle number acquisition unit for acquiring the number of detected obstacles,
A vehicle body information storage unit that stores vehicle body information acquired by the vehicle body information detection sensor,
A dirt determination unit that determines the presence or absence of dirt on the obstacle detection sensor using the number of obstacles and the vehicle body information,
When the dirt determination unit uses the number of the obstacles to calculate an undetected period in which the number of detected obstacles is a predetermined number or less, and the calculated undetected period is equal to or more than a predetermined value. Using the vehicle speed and the steering amount in the vehicle body information, a steering continuation period, which is a period during which the traveling distance of the working machine and a steering amount of a predetermined amount or more during the undetected period are calculated, and the traveling distance is predetermined. A dirt determination device for an obstacle detection sensor, wherein dirt is determined to exist when at least one of a value or more and the steering duration is at least a predetermined value or more. A dirt determination device for an obstacle detection sensor according to claim 1,
The dirt determination unit uses the gradient value of the traveling path of the work machine obtained from the vehicle body information to determine a flatland continuation period as a period during which the gradient value during the undetected period continues to be a predetermined value or less. A dirt determination device for an obstacle detection sensor, which is calculated and further uses the calculated flat land duration for determination. A dirt determination device for an obstacle detection sensor according to claim 1 or 2,
The dirt determination unit calculates the amount of change in the load of the working machine during the undetected period using the vehicle body information, and further uses the calculated amount of change for determination. Sensor dirt determination device. A dirt determination device for an obstacle detection sensor according to any one of claims 1 to 3,
The dirt determination unit, using the vehicle body information, calculates the unevenness continuation period as a period during which the state in which the amount of change in the suspension pressure of the work machine is equal to or greater than a predetermined value during the undetected period continues and is calculated. A dirt determination device for an obstacle detection sensor, wherein the unevenness duration period is further used for the determination. A method for determining the contamination of an obstacle detection sensor for determining the presence or absence of contamination of an obstacle detection sensor mounted on a work machine,
An undetected period determination step of determining whether or not the undetected period, which is a period in which the number of obstacles detected by the obstacle detection sensor is a predetermined number or less, continues for a predetermined period or more,
When the undetected period continues for a predetermined time or more, the travel speed of the work machine during the undetected period is calculated using the vehicle speed of the work machine, and whether the calculated travel distance is a predetermined value or more. A mileage determination step of determining,
When the traveling distance is equal to or greater than a predetermined value, during the undetected period, a steering continuation period, which is a period in which a steering amount of a predetermined amount or more of the work machine is continued, is calculated, and the calculated steering continuation period is a predetermined value. In the case of the above, there is provided a dirt judging step for judging that there is dirt, and a dirt judging method for an obstacle detection sensor, comprising: