Inspection device and inspection method

Abstract

To allow for inspecting for the presence or absence of damage while gears are engaged in a vehicle having a motor mounted thereon.SOLUTION: An inspection device for inspecting for gear damage in a transmission that transmits torque generated by a motor mounted on a vehicle as a drive source is provided, the inspection device comprising a detection unit for detecting an AE signal while gears are engaged, and a processing unit configured to determine the presence or absence of damage while the gears are engaged on the basis of the AE signal.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to an inspection device and an inspection method. [Background technology]

[0002] Patent Document 1 discloses a technology in which a rotating shaft is rotated and multiple stages of gears are meshed while the vibration and rotation angle of the rotating shaft are detected, and the presence or absence of a dent in the gear and the location where the dent has occurred are detected based on the detected vibration waveform and the detected rotation angle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2005-91232 A Summary of the Invention [Problem to be solved by the invention]

[0004] In electric vehicles, it is preferable to inspect the gear meshing state for damage with the motor mounted on the vehicle, but there are concerns about the stability of the vehicle since the inspection is performed while the vehicle is in motion.

[0005] In view of the above-mentioned problems, the present invention has an object to provide an inspection technique capable of inspecting whether or not damage has occurred in the meshing state of gears with a motor mounted on a vehicle. [Means for solving the problem]

[0006] An inspection device according to one aspect of the present invention is an inspection device that inspects damage to a gear in a transmission that transmits torque generated by a motor installed as a drive source of a vehicle, a detection unit that detects an AE signal when the gears are in mesh; and a processing unit that determines whether or not damage has occurred in the meshing state of the gears based on the AE signal.

[0007] An inspection method according to another aspect of the present invention is a method for inspecting damage to a gear in a transmission that transmits torque generated by a motor installed as a drive source of a vehicle, the method comprising the steps of: a step of detecting an AE signal in a meshed state of the gears by a detection unit of the inspection device; The method includes a step in which a processing unit of the inspection device determines whether or not damage has occurred in the meshing state of the gears based on the AE signal. Effect of the Invention

[0008] According to the present invention, it is possible to inspect whether or not damage has occurred in the meshing state of gears with the motor mounted on a vehicle. [Brief description of the drawings]

[0009] [Figure 1] 1 is a block diagram of a vehicle and its control device according to an embodiment; [Diagram 2] FIG. 2 is a diagram showing an example of the configuration of a power unit of a vehicle according to an embodiment. [Diagram 3] FIG. 2 is a diagram showing the functional configuration of an inspection apparatus according to an embodiment. [Figure 4] 4A to 4C are diagrams for explaining exemplary signal waveforms of an AE sensor. [Diagram 5] FIG. 4 is a diagram illustrating an example of meshing of gears (DR, DN). [Figure 6] FIG. 4 is a diagram showing an example of examination date and time information stored in a storage unit. [Figure 7] 11A and 11B are diagrams for explaining an example of a process for controlling the stopping position of a vehicle in order to inspect a gear that has not been inspected for the longest period of time. [Figure 8] FIG. 4 is a diagram for explaining a process flow in the inspection device and the electronic control unit. [Figure 9] FIG. 9 is a diagram for explaining a specific process flow in step S1 of FIG. 8. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the invention according to the claims, and not all combinations of features described in the embodiments are essential to the invention. Two or more features among the multiple features described in the embodiments may be arbitrarily combined. In addition, the same reference numbers are used for the same or similar configurations, and duplicated descriptions are omitted.

[0011] <Outline of autonomous vehicles> A vehicle V (autonomous vehicle) of this embodiment is, as an example, a four-wheeled electric vehicle, and Fig. 1 shows an outline of the vehicle V in plan view and side view. An electronic control unit 1 (ECU) of this embodiment controls a hydraulic device 3, a motor 11, a transmission 12, various sensors 8a, 8b, etc. The electronic control unit 1 is not limited to being configured as a single unit, but may be configured from a plurality of ECUs, such as an ECU for controlling the motor 11 and an ECU for controlling the transmission 12.

[0012] The electronic control unit 1 includes a processor represented by a CPU (Central Processing Unit), a storage device such as a semiconductor memory, an interface with an external device, etc. The storage device stores programs executed by the processor, data used by the processor for processing, etc. The interfaces include an input / output interface and a communication interface.

[0013] The electronic control unit 1 controls the drive (acceleration) of the vehicle V by controlling the power unit 2. The power unit 2 is a traveling drive unit that outputs a drive force that rotates the drive wheels of the vehicle V, and can include a motor 11 and a transmission 12. The motor 11 can be used as a drive source that accelerates the vehicle V, and can also be used as a generator during deceleration, etc. (regenerative braking).

[0014] The power drive unit (PDU) 5 is a device that performs rotation control and stop control of the motor 11. The electronic control unit 1 generates a control signal for controlling the motor 11 and outputs it to the PDU 5. The PDU 5 can perform rotation control and stop control of the motor 11 based on the control signal acquired from the electronic control unit 1. The electronic control unit 1 can perform, as automatic driving control of the vehicle V, for example, stop control for stopping the vehicle V at a target stop position, acceleration / deceleration control for controlling the acceleration or deceleration of the vehicle V, lane keeping control, lane change control, and the like.

[0015] The electronic control unit 1 controls the output of the motor 11 and changes the gears of the transmission 12 in response to the driver's operation and vehicle speed detected by an operation detection sensor 2a provided on the accelerator pedal AP and an operation detection sensor 2b provided on the brake pedal BP. The motor 11 is provided with a sensor 2c that detects the rotation angle and rotation speed of the output shaft of the motor 11 as a sensor for detecting the running state of the vehicle V. The vehicle speed of the vehicle V can be calculated from the detection result of the sensor 2c.

[0016] The electronic control unit 1 controls the braking (deceleration) of the vehicle V by controlling the hydraulic device 3. The hydraulic device 3 is an actuator capable of controlling the hydraulic pressure of hydraulic oil supplied to brake devices 3a (e.g., disc brake devices) provided on each of the four wheels based on the hydraulic pressure transmitted from a brake master cylinder BM. The electronic control unit 1 controls the driving of solenoid valves and the like provided in the hydraulic device 3, thereby controlling the braking of the vehicle V and is capable of performing stop control to stop the vehicle V at a predetermined target position.

[0017] The electronic control unit 1 controls the steering of the vehicle V by controlling the electric power steering device 4. The electric power steering device 4 includes a mechanism for steering the front wheels in response to the driver's driving operation (steering operation) with respect to the steering wheel ST. The electric power steering device 4 includes a drive unit 4a including a motor that exerts a driving force for assisting the steering operation or for automatically steering the front wheels, a steering angle sensor 4b, a torque sensor 4c that detects the steering torque borne by the driver, and the like.

[0018] The electronic control unit 1 controls the parking gear 50 and the parking pole 51 of the transmission 12, and also controls the electric parking brake device 3c provided on the rear wheels, thereby bringing the vehicle V to a stop.

[0019] The electronic control unit 1 performs driving assistance or automatic driving of the vehicle V based on the detection results of various detection units provided in the vehicle V. The vehicle V is provided with surrounding detection units 8a to 8b, which are external sensors that detect the outside (surrounding conditions) of the vehicle V. The electronic control unit 1 can grasp the surrounding conditions of the vehicle V based on the detection results of the surrounding detection units 8a to 8b, and can perform automatic driving assistance according to the surrounding conditions. The surrounding detection unit 8a is an imaging device that captures an image in front of the vehicle V (front camera 8a), and the electronic control unit 1 can extract the contours of targets and lane markings (white lines, etc.) on the road by analyzing the image captured by the front camera 8a.

[0020] The surroundings detection unit 8b is a millimeter wave radar (sometimes referred to as radar 8b) that uses radio waves to detect targets around the vehicle V and detects (measures) the distance to the target and the direction (azimuth) of the target relative to the vehicle V. Note that the surroundings detection unit provided in the vehicle V is not limited to the above configuration, and a lidar (Light Detection and Ranging: LIDAR) that detects targets around the vehicle V may be provided.

[0021] The electronic control unit 1 recognizes and determines the current position and course (attitude) of the vehicle V. In this embodiment, the vehicle V is provided with a gyro sensor 7a, a GNSS (Global Navigation Satellite System) sensor 7b, and a communication device 7c. The gyro sensor 7a detects the rotational motion (yaw rate) of the vehicle V. The GNSS sensor 7b detects the current position of the vehicle V. The communication device 7c performs wireless communication with external devices and inspection devices to transmit and receive various information. The information acquired from the gyro sensor 7a, the GNSS sensor 7b, and the communication device 7c is stored in a database 7d (storage device). In this embodiment, the electronic control unit 1 can specify the current position of the vehicle V based on the detection results of the gyro sensor 7a and the GNSS sensor 7b, and perform control to stop the vehicle V on the course of the vehicle V or at a target position.

[0022] The electronic control unit 1 controls an information output device 6 that notifies the driver of various things. The information output device 6 includes, for example, an information display device 6a that notifies (displays) information to the driver by image, and / or an audio output device 6b such as a speaker that notifies the driver of information by sound. The information display device 5a may be, for example, an indicator that can be provided on an instrument panel.

[0023] <Power unit overview> 2, the power unit of the vehicle V has a housing 14 that houses the motor 11, the transmission 12, and the differential gear 13 therein, and the housing 14 is divided into three parts in the vehicle width direction: a left housing 15, a center housing 16, and a right housing 17. A first housing section 43 is defined between the left housing 15 and the center housing 16, and a second housing section 44 is defined between the center housing 16 and the right housing 17.

[0024] The motor 11 disposed in the first housing portion 43 includes a motor shaft 20 supported by the left housing 15 and the central housing 16 via ball bearings 18, 19, respectively, a rotor 21 fixed to the motor shaft 20, and a stator 22 fixed to the central housing 16 so as to surround the outer periphery of the rotor 21. Oil is stored in the bottom of the housing 14.

[0025] The transmission 12 disposed in the second housing portion 44 includes a first reduction gear 23 (first drive gear) fixed to a tip of a motor shaft 20 protruding from the right housing 17 to the right. The transmission 12 also includes a reduction shaft 26 supported by the central housing 16 and the right housing 17 via angular roller bearings 24, 25, respectively, and a second reduction gear 27 (first driven gear) fixed to the reduction shaft 26 and meshing with the first reduction gear 23. The transmission 12 also includes a final drive gear 28 (second drive gear) fixed to the reduction shaft 26, and a final driven gear 29 (second driven gear) fixed to the outer periphery of the differential gear 13 and meshing with the final drive gear 28.

[0026] The differential case 30 constituting the outer shell of the differential gear 13 arranged in the second housing 44 is supported by the central housing 16 and the right housing 17 via angular roller bearings 31 and 32, respectively. An inboard joint 34 provided at the tip of a long left output shaft 33 extending leftward from the differential case 30 protrudes outward from the left housing 15, and an inboard joint 36 provided at the tip of a short right output shaft 35 extending rightward from the differential case 30 protrudes outward from the right housing 17. The left inboard joint 34 is connected to the left rear wheel via a left half shaft (not shown), and the left inboard joint 36 is connected to the right rear wheel via a right half shaft (not shown). The left end of the left output shaft 33, the right end of which is supported by the differential gear 13, is supported by the left housing 15 via a ball bearing 37. A parking gear 50 is fixed to the right output shaft 35, and a parking pole 51 is attached to the right housing 17. Concave portions and convex portions are formed alternately in the circumferential direction on the outer peripheral surface of the parking gear 50. The parking pole 51 has claw portions that can engage with the concave portions of the parking gear 50. When parking, the concave portions of the parking gear 50 engage with the claw portions of the parking pole 51 attached to the right housing 17, thereby locking the parking gear 50 so that it cannot rotate.

[0027] <Functional configuration of inspection device 300> 3 is a diagram showing a functional configuration of an inspection device 300 of this embodiment. The inspection device 300 has a processing unit 301, a communication unit 302, and a storage unit 303. The processing unit 301 is a processor represented by a CPU, and executes a program stored in the storage unit 303 to process a signal detected by the AE sensor 320. The storage unit 303 is a storage device such as a ROM, a RAM, or a HDD, and stores various control information and history information (inspection date and time information) on the processing of the signal detected by the AE sensor 320 in addition to the program executed by the processing unit 301. The communication unit 302 is a communication device that communicates with other external devices, etc. The processing unit 301 communicates with the electronic control unit 1 via the communication unit 302.

[0028] The functional configuration of the processing unit 301 is realized by reading a predetermined computer program stored in the storage unit 303 into the RAM and executing the processing by the CPU of the inspection device 300. In addition, as long as they perform the same functions, they may be configured by integrated circuits or the like.

[0029] The AE sensor 320 is a sensor that detects a certain vibration (AE signal). AE is an abbreviation of Acoustic Emission, and the AE sensor 320 detects vibration (AE signal) in which sound generated when a part of an object is deformed or broken or when an impact is applied is emitted as an elastic wave. Since the AE signal can be generated by minute deterioration that occurs before the object is completely broken, it is possible to detect the early stage of deterioration of the object. The frequency of the vibration (AE signal) is an elastic wave that is determined by the type of metal, and when pitting, peeling, or cracks occur in the gear, a sudden waveform in which the vibration waveform changes significantly and discontinuously is generated instantaneously. In this embodiment, the AE sensor 320 is used for non-destructive inspection of the gears (DR, DN) in the transmission 12. The gears (DR, DN) in the transmission 12 include a combination of the first reduction gear 23 and the second reduction gear 27, and a combination of the final drive gear 28 and the final driven gear 29. The inspection device 300 of this embodiment detects the presence or absence of pitting, spalling, and cracks in the gears (DR, DN) as defects (damage) in the gears. Here, gear pitting refers to damage in which fatigue failure occurs in the material, resulting in micropores on the tooth surface, and spalling refers to damage in which material falls off from the tooth surface. Additionally, cracks refer to damage in which cracks occur in the gear or the cracks propagate (advance).

[0030] The AE sensor 320 is provided on a side surface of the housing 14 of the power unit. A signal detected by the AE sensor 320 is input to the inspection device 300, and a processing unit 301 of the inspection device 300 processes the signal detected by the AE sensor 320 to determine the presence or absence of damage (pitting, peeling, or cracks) in the gears (DR, DN).

[0031] The inspection device 300 applies torque to the gears (DR, DN) and grasps the state of the gears based on the load. When performing state detection during driving, since torque may be added due to the driver's intervention, variations may occur in the inspection conditions, and there may be cases where stable state estimation cannot be achieved. Therefore, in order to perform the inspection under stable conditions, in this embodiment, the inspection device 300 (inspection unit) performs inspection of the gears (DR, DN) when the vehicle V is stopped. The inspection device 300 detects the presence or absence of damage (pitching, peeling, cracking) in the gears (DR, DN) as a gear defect (damage) when the vehicle V is stopped.

[0032] When performing inspection in a stopped state, the tooth engagement in the gears (DR, DN) to be inspected can be for several teeth. For this reason, the inspection device 300 of this embodiment provides a technology that can control the stop position of the vehicle V in cooperation with the automatic driving control of the vehicle V, prioritize the inspection of the gear engagement with the longest uninspected period from the previous inspection time point, and detect gear damage at an early stage.

[0033] If inspection has not been performed for a long time, the possibility of gear damage (pitching, peeling, cracking) occurring during the uninspected period increases. Therefore, as the time period during which inspection has not been performed, the inspection is prioritized for the gear (DR, DN) engagement with the longest uninspected period.

[0034] When the vehicle V is stopped, the inspection device 300 generates a predetermined torque (for example, a sinusoidal waveform torque) in the motor 11, which is a drive source, and acquires the vibration (AE signal) generated at the time of gear (DR, DN) engagement from the AE sensor 320. When the inspection device 300 receives a signal that the motor 11 has stopped from the electronic control unit 1, the processing unit 301 of the inspection device 300 outputs a drive request signal for generating a predetermined torque in the motor 11. The electronic control unit 1 outputs the drive request signal received from the processing unit 301 to the PDU 5 to generate a predetermined torque in the motor 11.

[0035] <Example of AE signal waveform> Fig. 4 is a diagram illustrating an example of a signal waveform of the AE sensor 320. A torque waveform 401 illustrates an example of a torque waveform generated by the motor 11 based on a drive request signal, and Fig. 4 illustrates an example of torque having a sine waveform.

[0036] Moreover, an AE waveform 402 illustrates an example of a waveform of vibration (AE signal) detected by the AE sensor 320 when the gears (DR, DN) mesh due to application of torque from the motor 11. When the vehicle V is in a stopped state, the processing unit 301 generates a drive request signal for generating a sinusoidal torque having a preset period and amplitude as a predetermined torque, and brings the gears into mesh.

[0037] The processing unit 301 of the inspection device 300 acquires a detection signal from the AE sensor 320 when torque is generated in the motor 11 based on the drive request signal. The processing unit 301 determines whether or not damage has occurred in the meshing of the gears (DR, DN) based on the waveform of the AE signal. The processing unit 301 determines whether or not a sudden signal 403 as shown in FIG. 4 has occurred in the meshing of the gears (DR, DN) to be inspected. If the sudden signal 403 is detected, the processing unit 301 determines that peeling or cracks have occurred in the gear meshing. The processing unit 301 outputs a notification signal to notify the occurrence of peeling or cracks.

[0038] On the other hand, when no peeling or cracking occurs in the gears, for example, a high-frequency continuous signal 404 is output from the AE sensor 320. When the high-frequency continuous signal 404 is detected by the AE sensor 320, the processing unit 301 determines that no peeling or cracking occurs in the gears (DR, DN).

[0039] 5 is a diagram illustrating an example of the meshing pattern of the gears (DR, DN). For simplicity, meshing pattern 501 illustrates an example of a meshing combination in which the number of teeth of the driving gear DR is 3 and the number of teeth of the driven gear DN is 5. There are 15 (=3×5) possible meshing combination patterns.

[0040] In normal gear design, the gear ratio is designed so that it is not an integer multiple in order to reduce wear caused by meshing of identical combinations.

[0041] In the gear meshing shown in the drive unit of FIG. 2, if the number of teeth of the first reduction gear 23 (first drive gear: DR) is DR1 and the number of teeth of the second reduction gear 27 (first driven gear: DN) is DN1, the ratio (DR1 / DN1) is designed not to be an integer multiple (for example, 502 in FIG. 5). Also, if the number of teeth of the final drive gear 28 (second drive gear: DR) is DR2 and the number of teeth of the final driven gear 29 (second driven gear: DN) is DN2, the ratio (DR2 / DN2) is designed not to be an integer multiple (for example, 502 in FIG. 5). The specification values ​​of the gears (DR, DN) are stored in a database 7d (storage device), and the electronic control unit 1 can acquire meshing information of the gears (DR, DN) by referring to information in the database 7d during the stop control of the vehicle V.

[0042] <Storage of examination date and time information> The inspection device 300 monitors (inspects) the combination of meshing gears, and accumulates inspection date and time information, including the date of inspection, as inspection history information in the storage unit 303. The processing unit 301 identifies, from the inspection date and time information, the gear meshing that has not been inspected for the longest period since the previous inspection as the target for inspection.

[0043] 6 is a diagram showing an example of inspection date and time information stored in the storage unit 303. Here, as an example, an accumulated example 601 of inspection date and time information for meshing between tooth "1" of the driving gear DR and teeth "1 to 17" of the driven gear DN is shown. In the accumulated example 601 of inspection date and time information, the vertical axis indicates the time axis, and the upper end of the accumulated example 601 indicates a reference time (for example, the current time). The upper end of the bar graph for each meshing indicates the inspection date and time information when the last inspection was performed using the AE sensor 320. The portion between the reference time (current time) and the upper end of the bar graph indicates an uninspected period for the meshing of the gears (DR, DN).

[0044] 6, the combination of tooth "1" of the drive-side gear DR and tooth "9" of the driven-side gear DN is the gear meshing with the longest uninspected period. The inspection device 300 controls the stopping position of the vehicle V in cooperation with the automatic driving control of the vehicle V so that inspection can be given priority to the combination of tooth "1" of the drive-side gear DR and tooth "9" of the driven-side gear DN, as shown in uninspected period 602.

[0045] <Example of updating stop position> 7 is a diagram for explaining an example of a process for controlling the stopping position of the vehicle V in order to give priority to the meshing of the gear that has not been inspected for the longest period of time. For example, assume that the tooth "1" of the drive-side gear DR at the current position is in mesh with the tooth "1" of the driven-side gear DN. When the vehicle travels from this state to a planned stopping position (target stopping position) according to the base automatic driving travel plan, the tooth "8" of the drive-side gear DR will be in mesh with the tooth "48" of the driven-side gear DN.

[0046] The inspection device 300 of this embodiment acquires the inspection date and time information stored in the storage unit 303 for the meshing combination at the target stop position. Since the gear meshing that can be inspected when the vehicle V is stopped is several teeth, the inspection date and time information of a predetermined range is acquired based on the meshing combination (meshing position) at the target stop position, and the gear meshing combination with the longest uninspected period is identified. Here, the predetermined range includes, for example, the inspection date and time information of meshing at several teeth before and after the reference meshing position. The acquisition example 704 of the inspection date and time information in FIG. 7 shows an example of acquiring the inspection date and time information about five meshings before and after the meshing combination at the target stop position 705. In the acquisition example 704 in FIG. 7, the processing unit 301 identifies the meshing between the tooth "10" of the drive side gear DR and the tooth "50" of the driven side gear DN as the gear meshing combination with the longest uninspected period from the acquired inspection date and time information in the predetermined range. The processing unit 301 updates the target stopping position 705 planned in the automatic driving control of the vehicle V to a target stopping position 706 so that the vehicle V stops at the meshing position of the gear to be inspected.

[0047] When the processing unit 301 identifies the gear meshing combination that has not been inspected for the longest period of time, it transmits a request to inspect the identified meshing combination (inspection request) to the electronic control unit 1. The processing unit 301 is capable of mutual communication with the electronic control unit 1 via the communication unit 302, and the processing unit 301 receives a signal of the determination result of permission or non-permission for the transmitted inspection request via the communication unit 302.

[0048] The electronic control unit 1 determines whether the vehicle V can be stopped with the meshing combination in the inspection request. When the electronic control unit 1 determines that the vehicle V can be stopped based on the inspection request, it updates the target stop position to a stop position based on the inspection request and performs stop control of the vehicle V. That is, the electronic control unit 1 controls the motor 11 so as to stop the vehicle V at the updated stop position based on the meshing combination identified by the inspection device 300. In the acquisition example 704 in FIG. 7, the correction amount exemplarily indicates a numerical value of a change in the stop position relative to the reference target stop position. The unit of the numerical value is determined by the gear specifications and may be meters or centimeters.

[0049] <Processing flow> The flow of processing in the inspection device 300 and the electronic control unit 1 will be described with reference to the flowchart of FIG. 8. In S1, the processing unit 301 of the inspection device 300 acquires meshing information of the gears (DR, DN) when the vehicle travels to a stop position (target stop position: for example, 705 in FIG. 7) planned in the automatic driving control from the electronic control unit 1. Here, the meshing information includes not only the meshing position of the gears (DR, DN) but also a meshing range of several teeth before and after the meshing position. Based on the acquired meshing information, the processing unit 301 specifies the meshing position of the inspection target, and determines a stop target position (for example, 706 in FIG. 7) for performing the inspection based on the meshing information. Then, the processing unit 301 transmits a stop position request (inspection request) to the electronic control unit 1 to stop the vehicle V at the determined stop target position 706.

[0050] In S2, the electronic control unit 1 judges whether to permit or not permit the vehicle V to stop based on the stop position request (inspection request) that has updated the target stop position. If the stop position request (inspection request) can be permitted based on the detection information around the vehicle V, the electronic control unit 1 judges to permit, and if the stop position request (inspection request) cannot be permitted, it judges to not permit.

[0051] The electronic control unit 1 transmits the determination result to the processing unit 301. Based on the received signal of the determination result of permission or non-permission, the processing unit 301 can determine whether the vehicle V will stop at the target stop position before the update or at the updated stop target stop position.

[0052] In S3, the electronic control unit 1 generates a control signal for controlling the motor 11 and outputs it to the PDU 5. The PDU 5 performs rotation control and stop control of the motor 11 based on the control signal acquired from the electronic control unit 1.

[0053] If the determination result is not permitted, the electronic control unit 1 generates a control signal for controlling the motor 11 so as to stop it at the pre-update target stop position. If the determination result is permitted, the electronic control unit 1 generates a control signal for controlling the motor 11 so as to stop it at the updated stop target stop position. The power drive unit (PDU) 5 outputs the generated control signal to the motor 11. When the stop control of the motor 11 is completed, the PDU 5 outputs a stop signal indicating the stopped state of the motor 11 to the electronic control unit 1.

[0054] The electronic control unit 1 determines whether the motor 11 has stopped based on the presence or absence of a stop signal output from the PDU 5, and if the motor 11 has not stopped (S4-NO), continues to monitor the stop determination of the motor 11. On the other hand, if the determination in S indicates that the motor 11 has stopped (S4-YES), a signal notifying the inspection device 300 of the completion of stopping is transmitted.

[0055] In S5, when the inspection device 300 receives a notification signal of completion of stopping from the electronic control unit 1, the processing unit 301 of the inspection device 300 generates a drive request signal for applying a predetermined torque to the motor 11 and outputs it to the electronic control unit 1. The processing unit 301 generates a drive request signal for generating a predetermined torque in the motor 11 while the vehicle V is stopped, and brings the gears into meshing state. The processing unit 301 generates a drive request signal for generating a sinusoidal torque having a preset period and amplitude as the predetermined torque while the vehicle V is stopped, and brings the gears into meshing state. The processing unit 301 outputs the generated drive request signal to the electronic control unit 1.

[0056] In S6, the electronic control unit 1 outputs the drive request signal received from the inspection device 300 to the PDU 5, and the PDU 5 causes the motor 11 to generate a predetermined torque based on the drive request signal. The torque generated by the motor 11 is, for example, a torque as shown in a torque waveform 401 in FIG.

[0057] In S7, the motor 11 generates torque to bring the gears (DR, DN) of the transmission 12 into meshing state.

[0058] In S8, the processing unit 301 of the inspection device 300 acquires a signal (AE signal) from the AE sensor 320 when torque is applied. Upon receiving the AE signal, the processing unit 301 updates the inspection date and time information and stores it in the storage unit 303.

[0059] The processing unit 301 can specify whether the vehicle V will stop at the target stop position before the update or at the updated stop target stop position based on a signal of the determination result of permission or non-permission acquired from the electronic control unit 1. The processing unit 301 updates the inspection date and time information based on the meshing information corresponding to the specified stop position. For example, when the vehicle V stops at the target stop position 705 in FIG. 7, the processing unit 301 updates the inspection date and time information in the meshing information of DR8-DN48. Also, when the vehicle V stops at the updated stop target position 706, the processing unit 301 updates the inspection date and time information in the meshing information of DR10-DN50.

[0060] Even if a crack occurs in a gear while the vehicle is moving, when a predetermined torque is applied to the gear during inspection in a stopped state, if the crack progresses (propagates), an AE signal is generated, and the processing unit 301 can detect the occurrence of a crack.

[0061] In S9, the processing unit 301 judges whether or not a sudden signal 403 (FIG. 4) as shown in FIG. 4 has occurred during meshing of the gears (DR, DN) to be inspected. If no sudden signal is detected (S9-NO) and a high-frequency continuous signal 404 (FIG. 4) is detected, the processing unit 301 judges the result as normal (S12) and ends the process.

[0062] On the other hand, if the sudden signal 403 is detected in the determination of S9 (S9-YES), the processing unit 301 determines that separation or a crack has occurred in the meshing of the gears (DR, DN) being inspected (S10: abnormality determination).

[0063] In S11, the processing unit 301 outputs a notification signal to the electronic control unit 1 to notify the occurrence of peeling or cracking.

[0064] When the electronic control unit 1 receives the notification signal, the electronic control unit 1 may generate a notification sound from the audio output device 6b such as a speaker, or may turn on a display of the information display device 6a such as an indicator.

[0065] <Specific example of processing in step S1> A specific process flow in step S1 in Fig. 8 will be described with reference to the flowchart in Fig. 9. In S21, the electronic control unit 1 acquires information on a target stop position in the automatic driving control (for example, 705 in Fig. 7). A predetermined allowable range may be set for the information on the target stop position, taking into consideration various factors in the automatic driving control, such as changes in information about the surroundings of the vehicle V while it is traveling.

[0066] In S22, the electronic control unit 1 calculates the distance from the current position to the target stop position. The electronic control unit 1 calculates the distance based on the difference between the target stop position and the current position.

[0067] In S23, the electronic control unit 1 calculates the number of rotations of the wheel to the target stop position based on the calculated distance and the wheel diameter (tire diameter). The electronic control unit 1 calculates the number of rotations of the wheel by dividing the distance by (2 × wheel radius × π).

[0068] The wheel diameter (tire diameter: 2 × wheel radius) may be a fixed value, or the wheel diameter (tire diameter) may be corrected according to the wear amount of the wheel diameter (tire diameter) taking into account the driving history and driving distance during autonomous driving. Information on the wheel diameter and the wear amount of the wheel diameter (tire diameter) taking into account the driving history and driving distance is stored in, for example, database 7d (storage device), and the electronic control unit 1 refers to the information in database 7d to calculate the number of wheel revolutions. Alternatively, the electronic control unit 1 refers to the information in database 7d to correct the wheel diameter (tire diameter) and calculate the number of wheel revolutions.

[0069] In S24, the electronic control unit 1 calculates the meshing position (range) of the teeth when traveling to the target stop position from the calculated rotation speed and the current meshing position of the teeth (meshing combination position). The calculated meshing position of the teeth is not limited to one meshing position, and for example, a range of several teeth before and after the meshing position may be acquired as the meshing position of the teeth. The electronic control unit 1 outputs the calculated meshing position (range) of the teeth to the inspection device 300 as the predicted meshing position (range) in the automatic driving control.

[0070] Next, in S25, the processing unit 301 of the inspection device 300 reads inspection date and time information of a predetermined range (FIG. 7) from the storage unit 303 based on the predicted meshing position (range) calculated by the electronic control unit 1.

[0071] In S26, the processing unit 301 identifies the meshing combination (meshing position) of the gears that has not been inspected for the longest period of time among the inspection date and time information within a predetermined range (for example, 706 in FIG. 7).

[0072] Then, in S27, the processing unit 301 determines the target stop position 706 based on the identified combination of meshing gears.

[0073] The processing unit 301 updates the target stop position planned in the automatic driving control of the vehicle V so that the vehicle V stops at the meshing position of the gears to be inspected. For example, as shown in 706 in Fig. 7, the processing unit 301 identifies the gear meshing combination (DR10-DN50) that has not been inspected for the longest period, and determines the stop position of the vehicle V based on this meshing combination as the stop target position 706. The determined stop target position 706 is a stop position obtained by updating the target stop position 705 in the automatic driving control.

[0074] As described above in S1 of FIG. 8, the processing unit 301 transmits a stop position request (inspection request) for stopping the vehicle V at the determined stop target position 706 to the electronic control unit 1.

[0075] (Modification) In the above embodiment, an example of storing inspection date and time information in the memory unit 303 has been described. However, the information stored in the memory unit 303 is not limited to the inspection date and time information. Information on the number of inspections (number of evaluations) for each meshing combination may be stored together with the inspection date and time information.

[0076] When multiple pieces of meshing information are identified as the gear combination with the longest uninspected period, the processing unit 301 may identify the gear mesh with the least number of inspections as the inspection target based on the number of times information. For example, when multiple pieces of meshing information (D1, D2, D3) are identified as the gear combination with the longest uninspected period, the inspection device 300 may refer to the number of inspections information (number of evaluations) in the storage unit 303 and perform inspection preferentially on the combination with the least number of inspections (e.g., D1) among the multiple pieces of meshing information (D1, D2, D3).

[0077] In addition, in the above embodiment, a configuration example was described in which inspection is performed when the vehicle V is stopped, but it is also possible to acquire an AE signal while the vehicle V is traveling and inspect multiple gears multiple times.

[0078] Furthermore, the number of AE sensors 320 is not limited to one, and inspection can be performed using information from a plurality of AE sensors 320. For example, by setting, for each AE sensor 320, time difference information until the processing unit 301 acquires a signal from each AE sensor 320, it is possible to determine which AE sensor 320 detected the sudden signal 403. This makes it possible to determine the presence or absence of damage for each of the plurality of gears included in the transmission 12.

[0079] (Summary of the embodiment) The above embodiments disclose at least the following inspection apparatus and inspection method.

[0080] The inspection device of the embodiment is an inspection device (300) that inspects damage to gears in a transmission (12) that transmits torque generated by a motor (11) installed as a drive source of a vehicle (V), A detection unit (320) that detects an AE signal when the gears are in meshing state; and a processing unit (301) that determines whether or not damage has occurred in the meshing state of the gears based on the AE signal.

[0081] According to the inspection device of configuration 1, it is possible to inspect whether or not damage has occurred in the meshing state of the gears with the motor mounted on a vehicle.

[0082] Configuration 2: The processing unit (301) generates a drive request signal for causing the motor to generate a predetermined torque while the vehicle is stopped, and brings the gear into meshing state.

[0083] According to the inspection device of configuration 2, when the vehicle is stopped, there is no possibility of torque being applied due to driver intervention, so that it is possible to perform the inspection in a stable state while reducing the variation in the inspection conditions.

[0084] Configuration 3: The processing unit (301) updates a target stopping position planned in the automatic driving control of the vehicle so that the vehicle stops at the meshing position of the gear that is the subject of the inspection.

[0085] Configuration 4. The apparatus further includes a storage unit (303) for storing information on the date and time of an examination performed based on the AE signal, The processing unit (301) identifies, from the inspection date and time information, the meshing of the gear that has not been inspected for the longest period since the previous inspection as the target of the inspection.

[0086] Configuration 5. The processing unit (301) identifies, as the target for inspection, the meshing of the gear with the longest uninspected period from among meshing information of a predetermined range acquired based on the meshing position at a target stopping position planned in the automatic driving control of the vehicle.

[0087] When the inspection is performed in a stopped state, the gears (DR, DN) to be inspected may have only a few teeth engaged. Therefore, according to the inspection device of configurations 3 to 5, the stopping position of the vehicle V is controlled in cooperation with the automatic driving control of the vehicle V, and the gear mesh that has not been inspected for the longest period since the last inspection is inspected with priority, making it possible to detect damage to the gears early.

[0088] Configuration 6: The processing unit (301) judges whether or not the damage has occurred based on the waveform of the AE signal.

[0089] Configuration 7. When the vehicle is stopped, the processing unit generates a drive request signal for generating a sine wave torque having a preset period and amplitude as the specified torque, and brings the gears into meshing state.

[0090] According to the inspection devices of configurations 6 and 7, since an AE signal can be generated by minute deterioration that occurs before an object is completely damaged, it is possible to detect the early stage of gear deterioration at an early stage.

[0091] Configuration 8. The storage unit (303) stores the examination number information together with the examination date and time information, When multiple pieces of meshing information are identified as the gear combination with the longest uninspected period, the processing unit identifies the gear meshing that has been inspected the fewest times as the target for inspection based on the number of times information.

[0092] According to the inspection device of configuration 8, even if the subject of the inspection cannot be identified based on the inspection date and time information, it is possible to identify the subject of the inspection by using the inspection date and time information and the number information.

[0093] Configuration 9: The processing unit (301) outputs a notification signal for notifying the occurrence of the damage based on the determination.

[0094] According to the inspection device of configuration 9, it is possible to notify the driver of the early stage of gear deterioration at an early stage.

[0095] The inspection method of the embodiment of the present invention is an inspection method for an inspection device (300) that inspects for damage to a gear in a transmission (12) that transmits torque generated by a motor (11) installed as a drive source of a vehicle (V), comprising: a step of detecting an AE signal when the gears are in mesh with each other by a detection unit (320) of the inspection device (300); The method further comprises a step in which a processing unit (301) of the inspection device (300) judges whether or not damage has occurred in the meshing state of the gears based on the AE signal.

[0096] According to the inspection method of aspect 10, it is possible to inspect whether or not damage has occurred in the meshing state of the gears while the motor is mounted on a vehicle.

[0097] (Other embodiments) The present invention also makes it possible to supply a program that realizes the functions of the above-described embodiments to a system or an inspection device that constitutes the system via a network or a storage medium, and have one or more processors in the computer of the inspection device read the program and execute the processing of the inspection device.

[0098] The invention is not limited to the above-described embodiment, and various modifications and variations are possible within the scope of the gist of the invention. [Explanation of symbols]

[0099] 1: Electronic control unit (vehicle control device), 11: Motor (electric motor), 12: Transmission, 300: Inspection device, 301: Processing unit (signal processing unit), 302: Communication unit, 303: Storage unit, 320: AE sensor (detection unit)

Claims

1. An inspection device for inspecting damage to a gear in a transmission that transmits torque generated by a motor installed as a drive source of a vehicle, comprising: A detection unit that detects an AE signal when the gears are in mesh; a processing unit that determines whether or not damage has occurred in a meshing state of the gears based on the AE signal; An inspection device comprising:

2. 2. The inspection device according to claim 1, wherein the processing unit generates a drive request signal for causing the motor to generate a predetermined torque while the vehicle is stopped, thereby bringing the gear into an engaged state.

3. The inspection device according to claim 1, characterized in that the processing unit updates a target stopping position planned in the automatic driving control of the vehicle so that the vehicle stops at an engagement position of the gear that is the subject of the inspection.

4. A storage unit that stores information on the date and time of an inspection performed based on the AE signal, 2 . The inspection device according to claim 1 , wherein the processing unit is configured to specify, as the target of inspection, the meshing of the gear that has not been inspected for the longest period since the previous inspection, from the inspection date and time information.

5. The inspection device according to claim 4, characterized in that the processing unit identifies, as the target for inspection, the meshing of the gear with the longest uninspected period from among a predetermined range of meshing information acquired based on a meshing position at a target stopping position planned in automatic driving control of the vehicle.

6. 2. The inspection device according to claim 1, wherein the processing unit determines whether or not the damage has occurred based on a waveform of the AE signal.

7. 3. The inspection device according to claim 2, wherein the processing unit generates a drive request signal for generating a sine wave torque having a preset period and amplitude as the predetermined torque while the vehicle is stopped, and brings the gears into meshing state.

8. The storage unit stores information on the number of tests together with the test date and time information, 5. The inspection device according to claim 4, wherein when a plurality of pieces of meshing information are identified as the gear combination with the longest uninspected period, the processing unit identifies the gear meshing with the least number of inspections as the target for inspection based on the number information.

9. The inspection device according to claim 1 , wherein the processing unit outputs a notification signal for notifying the occurrence of the damage based on the determination.

10. An inspection method for an inspection device that inspects for damage to a gear in a transmission that transmits torque generated by a motor installed as a drive source of a vehicle, comprising: a step of detecting an AE signal when the gears are in mesh with each other by a detection unit of the inspection device; a step of determining whether or not damage has occurred in the meshing state of the gears based on the AE signal by a processing unit of the inspection device; An inspection method comprising the steps of:

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