Inspection device and inspection method

Abstract

The invention provides an inspection apparatus and an inspection method, which inspect the presence or absence of damage in a gear meshing state in a state in which a motor is mounted on a vehicle. An inspection device for inspecting damage to gears in a transmission that transmits torque generated by a motor mounted as a drive source of a vehicle is provided with: a detection unit that detects an AE signal when the gears are in an engaged state; and a processing unit that determines, on the basis of the AE signal, the presence or absence of the occurrence of damage in the engaged state of the gear.

Description

Technical Field

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

[0002] Patent document 1 discloses a technology that detects the vibration and rotation angle of the rotating shaft while rotating the rotating shaft to mesh multiple gears, and detects the presence and location of scratches in the gears based on the vibration detection waveform and the rotation angle detection value.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2005-91232 Summary of the invention

[0006] Problems to be solved by the invention

[0007] In an electric vehicle, it is preferred to inspect the meshing state of gears for damage while the motor is mounted on the vehicle. However, since the inspection is performed while the vehicle is running, there is a concern about the stability of the vehicle.

[0008] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an inspection technology capable of inspecting the presence or absence of damage in a meshing state of gears while a motor is mounted on a vehicle.

[0009] Means used to solve problems

[0010] An inspection device according to one embodiment of the present invention inspects damage to a gear in a transmission that transmits torque generated by a motor mounted as a driving source of a vehicle, and is characterized in that:

[0011] The inspection device comprises:

[0012] a detection unit for detecting an AE signal in a meshing state of the gear; and

[0013] A processing unit determines whether damage has occurred in the meshing state of the gear based on the AE signal.

[0014] Another aspect of the present invention is an inspection method for an inspection device for inspecting damage to a gear in a transmission that transmits torque generated by a motor mounted as a driving source of a vehicle, wherein:

[0015] The inspection method comprises the following steps:

[0016] The detection unit of the inspection device detects the AE signal in the meshing state of the gear; and

[0017] The processing unit of the inspection device determines the presence or absence of damage in the meshing state of the gear based on the AE signal.

[0018] Effects of the Invention

[0019] According to the present invention, it is possible to inspect whether damage has occurred in a meshing state of gears while the motor is mounted on a vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a block diagram of a vehicle and a control device thereof according to an embodiment.

[0021] Figure 2 It is a diagram showing a configuration example of a power unit of a vehicle according to an embodiment.

[0022] Figure 3 It is a diagram showing the functional structure of the inspection device according to the embodiment.

[0023] Figure 4 It is a diagram for explaining an example of a signal waveform of an AE sensor.

[0024] Figure 5 It is a diagram for explaining the meshing of gears (DR, DN) by way of example.

[0025] Figure 6 It is a diagram showing an example of the examination date and time information stored in the storage unit.

[0026] Figure 7 This is a diagram for explaining a processing example of controlling the stop position of the vehicle in order to inspect the gear that has not been inspected for the longest period of time.

[0027] Figure 8 It is a diagram for explaining the processing flow in the inspection device and the electronic control unit.

[0028] Fig. 9 Yes Description Figure 8 FIG. 5 is a diagram of the specific processing flow in step S1.

[0029] Description of Reference Numerals

[0030] 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). DETAILED DESCRIPTION

[0031] Hereinafter, the embodiments are described in detail with reference to the accompanying drawings. It should be noted that the following embodiments do not limit the invention involved in the technical solution. In addition, the combination of features described in the embodiments may not all be necessary for the invention. It is also possible to arbitrarily combine two or more of the multiple features described in the embodiments. In addition, the same or identical configurations are marked with the same reference numerals, and repeated descriptions are omitted.

[0032] <Overview of Autonomous Driving Vehicles>

[0033] As an example, the vehicle V (autonomous driving vehicle) of this embodiment is a four-wheeled electric vehicle. Figure 1 In the figure, the outline of the vehicle V is shown by a top view and a side view. The electronic control unit 1 (ECU: Electronic Control Unit) of this embodiment controls the hydraulic device 3, the motor 11, the transmission 12, various sensors 8a, 8b, etc. The electronic control unit 1 is not only composed of a single unit, but can also be composed of a plurality of ECUs such as an ECU for controlling the motor 11 and an ECU for controlling the transmission 12.

[0034] 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 external devices, etc. The storage device stores programs executed by the processor, data used by the processor in processing, etc. The interface includes an input / output interface and a communication interface.

[0035] The electronic control unit 1 controls the driving (acceleration) of the vehicle V by controlling the power unit 2. The power unit 2 is a travel drive unit that outputs a driving force for rotating the driving wheels of the vehicle V, and can include a motor 11 and a transmission 12. The motor 11 can be used as a driving source for accelerating the vehicle V, and can also be used as a generator (regenerative braking) during deceleration, etc.

[0036] The power drive unit (PDU) 5 is a device for performing 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 obtained from the electronic control unit 1. As an automatic driving control of the vehicle V, the electronic control unit 1 can, for example, perform stop control to stop the vehicle V at a target stop position, acceleration and deceleration control to control the acceleration or deceleration of the vehicle V, lane keeping control, and lane change control.

[0037] The electronic control unit 1 controls the output of the motor 11 or switches the gear of the transmission 12 in accordance with the driver's driving operation, the vehicle speed, etc. detected by the operation detection sensor 2a provided on the accelerator pedal AP and the operation detection sensor 2b provided on the brake pedal BP. It should be noted that the motor 11 is provided with a sensor 2c for detecting the rotation angle and the rotation speed of the output shaft of the motor 11 as a sensor for detecting the driving state of the vehicle V. The vehicle speed of the vehicle V can be calculated based on the detection result of the sensor 2c.

[0038] 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 that can control the hydraulic pressure of the working oil supplied to the brake devices 3a (e.g., disc brake devices) provided on the four wheels, based on the hydraulic pressure transmitted from the brake master cylinder BM. The electronic control unit 1 can control the braking of the vehicle V by performing drive control of the solenoid valve and the like provided in the hydraulic device 3, and can perform stop control to stop the vehicle V at a predetermined target position.

[0039] 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 according to the driver's driving operation (steering operation) of the steering wheel ST. The electric power steering device 4 includes a drive unit 4a, a steering angle sensor 4b, a torque sensor 4c for detecting the steering torque borne by the driver, etc. The drive unit 4a includes a motor that exerts a driving force for assisting the steering operation or for automatically steering the front wheels.

[0040] The electronic control unit 1 controls the parking gear 50 and the parking pawl 51 of the transmission 12 and controls the electric parking brake device 3 c provided on the rear wheels, thereby bringing the vehicle V into a stopped state.

[0041] 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 external sensors, namely surrounding detection units 8a~8b, which 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~8b, and perform automatic driving assistance according to the surrounding conditions. The surrounding detection unit 8a is a shooting device (front camera 8a) that shoots the front of the vehicle V. The electronic control unit 1 can extract the outline of the target object and the lane dividing lines (white lines, etc.) on the road by analyzing the image captured by the front camera 8a.

[0042] The surrounding detection unit 8b is a millimeter wave radar (sometimes described as radar 8b), which 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. It should be noted that the surrounding detection unit provided in the vehicle V is not limited to the above-mentioned structure, and an optical radar (LIDAR: Light Detection and Ranging) for detecting targets around the vehicle V may also be provided.

[0043] The electronic control unit 1 identifies / determines the current position and the path (posture) of the vehicle V. In the case of the present embodiment, a gyro sensor 7a, a GNSS (Global Navigation Satellite System) sensor 7b, and a communication device 7c are provided in the vehicle V. 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. In addition, the communication device 7c wirelessly communicates with external devices and inspection devices to send and receive various information. The information obtained from the gyro sensor 7a, the GNSS sensor 7b, and the communication device 7c is stored in a database 7d (storage device). In the case of the present embodiment, the electronic control unit 1 can determine the current position of the vehicle V based on the detection results of the gyro sensor 7a and the GNSS sensor 7b, and control the vehicle V to stop at the vehicle V's route and target position.

[0044] The electronic control unit 1 controls the information output device 6 that reports various information. The information output device 6 includes, for example, an information display device 6a that reports (displays) information to the driver through images and / or a sound output device 6b such as a speaker that reports information to the driver through sound. The information display device 6a may also be an indicator that can be set on a dashboard, for example.

[0045] <Overview of Power Unit>

[0046] like Figure 2 As shown, the power unit of the vehicle V has a housing 14 that accommodates the motor 11, the transmission 12, and the differential gear 13. The housing 14 is composed of a left housing 15, a center housing 16, and a right housing 17 that are divided into three parts in the vehicle width direction. A first housing portion 43 is defined between the left housing 15 and the center housing 16, and a second housing portion 44 is defined between the center housing 16 and the right housing 17.

[0047] The motor 11 disposed in the first housing portion 43 includes a motor shaft 20 supported by the left housing 15 and the center housing 16 via ball bearings 18 and 19, a rotor 21 fixed to the motor shaft 20, and a stator 22 fixed to the center housing 16 so as to surround the outer circumference of the rotor 21. Oil is stored at the bottom of the housing 14.

[0048] The transmission 12 disposed in the second housing portion 44 includes a first reduction gear 23 (first drive gear) fixed to the front end of the motor shaft 20 protruding to the right from the right housing 17. In addition, the transmission 12 includes a reduction shaft 26 supported by the center housing 16 and the right housing 17 via an angular contact roller bearing 24 and an angular contact roller bearing 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. In addition, the transmission 12 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.

[0049] The differential case 30 constituting the outer contour of the differential gear 13 disposed in the second housing portion 44 is supported by the center case 16 and the right case 17 via angular contact roller bearings 31 and 32, respectively. The inner joint 34 provided at the front end of the long left output shaft 33 extending in the left direction from the differential case 30 protrudes outward from the left case 15, and the inner joint 36 provided at the front end of the short right output shaft 35 extending in the right direction from the differential case 30 protrudes outward from the right case 17. The left inner joint 34 is connected to the left rear wheel via the left half shaft not shown, and the right inner joint 36 is connected to the right rear wheel via the right half shaft not shown. The left end of the left output shaft 33, whose right end is supported by the differential gear 13, is supported by the left case 15 via a ball bearing 37. The parking gear 50 is fixed to the right output shaft 35, and the parking pawl 51 is mounted on the right case 17. Concave portions and convex portions are alternately formed along the circumferential direction on the outer peripheral surface of the parking gear 50. The parking pawl 51 has a pawl portion that can engage with the concave portion of the parking gear 50. When parking, the concave portion of the parking gear 50 engages with the pawl portion of the parking pawl 51 mounted on the right housing 17, thereby putting the parking gear 50 in a locked state that cannot rotate.

[0050] <Functional Structure of Inspection Device 300>

[0051] Figure 330 is a diagram showing the functional structure of the inspection device 300 of the present embodiment. The inspection device 300 includes 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 the signal detected by the AE sensor 320. The storage unit 303 is a storage device such as a ROM, RAM, HDD, etc., and in addition to storing the program executed by the processing unit 301, it also stores various control information and historical record information (inspection date and time information) of the signal detected by the AE sensor 320. The communication unit 302 is a communication device for communicating with other external devices, etc. The processing unit 301 communicates with the electronic control unit 1 via the communication unit 302.

[0052] 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 have the same function, they may be configured by an integrated circuit or the like.

[0053] The AE sensor 320 is a sensor for detecting specific vibrations (AE signals). AE is the abbreviation of acoustic emission. The AE sensor 320 detects the vibration (AE signal) emitted as an elastic wave when a part of an object is deformed, damaged, or impacted. The AE signal may be generated due to a slight degradation that occurs before the object is completely damaged, so it is possible to detect the initial stage of degradation of the object. The frequency of the vibration (AE signal) is an elastic wave determined by the type of metal. If the gear has pitting, peeling, or cracking, a sudden waveform in which the waveform of the vibration changes discontinuously and greatly in an instant is generated. 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 a first reduction gear 23 and a second reduction gear 27, and a combination of a final driving gear 28 and a final driven gear 29. The inspection device 300 of this embodiment detects whether the gears (DR, DN) have pitting, peeling, or cracking as defects (damage) of the gears. Here, pitting of gears refers to damage in which fatigue failure of the material occurs and microscopic holes are formed on the tooth surface, and debonding refers to damage in which material falls off the tooth surface. In addition, cracking refers to damage in which cracks occur in the gear or the generated cracks propagate (develop).

[0054] The AE sensor 320 is provided on the side of the housing 14 of the power unit. The signal detected by the AE sensor 320 is input to the inspection device 300, and the processing unit 301 of the inspection device 300 processes the signal detected by the AE sensor 320 to determine whether the gear (DR, DN) is damaged (pitting, peeling, cracking).

[0055] The inspection device 300 applies a torque to the gears (DR, DN), and grasps the state of the gears (DR, DN) based on this load. When grasping the state during driving, since a torque based on the driver's intervention may be applied, there may be a case where the inspection conditions deviate and stable state estimation cannot be performed. Therefore, in order to perform the inspection under stable conditions, in the present embodiment, the inspection device 300 (inspection unit) inspects the gears (DR, DN) when the vehicle V stops. The inspection device 300 detects whether there is damage (pitting, peeling, cracking) in the gears (DR, DN) as a defect (damage) of the gears when the vehicle V stops.

[0056] When performing the inspection in the stopped state, the meshing of the teeth in the gears (DR, DN) to be inspected may be a certain number of teeth. Therefore, the inspection device 300 of the present embodiment provides the following technology: By coordinating with the automatic driving control of the vehicle V, the stop position of the vehicle V is controlled so that the meshing of the gear with the longest uninspected period since the last inspection time point is preferentially inspected, and the damage of the gear can be detected as early as possible.

[0057] If the inspection is not performed for a long time, the possibility of damage (pitting, peeling, cracking) of the gear increases during the uninspected period. Therefore, as the period of time when the inspection has not been performed, the meshing of the gear (DR, DN) with the longest uninspected period is preferentially inspected.

[0058] When the vehicle V stops, the inspection device 300 causes the motor 11 as a drive source to generate a predetermined torque (for example, a sinusoidal waveform torque), and acquires the vibration (AE signal) generated during the meshing of the gears (DR, DN) from the AE sensor 320. When the inspection device 300 receives a signal indicating 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 to the motor 11. The electronic control unit 1 outputs the drive request signal received from the processing unit 301 to the PDU 5, causing the motor 11 to generate a predetermined torque.

[0059] <Example of AE signal waveform>

[0060] Figure 4 It is a diagram illustratively showing the signal waveform of the AE sensor 320. The torque waveform 401 illustrates the waveform of the torque generated by the motor 11 based on the drive request signal. In Figure 4 It shows an example of a sinusoidal waveform torque.

[0061] In addition, the AE waveform 402 illustrates a waveform of vibration (AE signal) detected by the AE sensor 320 when the gears (DR, DN) are meshed based on the application of the torque of the motor 11. The processing unit 301 generates a drive request signal for generating a torque of a sine wave having a preset period and amplitude as a predetermined torque when the vehicle V is stopped, so that the gears are in meshing state.

[0062] The processing unit 301 of the inspection device 300 obtains the detection signal of the AE sensor 320 when the motor 11 generates torque based on the drive request signal. The processing unit 301 determines whether the meshing of the gears (DR, DN) is damaged based on the waveform of the AE signal. The processing unit 301 determines whether the meshing of the gears (DR, DN) to be inspected is damaged. Figure 4 The processing unit 301 detects the burst signal 403 as shown. When the burst signal 403 is detected, the processing unit 301 determines that peeling or cracking has occurred in the meshing of the gears. The processing unit 301 outputs a reporting signal reporting the occurrence of peeling or cracking.

[0063] On the other hand, when the gear does not peel or crack, for example, the AE sensor 320 outputs a high-frequency continuous signal 404. When the AE sensor 320 detects the high-frequency continuous signal 404, the processing unit 301 determines that the gear (DR, DN) does not peel or crack.

[0064] Figure 5 This is a diagram for illustrating the meshing pattern of the gears (DR, DN). In the meshing pattern 501, for simplicity, the meshing combination is illustrated when the number of teeth of the driving side gear DR is set to 3 and the number of teeth of the driven side gear DN is set to 5. There are 15 (=3×5) types of meshing combination patterns.

[0065] In general gear design, in order to suppress wear caused by the same combination of meshing, the gear ratio is designed not to be an integral multiple.

[0066] exist Figure 2 In the meshing of the gears shown in the drive unit, if the number of teeth of the first reduction gear 23 (first drive gear: DR) is set to DR1 and the number of teeth of the second reduction gear 27 (first driven gear: DN) is set to DN1, the ratio (DR1 / DN1) is designed not to become an integer multiple (for example, Figure 5 In addition, if the number of teeth of the final drive gear 28 (second drive gear: DR) is set to DR2 and the number of teeth of the final driven gear 29 (second driven gear: DN) is set to DN2, the ratio (DR2 / DN2) is designed not to become an integer multiple (for example, Figure 5502). The specification values ​​of the gears (DR, DN) are stored in the database 7d (storage device), and the electronic control unit 1 can obtain the meshing information of the gears (DR, DN) by referring to the information in the database 7d during the stop control of the vehicle V.

[0067] <Storage of inspection date and time information>

[0068] The inspection device 300 monitors (inspects) the meshing combination of the gears, and stores the inspection date and time information including the year, month and day when the inspection was performed in the storage unit 303 as the history information of the inspection. The processing unit 301 determines the meshing of the gears with the longest uninspected period from the last inspection time point in the inspection date and time information as the inspection object.

[0069] Figure 6 3 is a diagram showing an example of inspection date and time information stored in the storage unit 303. Here, as an example, a storage example 601 of the inspection date and time information in the meshing between the tooth "1" of the gear DR on the driving side and the teeth "1 to 17" of the gear DN on the driven side is shown. In the storage example 601 of the inspection date and time information, the vertical axis represents the time axis, and the upper end of the storage example 601 represents the time serving as a reference (for example, the current time). The upper end of the bar graph in each meshing represents the inspection date and time information of the last inspection performed using the AE sensor 320. The period between the reference time (current time) and the upper end of the bar graph represents the uninspected period in the meshing of the gears (DR, DN).

[0070] exist Figure 6 In the storage example 601 shown, the combination of tooth "1" of the driving side gear DR and tooth "9" of the driven side gear DN is the meshing of the gears with the longest unchecked period. As shown in the unchecked period 602, the inspection device 300 controls the stop position of the vehicle V in coordination with the automatic driving control of the vehicle V in such a manner that the combination of tooth "1" of the driving side gear DR and tooth "9" of the driven side gear DN can be inspected preferentially.

[0071] <Example of updating the stop position>

[0072] Figure 7 This is a diagram for explaining a processing example of controlling the stop position of the vehicle V so as to give priority to checking the meshing of the gear with the longest unchecked period. For example, it is assumed that the tooth "1" of the gear DR on the driving side is meshed with the tooth "1" of the gear DN on the driven side at the current position. According to this state, when the vehicle travels to the planned stop position (target stop position) according to the driving plan of the automatic driving that serves as the basis, the tooth "8" of the gear DR on the driving side is meshed with the tooth "48" of the gear DN on the driven side.

[0073] The inspection device 300 of this embodiment obtains the inspection date and time information stored in the storage unit 303 for the combination of meshing at the target stop position. Since the meshing of the gears that can be inspected when the vehicle V is stopped is a number of teeth, the inspection date and time information of a predetermined range is obtained based on the combination of meshing (meshing position) at the target stop position, and the meshing combination of the gears with the longest uninspected period is determined. Here, the predetermined range includes, for example, the inspection date and time information of the meshing of a number of teeth before and after the meshing position serving as the reference. Figure 7 In the example 704 of obtaining the inspection date and time information, an example of obtaining the inspection date and time information related to the five previous and next meshings is shown based on the combination of meshings at the target stop position 705. Figure 7 In the acquisition example 704, the processing unit 301 determines the meshing of the tooth "10" of the gear DR on the driving side and the tooth "50" of the gear DN on the driven side as the meshing combination of the gears with the longest uninspected period in the acquired inspection date and time information within the predetermined range. The processing unit 301 updates the target stop position 705 to the stop target position 706 so that the vehicle V stops at the target stop position 705 planned in the automatic driving control of the vehicle V at the meshing position of the gears to be inspected.

[0074] If the meshing combination of the gears with the longest unchecked period is determined, the processing unit 301 sends a request (check request) to check the determined meshing combination to the electronic control unit 1. The processing unit 301 can communicate with the electronic control unit 1 via the communication unit 302, and the processing unit 301 receives a signal of a determination result of permission or non-permission in response to the sent check request via the communication unit 302.

[0075] The electronic control unit 1 determines whether the vehicle V can be stopped by the combination of engagements 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 the 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 combination of engagements determined by the inspection device 300. Figure 7 In the acquisition example 704, the correction amount illustratively represents the numerical value of the change in the relative stop position relative to the target stop position serving as a reference. The unit of the numerical value is a numerical value determined by the specifications of the gear, and may be either meter or centimeter.

[0076] <Processing Flow>

[0077] Reference Figure 8The flowchart of the inspection device 300 and the processing flow in the electronic control unit 1 is described. In S1, the processing unit 301 of the inspection device 300 obtains from the electronic control unit 1 the target stop position (target stop position: for example, Figure 7 The meshing information of the gears (DR, DN) in the case of 705) is obtained. Here, the meshing information includes not only the meshing position of the gears (DR, DN) but also the meshing range of the front and rear teeth based on the meshing position. The processing unit 301 determines the meshing position of the inspection object based on the acquired meshing information, and determines the stop target position for inspection based on the meshing information (for example, Figure 7 Then, the processing unit 301 sends a stop position request (check request) for stopping the vehicle V at the determined stop target position 706 to the electronic control unit 1 .

[0078] In S2, the electronic control unit 1 determines whether the vehicle V can be allowed to stop or not to stop based on the stop position request (check request) in which the target stop position is updated. The electronic control unit 1 determines to allow the stop position request (check request) if it can be allowed, or to not allow the stop position request (check request) if it cannot be allowed, based on the detection information around the vehicle V.

[0079] The electronic control unit 1 sends the determination result to the processing unit 301. The processing unit 301 can determine whether the vehicle V stops at the target stop position before update or at the target stop position after update based on the received signal of the determination result of permission or non-permission.

[0080] In S3, the electronic control unit 1 generates a control signal for controlling the motor 11 and outputs the control signal to the PDU 5. The PDU 5 performs rotation control and stop control of the motor 11 based on the control signal received from the electronic control unit 1.

[0081] If the result of the determination is not allowed, the electronic control unit 1 generates a control signal for controlling the motor 11 to stop at the target stop position before the update. In addition, if the result of the determination is allowed, the electronic control unit 1 generates a control signal for controlling the motor 11 to stop at the updated stop target 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 stop state of the motor 11 to the electronic control unit 1.

[0082] The electronic control unit 1 determines whether the motor 11 has stopped based on the presence or absence of the stop signal output from the PDU 5, and if the motor 11 has not stopped (S4-No), the monitoring of the stop determination of the motor 11 is continued. On the other hand, in the determination of S, if the motor 11 has stopped (S4-Yes), a signal notifying the completion of the stop is sent to the inspection device 300.

[0083] In S5, if the inspection device 300 receives a notification signal of stop completion 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. When the vehicle V is stopped, the processing unit 301 generates a drive request signal for generating a predetermined torque in the motor 11, so that the gears are in meshing state. When the vehicle V is stopped, the processing unit 301 generates a drive request signal for generating a torque of a sine wave having a preset period and amplitude as a predetermined torque, so that the gears are in meshing state. The processing unit 301 outputs the generated drive request signal to the electronic control unit 1.

[0084] 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, Figure 4 The torque is as shown in the torque waveform 401.

[0085] In S7 , the gears (DR, DN) of the transmission 12 are brought into meshing state by the generation of torque by the motor 11 .

[0086] In S8 , the processing unit 301 of the inspection device 300 acquires a signal (AE signal) from the AE sensor 320 when the 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 .

[0087] The processing unit 301 can determine whether the vehicle V stops at the target stop position before the update or at the target stop position after the update based on the signal of the determination result of permission or non-permission obtained from the electronic control unit 1. The processing unit 301 updates the inspection date and time information based on the engagement information corresponding to the determined stop position. For example, Figure 7 When the vehicle stops at the target stop position 705, the processing unit 301 updates the inspection date and time information in the meshing information of DR8-DN48. In addition, when the vehicle 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.

[0088] It should be noted that even if cracks occur in the gears during driving, by applying a predetermined torque to the gears during inspection of the stopped state, an AE signal is generated when the cracks develop (expand), so that the processing unit 301 can detect the occurrence of cracks.

[0089] In S9, the processing unit 301 determines whether a friction occurs in the meshing of the gears (DR, DN) to be inspected. Figure 4 The burst signal 403 ( Figure 4 When no burst signal is detected (S9-No), a high-frequency continuous signal 404 is detected ( Figure 4 ), the processing unit 301 determines it as normal (S12) and ends the processing.

[0090] On the other hand, when the burst signal 403 is detected in the determination of S9 (S9-Yes), the processing unit 301 determines that peeling or cracking has occurred in the meshing of the gears (DR, DN) to be inspected (S10: abnormality determination).

[0091] In S11 , the processing unit 301 outputs a notification signal for notifying the occurrence of peeling or cracking to the electronic control unit 1 .

[0092] When receiving the notification signal, the electronic control unit 1 may generate a notification sound from the sound output device 6b such as a speaker. Alternatively, the electronic control unit 1 may light up the display of the information display device 6a such as an indicator.

[0093] <Specific Example of Processing in Step S1>

[0094] Reference Fig. 9 Flowchart of Figure 8 In step S21, the electronic control unit 1 obtains information on the target stop position in the automatic driving control (for example, Figure 7 In the target stop position information, a predetermined allowable range may be set by taking into account various factors in the automatic driving control, such as changes in information around the traveling vehicle V.

[0095] 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.

[0096] In S23, the electronic control unit 1 calculates the rotation speed 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 rotation speed of the wheel by distance / (2×wheel radius×π).

[0097] It should be noted that the wheel diameter (tire diameter: 2×wheel radius) can be a fixed value, or the wheel diameter (tire diameter) can be corrected based on the wear amount of the wheel diameter (tire diameter) taking into account the driving history and driving distance in autonomous driving. The information on the wheel diameter, driving history, and wear amount of the wheel diameter (tire diameter) taking into account the 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 wheel rotation speed. Alternatively, the electronic control unit 1 refers to the information in database 7d, corrects the wheel diameter (tire diameter), and calculates the wheel rotation speed.

[0098] In S24, the electronic control unit 1 calculates the meshing position (range) of the teeth when the vehicle reaches the target stop position based on the calculated rotation speed and the current meshing position of the teeth (combined meshing position). The meshing position of the teeth to be calculated is not limited to one meshing position, and for example, the range of the front and rear teeth can be obtained 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 expected meshing position (range) in the automatic driving control.

[0099] Next, in S25, the processing unit 301 of the inspection device 300 reads a predetermined range ( Figure 7 )’s inspection date and time information.

[0100] In S26, the processing unit 301 specifies the meshing combination (meshing position) of the gears with the longest uninspected period among the inspection date and time information within the predetermined range (for example, Figure 7 706).

[0101] Then, in S27 , the processing unit 301 determines the stop target position 706 based on the determined combination of meshing of the gears.

[0102] The processing unit 301 updates the target stop position so that the vehicle V stops at the meshing position of the gear of the inspection object at the target stop position planned in the automatic driving control of the vehicle V. The processing unit 301, for example, Figure 7 As shown in 706, the meshing combination of the gears with the longest unchecked period (DR10-DN50) is determined, and the stop position of the vehicle V based on the meshing combination is determined as the stop target position 706. The determined stop target position 706 is the stop position of the target stop position 705 in the automatic driving control updated.

[0103] As before Figure 8As described in S1 of FIG. 7 , the processing unit 301 transmits a stop position request (check request) for stopping the vehicle V at the determined stop target position 706 to the electronic control unit 1 .

[0104] (Variation Example)

[0105] In addition, in the above-mentioned embodiment, an example of storing inspection date and time information in the storage unit 303 is described, but the information stored in the storage unit 303 is not limited to the inspection date and time information, and the number of inspections (number of evaluations) in each meshing combination may also be stored together with the inspection date and time information.

[0106] The processing unit 301 may also determine the meshing of the gear with the least number of inspections as the inspection object based on the number information when a plurality of meshing information is determined as the combination of gears with the longest uninspected period. For example, when a plurality of meshing information (D1, D2, D3) is determined as the combination of gears with the longest uninspected period, the inspection device 300 may also refer to the number of inspection information (evaluation number) of the storage unit 303 and give priority to inspecting the combination with the least number of inspections (e.g., D1) among the plurality of meshing information (D1, D2, D3).

[0107] Furthermore, in the above-described embodiment, a configuration example in which the inspection is performed when the vehicle V is stopped is described. However, the AE signal may be acquired while the vehicle V is traveling so that a plurality of gears can be inspected a plurality of times.

[0108] In addition, the number of AE sensors 320 is not limited to one, and the inspection can be performed using information from a plurality of AE sensors 320. For example, by presetting the time difference information until the processing unit 301 acquires the signal from each AE sensor 320 for each AE sensor 320, it is possible to determine which AE sensor 320 has detected the burst signal 403. Thus, for a plurality of gears included in the transmission 12, it is possible to determine whether there is damage on a gear-by-gear basis.

[0109] (Summary of Implementation Methods)

[0110] The above-mentioned embodiments disclose at least the following inspection apparatus and inspection method.

[0111] Structure 1. An inspection device according to an embodiment is an inspection device (300) for inspecting damage to a gear in a transmission (12) that transmits torque generated by a motor (11) mounted as a driving source of a vehicle (V), and is characterized in that:

[0112] The inspection device comprises:

[0113] a detection unit (320) for detecting an AE signal in a meshing state of the gears; and

[0114] A processing unit (301) determines the occurrence of damage in the meshing state of the gear based on the AE signal.

[0115] According to the inspection device of configuration 1, it is possible to inspect whether damage has occurred in the meshing state of the gears while the motor is mounted on the vehicle.

[0116] Configuration 2: When the vehicle is stopped, the processing unit (301) generates a drive request signal for causing the motor to generate a predetermined torque, thereby causing the gear to be in meshing state.

[0117] According to the inspection device of Configuration 2, since there is no possibility of torque application due to driver intervention when the vehicle is stopped, it is possible to perform inspection in a stable state while reducing variations in inspection conditions.

[0118] Configuration 3. The processing unit (301) updates a target stop position planned in the automatic driving control of the vehicle so that the vehicle stops at the meshing position of the gear of the object to be inspected.

[0119] Configuration 4. The inspection device further comprises a storage unit (303) for storing information on the date and time of inspections performed based on the AE signal.

[0120] The processing unit (301) specifies the meshing of the gears having the longest non-inspection period from the last inspection time point in the inspection date and time information as the object of the inspection.

[0121] Structure 5. The processing unit (301) determines the meshing of the gear with the longest uninspected period as the object of inspection among the meshing information within a predetermined range obtained based on the meshing position at the target stop position planned in the automatic driving control of the vehicle.

[0122] When the inspection is performed in a stopped state, the meshing of the teeth in the gear (DR, DN) to be inspected can be an amount corresponding to the number of teeth. Therefore, according to the inspection device of structures 3 to 5, the stop position of the vehicle V can be controlled by coordinating with the automatic driving control of the vehicle V, and the meshing of the gear that has not been inspected for the longest period since the last inspection time point is prioritized for inspection, thereby detecting gear damage as early as possible.

[0123] Configuration 6. The processing unit (301) determines whether the damage has occurred based on the waveform of the AE signal.

[0124] Configuration 7. The processing unit generates a drive request signal for generating a torque of a sine wave having a preset period and amplitude as the predetermined torque when the vehicle is stopped, so as to bring the gear into a meshing state.

[0125] According to the inspection device of the sixth and seventh structures, since the AE signal can be generated by the minute degradation that occurs before the object is completely damaged, the initial stage of the gear degradation can be detected at an early stage.

[0126] Configuration 8. The storage unit (303) stores the number of inspections and the inspection date and time information together.

[0127] When the processing unit specifies a plurality of meshing information as a combination of the gears having the longest uninspected period, the processing unit specifies the meshing of the gear having the least number of inspections as the object of inspection based on the number of times information.

[0128] According to the inspection device of Configuration 8, even when the inspection object cannot be identified based on the inspection date and time information, the inspection object can be identified using the inspection date and time information and the frequency information.

[0129] Configuration 9. The processing unit (301) outputs a reporting signal reporting the occurrence of the damage based on the determination.

[0130] According to the inspection device of configuration 9, the initial stage of gear deterioration can be reported to the driver as early as possible.

[0131] Structure 10. An inspection method of an embodiment is an inspection method of an inspection device (300) for inspecting damage to a gear in a transmission (12) that transmits torque generated by a motor (11) mounted as a driving source of a vehicle (V), characterized in that:

[0132] The inspection method comprises the following steps:

[0133] The detection unit (320) of the inspection device (300) detects the AE signal in the meshing state of the gear; and

[0134] The processing unit (301) of the inspection device (300) determines the presence or absence of damage in the meshing state of the gear based on the AE signal.

[0135] According to the inspection method of configuration 10 , it is possible to inspect whether damage has occurred in the meshing state of the gears while the motor is mounted on the vehicle.

[0136] (Other embodiments)

[0137] The present invention can be realized by supplying a program realizing the functions of the above-described embodiments to a system or an inspection device constituting the system via a network or a storage medium, and by enabling one or more processors in a computer of the inspection device to read and execute the processing of the inspection device.

[0138] The present invention is not limited to the above-described embodiments, and various modifications and changes can be made within the scope of the gist of the present invention.

Claims

1. An inspection device for inspecting damage to a gear in a transmission that transmits torque generated by a motor mounted as a driving source of a vehicle, characterized in that: The inspection device comprises: a detection unit for detecting an AE signal in a meshing state of the gear; and A processing unit determines whether damage has occurred in the meshing state of the gear based on the AE signal.

2. The inspection device according to claim 1, characterized in that: The processing unit generates a drive request signal for causing the motor to generate a predetermined torque and causes the gear to be in a meshing state when the vehicle is stopped.

3. The inspection device according to claim 1, characterized in that: The processing unit updates a target stop position planned in the automatic driving control of the vehicle so that the vehicle stops at a meshing position of the gear of the inspection object.

4. The inspection device according to claim 1, characterized in that: The inspection device further includes a storage unit that stores information on the date and time of the inspection based on the AE signal. The processing unit specifies, as the object of the inspection, the meshing of the gears having the longest non-inspection period from the last inspection time point in the inspection date and time information.

5. The inspection device according to claim 4, characterized in that: The processing unit determines, as the inspection target, the meshing of the gear having the longest uninspected period among the meshing information within a predetermined range acquired based on the meshing position at the target stop position planned in the automatic driving control of the vehicle.

6. The inspection device according to claim 1, characterized in that: The processing unit determines the presence or absence of the damage based on the waveform of the AE signal.

7. The inspection device according to claim 2, characterized in that: The processing unit generates a drive request signal for generating a sine wave torque having a preset period and amplitude as the predetermined torque when the vehicle is stopped, thereby bringing the gear into a meshing state.

8. The inspection device according to claim 4, characterized in that: The storage unit stores the number of inspections and the inspection date and time information together. When the processing unit specifies a plurality of meshing information as a combination of the gears having the longest uninspected period, the processing unit specifies the meshing of the gear having the least number of inspections as the object of inspection based on the number of times information.

9. The inspection device according to claim 1, characterized in that: The processing unit outputs a reporting signal reporting the occurrence of the damage based on the determination.

10. An inspection method for an inspection device for inspecting damage of a gear in a transmission that transmits torque generated by a motor mounted as a driving source of a vehicle, characterized in that: The inspection method comprises the following steps: The detection unit of the inspection device detects the AE signal in the meshing state of the gear; and The processing unit of the inspection device determines the presence or absence of damage in the meshing state of the gear based on the AE signal.

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