Vehicle control system

Abstract

A vehicle control system (1) for controlling the driving of a vehicle (99) is provided with a drive source (15), clutches (31, 32), a clutch actuator (35), and a control unit (50). The clutches (31, 32) are provided in a power transmission path from the drive source (15) to the drive wheels (11), and can switch between disconnection and connection of power transmission. A clutch actuator (35) drives the clutches (31, 32). Between the clutches (31, 32) and the drive wheel (11), at least one portion is provided with a portion that meshes obliquely with respect to the rotational direction. The control unit (50) controls the clutch actuator (35) so as to generate a load greater than the load required for engagement of the clutches (31, 32) when the clutches (31, 32) are switched from the released state to the engaged state and a transient torque input in which the driving force from the drive source (15) is input.

Description

[0001] Cross-references of related applications

[0002] This application is based on Japanese Patent Application No. 2022-149132 filed on September 20, 2022, and the contents thereof are cited herein. Technical Field

[0003] The present disclosure relates to vehicle control systems. Background Art

[0004] Conventionally, there are known control devices for controlling the driving of a vehicle. For example, in Patent Document 1, a dog clutch is provided between a second rotating machine, which is a driving source, and a reduction gear as a controllable power disconnection and connection device.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2015-123897 Summary of the invention

[0008] In Patent Document 1, the abnormal position is determined based on the rotation signal when the dog clutch is connected and disconnected. Patent Document 1 does not mention abnormality detection and clutch control other than abnormality detection. The purpose of the present disclosure is to provide a vehicle control system that can appropriately control vehicle driving.

[0009] The vehicle drive system disclosed herein controls the driving of the vehicle and includes a driving source, a clutch, a clutch actuator, and a control unit. The clutch is provided in a power transmission path from the driving source to the driving wheel and can switch the disconnection of the power transmission. The clutch actuator drives the clutch. The control unit controls the driving of the driving source and the clutch actuator.

[0010] In the first embodiment, a portion meshing obliquely with respect to the rotation direction is provided at least at one location between the clutch and the drive wheel. When the clutch is switched from a released state to an engaged state and a transient torque input of a driving force from a driving source is input, the control unit controls the clutch actuator in such a manner that a load greater than a load required for the engagement of the clutch is generated.

[0011] In the second mode, the control unit releases the clutch when the torque variation frequency of the driving source is in the resonance region of the driving shaft connected to the driving wheel. In the third mode, the control unit determines whether the vehicle has climbed a step, and releases the clutch when it is determined that the vehicle has climbed a step. In the fourth mode, the clutch is released when the driving wheel is not rotating, and the driving source is driven to perform abnormality diagnosis. In this way, the driving of the vehicle can be appropriately controlled by controlling the clutch. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The above-mentioned object and other objects, features and advantages of the present disclosure will become more apparent through the following detailed description with reference to the accompanying drawings. The accompanying drawings are as follows:

[0013] Figure 1 is a schematic diagram showing a vehicle control system according to a first embodiment,

[0014] Figure 2 1 is a schematic diagram showing a clutch and a speed reducer according to a first embodiment.

[0015] Figure 3 is a schematic diagram showing a clutch according to a first embodiment,

[0016] Figure 4 2 is a diagram for explaining the gap reduction in the first embodiment.

[0017] Figure 5A is a diagram showing the relationship between the gear rotation angle and the output torque when the clearance is not reduced.

[0018] Figure 5B is a diagram showing the relationship between the gear rotation angle and the output torque when the clearance is reduced.

[0019] Figure 6 is a flowchart illustrating clutch control according to the first embodiment.

[0020] Figure 7 is a schematic diagram showing a fitting portion of a drive shaft according to a second embodiment.

[0021] Fig. 8A 2 is a schematic diagram showing a clutch and a speed reducer according to a third embodiment.

[0022] Figure 8B is a schematic diagram showing the meshing teeth of the clutch.

[0023] Fig. 9 This is a schematic diagram showing the case where the reducer is a spur gear.

[0024] Fig.10 This is a flowchart illustrating clutch control according to the fourth embodiment.

[0025] Fig.11 is a timing chart for explaining clutch control according to the fourth embodiment.

[0026] Fig. 12A This is a schematic diagram showing the state of a vehicle climbing up a step.

[0027] Fig. 12B This is a schematic diagram showing the state of a vehicle after climbing over the steps.

[0028] Fig.13 is a flowchart illustrating clutch control according to the fifth embodiment.

[0029] Fig.14 is a timing chart for explaining clutch control according to the fifth embodiment.

[0030] Fig.15 This is a flowchart for explaining the operation confirmation process according to the sixth embodiment. DETAILED DESCRIPTION

[0031] Hereinafter, the vehicle control system of the present disclosure will be described based on the drawings. In the following, in a plurality of embodiments, substantially the same configurations are denoted by the same reference numerals and description thereof will be omitted.

[0032] exist Figure 1 to Figure 6 A first embodiment is shown in FIG. Figure 1 As shown, the vehicle control device 30 is applied to the vehicle control system 1. The vehicle control system 1 includes a front wheel drive unit 10, a rear wheel drive unit 20, a clutch 31, a clutch actuator 35, a control unit 50, and the like.

[0033] The front wheel drive unit 10 includes a drive shaft 12 connected to the front wheel 11, a main motor 15, a power transmission unit 18, etc. The rear wheel drive unit 20 includes a drive shaft 22 connected to the rear wheel 21, a main motor 25, a power transmission unit 28, etc. The vehicle control system 1 of the present embodiment is a so-called four-wheel drive system in which main motors 15 and 25 as drive sources are provided on the front wheel side and the rear wheel side, respectively.

[0034] The main motors 15 and 25 are so-called electric generators that have the function of an electric motor that generates torque by being supplied with electric power from a battery (not shown) and the function of a generator that is driven to generate electric power when the vehicle 99 is braked. The driving force of the main motor 15 is transmitted to the drive shaft 12 via the power transmission unit 18, so that the front wheel 11 is rotationally driven. The driving force of the main motor 25 is transmitted to the drive shaft 22 via the power transmission unit 28, so that the rear wheel 21 is rotationally driven. The power transmission units 18 and 28 include a speed reducer and a differential device that absorbs the left and right rotation difference. Hereinafter, the front wheel drive unit 10 and the rear wheel drive unit 20 are appropriately referred to as a "drive system", and the main motor is referred to as "MG".

[0035] The clutch 31 is provided in the front wheel drive unit 10, and can switch the disconnection and connection between the main engine motor 15 and the front wheel 11. The clutch 31 can be provided at any position of the power transmission path between the main engine motor 15 and the front wheel 11. In the present embodiment, the clutch 31 is provided at the reduction gear 41 (see Figure 2 In addition, Figure 1In FIG. 1 , for simplicity, the clutch 31 is shown to be provided on the drive shaft 12. The clutch actuator 35 switches the clutch 31 between the engaged state and the released state by applying a load to the clutch 31.

[0036] like Figure 2 and Figure 3 As shown, the clutch 31 of this embodiment is a dog clutch (engagement clutch), and has bases 311, 313 and meshing teeth 312, 314. In this embodiment, the meshing teeth 312, 314 are formed substantially perpendicular to the rotation direction. In addition, the clutch 31 is not limited to the dog clutch, and may also be a multi-plate or single-plate friction clutch.

[0037] return Figure 1 The control unit 50 is mainly composed of a microcomputer, etc., and has a CPU, ROM, RAM, I / O, and a bus connecting these components, all of which are not shown in the figure. Each process in the control unit 50 can be a software process performed by the CPU executing a program pre-stored in a physical memory device such as a ROM (i.e., a readable non-temporary tangible recording medium), or a hardware process based on a dedicated electronic circuit.

[0038] The control unit 50 obtains detection values ​​of current sensors 61 and 63 for detecting the current of the main motors 15 and 25, rotation angle sensors 62 and 64 for detecting the rotation of the main motors 15 and 25, a wheel speed sensor 65, and an accelerator opening sensor (not shown) for detecting the pedal opening of the accelerator pedal 40, and controls the driving of the main motors 15 and 25 and the clutch actuator 35. Figure 1 In the figure, the control unit 50 is described as one, but the functions may be divided into a plurality of ECUs, etc. In addition, in order to avoid complexity, some control lines are omitted.

[0039] However, in a mechanism that transmits power via gears, impact is generated due to collision between gears. Here, for example, by providing chamfers and spring mechanisms on the teeth of a dog clutch, the engagement impact can also be reduced by hardware. However, in a structure that reduces the engagement impact by hardware, the number of components increases.

[0040] like Figure 2 to Figure 4 As shown in FIG. 1 , in this embodiment, the clutch 31 is provided between the main engine motor 15 and the reduction gear 41. In addition, the reduction gear 41 is composed of a helical gear. Figure 4 As shown by the arrow A1, when the reduction gear 41 is pressed in the thrust direction, the helical gears rotate as shown by the arrow A2, and the play between the gears is reduced. Hereinafter, the total of the play provided in the power transmission part 18 and the like is referred to as "clearance".

[0041] Therefore, in this embodiment, when the transition torque is input, the clutch 31 is used to press the reduction gear 41 in the thrust direction, thereby rotating the helical gear. As a result, the gaps in the thrust direction and the rotation direction can be tightened. In addition, as shown by arrow A3, the torque of the main engine motor 15 is input from the state where the gap is tightened, thereby suppressing the gap hitting sound.

[0042] exist Figure 5A and Figure 5B In FIG. 4 , the horizontal axis represents the gear rotation angle on the input side of the reduction gear 41, and the vertical axis represents the torque output from the reduction gear 41. Figure 5A As shown in FIG. 1 , when the clearance is not reduced on the output side of the reduction gear 41, even if the input side rotates, the MG torque Tmg is transmitted to the output side, and a clearance hit sound is generated when the clearance is reduced. The intensity of the clearance hit sound is roughly proportional to the clearance amount. Figure 5B As shown, if the backlash is reduced on the output side of the reduction gear 41, backlash hitting sound is not generated, and torque is transmitted to the output shaft immediately after the main engine motor 15 is driven.

[0043] based on Figure 6 The clutch control of the present embodiment is described with reference to the flowchart of FIG. This process is performed by the control unit 50 at a predetermined cycle. Hereinafter, the "steps" such as step S101 are omitted and simply referred to as "S".

[0044] In S101, the control unit 50 determines whether it is a transition torque input. Here, when the vehicle starts, that is, when the main engine motor 15 is driven from a vehicle speed of 0 to generate MG torque, when switching from inertial driving to drive driving (acceleration), and when switching from regeneration to drive driving (acceleration), it is considered that the transition torque is input and a positive judgment is made. In the case where it is judged that it is not a transition torque input (S101: No), the processing after S102 is skipped. In the case where the clutch 31 is engaged other than when the transition torque is input, the drive of the clutch actuator 35 is controlled by a processing different from this processing to engage the clutch 31. In the case where it is judged that it is a transition torque input (S101: Yes), move to S102.

[0045] In S102, the control unit 50 drives the clutch actuator 35 to engage the clutch 31. In S103, the control unit 50 determines whether the engagement of the clutch 31 is completed. If it is determined that the engagement of the clutch 31 is not completed (S103: No), the control unit 50 returns to S102 and continues to drive the clutch actuator 35. If it is determined that the engagement of the clutch 31 is completed (S103: Yes), the control unit 50 moves to S104.

[0046] In S104, the control unit 50 controls the clutch actuator 35 to apply a pressing force in the thrust direction. As a result, the gap in the thrust direction is tightened, and the reduction gear 41 with helical teeth rotates, thereby tightening the gap in the rotation direction (see Figure 4 ).

[0047] In S105, the control unit 50 determines whether the gap reduction is completed. If it is determined that the gap reduction is not completed (S105: No), the process returns to S104 and continues the pressing control in the thrust direction. If it is determined that the gap reduction is completed (S105: Yes), the process moves to S106.

[0048] In S106, the control unit 50 releases the pressing force in the thrust direction and controls the driving of the clutch actuator 35 so as to achieve a pressing force capable of maintaining the engaged state of the clutch 31. In addition, when a locking mechanism (not shown) for maintaining the engaged state of the clutch 31 is provided, the locking mechanism may be operated to disconnect the power supply to the clutch actuator 35.

[0049] In S107, the control unit 50 drives the main engine motor 15 to generate torque. At this time, since the gap on the output side is already tightened, the generation of gap impact sound is suppressed. In addition, the processing order of S106 and S107 can also be reversed, and the pressing force in the thrust direction is released after the driving of the main engine motor 15 starts.

[0050] In this embodiment, when the transition torque is input, a pressing force is generated in the thrust direction from the state where the clutch 31 is engaged. Here, when the reduction gear 41 has a helical gear, the pressing force in the thrust direction is converted into the rotation direction, so that the gaps in the thrust direction and the rotation direction can be tightened. By tightening the gap before the torque is generated in the main engine motor 15, the generation of the gap hitting sound can be suppressed.

[0051] As described above, the vehicle control system 1 of the present embodiment controls the driving of the vehicle 99, and includes the main engine motor 15, the clutch 31, the clutch actuator 35, and the control unit 50. The clutch 31 is provided in the power transmission path from the main engine motor 15 to the front wheel 11, and can switch the disconnection and connection of the power transmission. The clutch actuator 35 drives the clutch 31. The control unit 50 controls the driving of the main engine motor 15 and the clutch actuator 35.

[0052] At least one portion is provided on the power transmission path, which meshes obliquely with respect to the rotation direction. In the present embodiment, the reduction gear 41 has a helical gear, which meshes obliquely with respect to the rotation direction. The control unit 50 switches the clutch 31 from the released state to the engaged state, and controls the clutch actuator 35 in a manner that generates a load greater than the load required for the engagement of the clutch 31 when a transient torque input of the driving force from the main engine motor 15 is input.

[0053] Thus, by controlling the clutch 31, the driving of the vehicle 99 can be properly controlled. Specifically, in the present embodiment, if a load greater than the load required for engagement is generated when a transition torque is input, and the clutch 31 is pressed in the thrust direction, the force in the thrust direction is converted to the rotation direction at the obliquely engaged portion. Thus, the gaps in the thrust direction and the rotation direction can be tightened. In addition, after the gap is tightened, it returns to the normal engagement state. Thus, the gap impact sound generated when the transition torque is input can be suppressed.

[0054] (Second embodiment, third embodiment)

[0055] Figure 7 Indicates the second embodiment, Fig. 8A and Figure 8B 3. In the second embodiment, the engaging portion 121 between the clutch 31 and the drive shaft 12 is formed with an oblique groove d. Figure 7 , the drive shaft 12 side is described, and the description of the fitting portion on the clutch 31 side is omitted.

[0056] In a third embodiment, if Fig. 8A As shown, the clutch 32 has bases 321, 323 and meshing teeth 322, 324. Figure 8B As shown, the meshing teeth 322 , 324 are formed obliquely with respect to the rotation direction.

[0057] As in the second and third embodiments, by forming a portion that meshes obliquely with respect to the rotational direction on the power transmission path from the clutch to the reduction gear, the force in the thrust direction of the clutch actuator 35 can be converted into the rotational direction. Thus, by performing control similar to the first embodiment when transient torque is input, the gap can be narrowed, and the gap hitting sound when the torque of the main engine motor 15 is input can be suppressed.

[0058] In addition, when a structure that meshes obliquely is provided at a portion other than the reduction gear as in the second embodiment or the third embodiment, Fig. 9 As shown, even if the reduction gear 42 is a spur gear, the same backlash reduction as in the first embodiment can be performed. This configuration also produces the same effects as in the above embodiment.

[0059] (Fourth Embodiment)

[0060] exist Fig.10 and Fig.11 A fourth embodiment is shown in FIG. During the running of the vehicle 99, if the variation period of the cogging torque and the torque ripple of the main motor 15 reaches a rotation speed equivalent to the resonance frequency of the drive system, resonance occurs. Therefore, in this embodiment, when the torque variation frequency of the main motor 15 is in the resonance region of the drive system, the clutch 31 is released and the vehicle is driven by the driving force of the rear wheel drive unit 20. In other words, when the torque variation frequency of the main motor 15 is in the resonance region of the drive system, the vehicle is switched from four-wheel drive to two-wheel drive.

[0061] based on Fig.10 The flowchart of the clutch control of this embodiment is described. In S201, the control unit 50 determines whether there is an engagement instruction of the clutch 31. Determine whether there is an engagement instruction of the clutch 31. In the case where it is determined that there is no engagement instruction of the clutch 31 (S201: No), skip the processing after S202. In the case where it is determined that there is an engagement instruction of the clutch 31 (S201: Yes), move to S202.

[0062] In S202, the control unit 50 calculates the torque variation frequency based on the torque ripple and the cogging torque based on the number of poles of the main motor 15 and the MG rotation speed Nmg, etc. In addition, a plurality of torque variation frequencies may be calculated in the case of the variation frequency based on the torque ripple and the variation frequency based on the cogging torque.

[0063] In S203, it is determined whether the calculated torque change frequency is equivalent to the resonant frequency of the drive system. Here, when the torque change frequency is within the specified range including the resonant frequency, a positive determination is made. In the following, the specified range including the resonant frequency is appropriately set as the "resonance region". When it is determined that the torque change frequency is equivalent to the resonant frequency of the drive system (S203: Yes), move to S204. When it is determined that the torque change frequency is not equivalent to the resonant frequency of the drive system (S203: No), move to S205.

[0064] In S204, the control unit 50 releases the clutch 31 and sets the two-wheel drive by the rear-wheel drive unit 20. In S205, the control unit 50 engages the clutch 31 and sets the four-wheel drive.

[0065] based on Fig.11 The clutch control of this embodiment is described in detail with reference to the timing chart. Fig.11In the figure, the common time axis is set as the horizontal axis, and the vehicle speed, MG speed, clutch stroke, and drive torque are set from the upper section. Here, the speed of the main motor 15 on the front wheel side is set to Nmg_f, the drive torque is set to Td_f and recorded with a solid line, and the speed of the main motor 25 on the rear wheel side is set to Nmg_r, the drive torque is set to Td_r and recorded with a single-point chain line. In addition, in this specification, the operation of the front wheel side provided with the clutch 31 is mainly described, and the suffixes _f and _r are omitted except when it is necessary to distinguish it from the rear wheel side. Fig.11 , the case where the front-rear wheel distribution ratio of the driving torque in the four-wheel drive is 1:1 is described, but the front-rear wheel distribution ratio may be a ratio different from 1:1.

[0066] Before time x10, the MG speed Nmg is lower than the speed range (hereinafter referred to as the "resonance range") corresponding to the resonance range of the front wheel drive unit 10 in which the torque variation frequency is lower than the clutch 31, and the MG speed Nmg is set to a speed corresponding to the vehicle speed. At this time, the total torque Td_t is distributed to the main motors 15 and 25.

[0067] At time x10, when the MG rotation speed Nmg_f corresponding to the vehicle speed reaches the resonance region, the clutch 31 is released to make the rotation speed of the main motor 15 0. That is, since the driving torque Td_f on the front side is 0, the main motor 25 is controlled in such a way that the total torque Td_t is output on the rear wheel side. During the period from time x10 to time x11 when the torque variation frequency reaches the resonance region when the main motor 15 is driven, the clutch 31 is released, thereby suppressing the resonance in the front wheel drive unit 10, so that even if vibration occurs on the rear wheel drive unit 20 side, the total vibration amount can be reduced. In addition, if the resonance frequency characteristics are different between the front wheel drive unit 10 and the rear wheel drive unit 20, the resonance region of the rear wheel drive unit 20 is different from the resonance region of the front wheel drive unit 10.

[0068] At time x11, if the MG speed Nmg corresponding to the vehicle speed exceeds the resonance region, the clutch 31 is engaged to drive the main motor 15. In addition, at time x11, the transition torque is input, so the control of the first embodiment can also be performed. After time x11, the total torque Td_t is distributed to the main motors 15 and 25.

[0069] Thus, by controlling the clutch 31, the driving of the vehicle 99 can be appropriately controlled. Specifically, in this embodiment, when the torque fluctuation frequency of the main motor 15 is in the resonance region of the drive shaft 12 connected to the front wheel 11, the control unit 50 releases the clutch 31. Thus, the vibration of the vehicle 99 can be reduced.

[0070] (Fifth Embodiment)

[0071] exist Figure 12A to Figure 14 The fifth embodiment is shown in FIG. In this embodiment, the control when climbing a step, especially just after climbing a step, is described as the center. In addition, the control before climbing a step is not limited.

[0072] Fig. 12A as well as Fig. 12B The schematic diagram shows the vehicle 99 climbing a step, and the square arrows show the driving force of the front wheel drive unit 10, the rear wheel drive unit 20 and the vehicle as a whole. For example, when climbing a step in a situation where it is difficult to reflect the driver's intention, such as in the automatic driving of an electric vehicle, it is necessary to reduce the MG torque Tmg after climbing the step to suppress excessive acceleration and a sudden flying feeling after climbing. In this embodiment, after the step is climbed, the MG torque Tmg is reduced and the clutch 31 is disconnected, thereby further suppressing the flying feeling after climbing the step.

[0073] based on Fig.13 The flowchart of the present embodiment is used to explain the clutch control. In S301, the control unit 50 determines whether there is a step on the driving path. If it is determined that there is no step (S301: No), the processing after S302 is skipped. In S302, the drive of the main engine motor 15 is controlled in such a way that the vehicle 99 climbs over the step.

[0074] In S303, the control unit 50 determines whether the vehicle 99 has climbed up a step. If it is determined that the vehicle 99 has not climbed up a step (S303: No), the control unit 50 returns to S302 and continues the step climbing control. If it is determined that the vehicle 99 has climbed up a step (S303: Yes), the control unit 50 moves to S304.

[0075] The control unit 50 releases the clutch 31 in S304 and performs MG speed control in S305. When the clutch 31 is released and the load is removed, the MG speed Nmg increases, so the MG speed Nmg is controlled to be a value obtained by converting the tire speed Nt corresponding to the vehicle speed when running with creep torque into the gear ratio of the reduction gear.

[0076] In S306, the control unit 50 determines whether the MG speed Nmg has reached the target speed Nmg. * Here, the target speed Nmg is included. * If the MG speed Nmg is within the prescribed range, an affirmative judgment is made. * If it is determined that the MG speed Nmg has reached the target speed (S306: Yes), the process proceeds to S307.

[0077] In S307, the control unit 50 determines whether the vehicle speed V is less than the vehicle speed determination threshold value Vth. When it is determined that the vehicle speed V is greater than the vehicle speed determination threshold value Vth (S307: No), the process moves to S308, and brake control is performed to reduce the vehicle speed V. When it is determined that the vehicle speed V is less than the vehicle speed determination threshold value Vth (S307: Yes), the process moves to S309, and the clutch 31 is engaged.

[0078] based on Fig.14 The timing diagram of the step diagram illustrates the clutch control after the step. Fig.14 In the figure, the accelerator opening, MG torque, clutch stroke, brake torque, MG speed, and tire speed are shown from the top, with the common time axis as the horizontal axis.

[0079] At time x50, if the front wheel 11 climbs over the step, the driver reduces the pedal force, thereby reducing the accelerator opening and reducing the MG torque Tmg. When it is determined at time x51 that the step is climbed, the clutch 31 is released. This can suppress the flying feeling after climbing the step.

[0080] When the clutch 31 is released at time x51, the MG speed Nmg increases, and the MG speed Nmg becomes the target speed Nmg. * MG speed control is performed in this way. Since MG speed Nmg becomes target speed Nmg * Since the tire speed Nt at this time is greater than the tire speed threshold TH corresponding to the vehicle speed determination threshold Vth, braking control is performed at time x52. At time x53 after the tire speed Nt reaches the tire speed threshold TH, the clutch 31 is engaged and normal control is restored.

[0081] Thus, by controlling the clutch 31, the driving of the vehicle 99 can be appropriately controlled. Specifically, in the present embodiment, the control unit 50 determines the step climbing state of the front wheel 11, and releases the clutch 31 when it is determined that the front wheel 11 has climbed the step. After climbing the step, the clutch 31 is released to separate the main engine motor 15 from the drive shaft 12, thereby suppressing the sudden acceleration after the climbing is completed. As a result, the vehicle stability after climbing the step is further improved.

[0082] (Sixth Embodiment)

[0083] Fig.15 A sixth embodiment is shown. In this embodiment, the operation of the main engine motor 15 is confirmed when the vehicle is stopped by releasing the clutch 31. Fig.15 The flowchart of FIG. 1 illustrates the operation confirmation process of the present embodiment. This process is performed when the operation check is performed after the vehicle system is started or before the vehicle system is stopped.

[0084] In S401, the control unit 50 determines whether the vehicle speed is 0 and the brake is on (ON), that is, the vehicle is stopped. If it is determined that the vehicle is not stopped (S401: No), the processing after S402 is skipped. If it is determined that the vehicle is stopped (S401: Yes), it moves to S402.

[0085] The control unit 50 confirms in S402 that the clutch 31 is engaged, and in S403, drives the clutch actuator 35 to release the clutch 31. In S404, the control unit 50 performs abnormality diagnosis of the clutch 31 based on the detection value of the stroke sensor and the detection value of the current sensor of the clutch actuator 35. In the case where the clutch 31 is a friction clutch, the detection value of the load sensor can also be used instead of the stroke sensor. Here, abnormalities of the stroke sensor or the load sensor, abnormalities of the clutch actuator 35, and abnormalities in fixing or releasing the clutch 31 are diagnosed. In the abnormality diagnosis, for example, the difference between the calculated detection value and the target value is determined to be normal if it is within the allowable range, and it is determined to be abnormal if it is not within the allowable range. The same applies to S408.

[0086] In S405, the control unit 50 determines whether the release of the clutch 31 is completed. If it is determined that the clutch 31 is not released (S405: No), the process returns to S403 and continues the release drive of the clutch actuator 35. If it is determined that the release of the clutch 31 is completed (S405: Yes), the process moves to S406.

[0087] The control unit 50 confirms that the MG speed Nmg is 0 in S406, and sets the MG speed Nmg to the target speed Nmg in S407. * In S408, the control unit 50 performs abnormality diagnosis of the main motor 15 based on the detection value of the rotation angle sensor and the detection value of the current sensor of the main motor 15. Here, the main motor 15 is diagnosed to have abnormal rotation speed and output.

[0088] In S409, the control unit 50 determines whether the MG speed Nmg has reached the target speed Nmg. * When it is determined that the MG speed Nmg has not reached the target speed Nmg * If the MG speed Nmg reaches the target speed Nmg, the process returns to S407 and the driving of the main engine motor 15 is continued. * (S409: Yes), proceed to S410.

[0089] In S410, the control unit 50 stops driving the main engine motor 15 and engages the clutch 31. In S411, the control unit 50 sets the driving mode to the standby mode. If an abnormality is detected in S404 or S408, the control unit 50 switches to fail-safe control.

[0090] In this embodiment, the control unit 50 performs abnormality diagnosis by releasing the clutch 31 and driving the main motor 15 when the front wheels 11 are not rotating. By driving the main motor 15 with the clutch 31 released, abnormality diagnosis can be performed without moving the vehicle 99.

[0091] In the embodiment, the clutch 31 is provided in the front wheel drive unit 10 , the front wheel 11 corresponds to the “drive wheel”, the drive shaft 12 corresponds to the “drive shaft”, and the main engine motor 15 corresponds to the “drive source”.

[0092] (Other embodiments)

[0093] In the above embodiment, the clutch is provided in the front wheel drive unit. In other embodiments, the clutch may be provided in the rear wheel drive unit, or in the front wheel drive unit and the rear wheel drive unit. In the case where the clutch is provided in the rear wheel drive unit, the rear wheel 21 corresponds to the "drive wheel", the drive shaft 22 corresponds to the "drive shaft", and the main engine motor 25 corresponds to the "drive source". In addition, by disconnecting both the brake and the clutch of the two-stage transmission mechanism, the main engine motor can be rotated in a state where the drive wheel is stopped, so it can also be applied to the two-stage transmission mechanism.

[0094] In the above-mentioned embodiment, the vehicle drive system is a so-called four-wheel drive system in which the main engine motor as the drive source is provided in the front wheel drive unit and the rear wheel drive unit. In other embodiments, the vehicle drive system may also be a so-called two-wheel drive system in which the main engine motor is provided in one of the front wheel drive unit or the rear wheel drive unit. The various embodiments can be implemented in combination, but the fourth embodiment is applicable to the four-wheel drive system.

[0095] The control unit and method described in the present disclosure may also be implemented by a special-purpose computer, which is provided by a processor and a memory programmed to execute one or more functions embodied by a computer program. Alternatively, the control unit and method described in the present disclosure may also be implemented by a special-purpose computer provided by a processor composed of one or more special-purpose hardware logic circuits. Alternatively, the control unit and method described in the present disclosure may also be implemented by one or more special-purpose computers, which are composed of a combination of a processor and a memory programmed to execute one or more functions and a processor composed of one or more hardware logic circuits. In addition, the computer program may also be stored as an instruction executed by a computer in a computer-readable non-transitional tangible recording medium. As described above, the present disclosure is not limited to the above-mentioned embodiments, and can be implemented in various ways without departing from its main purpose.

[0096] The present disclosure is described based on the implementation mode. However, the present disclosure is not limited to the implementation mode and structure. The present disclosure also includes various modifications and modifications within the equivalent range. In addition, various combinations and methods, and other combinations and methods that only include one element, above or below them also fall within the scope and scope of thought of the present disclosure.

Claims

1. A vehicle control system for controlling the driving of a vehicle (99), It is characterized in that have: A driving source (15); A clutch (31, 32) is provided in a power transmission path from the driving source to the driving wheel (11) and is capable of switching the disconnection of the power transmission; a clutch actuator (35) for driving the clutch; as well as A control unit (50) controls the driving of the driving source and the clutch actuator, A meshing portion obliquely relative to the rotational direction is provided at at least one location between the clutch and the drive wheel. The control unit controls the clutch actuator to generate a load greater than a load required for engagement of the clutch when a transient torque of a driving force from the driving source is input to switch the clutch from a released state to an engaged state.

2. A vehicle control system for controlling the driving of a vehicle (99), It is characterized in that have: A driving source (15); A clutch (31, 32) is provided in a power transmission path from the driving source to the driving wheel (11) and is capable of switching the disconnection of the power transmission; a clutch actuator (35) for driving the clutch; as well as A control unit (50) controls the driving of the driving source and the clutch actuator, The control unit releases the clutch when the torque fluctuation frequency of the driving source is in a resonance region of a driving shaft (12) connected to the driving wheel.

3. A vehicle control system for controlling the driving of a vehicle (99), It is characterized in that have: A driving source (15); A clutch (31, 32) is provided in a power transmission path from the driving source to the driving wheel (11) and is capable of switching the disconnection of the power transmission; a clutch actuator (35) for driving the clutch; as well as A control unit (50) controls the driving of the driving source and the clutch actuator, The control unit determines whether the vehicle is in a step climbing state, and releases the clutch when it is determined that the vehicle has climbed a step.

4. A vehicle control system for controlling the driving of a vehicle (99), It is characterized in that have: A driving source (15); A clutch (31, 32) is provided in a power transmission path from the driving source to the driving wheel (11) and is capable of switching the disconnection of the power transmission; a clutch actuator (35) for driving the clutch; as well as A control unit (50) controls the driving of the driving source and the clutch actuator, The control unit releases the clutch in a state where the drive wheel is not rotating, and drives the drive source to perform abnormality diagnosis.

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