Vehicle control device

Abstract

The purpose of this invention is to provide a technique for appropriately suppressing the ratchet effect when shifting to Park (P) gear, regardless of individual differences between vehicles. The solution of this invention is to determine whether a ratchet effect is present when performing parking control to shift to P gear. If a ratchet effect is detected (the determination in S3 is "yes"), parking control is stopped in S5, and the parking pawl moves to a non-parking position where it is disengaged from the parking gear. Therefore, regardless of individual differences between vehicles, such as dimensional errors in the parking pawl and parking gear, and accuracy errors in the vehicle speed sensor, the ratchet effect of the electric parking device can be appropriately suppressed.

Description

Technical Field

[0001] This invention relates to a vehicle control device, and more particularly to a vehicle control device equipped with an electric parking system. Background Technology

[0002] A known vehicle control device comprises: (a) a vehicle equipped with an electric parking device and a gear selection device, wherein the electric parking device, through electrical control, engages a parking pawl with a parking gear to lock the wheels in a non-rotating position, and the parking gear rotates in conjunction with the wheels; and the gear selection device is capable of selecting multiple gears, including a parking gear (P gear) where the wheels are locked in a non-rotating position by the electric parking device, and the driving states of the vehicle are different; (b) the vehicle control device includes a parking control unit that, when the P gear is selected, performs parking control by moving the parking pawl of the electric parking device to a parking position engaged with the parking gear. The device described in Patent Document 1 is an example of this. In Patent Document 1, switching to the P gear is permitted when the vehicle speed is below a predetermined speed, and switching to the P gear is prohibited when the speed is above the predetermined speed, thus suppressing emergency stopping or ratcheting caused by switching to the P gear. The so-called ratchet effect is the phenomenon that the pawl will not engage with the parking gear and will be ejected when the parking process is repeated.

[0003] Prior art literature

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 5-280637 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] However, due to individual vehicle differences such as dimensional errors in the parking pawl and parking gear, and accuracy errors in the vehicle speed sensor, a ratcheting effect can sometimes occur even when shifting to P gear below the aforementioned specified speed. If the ratcheting effect persists, it may damage the durability of the parking pawl and parking gear. If a shift speed to P gear is set regardless of individual vehicle differences to avoid the ratcheting effect, there is a possibility that shifting to P gear may be restricted beyond what is necessary.

[0008] This invention was made against the background of the above situation, and its purpose is to provide a technology that can appropriately suppress the ratchet effect when shifting to P gear, regardless of the individual differences of each vehicle.

[0009] Solution for solving the problem

[0010] To achieve the above objectives, the first invention is a vehicle control device, (a) relating to a vehicle having: an electric parking device that, by electrical control, engages a parking pawl with a parking gear to lock the wheels in a non-rotating state, the parking gear rotating in conjunction with the wheels; and a gear selection device capable of selecting multiple gears for different driving states of the vehicle, the gears including a P gear for parking where the wheels are locked in a non-rotating state by the electric parking device; (b) the vehicle control device has a parking control unit that, when the P gear is selected, performs parking control by moving the parking pawl of the electric parking device to a parking position engaged with the parking gear; the vehicle control device is characterized in that, (c) when performing the parking control, the parking control unit determines whether the parking pawl is in a ratchet effect state where it is not engaged with the parking gear and is disengaged; if the ratchet effect state is determined to be present, the parking control is stopped, and the parking pawl is moved to a non-parking position where it is disengaged from the parking gear.

[0011] The second invention is characterized in that, in the vehicle control device of the first invention, after the parking control unit stops the parking control due to the ratchet effect state, it resumes the parking control when a predetermined re-execution condition is met.

[0012] The third invention is characterized in that, in the vehicle control device of the second invention, the re-execution condition is: the vehicle speed at which it is determined to be in the ratchet effect state is taken as the reference vehicle speed, and the decrease in vehicle speed from the reference vehicle speed is more than or equal to a predetermined re-execution determination decrease amount.

[0013] The fourth invention is characterized in that, in the vehicle control device of the second invention, the above-mentioned re-execution condition is: the elapsed time after the ratchet effect state is determined is more than a predetermined re-execution determination time.

[0014] The fifth invention is characterized in that, in the vehicle control device of the first invention, (a) the vehicle is equipped with an electric braking device capable of electrically controlling the braking force of the vehicle, and (b) the control device has a braking control unit that generates the braking force by means of the electric braking device when the parking control unit determines that the vehicle is in the ratchet effect state and the parking control stops.

[0015] The sixth invention is characterized in that, in the vehicle control device of the fifth invention, the braking control unit uses the vehicle speed when the parking control unit determines that the ratchet effect is in place as the reference vehicle speed, and continues to generate the braking force generated by the electric braking device until the amount of speed reduction from the reference vehicle speed reaches or exceeds a predetermined braking duration determination reduction amount.

[0016] The seventh invention is characterized in that, in the vehicle control device of the fifth invention, the braking control unit continues to generate the braking force generated by the electric braking device until the time elapsed after the parking control unit determines that the vehicle is in the ratchet effect state becomes a predetermined braking duration determination time.

[0017] The eighth invention is characterized in that, in the vehicle control device of the fifth invention, the braking control unit continues to generate the braking force generated by the electric braking device when the parking control unit performs the parking control again after the parking control unit has met the predetermined re-execution conditions.

[0018] The ninth invention is characterized in that, in the vehicle control device of the eighth invention, (a) the parking control unit performs the parking control again when the above-mentioned re-execution condition is met, determines whether the ratchet effect state is present, and continues to perform the parking control repeatedly when the above-mentioned re-execution condition is met; on the other hand, (b) if the braking control unit determines that the ratchet effect state is no longer present through the parking control unit, the braking force generated by the above-mentioned electric braking device is released.

[0019] The tenth invention is characterized in that, in the vehicle control device of the second invention, (a) the vehicle is equipped with an electric braking device capable of electrically controlling the braking force of the vehicle, and (b) the control device has a braking control unit, which generates the braking force through the electric braking device when the parking control unit satisfies the re-execution condition and re-executes the parking control, and when it is determined again to be in the ratchet effect state and stops the parking control.

[0020] Furthermore, the tenth invention is that generating braking force is a requirement when the parking control is again judged to be in a ratchet effect state after the re-execution condition is met, so it is appropriate to determine whether to generate braking force when the parking control is judged to be in a ratchet effect state in the initial parking control.

[0021] The eleventh invention is characterized in that, in the vehicle control device of the tenth invention, (a) the parking control unit performs the parking control again when the above-mentioned re-execution condition is met, determines whether the ratchet effect state is present, and continues to perform the parking control repeatedly when the above-mentioned re-execution condition is met; on the other hand, (b) the braking control unit continues to generate the braking force generated by the electric braking device until the parking control unit no longer determines that the ratchet effect state is present.

[0022] The effects of the invention

[0023] According to the control device of such a vehicle, when executing parking control, it is determined whether the ratchet effect is in effect. If the ratchet effect is determined to be in effect, the parking control is stopped and the parking pawl is moved to the non-parking position. Therefore, regardless of the individual differences of each vehicle, the ratchet effect can be appropriately suppressed.

[0024] In the second to fourth inventions, parking control is executed again only after a predetermined re-execution condition is met following the initial parking control. Therefore, the ratchet effect can be suppressed while quickly shifting to the P gear through re-execution of parking control. Particularly in the third invention, since parking control is executed based on the reduction in vehicle speed (i.e., the reduction in the rotational speed of the parking gear), the parking pawl easily engages with the reduction in the rotational speed of the parking gear, reducing the number of ratchet effects and the number of parking control executions, thus saving power consumption.

[0025] In the fifth to ninth inventions, when a ratchet effect is detected and parking control stops, an electric braking device generates braking force. Therefore, even when parking control stops, the prescribed braking force is obtained, suppressing any sense of incoordination in the driver. Furthermore, since the vehicle speed decreases due to the braking force generated by the electric braking device, the rotational speed of the parking gear decreases accordingly. Therefore, by re-executing parking control, the parking pawl quickly shifts to the P gear, which engages with the parking gear. In the ninth invention, when the parking control unit no longer detects a ratchet effect, the braking force generated by the electric braking device is released, ensuring that the application of braking force is controlled to the necessary minimum.

[0026] In the tenth and eleventh inventions, when the parking control unit meets the re-execution conditions and re-executes parking control, and when the ratchet effect state is determined again and parking control is stopped, the electric braking device generates braking force, which reduces the vehicle speed due to the braking force. Along with this braking force, the rotational speed of the parking gear decreases. Therefore, by re-executing parking control, the parking pawl is quickly switched to the P gear that meshes with the parking gear. Attached Figure Description

[0027] Figure 1 This is a block diagram illustrating the general structure of a vehicle having a control device as an embodiment of the present invention, and also a diagram showing the main parts of the control system.

[0028] Figure 2 This is an explanation Figure 1 A schematic perspective view of an example of an electric parking device for a vehicle.

[0029] Figure 3 This is an explanation of the reason. Figure 1 The flowchart shows the signal processing performed by the parking control unit, which is functionally equipped with the vehicle's electronic control device.

[0030] Figure 4 This means that in Figure 3 An example of a time graph showing the change in the working state of each part when the vehicle speed V decreases by (V0-V) in S7 and the determination of a decrease of more than ΔVs is executed, and steps S8 and below are executed.

[0031] Figure 5 This means that in Figure 3 An example of a timing diagram showing the changes in the working state of each part when the decision timer T0 becomes 0 after S7 and the steps below S8 are executed.

[0032] Figure 6 The figures illustrate other embodiments of the present invention, showing that a parking control unit is used instead. Figure 3 A flowchart of the signal processing performed. Detailed Implementation

[0033] An electric parking device is a so-called shift-by-wire (SBW) parking device, in which the gear selected by a gear selector such as a gear lever is electrically established via a shift actuator, for example, an electric one. As a gear, it has at least a P (Parking) gear for parking that mechanically prevents the rotation of the parking gear. When this P gear is selected, the parking pawl of the electric parking device engages with the parking gear, resulting in a parking state. In this P gear, power transmission is preferably cut off. As a vehicle, it can be applied to various vehicles such as engine-driven vehicles that generate power through fuel combustion, electric vehicles driven by electric motors, or hybrid vehicles with multiple power sources.

[0034] A parking gear is mounted on a rotating shaft (output shaft, etc.) that rotates mechanically with the rotation of the wheels. A parking pawl engages with this parking gear, thereby mechanically preventing the rotation of the rotating shaft and, consequently, the rotation of the wheels. The parking pawl reciprocates between a parking position and a non-parking position via an actuator, such as an electric motor. If necessary, a force-applying device, such as a spring, is provided between the parking pawl and the actuator to allow relative movement when the parking pawl interferes with the parking gear. The ratchet effect, where the parking pawl is not engaged with the parking gear and is released, is caused by the rotation of the parking gear while the vehicle is in motion, for example, by the parking pawl repeatedly being released by multiple teeth of the parking gear against the force of the force-applying device. For example, the ratchet effect can be determined by the position of the parking pawl, but it can also be determined by the rotational speed of the wheels, the rotational speed of the parking gear, etc.

[0035] After a ratchet effect state is detected and parking control is stopped, the conditions for re-execution of parking control are determined, for example, based on the amount of speed reduction after the ratchet effect state was detected. However, they can also be determined in various forms based on the elapsed time after the ratchet effect state was detected, the travel distance after the ratchet effect state was detected, etc. As an electric braking device that generates braking force when parking control is stopped due to a ratchet effect state, an electric wheel braking device capable of electrically controlling the hydraulic pressure of the wheel brakes can be used. However, if an electric motor is provided, which functions as both a power source for travel and a generator, regenerative control can be performed to make the electric motor function as a generator, thereby generating braking force. That is, an electric motor provided as a power source for travel can also be used as an electric braking device. However, the application of braking force by the electric braking device can be omitted.

[0036]

Example

[0037] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. In the following embodiments, for illustrative purposes, the drawings have been appropriately simplified or modified, and the shapes, size ratios, angles, etc., of the parts may not be accurately depicted.

[0038] Figure 1 This is a block diagram illustrating the general structure of a vehicle 8 equipped with an electronic control device 10, which functions as a control device to which the present invention is applied. Figure 1This diagram shows the main components of the control system. Vehicle 8 is an electric vehicle with an electric motor MG as its driving power source. The electric motor MG is a so-called motor generator that also functions as a generator. It is mechanically connected to the wheels 22 via a power transmission mechanism 20, such as a transmission drive axle, and electrically connected to the battery 26 via an inverter 24. Vehicle 8 is equipped with an electric parking device 30 that can lock the wheels 22 into a non-rotating state via electrical control, and an electric wheel braking device 32 that generates braking force via electrical control.

[0039] Figure 2 This is a schematic perspective view illustrating one example of the aforementioned electric parking device 30. This electric parking device 30 is an SBW (Side-by-Side) parking device, which uses a gear selection device 62 (see reference 62) via a gear shift lever or the like. Figure 1 The selected gear position actuates the SBW actuator 40 of the electric motor, etc., which rotates the brake plate 44 via the shift shaft 42, thereby electrically switching to multiple gears with different driving states of the vehicle 8. The gear selection device 62 is located near the driver's seat and can select, for example, the P (Parking) gear for parking, the R (Reverse) gear for reverse driving, the N (Neutral) gear for cutting off power transmission, and the D (Drive) gear for forward driving. Signals indicating these selected gear positions are supplied to the electronic control unit 10. In the P gear position, power transmission is cut off in the same way as in the N gear position.

[0040] The brake plate 44 rotates around the axis of the shift shaft 42 via the SBW actuator 40, and is positioned in four rotational positions: P (Park) position, R (Reverse) position, N (Neutral) position, and D (Drive) position. The parking lever 46 is connected to the brake plate 44. As the brake plate 44 rotates, the parking lever 46 moves back and forth in a roughly linear manner, and the operating state of the electric parking device 30 is switched according to the position of the parking lever 46. The parking head 48 is connected to the front end of the parking lever 46. When the parking head 48 is moved from the shift shaft 42 by the SBW actuator 40... Figure 2 When the device moves (advances) from the non-stop position to the parking position in the upper left direction, the parking pawl 50 rotates upward, engaging the parking gear 52 with the meshing teeth 50t. The parking head 48 is cone-shaped, which pushes the parking pawl 50 upward. Regarding the electric parking device 30, to simplify the operation of the SBW actuator 40, the parking position corresponding to the P position and the operating positions other than the P position are referred to as the non-stop position. Furthermore, various electric parking devices 30 capable of switching between electric parking and non-stop states can be used, including devices with parking heads having one or more rollers, or devices that move the parking pawl by means of an electromagnet.

[0041] The parking gear 52 is mounted non-rotatably on a rotating shaft 54, such as the output shaft of the power transmission mechanism 20, which mechanically rotates with the rotation of the wheel 22. The parking pawl 50 is rotatably mounted on a transmission housing or similar component, about an axis 56 parallel to the rotating shaft 54, and is directed in the disengagement direction by a return spring (not shown). Figure 2 Applying force in the counter-clockwise direction, the parking head 48 resists the force of the return spring, causing the parking pawl 50 to move in the engagement direction. Figure 2 (In a clockwise direction). That is, the parking pawl 50 is configured to approach or move away from the parking gear 52, such as... Figure 2 As shown, the parking pawl 50 moves to a non-parking position where the engagement with the parking gear 52 is disengaged, and to a parking position where the engaging teeth 50t engage with the parking gear 52. Furthermore, by engaging the engaging teeth 50t with the parking gear 52 in the parking position, a parking state is achieved that mechanically prevents the rotation of the parking gear 52, and consequently mechanically prevents the rotation of the rotating shaft 54 ​​and the wheel 22.

[0042] The parking head 48 is movably disposed relative to the parking lever 46 in the axial direction and is generally held relative to the parking lever 46 by a spring member (in the embodiment, a compression coil spring) 58, which serves as a force-applying device. Figure 2 On the upper left front side, when the SBW actuator 40 moves from the non-parking position to the parking position, the parking pawl 50 rotates to the parking position via the parking head 48. However, even when the meshing teeth 50t of the parking pawl 50 interfere with the parking gear 52, the parking head 48 is allowed to resist the force of the spring member 58 and move relative to the parking lever 46. Figure 2 The relative displacement is to the lower right. In this case, when the parking gear 52 rotates due to road incline, the parking pawl 50 engages with the parking gear 52 under the force of the spring member 58, thus entering a parking state. Additionally, if the P gear is selected while the vehicle is in motion, a ratchet effect may occur where the rotation of the parking gear 52 resists the force of the spring member 58, causing the parking pawl 50 to be repeatedly disengaged by multiple teeth of the parking gear 52. That is, although the SBW actuator 40 and the parking lever 46 are actuated to the parking position, the parking head 48 and the parking pawl 50 remain in a state where they cannot reach the parking position, maintaining the drivable state of the vehicle 8.

[0043] The aforementioned electric wheel braking device 32 includes a brake master cylinder (not shown) and a cylinder actuator for generating brake hydraulic fluid, and is capable of electrically controlling the braking force, i.e., brake hydraulic fluid, of the wheel brakes installed on all wheels of the vehicle 8, including the wheels 22. The electric wheel braking device 32 generates brake hydraulic fluid, for example, based on the driver's deceleration demand Bra caused by the operation of the brake pedal, etc. Furthermore, it electrically controls the increase or decrease of brake hydraulic fluid during ABS (Anti-locking ABS), lateral slip suppression control, automatic speed control, automatic driving control, and automatic braking, in order to obtain the wheel braking torque TBw obtained through each control.

[0044] The electronic control unit 10 is configured as a so-called microcomputer with a CPU, ROM, RAM, and input / output interfaces. It executes various controls of the vehicle 8 by utilizing the temporary storage function of RAM and processing signals according to a program pre-stored in the ROM. In addition to supplying the electronic control unit 10 with a signal indicating the selected gear Sra by the gear selection device 62, various vehicle information required for controlling the vehicle 8 is supplied from the vehicle information detection device 60. This vehicle information includes, for example, the deceleration requirement Bra, the accelerator opening θacc indicating the driver's acceleration requirement generated by the accelerator pedal operation, the MG rotation speed Nm (the rotation speed of the electric motor MG), the rotation speed Nout of the output shaft of the power transmission mechanism 20 corresponding to the vehicle speed V, and the wheel speed ωfr (the rotation speed of all wheels including the wheels 22). The vehicle information detection device 60 includes various rotation angle sensors, load sensors, vehicle speed sensors, etc.

[0045] Furthermore, the ratchet effect detection device 64 supplies ratchet information Prt to the electronic control device 10, which determines whether the aforementioned electric parking device 30 is in a ratchet effect state. The ratchet effect detection device 64 can be, for example, a non-contact switch or limit switch that switches on and off when the parking pawl 50 has rotated to the parking position, or an angle sensor that detects the rotation angle of the parking pawl 50. If the SBW actuator 40 moves to the parking position while the vehicle is in motion, but the parking pawl 50 has not rotated to the parking position, it can be determined that a ratchet effect state exists. Alternatively, it can be determined that a ratchet effect state exists when the rotation angle of the parking pawl 50 repeatedly increases or decreases by a predetermined angle. Alternatively, instead of detecting the position of the parking pawl 50, it can be determined whether the ratchet effect state exists based on whether the wheel speed ωfr and MG speed Nm corresponding to the rotation of the parking gear 52 decrease or stop rotating.

[0046] The electronic control unit 10 includes an MG control unit 12, a brake control unit 14, and a parking control unit 16.

[0047] The MG control unit 12 calculates the driver's driving demand for the vehicle 8 by applying the accelerator opening θacc and vehicle speed V to a driving demand mapping. The driving demand mapping is used to determine the relationship between the aforementioned driving demands, which are experimentally or designally determined and stored in advance. The driving demands are, for example, the required driving torque Trdem [Nm] of the wheels 22, the required driving force Frdem [N], and the required driving power Prdem [W]. The MG control unit 12 calculates the target MG torque Tmtgt that can achieve the required driving demand by considering transmission losses, auxiliary device load, and the reduction ratio of the power transmission mechanism 20. Then, the target MG torque Tmtgt is output by controlling the motor MG via the inverter 24.

[0048] The braking control unit 14 sets the required braking torque TBdem based on factors such as the driver's accelerator operation (e.g., accelerator opening θacc, the rate of decrease of accelerator opening θacc), vehicle speed V, the gradient of the downhill road, and the deceleration requirement Bra generated by the driver's braking operation. During the deceleration of the vehicle 8, the braking control unit 14 generates the braking torque TB of the vehicle 8 to obtain the required braking torque TBdem. The required braking torque TBdem is essentially the required braking torque of the wheel braking torque TBw of the electric wheel braking device 32, achieved through the wheel braking torque TBw. However, from the viewpoint of improving energy efficiency, the regenerative braking torque TBr can also be used concurrently or preferentially. The regenerative braking torque TBr is the braking torque TB obtained by the regenerative braking of the electric motor MG, generated by the regenerative control of the electric motor MG by the MG control unit 12. The regenerative torque of the electric motor MG is the MG torque Tm of the electric motor MG during regeneration, obtained by converting the regenerative braking torque TBr of the wheel 22 based on the reduction ratio of the power transmission mechanism 20, etc.

[0049] The parking control unit 16 switches the operating state of the electric parking device 30 according to the selection gear Sra selected by the gear selection device 62. Specifically, according to Figure 3 The steps S1 to S10 of the flowchart (hereinafter, steps are omitted and simply referred to as S1 to S10, and the same applies to other flowcharts) perform signal processing. In this flowchart, the judgment steps shown by diamonds indicate "yes" for affirmation and "no" for negation. Figure 4 and Figure 5 This means that when the P gear is selected, according to Figure 3 The flowchart is an example of a time-sharing diagram showing the changes in the operational states of each part when the electric parking device 30 is switched to the parking state during parking control.

[0050] exist Figure 3In step S1, it is determined whether the gear selection device 62 has selected the P gear. If a non-P gear is selected, the process ends directly. If the P gear is selected, the following steps (S2 and below) are executed. In S2, the SBW actuator 40 of the electric parking device 30 is driven to the parking position to establish the P gear. Essentially, the parking head 48 and parking lever 46 move together to the parking position, the parking pawl 50 engages with the parking gear 52, and the rotating shaft 54 ​​and wheel 22 are locked in a non-rotatable parking state. However, if the vehicle is switched to the P gear while in motion, the rotation of the parking gear 52 may cause a ratchet effect, where the parking pawl 50 is repeatedly pushed back by multiple teeth of the parking gear 52. If this ratchet effect continues, it may damage the durability of the parking pawl 50 and the parking gear 52. Therefore, in the next step S3, based on the ratchet information Prt supplied from the ratchet effect detection device 64, it is determined whether the ratchet effect is in effect. If it can be determined that the ratchet effect is in effect, the steps below S4 are executed. If it cannot be determined that the ratchet effect is in effect, the process ends directly because the parking pawl 50 is in a proper parking state with the parking gear 52 engaged.

[0051] In step S4, which is executed under ratchet effect conditions, the vehicle speed V at this time (when the ratchet effect condition is determined) is stored as the reference vehicle speed V0, and the re-execution determination timer T0 is set to a predetermined re-execution determination time. The remaining time of the re-execution determination timer T0 decreases according to the elapsed time since the ratchet effect condition was determined in step S3. If the set time (= re-execution determination time) is reached, then T0 = 0. In step S5, in order to prevent the ratchet effect condition from continuing, the SBW actuator 40 temporarily returns to the non-stop position, and switches to the non-stop state where the parking pawl 50 of the electric parking device 30 is away from the parking gear 52. Furthermore, in step S6, a braking request to apply a predetermined braking force to the vehicle 8 is output to the braking control unit 14. The braking control unit 14 generates a predetermined braking force according to the braking request, for example, via the electric wheel brake device 32. The predetermined braking force can also be generated by the regenerative control of the electric motor MG, or by both. The electric wheel brake device 32 and the electric motor MG are equivalent to an electric braking device.

[0052] exist Figure 4 and Figure 5In the sequence, time t1 is the time when the P gear is selected, and time t2 is the time when the SBW actuator 40 is driven to the parking position (P position) by executing S2. Additionally, time t3 is the time when the ratchet effect is detected, and the SBW actuator 40 returns to the non-parking position (non-P position) by executing S5, and the braking force is applied starting by executing S6. The braking force increases to a predetermined set value at a predetermined rate of change. The magnitude of the braking force at this time can be a fixed value or can be variablely set according to vehicle speed V, etc.

[0053] Return to Figure 3 In step S7, it is determined whether the speed reduction ΔV (=V0-V) from the reference speed V0 minus the current speed V is greater than or equal to the predetermined re-execution determination reduction ΔVs. If ΔVs≤ΔV, in step S8, the switch to P gear is executed again, that is, the electric parking device 30 is switched to the parking state for parking control. In step S7, it is also determined whether the re-execution determination timer T0 becomes 0, that is, whether the elapsed time after the ratchet effect state was determined in step S3 has become the set time of the re-execution determination timer T0 (=re-execution determination time). If T0=0, the switch to P gear is executed again in step S8. ΔVs≤ΔV and T0=0 are the re-execution conditions for the switch to P gear. If either condition is met, the switch to P gear is executed again in step S8. The re-execution decision reduction amount ΔVs and the set time of the re-execution decision timer T0 (=re-execution decision time) can be predetermined to a fixed value, but they can also be set variably according to the vehicle speed V, etc. Alternatively, either ΔVs≤ΔV or T0=0 can be used as the re-execution condition.

[0054] In the following S9, similar to step S3, the ratchet information Prt is used to determine whether a ratchet effect state exists. If a ratchet effect state is determined, the steps from S4 onwards are repeatedly executed. On the other hand, if a ratchet effect state cannot be determined, since it is a proper parking state with the parking pawl 50 and parking gear 52 engaged, a brake release request to release the braking force is output to the brake control unit 14 in S10, ending the series of controls. The brake control unit 14 gradually reduces the braking force generated by the regenerative control of the electric wheel brake device 32 and / or the electric motor MG at a predetermined rate of change according to the brake release request. That is, if the brake control unit 14 determines that a ratchet effect state exists, the electric parking device 30 switches to a non-parking state in S5, and after generating the prescribed braking force according to the initial braking request in S6, the braking force generation continues even if the re-execution condition is met and the shift to P gear is executed again in S8. If a ratchet effect state is not determined in S9 but a brake release request is made in S10, the braking force is released. From another perspective, the vehicle speed V when it is determined to be in a ratchet effect state in S3 is taken as the base vehicle speed V0. The continuous braking force generation state continues until the decrease in vehicle speed V from the base vehicle speed V0 reaches or exceeds the pre-set re-execution determination decrease amount ΔVs. The re-execution determination decrease amount ΔVs can be considered as the braking continuation determination decrease amount for the continuous braking force generation state. Furthermore, the continuous braking force generation state continues until the elapsed time after the ratchet effect state is determined in S3 reaches the set time of the re-execution determination timer T0 (= re-execution determination time). The re-execution determination timer T0 can be considered as the braking continuation determination time for the continuous braking force generation state.

[0055] Figure 4 This illustrates a scenario where the vehicle speed reduction ΔV (=V0-V) is calculated by subtracting the current vehicle speed V from the reference vehicle speed V0. If the speed reduction ΔVs is greater than or equal to the previous reduction, and the judgment at time t4, S7 is "yes", then steps S8 and below are executed, followed by switching to the P gear, i.e., parking control that puts the electric parking device 30 into a parking state. Figure 4 In step S9, if the ratchet effect state is determined again and the steps below S4 are repeatedly executed, when ΔVs≤ΔV again, the electric parking device 30 will enter a parking state when parking control is executed again at time t5. The judgment of S9 will be "no", and S10 will be executed. At time t6, the braking force will be released at the specified rate of change.

[0056] Figure 5 This illustrates the scenario where the re-execution decision timer T0 becomes 0, and at time t4, the decision in S7 becomes "yes," executing steps S8 and below, and then switching to the P gear, i.e., the parking control that puts the electric parking device 30 into a parking state. Figure 5If the ratchet effect state is determined again in S9 and the steps below S4 are repeatedly executed, when T0 = 0 again, and the parking control is executed again at time t5, the electric parking device 30 becomes a parking state, the determination of S9 is "no", and S10 is executed, and the braking force is released at time t6 with a specified rate of change.

[0057] The above Figure 4 The results show that the re-execution of the parking control at times t4 and t5 both satisfy the condition that ΔVs ≤ ΔV. Figure 5 The diagram shows that the re-execution of the parking control at times t4 and t5 both satisfy the condition T0 = 0. However, it could also be executed by satisfying ΔVs ≤ ΔV. Figure 5 The second execution of the parking control at time t5. That is, if either ΔVs≤ΔV or T0=0, which are the conditions for re-execution, is satisfied, the judgment of S7 is "yes", and S8 is executed.

[0058] According to the electronic control device 10 of the vehicle 8 in this embodiment, when performing parking control, it determines whether a ratchet effect state is present. If a ratchet effect state is present (the determination in S3 is "yes"), in S5, parking control is stopped and the parking pawl 50 is moved to the non-parking position. Therefore, regardless of the individual differences of each vehicle 8, such as the size error of the parking pawl 50 and parking gear 52, the accuracy error of the vehicle information detection device 60 such as the vehicle speed sensor, the ratchet effect of the electric parking device 30 can be appropriately suppressed.

[0059] Furthermore, if the predetermined re-execution condition is met after the parking control has stopped (i.e., if the judgment in S7 is "yes"), the parking control is re-executed in S8. Therefore, the ratchet effect can be suppressed while quickly shifting to P gear through the re-execution of parking control. In particular, when the parking control is re-executed based on the reduction amount ΔV of the vehicle speed V, i.e., the reduction amount of the rotational speed of the parking gear 52, the parking pawl 50 easily engages with the reduction amount of the rotational speed of the parking gear 52. Therefore, the number of ratchet effects is reduced, and the number of parking control executions is reduced, which saves power consumption.

[0060] Furthermore, when the parking control is stopped due to a ratchet effect, the electric wheel brake device 32 (which is an electric braking device) and the regenerative control of the electric motor MG generate braking force in the vehicle 8. Therefore, even though the parking control is stopped, the prescribed braking force can be obtained, suppressing any sense of disharmony for the driver. In addition, since the vehicle speed V decreases due to the braking force generated by the electric braking device, the rotational speed of the parking gear 52 decreases accordingly. Therefore, by re-executing the parking control, the vehicle can quickly shift to the P gear, where the parking pawl 50 and the parking gear 52 are engaged. Moreover, when the ratchet effect is not detected and the judgment in S9 is "no", the braking force generated by the electric braking device is released in S10, thus controlling the application of braking force to the necessary minimum.

[0061] Furthermore, in the above embodiment, when it is determined that the vehicle is in a ratchet effect state during the initial shift control to P gear, the parking control is stopped in S5, and S6 is executed, immediately generating braking force by the electric braking device. However, it can also be done as follows: Figure 6 The flowchart shows S6 omitted. In S8, even if the shift control to P gear is executed again, it is again determined to be in a ratchet effect state. If the judgment in S9 is "yes", braking force is generated by the electric braking device in S13. That is, even if the vehicle speed V is not sufficiently reduced and the ratchet effect occurs repeatedly, only braking force can be generated, and the application of braking force can be suppressed to the necessary minimum. Figure 6 In the above, S11 to S17 are related to... Figure 3 S4 to S10 are essentially the same, so detailed explanations are omitted.

[0062] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, these are only one implementation method. The present invention can be implemented in various ways with modifications and improvements based on the knowledge of those skilled in the art.

[0063] Explanation of reference numerals in the attached figures

[0064] 8: Vehicle; 10: Electronic control unit (control device); 14: Braking control unit; 16: Parking control unit; 22: Wheel; 30: Electric parking device; 32: Electric wheel braking device (electric braking device); 50: Parking pawl; 52: Parking gear; 62: Gear selection device; 64: Ratchet effect detection device; MG: Electric motor (electric braking device); V0: Reference vehicle speed; ΔVs: Re-execution decision reduction amount (re-execution condition, braking duration decision reduction amount); T0: Re-execution decision timer (re-execution condition, re-execution decision time, braking duration decision time).

Claims

1. A control device (10) of a vehicle (8), The vehicle (8) is provided with: an electric parking device (30) that locks a wheel (22) so as not to be able to rotate by electrically controlling a parking pawl (50) to engage with a parking gear (52) that rotates in conjunction with the wheel (22); and a range selection device (62) that can select a plurality of ranges in which a driving state of the vehicle (8) is different, the ranges including a P range for parking in which the wheel (22) is locked so as not to be able to rotate by the electric parking device (30), The control device (10) of the vehicle (8) has a parking control section (16), The parking control section (16) executes parking control in a case where the P range is selected, the parking control moving the parking pawl (50) of the electric parking device (30) to a parking position in which the parking pawl (50) engages with the parking gear (52), The control device (10) of the vehicle (8) is characterized in that: The parking control section (16) determines whether the parking pawl (50) is in a ratchet effect state in which the parking pawl (50) is elastically moved away from the parking gear (52) while the parking control is being executed, and stops the parking control and moves the parking pawl (50) to a non-parking position in which the parking pawl (50) is disengaged from the parking gear (52) in a case where the ratchet effect state is determined, The parking control section (16) re-executes the parking control in a case where the ratchet effect state is determined and after the parking control is stopped, in a case where a predetermined re-execution condition is satisfied, The re-execution condition is that a vehicle speed (V) at the time when the ratchet effect state is determined is taken as a reference vehicle speed (Vo), and a reduction amount (Vo-V) of the vehicle speed (V) from the reference vehicle speed (Vo) is equal to or greater than a predetermined re-execution determination reduction amount (ΔVs).

2. The control device (10) of the vehicle (8) according to claim 1, characterized in that: The re-execution condition is that an elapsed time after the ratchet effect state is determined is equal to or greater than a predetermined re-execution determination time (To).

3. The control device (10) of the vehicle (8) according to claim 1, characterized in that: The vehicle (8) is provided with an electric brake device (32, MG) that can electrically control a brake force of the vehicle (8), The control device (10) has a brake control section (14) that generates the brake force by the electric brake device (32, MG) in a case where the parking control section (16) determines the ratchet effect state and stops the parking control.

4. The control device (10) of the vehicle (8) according to claim 3, characterized in that: The brake control section (14) continues the state in which the braking force is generated by the electric brake device (32, MG) when the vehicle speed (V) at the time when the ratcheting effect state is determined by the parking control section (16) is taken as a reference vehicle speed (V0) and the amount of decrease (V0-V) in the vehicle speed (V) from the reference vehicle speed (V0) is equal to or greater than a predetermined brake continuation determination amount of decrease (ΔVs) until the amount of decrease (V0-V) in the vehicle speed (V) from the reference vehicle speed (V0) becomes equal to or greater than the predetermined brake continuation determination amount of decrease (ΔVs).

5. The control device (10) of the vehicle (8) according to claim 3, characterized in that, The brake control section (14) continues the state in which the braking force is generated by the electric brake device (32, MG) when the elapsed time after the ratcheting effect state is determined by the parking control section (16) is equal to or greater than a predetermined brake continuation determination time (T0) until the elapsed time after the ratcheting effect state is determined by the parking control section (16) becomes equal to or greater than the predetermined brake continuation determination time (T0).

6. The control device (10) of the vehicle (8) according to claim 3, characterized in that, The brake control section (14) continues the state in which the braking force is generated by the electric brake device (32, MG) when the parking control is re-executed by the parking control section (16) in a case where a predetermined re-execution condition is satisfied.

7. The control device (10) of the vehicle (8) according to claim 6, characterized in that, The parking control section (16) re-executes the parking control in a case where the re-execution condition is satisfied, determines whether or not the ratcheting effect state is present, and repeatedly re-executes the parking control in a case where the re-execution condition is satisfied until the ratcheting effect state is no longer determined by the parking control section (16), and The brake control section (14) cancels the braking force generated by the electric brake device (32, MG) when the ratcheting effect state is no longer determined by the parking control section (16).

8. The control device (10) of the vehicle (8) according to claim 1, characterized in that, The vehicle (8) is provided with an electric brake device (32, MG) that is capable of electrically controlling a braking force of the vehicle (8), The control device (10) has a brake control section (14) that generates the braking force by the electric brake device (32, MG) when the parking control is re-executed by the parking control section (16) in a case where the re-execution condition is satisfied and the parking control is stopped again when the ratcheting effect state is determined again.

9. The control device (10) of the vehicle (8) according to claim 8, characterized in that, The parking control section (16) re-executes the parking control in a case where the re-execution condition is satisfied, determines whether or not the ratcheting effect state is present, and repeatedly re-executes the parking control in a case where the re-execution condition is satisfied until the ratcheting effect state is no longer determined by the parking control section (16), and The brake control section (14) continues the state in which the braking force is generated by the electric brake device (32, MG) until the ratcheting effect state is no longer determined by the parking control section (16).

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