CN115139812A

CN115139812A - Vehicle control device

Info

Publication number: CN115139812A
Application number: CN202210005152.5A
Authority: CN
Inventors: 尾梶智哉
Original assignee: Honda Motor Co Ltd
Current assignee: Honda Motor Co Ltd
Priority date: 2021-03-31
Filing date: 2022-01-04
Publication date: 2022-10-04
Also published as: JP7373520B2; JP2022157687A

Abstract

The invention provides a vehicle control device which can prevent the down-sliding of a ramp during parking without causing adverse conditions caused by the temperature rise of a driving motor and without increasing the cost of a control structure. The vehicle control device includes: a drive motor for driving the vehicle; a drive shaft connected to the drive motor; a parking gear fixed to the drive shaft; a parking pawl meshed with the parking gear; an actuator that moves the parking pawl to a lock position and a lock release position where the parking pawl engages with the parking gear to lock the drive shaft by operation of the parking switch; a slope detection unit that detects a slope of the vehicle; a rotation angle detection unit that detects a rotation angle of the drive motor; and a motor angle control unit that rotates the drive motor by a predetermined angle corresponding to the slope detected by the slope detection unit after the actuator is operated.

Description

Vehicle control device

Technical Field

The present invention relates to a vehicle control device for controlling an operation of a vehicle.

Background

Vehicles such as automobiles are provided with a parking mechanism for locking wheels when the vehicles are parked. When the wheel is locked by the parking mechanism on a slope, if the response speed of the actuator is slow after the parking switch is pressed, the engagement of the parking pawl (parking paw) with the parking gear is slow, and a phenomenon in which the vehicle slightly moves downward along the slope of the slope (hereinafter, this phenomenon is referred to as "slip-down of the vehicle") may occur.

In order to suppress such a slip-down, patent document 1 describes control in which: whether the vehicle is a hill is determined based on a signal from a gyro-sensor, and when the vehicle speed is equal to or less than a predetermined value (threshold value) in a state where the vehicle is determined to be a hill and the brake is on, the motor control is performed to wait until a parking switch is pressed. In the motor control, a position of the parking gear and an angle by which the parking gear rotates when the actuator moves the parking pawl from the unlock position to the lock position are calculated in advance, and a motor torque is applied based on the position and the angle so that the parking gear becomes a position where the parking pawl engages, to rotate the driving motor. Since the phases of the parking gear and the parking pawl are aligned in advance by the rotation of the driving motor in the motor control, when the parking switch is pressed and the actuator is operated, the parking gear and the parking pawl mesh with each other, and the slip-down of the vehicle can be suppressed.

[ Prior art documents ]

[ patent document ]

[ patent document 1] Japanese patent laid-open No. 2009-30637

Disclosure of Invention

[ problems to be solved by the invention ]

However, in the above control, as shown in fig. 7, since the state in which torque is applied by the motor control is kept waiting until the parking switch (P switch) is pressed, if the time t until the parking switch is pressed is long, there is a concern that the motor temperature becomes high and torque cannot be applied. In addition, assuming that there is a possibility that the correspondence relationship between the rotation angle of the driving motor and the rotation position of the parking gear may be deviated, the correspondence relationship between the rotation angle of the driving motor and the rotation position of the parking gear may be corrected by learning the rotation position of the parking gear when the vehicle is powered on, which may increase the cost of the control structure.

In view of the above-described problems, an object of the present invention is to provide a vehicle control device that can suppress a slip-down of a vehicle when the vehicle is parked on a slope without causing a trouble due to a temperature rise of a drive motor and without increasing the cost of a control structure.

[ means for solving problems ]

In order to solve the problem, a vehicle control device 1 of the present invention includes: a drive motor 8 for driving the vehicle; a drive shaft 22 connected to the drive motor 8; a parking gear 24 fixed to the drive shaft 22; a parking pawl 40 engaged with the parking gear 24; an actuator 44 that moves the parking pawl 40 to a lock position and a lock release position where it engages with the parking gear 24 and locks the drive shaft 22 by operating a parking lock operation member 58; a slope detection unit 56 that detects the slope of the vehicle 2; a rotation angle detection unit 60 that detects the rotation angle of the drive motor 8; and a motor angle control unit 48 that rotates the drive motor 8 by a predetermined angle corresponding to the slope detected by the slope detection unit 56 after the actuator 44 is operated.

According to the vehicle control device of the present invention, the motor torque is applied to rotate the driving motor by the predetermined angle after the actuator is operated regardless of the deviation of the phase between the parking gear and the parking pawl, so that the driving motor can be prevented from becoming high in temperature, and the phase alignment between the parking gear and the parking pawl and the learning process are not required, so that the down-sliding during the hill parking can be suppressed without increasing the cost of the control structure.

In the vehicle control device, the predetermined angle is preferably a maximum angle α of rotation of parking gear 24 until it engages with parking pawl 40 _max . Thus, by setting the predetermined angle to the maximum angle, the geared state in which the parking gear is engaged with the parking pawl can be reliably obtained by simple control.

In the vehicle control device, it is preferable that motor angle control unit 48 calculates a motor torque required to rotate parking gear 24 by a predetermined angle, sets the motor torque as a target torque, and gradually increases the motor torque so as to reach the target torque for a predetermined time. Thus, the relationship between the amount of application of the motor torque and the integrated angle is monitored, thereby enabling highly accurate control.

In the vehicle control device, it is preferable that the motor angle control means 48 determine that the parking gear 24 is engaged with the parking pawl 40 and terminate the control when the rotation angle of the driving motor 8 is not increased for a certain period of time with respect to an increase in the motor torque. Thus, the time for controlling the motor angle can be shortened.

Further, the vehicle control device preferably includes: the parking operation permission determination unit 48 detects the vehicle speed v after the operation of the parking lock operation element 58, and determines whether or not to permit the operation of the actuator 44 based on the detected vehicle speed. This prevents an unnecessary parking operation of the vehicle in a state where the vehicle is moving on a slope.

Further, the vehicle control device preferably includes: the motor angle control execution determination means 48 determines whether or not to execute the motor angle control by the motor angle control means 48 based on the slope detected by the slope detection means 56 after the parking operation is permitted by the parking operation permission determination means 48 and the actuator 44 is operated. This prevents unexpected behavior of the vehicle by the driver, such as excessive upward sliding (a phenomenon in which the vehicle slightly moves upward along the slope of the slope, which will be the same hereinafter).

[ Effect of the invention ]

According to the present invention, it is possible to suppress a slip-down of a vehicle when parking on a slope without causing a problem due to a temperature rise of a driving motor and without increasing the cost of a control structure.

Drawings

Fig. 1 is a schematic configuration diagram of a vehicle in which a vehicle control device according to an embodiment of the present invention is mounted.

Fig. 2 is a control block diagram as a part of the vehicle control apparatus.

Fig. 3 is a diagram showing a specific engagement state of the parking gear and the parking pawl in the vehicle control device.

Fig. 4 is a schematic diagram for explaining the relationship of forces acting on the vehicle on a slope.

Fig. 5 is a flowchart showing a control operation for suppressing a slip-down performed by the vehicle control device.

Fig. 6 is a time flow chart showing a control operation for suppressing a slip-down performed by the vehicle control device.

Fig. 7 is a time flow chart for explaining a problem point of the prior art.

[ description of symbols ]

1: a vehicle control device;

2: a vehicle;

8: a traction motor (drive motor);

22: a drive shaft;

24: a parking gear;

40: a parking pawl;

44: an actuator;

46: an electronic control unit for mixing;

48: a CPU (motor angle control means, parking operation permission determination means, motor angle control execution determination means);

56: a tilt angle detection sensor (slope detection means);

60: an analyzer (rotation angle detection section);

n: a certain time;

α _max : the predetermined angle (maximum angle).

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

Fig. 1 is a schematic configuration diagram of a vehicle on which a vehicle control device according to an embodiment of the present invention is mounted. As shown in the drawing, a vehicle 2 as a hybrid vehicle includes an engine 4, a generator 6, a traction motor (traction motor) 8 as a driving motor, a differential device 10, a parking mechanism 12, and the like. A gear 16 fixed to a drive shaft 14 of the engine 4 meshes with a gear 20 fixed to a main shaft 18 of the generator 6. A parking gear 24 of the parking mechanism 23 is fixed to a drive shaft 22 connected to a rotor of the traction motor 8, and a transmission gear 28 is fixed thereto, and the transmission gear 28 is engaged with a gear 26 rotationally driven by the engine 4. The transfer gear 28 meshes with an idler gear (idler gear) 30, and a gear 32 fixed coaxially with the idler gear 30 meshes with a final gear (final gear) 34 of the differential 10. Reference numeral 36 denotes an axle (rotation shaft) that transmits power from the differential device 10 to the left and right drive wheels 38.

Fig. 2 is a control block diagram of a part of the vehicle control apparatus. The vehicle control device 1 of the present embodiment is configured by a traction motor 8, a parking mechanism 12, a vehicle speed sensor 54, a tilt angle detection sensor 56, a P switch (parking lock operation) 58, an analyzer (resolver) 60, a brake sensor 62, an electronic control unit 46, and the like shown in fig. 2.

Fig. 3 is a diagram showing a specific engagement state of the parking gear and the parking pawl in the vehicle control device. As shown in fig. 1 and 3, the parking mechanism 12 includes: parking gear 24; a parking pawl 40 engaged with the parking gear 24; a parking lever 42 that moves in the direction of arrow X in fig. 1 to move the parking pawl 40 to a position where it engages with the parking gear 24 to lock the drive shaft 22 and a lock release position; and an actuator 44 that drives the parking lever 42 in the direction.

As shown in fig. 2, the vehicle control device 1 includes a hybrid electronic control unit (hereinafter simply referred to as an electronic control unit) 46 that controls the entire vehicle. The electronic control Unit 46 is configured as a microcomputer having a Central Processing Unit (CPU) 48, a Read Only Memory (ROM) 50 for storing a Processing program and the like, a Random Access Memory (RAM) 52 for temporarily storing data, an Input-Output (I/O) interface (not shown), and the like. The electronic control unit 46 is connected with a vehicle speed sensor 54, a tilt angle detection sensor 56, a P switch 58, an analyzer 60, and a brake sensor 62. The traction motor 8 is connected to an electronic control unit 46 via a motor ECU (electronic motor control unit) 7.

The vehicle speed sensor 54 detects a vehicle speed v of the vehicle 2, and outputs a signal corresponding to the detected vehicle speed v to the CPU48 of the electronic control unit 46. The CPU48 functions as a parking operation permission determination means for determining whether or not to permit the operation of the actuator 44 based on the value of the vehicle speed detected by the vehicle speed sensor 54. The inclination angle detection sensor 56 as the inclination detection means includes an acceleration sensor, a gyro sensor, or the like, detects the gravitational acceleration of the vehicle 2 in the horizontal and vertical directions, and outputs a signal corresponding to the detected gravitational acceleration to the CPU48 of the electronic control unit 46. The CPU48 functions as a motor angle control means, and rotates the traction motor 8 by a predetermined angle corresponding to the inclination detected by the inclination angle detection sensor 56 after the actuator 44 is operated.

When the P switch (parking switch) 58, which is an operation member for parking lock, is pressed by the driver of the vehicle, a signal for operating the actuator 44 is output to the CPU48 of the electronic control unit 46. The CPU48 functions as a motor angle control execution determination means, and determines whether or not to execute the motor angle control by the motor angle control means based on the slope detected by the inclination angle detection sensor 56 after the actuator 44 is operated. The analyzer 60 as a rotation angle detecting means detects the rotation angle of the traction motor 8, and outputs the detected angle to the CPU48 of the electronic control unit 46. The brake sensor 62 detects the on/off of a brake pedal, not shown, and outputs a signal corresponding to the detected state to the CPU48 of the electronic control unit 46.

As shown in fig. 3, the parking pawl 40 is supported rotatably about a rotation shaft 66, and is pressed and rotated by the parking lever 42 (see fig. 1) in accordance with the movement of the parking lever 42. Recesses 24a are formed in the parking gear 24 at equal intervals in the circumferential direction, and the drive shaft 22 is locked by the engagement (meshing) of the protrusions 40a of the parking pawls 40 with the recesses 24 a. When the traction motor 8 is rotated by applying a motor torque in a brake-on state, the parking gear 24 is always geared within an angle α corresponding to the angle between the teeth, and depending on the timing of engagement with the parking pawl 40, the rotation α is at most possible _max . That is, for example, when the angle α is 60 °, α is obtained _max =60 °. Therefore, in the present embodiment, α is set to _max Parking gear 24 is set to a predetermined angle at which the gear is reliably connected. Fig. 1 schematically shows parking gear 24 and parking pawl 40.

Fig. 4 is a schematic diagram for explaining the relationship of forces acting on the vehicle on a slope. As shown in the figure, when the vehicle weight of the vehicle 2 is M [ kg ], the tire diameter is R [ M ], the slope (climbing slope) is θ [ deg ], the rigidity of the drive spindle 36 obtained by left-right combination is k [ Nm/deg ], and the torsion angle of the drive spindle 36 is β [ deg ], the torsion force of the drive spindle 36 indicated by the upward arrow becomes k β/R, the glide force indicated by the downward arrow becomes Mgsin θ, and the torsion angle of the drive spindle 36 becomes β = Mgsin θ/k. Dr/sh in the figure means the drive spindle. When the parking brake (parking brake) is not performed after the parking lock is performed by the parking mechanism 12, the torsion angle β of the drive spindle 36 is set after the brake is turned off, based on the vehicle weight, the climbing slope, the tire diameter, and the rigidity of the drive spindle 36. If no control is performed, the vehicle slips down by a distance represented by the following equation (1) unless the parking brake is performed. In the formula (1), i is a ratio of the rotational speed of the axle 36 to the rotational speed of the drive shaft 22.

[ number 1]

The control operation of the vehicle control device 1 according to the present embodiment for preventing the slip-down will be described with reference to fig. 5 and 6.

Fig. 5 is a flowchart showing a control operation for suppressing a slip-down performed by the vehicle control device. Fig. 6 is a time flow chart showing a control operation for suppressing a slip-down performed by the vehicle control device. As shown in fig. 5, first, the CPU48 determines whether the brake is on based on a signal from the brake sensor 62 (step S1). When the brake is on (YES in step S1), it is determined whether the P switch 58 is pressed by the driver (step S2). If it is determined that the brake is off (NO in step S1), the process returns to step S1. When determining that the P switch 58 is pressed (YES in step S2), the CPU48 functions as parking operation permission determination means and performs parking operation permission determination as to whether or not to permit operation of the actuator 44 (step S3). If it is determined that the P switch 58 is not pressed (NO in step S2), the process returns to step S2. The parking operation permission determination is made based on whether or not the vehicle speed is less than a predetermined speed v. That is, the CPU48 compares the vehicle speed detected by the vehicle speed sensor 54 with the predetermined speed v stored in the ROM50 in advance and determines the vehicle speed. If the detected vehicle speed is equal to or higher than the predetermined speed v (NO in step S3), the process returns to step S3. In the case where the detected vehicle speed is less than the prescribed speed v, the CPU48 sends an operation signal to the actuator 44 to allow the actuator 44 to operate (step S4). As shown in fig. 6, there is a response delay until the actuator 44 operates after the P switch 58 is turned on.

Next, the CPU48 functions as a motor angle control execution determination means, and determines whether or not to execute the motor angle control by the motor angle control means (CPU 48) based on the slope detected by the inclination angle detection sensor 56 after the actuator 44 is operated (step S5). That is, the CPU48 compares the slope detected by the inclination angle detection sensor 56 with the predetermined slope d stored in the ROM50 in advance, and starts the "TRC angle control" of rotating the traction motor 8 by a predetermined angle according to the slope detected by the inclination angle detection sensor 56 when the detected slope is equal to or greater than the predetermined slope d (step S6). The TRC angle control is shown in fig. 6 as the motor control. If the detected slope is smaller than the predetermined slope d (NO in step S5), the process returns to step S5. In the TRC angle control, after the actuator 44 is operated, the traction motor 8 is rotated in a direction opposite to the direction in which the vehicle 2 slips down, and the amount of slip-down of the vehicle 2 is reduced to an amount represented by the following expression (2).

[ number 2]

In order to rotate parking gear 24 by a predetermined angle in the brake-on state, torque T of traction motor 8 represented by the following expression (3) is required _TRC . As shown in fig. 6, the TRC angle control is started with the torque of 0. CPU48 as a motor angle control means calculates a motor torque required for rotating parking gear 24 by a predetermined angle using equation (3) and sets the motor torque as a target torqueThe motor torque is gradually increased in such a manner that the target torque is reached at a prescribed time.

[ number 3]

Next, the CPU48 as the motor angle control means monitors the integrated value of the detected angles of the traction motor 8 from the analyzer 60, and determines whether or not the detected angle reaches a predetermined angle α _max (step S7). When a predetermined angle alpha is reached _max It is assumed that parking gear 24 is geared together and TRC angle control ends. Before reaching the specified angle alpha _max If it is determined that the time during which the integrated angle does not increase with respect to the increase in the motor torque continues for a fixed time n (if it is the fixed time n) (step S8), if it is determined that the time during which the integrated angle does not increase continues for the fixed time n (YES at step S8), it is determined that the parking pawls 40 are engaged with the parking gear 24 (connected gear), and the TRC angle control is terminated (NO at step S7). At this time, the angle alpha reaches a predetermined angle _max The front connection gear is established. That is, the time until parking gear 24 reaches the successive gear is shorter than the predetermined time. If the time during which the cumulative angle does not increase does not continue for a certain time (NO in step S8), the process returns to step S8.

As described above, although the amount of the slip-down can be reduced by the TRC angle control, the CPU48 does not permit the TRC angle control to be executed in step S5 within the range of the condition expressed by the following expression (4) because the unexpected behavior of the driver such as excessive slip-up is not good enough. This prevents the driver from being unexpectedly surprised or uneasy.

[ number 4]

As described above, in the vehicle control device 1 of the present embodiment, since the TRC angle control (motor control) for reliably interlocking the parking gear 24 is performed instead of aligning the phases of the parking gear and the parking pawl in advance by the rotation of the traction motor as in the conventional art, the parking gear 24 can be reliably interlocked within a predetermined angle regardless of the phase deviation between the parking gear 24 and the parking pawl 40. Therefore, the motor control can be started after the actuator 44 is operated, and there is no need to wait until the P switch 58 is pressed while the motor torque is applied as in the conventional technique. This prevents the motor from becoming too hot to apply torque. Further, since the operation of aligning the phases of the parking gear 24 and the parking pawl 40 in advance by rotating the traction motor 8 is not required and the learning process is not required, the slip-down at the time of parking on the slope can be suppressed without increasing the control cost.

While the embodiments of the present invention have been described above, the present invention is not limited to the embodiments, and various modifications can be made within the scope of the technical idea described in the claims, the specification, and the drawings. For example, although the above embodiment describes the case where the vehicle 2 is parked on an upper slope, the same effect can be obtained also in the case where the vehicle is parked on a lower slope.

Claims

1. A vehicle control apparatus characterized by comprising:

a drive motor for driving the vehicle;

a drive shaft coupled to the drive motor;

a parking gear fixed to the drive shaft;

a parking pawl engaged with the parking gear;

an actuator that moves the parking pawl to a lock position and a lock release position in which the drive shaft is locked by engaging the parking gear by an operation of a parking lock operation member;

a slope detection unit that detects a slope of the vehicle;

a rotation angle detection unit that detects a rotation angle of the drive motor; and

and a motor angle control unit configured to rotate the driving motor by a predetermined angle corresponding to the slope detected by the slope detection unit after the actuator is operated.

2. The vehicle control apparatus according to claim 1,

the predetermined angle is a maximum angle of rotation of the parking gear until the parking pawl is engaged.

3. The vehicle control apparatus according to claim 2,

the motor angle control means calculates a motor torque required to rotate the parking gear by the predetermined angle, sets the motor torque as a target torque, and gradually increases the motor torque so as to reach the target torque for a predetermined time.

4. The vehicle control apparatus according to claim 3,

the motor angle control means determines that the parking gear is engaged with the parking pawl and ends the control when the rotation angle of the driving motor does not increase for a certain period of time with respect to an increase in the motor torque.

5. The vehicle control apparatus according to claim 1,

6. The vehicle control apparatus according to claim 5,

7. The vehicle control apparatus according to any one of claims 1 to 6, characterized by comprising:

and a parking operation permission determination unit that detects a vehicle speed after the operation of the parking lock operation element, and determines whether or not to permit the actuator operation based on the detected vehicle speed.

8. The vehicle control apparatus according to claim 7, characterized by comprising:

and a motor angle control execution determination unit configured to determine whether or not to execute the motor angle control by the motor angle control unit, based on the slope detected by the slope detection unit, after the parking operation permission determination unit permits the parking operation and the actuator operates.