JP7091887B2 - Braking control device - Google Patents

Description

The present invention relates to a braking control device.

In recent years, electric parking brakes (hereinafter referred to as EPBs (Electric Parking Brakes) or electric brake devices) are widely used in various vehicles such as passenger cars. The braking control device that controls the EPB generates an electric braking force by driving the wheel brake mechanism by, for example, a motor.

Further, the EPB can be used not only when the vehicle is stopped but also when the vehicle is running. Examples of situations where the EPB is used when the vehicle is traveling include an emergency, automatic driving, and a hydraulic brake failure. When the EPB is used when the vehicle is running, high control accuracy is required.

Further, in EPB, braking control is performed based on the drive characteristics. As the drive characteristics, for example, the relationship between the motor current value and the electric braking force, the physical quantity related to the stroke amount of the propulsion shaft in EPB (for example, the motor rotation speed) and the electric braking force can be considered.

Japanese Unexamined Patent Publication No. 2012-96793

However, since the above-mentioned drive characteristics differ depending on individual differences of brake components, aging deterioration, environmental temperature, and the like, the control accuracy of the electric braking force may be lowered in the prior art.

Therefore, one of the problems of the present invention is to provide, for example, a braking control device that realizes an electric braking force with high control accuracy.

The present invention is, for example, a hydraulic braking device that presses a braking member by hydraulic pressure toward a braking member that rotates integrally with a wheel to generate a hydraulic braking force, and a motor toward the braking member. A braking control device applied to a vehicle including an electric brake device that presses the braking member to generate an electric braking force by driving the brake member, and controls the hydraulic brake device. A unit and an electric brake control unit that controls the electric brake device based on a drive characteristic value that is a detected value related to the drive characteristic of the electric brake device. The hydraulic brake control unit generates a predetermined hydraulic pressure by controlling the hydraulic brake device, and the electric brake control unit drives the electric brake device in a state where the predetermined hydraulic pressure is generated. , The drive characteristic value of the electric brake device with respect to the predetermined hydraulic pressure is detected.

Further, in the above-mentioned braking control device, for example, the electric brake control unit drives the electric brake device in a state where the predetermined hydraulic pressure is generated to move the propulsion shaft toward the braked member and piston. Then, after the hydraulic pressure becomes zero by the control of the hydraulic brake device by the hydraulic brake control unit, the control of moving the propulsion shaft to the side facing the braked member is executed. The current value of the motor at that time is detected as the drive characteristic value.

Further, in the above braking control device, for example, the electric brake control unit drives the electric braking device in a state where the predetermined hydraulic pressure is generated to move the propulsion shaft from the specified position to the braking member side. The stroke amount of the propulsion shaft when the vehicle is brought into contact with the piston is detected as the drive characteristic value.

Further, in the braking control device, for example, the hydraulic brake control unit generates a plurality of stepwise hydraulic pressures as the predetermined hydraulic pressure, and the electric brake control unit applies to each of the plurality of hydraulic pressures. The drive characteristic value of the electric brake device is detected.

FIG. 1 is a schematic view showing an overall outline of the vehicle brake device of the first embodiment. FIG. 2 is a schematic cross-sectional view of a rear wheel system wheel brake mechanism provided in the vehicle brake device of the first embodiment. FIG. 3 is a graph showing the state of changes over time such as W / C pressure when the characteristic information is corrected in the first embodiment. FIG. 4 is a graph showing characteristic information in the first embodiment. FIG. 5 is a flowchart showing processing by the braking control device of the first embodiment. FIG. 6 is a graph showing the state of changes over time such as W / C pressure when the characteristic information is corrected in the second embodiment. FIG. 7 is a graph showing characteristic information in the second embodiment. FIG. 8 is a flowchart showing processing by the braking control device of the second embodiment.

Hereinafter, exemplary embodiments of the present invention (Embodiments 1 and 2) will be disclosed. The configurations of the embodiments shown below, as well as the actions and results (effects) brought about by the configurations, are examples. The present invention can also be realized by configurations other than those disclosed in the following embodiments. Further, according to the present invention, it is possible to obtain at least one of various effects (including derivative effects) obtained by the following configurations.

(First Embodiment)
In the first embodiment, a vehicle brake device to which a disc brake type EPB is applied to the rear wheel system will be described as an example. FIG. 1 is a schematic view showing an overall outline of the vehicle brake device of the first embodiment. FIG. 2 is a schematic cross-sectional view of a rear wheel system wheel brake mechanism provided in the vehicle brake device of the first embodiment. Hereinafter, description will be made with reference to these figures.

As shown in FIG. 1, the vehicle brake device of the first embodiment includes a service brake 1 (hydraulic brake device) and EPB2 (electric brake device).

The service brake 1 is directed toward the braked member (brake disc 12 in FIG. 2) that rotates integrally with the wheel based on the driver's depression of the brake pedal 3, and the braking member (brake pad 11 in FIG. 2) is subjected to hydraulic pressure. ) Is pressed to generate a service braking force (hydraulic braking force). Specifically, the service brake 1 boosts the pedaling force corresponding to the driver's depression of the brake pedal 3 by the booster 4, and then applies the brake hydraulic pressure according to the boosted pedaling force to the master cylinder ( Hereinafter, it is referred to as M / C.) It is generated in 5. Then, the service braking force is generated by transmitting this brake fluid pressure to the wheel cylinder (hereinafter referred to as W / C) 6 provided in the wheel brake mechanism of each wheel. Further, an actuator 7 for controlling the brake fluid pressure is provided between the M / C 5 and the W / C 6. The actuator 7 adjusts the service braking force generated by the service brake 1 and performs various controls (for example, anti-skid control, etc.) for improving the safety of the vehicle.

Various controls using the actuator 7 are executed by the ESC (Electronic Stability Control) -ECU 8 (braking control device, hydraulic brake control unit) that controls the service braking force. For example, the ESC-ECU 8 outputs a control current for controlling various control valves (not shown) provided in the actuator 7 and a motor for driving a pump to control the hydraulic circuit provided in the actuator 7 and W / C6. Controls the W / C pressure transmitted to. As a result, wheel slip is avoided and the safety of the vehicle is improved.

For example, the actuator 7 controls the pressure increase control to control that the brake hydraulic pressure generated in the M / C 5 or the brake hydraulic pressure generated by the pump drive is applied to the W / C 6 for each wheel. It is equipped with a valve and a decompression control valve that reduces the W / C pressure by supplying the brake liquid in each W / C6 to the reservoir, and is configured to be able to increase, hold, and depressurize the W / C pressure. ing. Further, the actuator 7 makes it possible to realize the automatic pressurizing function of the service brake 1, and based on the pump drive and the control of various control valves, W / C6 is automatically applied even when there is no brake operation. I can press.

On the other hand, the EPB 2 generates an electric braking force by driving the wheel brake mechanism by the motor 10, and has an EPB-ECU 9 (braking control device; electric brake control unit) that controls the driving of the motor 10. It is configured. Specifically, for example, EPB2 is a braking member (FIG. 2) by driving a motor 10 toward a braked member (brake disc 12 in FIG. 2) so that the vehicle does not move unintentionally when parked. The brake pad 11) is pressed to generate an electric braking force. The EPB-ECU 9 and the ESC-ECU 8 transmit and receive information by, for example, CAN (Controller Area Network) communication.

The wheel brake mechanism has a mechanical structure that generates a braking force in the vehicle braking device of the first embodiment. First, the front wheel system wheel braking mechanism has a structure that generates a service braking force by operating the service brake 1. ing. On the other hand, the wheel brake mechanism of the rear wheel system has a shared structure that generates a braking force for both the operation of the service brake 1 and the operation of the EPB 2. Because the front wheel system wheel brake mechanism is a wheel brake mechanism that has been generally used in the past without a mechanism that generates an electric braking force based on the operation of EPB2 with respect to the rear wheel system wheel brake mechanism. , Here, the description is omitted, and the rear wheel system wheel brake mechanism will be described below.

In the rear wheel system wheel brake mechanism, the brake pad 11 which is the friction material shown in FIG. 2 is pressed not only when the service brake 1 is operated but also when the EPB 2 is operated, and the brake pad 11 is rubbed. By sandwiching the brake disc 12 (12RL, 12RR, 12FR, 12FL) which is a material, a frictional force is generated between the brake pad 11 and the brake disc 12, and a braking force is generated.

Specifically, the wheel brake mechanism rotates the motor 10 directly fixed to the body 14 of the W / C 6 for pressing the brake pad 11 as shown in FIG. 2 in the caliper 13 shown in FIG. As a result, the spur gear 15 provided on the drive shaft 10a of the motor 10 is rotated. Then, the brake pad 11 is moved by transmitting the rotational force (output) of the motor 10 to the spur gear 16 meshed with the spur gear 15, and the electric braking force by the EPB 2 is generated.

In the caliper 13, in addition to the W / C 6 and the brake pad 11, a part of the end face of the brake disc 12 is accommodated so as to be sandwiched between the brake pads 11. W / C6 can generate W / C pressure in the hollow portion 14a which is the brake fluid accommodating chamber by introducing the brake fluid pressure into the hollow portion 14a of the cylinder-shaped body 14 through the passage 14b. A rotating shaft 17, a propulsion shaft 18, a piston 19, and the like are provided in the hollow portion 14a.

One end of the rotary shaft 17 is connected to the spur gear 16 through an insertion hole 14c formed in the body 14, and when the spur gear 16 is rotated, the rotary shaft 17 is rotated along with the rotation of the spur gear 16. A male screw groove 17a is formed on the outer peripheral surface of the rotating shaft 17 at the end of the rotating shaft 17 opposite to the end connected to the spur gear 16. On the other hand, the other end of the rotating shaft 17 is pivotally supported by being inserted into the insertion hole 14c. Specifically, the insertion hole 14c is provided with a bearing 21 together with the O-ring 20 so that the brake liquid does not leak through between the rotating shaft 17 and the inner wall surface of the insertion hole 14c in the O-ring 20. While doing so, the other end of the rotating shaft 17 is pivotally supported by the bearing 21.

The propulsion shaft 18 is composed of a nut made of a hollow tubular member, and a female screw groove 18a screwed with the male screw groove 17a of the rotary shaft 17 is formed on the inner wall surface. The propulsion shaft 18 is configured in a columnar or polygonal columnar shape provided with a key for preventing rotation, for example, so that even if the rotation shaft 17 rotates, it can be rotated around the rotation center of the rotation shaft 17. It has no structure. Therefore, when the rotary shaft 17 is rotated, the rotational force of the rotary shaft 17 becomes a force for moving the propulsion shaft 18 in the axial direction of the rotary shaft 17 due to the engagement between the male screw groove 17a and the female screw groove 18a. Convert. When the drive of the motor 10 is stopped, the propulsion shaft 18 stops at the same position due to the frictional force due to the engagement between the male screw groove 17a and the female screw groove 18a, and becomes the target electric braking force. If the drive of the motor 10 is stopped at that time, the propulsion shaft 18 is held at that position, and the desired electric braking force is held so that the motor 10 can be self-locked (hereinafter, simply referred to as “lock”).

The piston 19 is arranged so as to surround the outer circumference of the propulsion shaft 18, is composed of a bottomed cylindrical member or a polygonal cylinder member, and the outer peripheral surface is in contact with the inner wall surface of the hollow portion 14a formed in the body 14. It is arranged like this. A structure in which a sealing member 22 is provided on the inner wall surface of the body 14 so that brake fluid does not leak between the outer peripheral surface of the piston 19 and the inner wall surface of the body 14, and W / C pressure can be applied to the end surface of the piston 19. It is said that. The seal member 22 is used to generate a reaction force for pulling back the piston 19 during release control after lock control. Since the seal member 22 is provided, basically, even if the brake pad 11 and the piston 19 are pushed by the inclined brake disc 12 during turning within a range not exceeding the elastic deformation amount of the seal member 22, they are braked. It can be pushed back to the disc 12 side so that the space between the brake disc 12 and the brake pad 11 is held by a predetermined clearance (clearance C2 in FIG. 2).

Further, if the propulsion shaft 18 is provided with a key for preventing rotation, the piston 19 is provided with a key for preventing rotation so that the piston 19 is not rotated about the rotation center of the rotation shaft 17 even if the rotation shaft 17 rotates. A sliding key groove is provided, and when the propulsion shaft 18 has a polygonal columnar shape, it has a polygonal tubular shape having a corresponding shape.

A brake pad 11 is arranged at the tip of the piston 19, and the brake pad 11 is moved in the left-right direction of the paper as the piston 19 moves. Specifically, the piston 19 can move to the left of the paper as the propulsion shaft 18 moves, and at the end of the piston 19 (the end opposite to the end on which the brake pad 11 is arranged). By applying W / C pressure, it is configured to be able to move to the left of the paper surface independently of the propulsion shaft 18. Then, when the propulsion shaft 18 is in the release position (the state before the motor 10 is rotated), which is the standby position at the time of normal release, the brake fluid pressure in the hollow portion 14a is not applied (W / C). When the pressure = 0), the piston 19 is moved to the right of the paper surface by the elastic force of the seal member 22 described later, and the brake pad 11 can be separated from the brake disc 12.

Further, when the motor 10 is rotated and the propulsion shaft 18 is moved to the left of the paper surface from the initial position, even if the W / C pressure becomes 0, the moved propulsion shaft 18 causes the piston 19 to move to the right of the paper surface. Movement to is restricted and the brake pads 11 are held in place. The clearance C1 in FIG. 2 indicates the distance between the tip of the propulsion shaft 18 and the piston 19. After the EPB release is complete, the propulsion shaft 18 is fixed in position with respect to the body 14.

In the wheel brake mechanism configured in this way, when the service brake 1 is operated, the piston 19 is moved to the left on the paper surface based on the W / C pressure generated by the service brake 1, and the brake pad 11 is braked. Pressed by the disc 12 to generate a service braking force. Further, when the EPB2 is operated, the spur gear 15 is rotated by driving the motor 10, and the spur gear 16 and the rotary shaft 17 are rotated accordingly, so that the male screw groove 17a and the female screw groove 18a are rotated. The propulsion shaft 18 is moved to the brake disc 12 side (to the left of the paper) based on the meshing of the above. Along with this, the tip of the propulsion shaft 18 abuts on the piston 19 to press the piston 19, and the piston 19 is also moved in the same direction, so that the brake pad 11 is pressed against the brake disc 12 and an electric braking force is generated. Let me. Therefore, it is possible to provide a shared wheel brake mechanism that generates a braking force for both the operation of the service brake 1 and the operation of the EPB 2.

In the vehicle braking device of the first embodiment, the state of electric braking force generated by EPB2 can be confirmed by confirming the current detection value by the current sensor (not shown) that detects the current of the motor 10. It is possible to recognize the current detection value.

The front-rear G sensor 25 detects G (acceleration) in the front-rear direction (traveling direction) of the vehicle, and transmits a detection signal to the EPB-ECU 9.

The M / C pressure sensor 26 detects the M / C pressure in the M / C 5 and transmits a detection signal to the EPB-ECU 9.

The temperature sensor 28 detects the temperature of the wheel brake mechanism (for example, the brake disc) and transmits the detection signal to the EPB-ECU 9.

The wheel speed sensor 29 detects the rotation speed of each wheel and transmits a detection signal to the EPB-ECU 9. The wheel speed sensor 29 is actually provided one by one corresponding to each wheel, but detailed illustration and description thereof will be omitted here.

The EPB-ECU 9 is composed of a well-known microcomputer equipped with a CPU, ROM, RAM, I / O, etc., and controls the parking brake by controlling the rotation of the motor 10 according to a program stored in the ROM or the like. Is.

The EPB-ECU 9 inputs, for example, a signal or the like according to the operation state of the operation SW (switch) 23 provided in the instrument panel (not shown) in the vehicle interior, and causes the motor 10 according to the operation state of the operation SW 23. Drive. Further, the EPB-ECU 9 executes lock control, release control, and the like based on the current detection value of the motor 10, and the lock control is being performed based on the control state, and the wheels are locked by the lock control. It recognizes that there is, that the release control is in progress, and that the wheel is in the release state (EPB release state) by the release control. Then, the EPB-ECU 9 outputs signals for performing various displays to the indicator lamp 24 provided on the instrument panel.

The vehicle brake device configured as described above basically performs an operation of generating a braking force in the vehicle by generating a service braking force by the service brake 1 when the vehicle is running. Further, when the vehicle is stopped by the service brake 1, the driver presses the operation SW23 to operate EPB2 to generate an electric braking force to maintain the stopped state, and then release the electric braking force. It does the action of doing something like that. That is, as the operation of the service brake 1, when the driver operates the brake pedal 3 while the vehicle is running, the brake fluid pressure generated in the M / C 5 is transmitted to the W / C 6 to generate the service braking force. .. Further, as the operation of EPB2, the piston 19 is moved by driving the motor 10 and the brake pad 11 is pressed against the brake disc 12 to generate an electric braking force to lock the wheels, or the brake pad 11 is pressed. By separating it from the brake disc 12, the electric braking force is released and the wheels are released.

Specifically, the lock / release control is used to generate and release the electric braking force. In the lock control, the EPB2 is operated by rotating the motor 10 in the forward direction, and the rotation of the motor 10 is stopped at a position where the desired electric braking force can be generated by the EPB2, and this state is maintained. As a result, a desired electric braking force is generated. In the release control, the EPB2 is operated by rotating the motor 10 in the reverse direction, and the electric braking force generated by the EPB2 is released.

In addition, even when the vehicle is running, there are situations where it is effective to use EPB2, for example, in an emergency, automatic driving, or when the service brake 1 fails, so use EPB2 in those situations. May be good. When EPB2 is used while the vehicle is running, high control accuracy of EPB2 is required. That is, if the control accuracy of EPB2 is low, an error will occur between the planned stop position and the actual stop position when the EPB is used while the vehicle is running.

Further, the EPB-ECU 9 controls the EPB2 based on the characteristic information (drive characteristic value) which is the information (detection value) regarding the drive characteristic of the EPB2. The drive characteristics include, for example, the relationship between the motor current value and the electric braking force, the relationship between the physical quantity (for example, the motor rotation speed) related to the stroke amount of the propulsion shaft 18 in EPB2, and the electric braking force. Further, the characteristic information may be stored in the form of, for example, a map, a table, a mathematical formula, or the like.

Further, in EPB2, by arranging a plurality of gears between the motor 10 and the propulsion shaft 18, the rotational speed decreases each time the rotational force of the motor 10 is transmitted through the gears, thereby ensuring the output torque. .. The sliding resistance differs depending on individual differences of parts such as a plurality of gears, deterioration over time, environmental temperature, and the like. The difference in sliding resistance means that the drive characteristics are different, and the control accuracy of the electric braking force may be lowered in the prior art. Therefore, in the first embodiment, the electric braking force with high control accuracy is realized by the following method.

First, the ESC-ECU 8 generates a predetermined hydraulic pressure by controlling the service brake 1. Further, the EPB-ECU 9 drives the EPB2 in a state where a predetermined hydraulic pressure is generated, and detects a drive characteristic value of the EPB2 with respect to the predetermined hydraulic pressure (corrects the characteristic information).

More specifically, the EPB-ECU 9 drives the EPB 2 in a state where a predetermined hydraulic pressure is generated, moves the propulsion shaft 18 toward the brake disc 12, and brings it into contact with the piston 19, and then the ESC-ECU 8 After the hydraulic pressure becomes zero by the control of the service brake 1 by the above, the current value of the motor 10 when the control for moving the propulsion shaft 18 to the side facing the brake disc 12 is executed is detected as the drive characteristic value ( Correct the characteristic information).

Further, when the ESC-ECU 8 generates a plurality of stepwise hydraulic pressures as predetermined hydraulic pressures, the EPB-ECU 9 detects the drive characteristic value of the EPB2 for each of the plurality of hydraulic pressures (corrects the characteristic information).

Hereinafter, the correction of the characteristic information will be described in detail with reference to FIGS. 3 to 5. FIG. 3 is a graph showing the state of changes over time such as W / C pressure when the characteristic information is corrected in the first embodiment. In the graph of FIG. 3A, the vertical axis represents the W / C pressure (MPa) and the horizontal axis represents the time (ms). Further, in the graph of FIG. 3B, the vertical axis represents the current detection value (A) of the motor 10 (hereinafter, may be simply referred to as “current value”), and the horizontal axis represents time (ms). .. Further, in the graph of FIG. 3C, the vertical axis represents the braking force (N (Newton)) and the horizontal axis represents the time (ms).

Further, FIG. 4 is a graph showing characteristic information in the first embodiment. In the graph of FIG. 4, the vertical axis represents the current detection value (A) of the motor 10, and the horizontal axis represents the W / C pressure (MPa). Further, FIG. 5 is a flowchart showing processing by the braking control device of the first embodiment. The following processing is started, for example, when the vehicle is stopped, in response to the operation of the operation SW23 by the user.

First, the ESC-ECU 8 generates a predetermined hydraulic pressure by controlling the service brake 1 (step S1 in FIG. 5). At this time, the W / C pressure (FIG. 3A) begins to increase at time t1 and reaches a predetermined hydraulic pressure (P) at time t2. Further, the braking force (FIG. 3 (c)) increases accordingly from the time t1 to the time t2.

Next, the EPB-ECU 9 drives the EPB 2 in a state where a predetermined hydraulic pressure is generated, moves the propulsion shaft 18 toward the brake disc 12, and brings it into contact with the piston 19 (step S2 in FIG. 5). At this time, the current value (FIG. 3B) suddenly increased due to the inrush current at the time t3 when the driving of the motor 10 was started, and after the current value became stable, the propulsion shaft 18 came into contact with the piston 19. (That is, the clearance C1 in FIG. 2 becomes zero) causes the current value to increase from time t4 to time t5.

Next, the hydraulic pressure is reduced to zero by controlling the service brake 1 by the ESC-ECU 8 (step S3 in FIG. 5). At this time, the W / C pressure (FIG. 3A) begins to decrease at time t6 and becomes zero at time t7. On the other hand, since the propulsion shaft 18 is in contact with the piston 19, the braking force (FIG. 3 (c)) is slightly reduced.

Next, the EPB-ECU 9 drives the EPB 2 to execute control to move the propulsion shaft 18 to the side facing the brake disc 12 (step S4 in FIG. 5). At this time, the current value (FIG. 3B) suddenly increased due to the inrush current at the time t8 when the driving of the motor 10 was started, and then the EPB-ECU 9 of the motor 10 at the time t9 when the influence of the inrush current disappeared. The current detection value I is acquired (step S5 in FIG. 5). Further, the current value (FIG. 3 (b)) and the braking force (FIG. 3 (c)) decrease from time t9 to time t10.

Next, the EPB-ECU 9 corrects the characteristic information (FIG. 4) based on the predetermined hydraulic pressure (P) and the current detection value I of the motor 10 acquired in step S5.

As described above, according to the first embodiment, the EPB-ECU 9 corrects the characteristic information based on the current drive characteristics in consideration of individual differences of brake components, aging deterioration, environmental temperature, and the like. It is possible to realize an electric braking force with control accuracy.

Further, a plurality of stepwise hydraulic pressures are set as predetermined hydraulic pressures (P in FIG. 3A), and the EPB-ECU 9 sets the drive characteristic values (current values) of EPB2 for each of the plurality of hydraulic pressures. If the characteristic information is corrected based on this, the control accuracy can be further improved.

In general, EPB-ECU 9 and brake components are treated separately before assembling the vehicle. Therefore, the calibration related to the control of EPB2 by the EPB-ECU 9 cannot be executed until the assembly of the vehicle is completed. However, according to the first embodiment, after the assembly of the vehicle is completed, the electric braking force with high control accuracy is realized by correcting the characteristic information as described above without using various sensors for calibration separately. can do. In addition, it can be easily dealt with when the drive characteristics of the left and right wheels are different.

(Second Embodiment)
Next, the second embodiment will be described. The same matters as in the first embodiment (matters described with reference to FIGS. 1 and 2) will be omitted as appropriate.

In the second embodiment, the EPB-ECU 9 drives the EPB 2 in a state where a predetermined hydraulic pressure is generated to move the propulsion shaft 18 from the specified position to the brake disc 12 side and bring it into contact with the piston 19. The stroke amount of the propulsion shaft 18 (the motor rotation speed corresponding to the stroke amount may be used) is detected as the drive characteristic value (the characteristic information is corrected).

Hereinafter, the correction of the characteristic information will be described in detail with reference to FIGS. 6 to 8. FIG. 6 is a graph showing the state of changes over time such as W / C pressure when the characteristic information is corrected in the second embodiment. In the graph of FIG. 6A, the vertical axis represents the W / C pressure (MPa) and the horizontal axis represents the time (ms). Further, in the graph of FIG. 6B, the vertical axis represents the current detection value (A) of the motor 10, and the horizontal axis represents the time (ms). Further, in the graph of FIG. 6 (c), the vertical axis represents the stroke amount (mm) of the piston 19, and the horizontal axis represents the time (ms). Further, in the graph of FIG. 6D, the vertical axis represents the stroke amount (mm) of the propulsion shaft 18, and the horizontal axis represents the time (ms).

Further, FIG. 7 is a graph showing characteristic information in the second embodiment. In the graph of FIG. 7, the vertical axis represents the stroke amount (mm) of the propulsion shaft 18, and the horizontal axis represents the W / C pressure (MPa). Further, FIG. 8 is a flowchart showing the processing by the braking control device of the second embodiment. The following processing is started, for example, when the vehicle is stopped, in response to the operation of the operation SW23 by the user.

First, the ESC-ECU 8 generates a predetermined hydraulic pressure by controlling the service brake 1 (step S11 in FIG. 8). At this time, the W / C pressure (FIG. 6A) begins to increase at time t21 and reaches a predetermined hydraulic pressure (P) at time t22. Further, the stroke amount of the piston 19 (FIG. 6 (c)) increases accordingly from the time t21 to the time t22.

Next, the EPB-ECU 9 drives the EPB 2 in a state where a predetermined hydraulic pressure is generated to move the propulsion shaft 18 from the specified position to the brake disc 12 side and bring it into contact with the piston 19 (step S12 in FIG. 8). ). At this time, the current value (FIG. 6B) suddenly increased due to the inrush current at the time t23 when the driving of the motor 10 was started, and after the current value became stable, the propulsion shaft 18 came into contact with the piston 19. (That is, the clearance C1 in FIG. 2 becomes zero) causes the current value to increase from time t24 to time t25. At this time, the stroke amount of the propulsion shaft 18 (FIG. 6 (d)) increases from the time t23 to the time t24. If the propulsion shaft 18 is not at the specified position at first, the propulsion shaft 18 may be moved to the specified position and then moved to the brake disc 12 side.

Next, the EPB-ECU 9 calculates the stroke amount of the propulsion shaft 18 based on the rotation speed of the motor 10 (step S13 in FIG. 8).

Next, the EPB-ECU 9 corrects the characteristic information (FIG. 7) based on the predetermined hydraulic pressure (P) and the stroke amount of the propulsion shaft 18 calculated in step S13.

Next, the hydraulic pressure is reduced to zero by controlling the service brake 1 by the ESC-ECU 8. At this time, the W / C pressure (FIG. 6A) begins to decrease at time t26 and becomes zero at time t27.

Next, the EPB-ECU 9 drives the EPB 2 to execute control to move the propulsion shaft 18 to the side facing the brake disc 12. At this time, the current value (FIG. 6B) suddenly increases due to the inrush current at the time t28 when the driving of the motor 10 is started, and then the influence of the inrush current disappears at the time t29. Further, the stroke amount of the piston 19 (FIG. 6 (c)) and the stroke amount of the propulsion shaft 18 (FIG. 6 (d)) decrease from the time t29 to the time t30.

As described above, according to the second embodiment, the EPB-ECU 9 corrects the characteristic information based on the current drive characteristics in consideration of individual differences of brake components, aging deterioration, environmental temperature, and the like. It is possible to realize an electric braking force with control accuracy.

It should be noted that a plurality of stepwise hydraulic pressures are set as predetermined hydraulic pressures (P in FIG. 6A), and the EPB-ECU 9 drives the EPB2 for each of the plurality of hydraulic pressures (propulsion shaft 18). If the characteristic information is corrected based on the stroke amount), the control accuracy can be further improved.

Although the embodiments of the present invention have been exemplified above, the above embodiments are merely examples and are not intended to limit the scope of the invention. The above embodiment can be implemented in various other embodiments, and various omissions, replacements, combinations, and changes can be made without departing from the gist of the invention. Further, specifications (structure, type, number, etc.) such as each configuration and shape can be appropriately changed and implemented.

For example, in the above-described embodiment, the case of the disc brake type EPB has been described as an example, but the present invention can also be applied to the drum brake type EPB.

Further, the shape of the graph showing the characteristic information in the first embodiment is not limited to the linear shape shown in FIG. 4, and may be another shape. Further, the shape of the graph showing the characteristic information in the second embodiment is not limited to the curved shape shown in FIG. 7, and may be another shape.

In addition, the characteristic information is corrected based on the detected value, and the stored map, table, mathematical formula, etc. are compared with the detected value, and when there is a deviation of a predetermined value or more between the stored value and the detected value. It may be determined that it is abnormal.

1 ... Service brake, 2 ... EPB, 5 ... M / C, 6 ... W / C, 7 ... Actuator, 8 ... ESC-ECU, 9 ... EPB-ECU, 10 ... Motor, 11 ... Brake pad (braking member), 12 ... Brake disc (braked member), 13 ... Caliper, 14 ... Body, 14a ... Hollow part, 14b ... Passage, 17 ... Rotating shaft, 17a ... Male thread groove, 18 ... Propulsion shaft, 18a ... Female thread groove, 19 ... Piston, 23 ... Operation SW, 24 ... Indicator lamp, 25 ... Front and rear G sensor, 26 ... M / C pressure sensor, 28 ... Temperature sensor, 29 ... Wheel speed sensor.

Claims (3)

A hydraulic braking device that generates hydraulic braking force by pressing the braking member with hydraulic pressure toward the braked member that rotates integrally with the wheel.
A braking control device applied to a vehicle comprising an electric braking device that presses the braking member toward the braked member by driving a motor to generate an electric braking force.
A hydraulic brake control unit that controls the hydraulic brake device,
A motor brake control unit that controls the electric brake device based on a drive characteristic value that is a detected value related to the drive characteristic of the electric brake device is provided.
The hydraulic brake control unit generates a predetermined hydraulic pressure by controlling the hydraulic brake device.
The electric brake control unit drives the electric brake device in a state where the predetermined hydraulic pressure is generated, detects the drive characteristic value of the electric brake device with respect to the predetermined hydraulic pressure, and at that time, the predetermined hydraulic brake device. In a state where hydraulic pressure is generated, the electric brake device is driven to move the propulsion shaft to the side to be braked to bring it into contact with the piston, and then the hydraulic brake control unit controls the hydraulic brake device. A braking control device that detects the current value of the motor as the drive characteristic value when the control to move the propulsion shaft to the side facing the braked member is executed after the hydraulic pressure becomes zero by the control. .. A hydraulic braking device that generates hydraulic braking force by pressing the braking member with hydraulic pressure toward the braked member that rotates integrally with the wheel.
A braking control device applied to a vehicle comprising an electric braking device that presses the braking member toward the braked member by driving a motor to generate an electric braking force.
A hydraulic brake control unit that controls the hydraulic brake device,
A motor brake control unit that controls the electric brake device based on a drive characteristic value that is a detected value related to the drive characteristic of the electric brake device is provided.
The hydraulic brake control unit generates a predetermined hydraulic pressure by controlling the hydraulic brake device.
The electric brake control unit drives the electric brake device in a state where the predetermined hydraulic pressure is generated, detects the drive characteristic value of the electric brake device with respect to the predetermined hydraulic pressure, and at that time, the predetermined. The drive characteristic is the stroke amount of the propulsion shaft when the electric brake device is driven in a state where hydraulic pressure is generated to move the propulsion shaft from a specified position to the side to be braked and brought into contact with the piston. Braking control device to detect as a value . A hydraulic braking device that generates hydraulic braking force by pressing the braking member with hydraulic pressure toward the braked member that rotates integrally with the wheel.
A braking control device applied to a vehicle comprising an electric braking device that presses the braking member toward the braked member by driving a motor to generate an electric braking force.
A hydraulic brake control unit that controls the hydraulic brake device,
A motor brake control unit that controls the electric brake device based on a drive characteristic value that is a detected value related to the drive characteristic of the electric brake device is provided.
The hydraulic brake control unit generates a predetermined hydraulic pressure by controlling the hydraulic brake device.
The electric brake control unit drives the electric brake device in a state where the predetermined hydraulic pressure is generated, and detects the drive characteristic value of the electric brake device with respect to the predetermined hydraulic pressure.
The hydraulic brake control unit generates a plurality of hydraulic pressures in stages as the predetermined hydraulic pressure.
The electric brake control unit is a braking control device that detects the drive characteristic value of the electric brake device for each of the plurality of hydraulic pressures .

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