JP2023063842A - Device and method for controlling electric brake, and electric brake device - Google Patents

Abstract

To provide a device and a method for controlling an electric brake, and an electric brake device which can suppress deterioration in estimation accuracy based on a current value of an electric motor.SOLUTION: A brake mechanism 22 includes an electric motor 26, a torsion spring 33, and a ratchet mechanism 34. The ratchet mechanism 34 is configured so that a tip 33 of the torsion spring 33 gets over projections 34A, in a case in which rotational torque acting on the torsion spring 33 exceeds a predetermined value when the electric motor 26 is normally rotated. Control devices 41, 10 for braking detect that the tip 33B of the torsion spring 33 gets over the projections 34B on the basis of reduction of a current value energized to the electric motor 26 with respect to a rotational amount of the electric motor 26, when the electric motor 26 is normally rotated.SELECTED DRAWING: Figure 3

Description

TECHNICAL FIELD The present invention relates to an electric brake control device, a control method, and an electric brake device.

Patent Literature 1 discloses a vehicle electric brake device having a rotating shaft supported by a case of an energy storage mechanism so as to be rotatable integrally with an output shaft of an electric motor. This vehicle electric brake device stores elastic energy by elastically deforming the spiral spring inside the energy storage mechanism when the rotary shaft rotates forward, and releases the elastic energy stored in the spiral spring when the rotary shaft rotates in the reverse direction. to apply rotational torque of reverse rotation to the rotating shaft.

Patent Literature 2 discloses a parking brake control device that detects an abnormality. This parking brake control device stores, as reference values, changes in the motor current value in three regions of inrush current, no-load current, and current rise in the normal state, and stores them as reference values when using the electric parking brake. Abnormalities are detected by comparing with the current value of the motor current value.

JP 2013-24389 A JP 2014-19235 A

In Patent Document 1, a torque limiter, a so-called ratchet mechanism, is provided to prevent the spiral spring from elastically deforming more than necessary. However, in the electric brake device, when the current value of the electric motor is used for thrust estimation, there is a risk that the current value will suddenly change due to the riding of the ratchet, degrading the thrust estimation accuracy. Further, in Patent Document 2, an abnormality is detected by comparing a reference current value and a current current value. However, no consideration is given to non-abnormal cases such as ratchet riding.

One of the objects of the present invention is to provide an electric brake control device, a control method, and an electric brake device capable of suppressing deterioration of estimation accuracy based on the current value of the electric motor.

An embodiment of the present invention is an electric motor controlled by a control unit, and the forward rotation of the electric motor accumulates elastic energy during forward movement to move the friction pad in the direction of pressing against the disc, and the electric motor reversely rotates. a torsion spring that releases the elastic energy during the backward movement that moves the friction pad away from the disk by means of a ratchet mechanism configured such that one end of the torsion spring climbs over the engaging portion when rotational torque acting on the torsion spring exceeds a predetermined value during forward rotation; When the electric motor rotates in the normal direction, the control unit causes one end of the torsion spring to move the engaging portion based on a decrease in a current value applied to the electric motor with respect to the amount of rotation of the electric motor. Detect overcoming.

In one embodiment of the present invention, an electric motor stores elastic energy during forward movement in which the friction pad is pressed against the disc by forward rotation of the electric motor, and the friction pad is rotated in the reverse direction by rotating the electric motor in the reverse direction. in a direction away from the disk, the torsion spring releasing the elastic energy during the backward movement, and a plurality of engaging portions with which one end of the torsion spring is engaged, and when the electric motor rotates forward and a ratchet mechanism configured such that one end of the torsion spring climbs over the engaging portion when the rotational torque acting on the torsion spring exceeds a predetermined value, the method comprising: A control unit for controlling an electric motor rotates one end of the torsion spring to the engaging portion based on a decrease in the value of current applied to the electric motor with respect to the amount of rotation of the electric motor when the electric motor rotates forward. Detects that the

Further, one embodiment of the present invention is an electric brake device, wherein an electric motor and an electric motor store elastic energy at the time of forward movement in which the friction pad is moved in a direction of pressing against the disc by forward rotation of the electric motor, and the electric motor a torsion spring that releases the elastic energy when the friction pad is moved away from the disk by reverse rotation of the torsion spring; a ratchet mechanism configured such that one end of the torsion spring overcomes the engaging portion when a rotational torque acting on the torsion spring exceeds a predetermined value when the electric motor rotates forward; and a control device that detects that one end of the torsion spring has passed over the engaging portion when rotating, based on a decrease in the value of current applied to the electric motor with respect to the amount of rotation of the electric motor.

ADVANTAGE OF THE INVENTION According to this invention, the deterioration of the estimation precision based on the electric current value of an electric motor can be suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic which shows the system configuration|structure of the vehicle by which the electric brake device by embodiment was mounted. FIG. 2 is a cross-sectional view of the electric brake in FIG. 1; FIG. 3 is an explanatory diagram of a deceleration mechanism and a fail-open mechanism of an electric brake in FIG. 2; It is a flowchart which shows the detection processing of overcoming by a control apparatus. It is a block diagram which shows the detection processing of overcoming by a control apparatus. It is a flow chart which shows an example of estimation processing of a bad contact position by a control device. FIG. 11 is a flow chart showing another example of a bad contact position estimation process by the control device; FIG. It is a flowchart which shows an example of the estimation process of the thrust by a control apparatus. FIG. 11 is a flowchart showing another example of thrust estimation processing by the control device; FIG. FIG. 4 is a characteristic diagram showing an example of time change of current (Q-axis current); FIG. 4 is a characteristic diagram showing an example of thrust over time;

Hereinafter, a case in which the electric brake device according to the embodiment is mounted on a four-wheeled vehicle will be described as an example with reference to the accompanying drawings. 4, 6, 7, 8 and 9 use the notation "S" (for example, step 1 = "S1"). In addition, two hatched lines in FIG. 1 represent electrical lines.

In FIG. 1, a vehicle 1 is equipped with a braking device 2 (vehicle braking device, braking system) that applies braking force to wheels (front wheels 3L, 3R, rear wheels 5L, 5R) to brake the vehicle 1. there is The brake device 2 includes left and right hydraulic brake devices 4, 4 (front brake mechanisms) provided corresponding to the left front wheel 3L and right front wheel 3R, respectively, and a left rear wheel 5L and a right rear wheel 5R. Left and right electric brake devices 21, 21 (rear braking mechanism) provided correspondingly, a master cylinder 7 that generates hydraulic pressure in accordance with the operation (depression) of the brake pedal 6 (operating tool), and the driver ( It includes a hydraulic pressure sensor 8 and a pedal stroke sensor 9 for measuring the amount of operation of the brake pedal 6 by the driver.

The hydraulic brake device 4 is composed of, for example, a hydraulic disc brake, and applies braking force to the wheels (front wheels 3L, 3R) by supplying hydraulic pressure (brake hydraulic pressure). The electric brake device 21 is composed of an electric disc brake, for example, and applies braking force to the wheels (rear wheels 5L, 5R) by driving the electric motor 26 . The hydraulic pressure sensor 8 and the pedal stroke sensor 9 are connected to the main ECU 10 .

A hydraulic pressure supply device 11 (hereinafter referred to as ESC 11) is provided between the master cylinder 7 and the hydraulic brake devices 4,4. The ESC 11 includes, for example, a plurality of control valves, a hydraulic pump that pressurizes the brake fluid pressure, an electric motor that drives the hydraulic pump, and a fluid pressure control reservoir that temporarily stores surplus brake fluid. (also not shown). Each control valve and electric motor of the ESC 11 are connected to the front hydraulic system ECU 12 . The front hydraulic system ECU 12 includes a microcomputer having an arithmetic circuit (CPU) and a memory. The front hydraulic system ECU 12 controls the opening and closing of each control valve of the ESC 11 and the driving of the electric motor based on commands from the main ECU 10 .

The main ECU 10 includes a microcomputer having an arithmetic circuit (CPU) and memory. The main ECU 10 receives signals from the hydraulic pressure sensor 8 and the pedal stroke sensor 9 and calculates a target braking force for each wheel (four wheels) according to a predetermined control program. Based on the calculated braking force, the main ECU 10 transmits a braking command for each of the two front wheels to the front hydraulic system ECU 12 (ie ESC ECU) via the CAN 13 (Controller area network) as a vehicle data bus. do. Based on the calculated braking force, the main ECU 10 also transmits a braking command (target thrust force) for each of the two rear wheels to the rear electric brake ECUs 41 , 41 via the CAN 13 .

The main ECU 10 receives vehicle information transmitted via the CAN 13 from another ECU (not shown) mounted on the vehicle. That is, the main ECU 10, via the CAN 13, for example, speeds of the wheels 3L, 3R, 5L, 5R (wheel speed), AT range position or MT shift position information, ignition on/off information, door open/close information , Driver's seat belt fastening information, Door mirror opening/closing information, Engine speed information, Steering wheel operation information, Clutch operation information, Accelerator operation information, Vehicle-to-vehicle communication information, Vehicle surroundings by in-vehicle camera information, acceleration sensor information (longitudinal acceleration, lateral acceleration), and other vehicle information.

The electric brake device 21 includes a brake mechanism 22 as an electric brake, and a main ECU 10 and a rear electric brake ECU 41 as control devices. Although not shown, the electric brake device 21 also includes a parking mechanism including a solenoid and the like. As shown in FIG. 1, in order to perform position control and thrust control, the electric brake device 21 includes a rotation angle sensor 36 as position detection means for detecting the motor rotation position, and a rotation angle sensor 36 as current detection means for detecting the motor current. and a current sensor 37 .

Note that the embodiment does not include a thrust sensor for detecting the thrust (piston thrust) of the brake mechanism 22 . As will be described later, the thrust is estimated based on the current (current value) supplied to the electric motor 26 . In addition, in the embodiment, the contact position (pad contact position) between the brake pad 23 and the disc rotor D is also estimated based on the current (current value) supplied to the electric motor 26 .

The brake mechanism 22 is provided for each of the left and right wheels of the vehicle 1, that is, the left rear wheel 5L side and the right rear wheel 5R side. The brake mechanism 22 is an electric brake mechanism driven by an electric motor 26 . As shown in FIG. 2, the brake mechanism 22 includes, for example, a brake pad 23 as a braking member (pad, friction pad), a caliper 24 as a cylinder (wheel cylinder), a piston 25 as a pressing member, and an electric motor. An electric motor 26 , a deceleration mechanism 27 , a rotation-to-linear motion conversion mechanism 28 , and a fail-open mechanism 29 are provided.

The electric motor 26 is driven (rotated) by power supply to propel the piston 25 . Thereby, the electric motor 26 applies a braking force. The electric motor 26 is controlled by the rear electric brake ECU 41 based on a braking command (target thrust) from the main ECU 10 . The deceleration mechanism 27 is composed of, for example, a spur-tooth multistage deceleration mechanism (not shown) and a planetary gear deceleration mechanism 27A. The deceleration mechanism 27 decelerates the rotation of the electric motor 26 and transmits it to the rotation/linear motion conversion mechanism 28 .

The rotation/linear motion conversion mechanism 28 converts the rotation of the electric motor 26 transmitted via the reduction mechanism 27 into axial displacement (linear motion displacement) of the piston 25 . The rotation/linear motion converting mechanism 28 has a spindle 28A and a nut 28B. The spindle 28A is rotatably provided within the caliper 24 via a rolling bearing 30. As shown in FIG. The piston 25 is driven by the electric motor 26 to move the brake pad 23 . The brake pad 23 is pressed against a disc rotor D as a member (disc) to be braked by a piston 25 . The disk rotor D rotates together with the wheels (rear wheels 5L, 5R).

The fail-open mechanism 29 applies a torque in the braking release direction to the rotating member (spindle 28A) of the rotation/linear motion conversion mechanism 28 when braking is applied. In the brake mechanism 22, the electric motor 26 drives the piston 25 to press the brake pad 23 against the disk rotor D. As shown in FIG. That is, the brake mechanism 22 transmits thrust generated by driving the electric motor 26 to the piston 25 that moves the brake pad 23 . The fail-open mechanism 29 releases the braking force applied to the disc rotor D by the piston 25 (brake pad 23) when the electric motor 26 or the rear electric brake ECU 41 fails during braking.

FIG. 3 shows the speed reduction mechanism 27 and the fail-open mechanism 29. As shown in FIG. The deceleration mechanism 27 includes, for example, a first gear 31 serving as a gear on the spindle 28A side of the rotation/linear motion converting mechanism 28 and a second gear 32 serving as a gear on the electric motor 26 side. The first gear 31 and the second gear 32 are in mesh with each other. A fail-open mechanism 29 is provided on the second gear 32 so as to face the side surface of the second gear 32 . The fail-open mechanism 29 includes, for example, a torsion spring 33 as an elastic member and a ratchet mechanism 34 as a torque limiter mechanism.

A torsion spring 33 , also called a return spring, is provided on the side of the second gear 32 and concentrically with the second gear 32 . As the second gear 32 rotates, the torsion spring 33 applies torque (rotational force) in the braking release direction to the second gear 32 . The torsion spring 33 is composed of, for example, a “spring”. A base end portion 33</b>A, which is an end portion on the inner diameter side of the torsion spring 33 , is supported by a support pin 35 provided on the inner diameter side of the second gear 32 . That is, a support pin 35 is provided on the side surface of the second gear 32 so as to protrude from the side surface. A base end portion 33A of the torsion spring 33 is fixed to a support pin 35. As shown in FIG. The base end portion 33A of the torsion spring 33 rotates together with the second gear 32 when the second gear 32 rotates.

The ratchet mechanism 34 releases part of the torque (load) applied to the second gear 32 via the torsion spring 33 to keep the torque within a certain range. The ratchet mechanism 34 is provided on the caliper 24 side. That is, the ratchet mechanism 34 is fixed to the caliper 24 without rotating. The ratchet mechanism 34 is formed in an annular shape, and the torsion spring 33 is arranged inside. The inner peripheral surface of the ratchet mechanism 34 is provided with a step on which one end of the torsion spring 33 is hooked. That is, on the inner peripheral surface of the ratchet mechanism 34, a plurality of projections 34A protruding toward the inner diameter side are provided at equal intervals in the circumferential direction. A projection 34A of the ratchet mechanism 34 is engaged with a tip portion 33B, which is an end portion of the torsion spring 33 on the outer diameter side. That is, the protrusion 34A corresponds to an engaging portion (ratchet) with which one end (tip portion 33B) of the torsion spring 33 is engaged.

When the spindle 28A rotates in the braking direction based on the rotation of the electric motor 26, spring force is accumulated in the torsion spring 33, which is a "coil spring", along with the rotation of the first gear 31 and the second gear 32. . At this time, if the electric motor 26 becomes uncontrollable due to failure of the electric motor 26 or the like, the spring force of the torsion spring 33 causes the spindle 28A to rotate in the opposite direction to the braking release direction. Thereby, the pressing force of the brake pad 23 can be reduced and the braking force can be released.

A tip 33B, which is one end of the torsion spring 33, is hooked on a projection 34A of the ratchet mechanism 34. As shown in FIG. Therefore, when the spring force accumulated in the torsion spring 33 reaches or exceeds a certain level, the tip portion 33B of the torsion spring 33 rides over the protrusion 34A of the ratchet mechanism 34, thereby releasing part of the spring force of the torsion spring 33. . Thereby, the spring force of the torsion spring 33 is kept within a certain range.

Such riding over of the tip portion 33B of the torsion spring 33 occurs every time the wear of the brake pad 23 progresses by a certain amount. That is, as the wear of the brake pad 23 progresses, the brake pad 23 becomes thinner, and the piston 25 is pushed out according to the amount of wear of the brake pad 23 . As the piston 25 is pushed out, spring force is accumulated in the torsion spring 33 accordingly. When the spring force of the torsion spring 33 exceeds a certain amount, overriding occurs and part of the spring force is released.

Next, the rear electric brake ECU 41 will be described. As shown in FIG. 1, the rear electric brake ECU 41 controls the brake mechanisms 22, 22, that is, the brake mechanism 22 on the left side (rear left wheel 5L side) and the brake mechanism 22 on the right side (rear right wheel 5R side). provided corresponding to each. The rear electric brake ECU 41 includes a microcomputer having an arithmetic circuit (CPU) and memory. The rear electric brake ECU 41 controls the brake mechanism 22 (electric motor 26 ) based on a command from the main ECU 10 .

That is, the rear electric brake ECU 41 constitutes a control device that controls the operation of the electric motor 26 together with the main ECU 10 . In this case, the rear electric brake ECU 41 controls the driving of the electric motor 26 based on the braking command (target thrust). A braking command is input from the main ECU 10 to the rear electric brake ECU 41 . The rear electric brake ECU 41 also controls a parking mechanism (eg, solenoid) (not shown) based on commands from the main ECU 10 .

A rotation angle sensor 36 and a current sensor 37 are connected to the rear electric brake ECU 41 . The rotation angle sensor 36 and the current sensor 37 are provided corresponding to the electric motors 26 of the brake mechanisms 22, respectively. The rotation angle sensor 36 detects the rotation angle of the rotating shaft of the electric motor 26 (motor rotation angle). That is, the rotation angle sensor 36 constitutes position detection means for detecting the rotation position of the electric motor 26 (motor rotation position). The current sensor 37 detects current (motor current) supplied to the electric motor 26 . That is, the current sensor 37 constitutes current detection means for detecting the motor current of the electric motor 26 .

The rear electric brake ECU 41 (and the main ECU 10 connected to the rear electric brake ECU 41 via the CAN 13 ) can acquire the rotation angle of the electric motor 26 based on the signal from the rotation angle sensor 36 . The rear electric brake ECU 41 (and the main ECU 10 ) can acquire the motor current supplied to the electric motor 26 based on the signal from the current sensor 37 .

As will be described later, the rear electric brake ECU 41 (and the main ECU 10 ) estimates the thrust acting on the piston 25 (pressing force applied from the piston 25 to the brake pad 23 ) based on the signal from the current sensor 37 . That is, the rear electric brake ECU 41 (and the main ECU 10) constitute a thrust estimating means for estimating the thrust acting on the piston 25 (piston thrust).

Next, a description will be given of the operation of the electric brake device 21 for applying and releasing braking during travel. In the following description, the operation when the driver operates the brake pedal 6 will be described as an example. However, automatic braking is substantially the same, except that, for example, an automatic braking command is output from the automatic braking ECU (not shown) or the main ECU 10 to the rear electric braking ECU 41 .

For example, when the driver depresses the brake pedal 6 while the vehicle 1 is running, the main ECU 10 outputs a command (for example, target thrust corresponding to the braking application command) to the rear electric brake ECU 41 . The rear electric brake ECU 41 drives (rotates) the electric motor 26 in the forward direction, that is, in the brake application direction (apply direction) based on a command (target thrust force) from the main ECU 10 . The rotation of the electric motor 26 is transmitted to the rotation/linear motion conversion mechanism 28 via the speed reduction mechanism 27 , and the piston 25 advances toward the brake pad 23 .

As a result, the brake pads 23, 23 are pressed against the disc rotor D and a braking force is applied. At this time, the braking state is established by controlling the drive of the electric motor 26 based on detection signals from the pedal stroke sensor 9, the rotation angle sensor 36, the current sensor 37, and the like. During such braking, the rotating member (spindle 28A) of the rotation-to-linear motion converting mechanism 28 and, by extension, the rotating shaft of the electric motor 26 are applied with force in the braking releasing direction by the torsion spring 33 of the fail-open mechanism 29. be.

On the other hand, when the brake pedal 6 is operated to the release side, the main ECU 10 outputs a command corresponding to this operation (for example, a target thrust force corresponding to the braking release command) to the rear electric brake ECU 41 . Based on a command from the main ECU 10, the rear electric brake ECU 41 drives (rotates) the electric motor 26 in the reverse direction, that is, in the braking release direction (release direction). The rotation of the electric motor 26 is transmitted to the rotation/linear motion conversion mechanism 28 via the speed reduction mechanism 27 , and the piston 25 retreats in the direction away from the brake pad 23 . When the brake pedal 6 is completely released, the brake pads 23, 23 are separated from the disc rotor D, and the braking force is released. In such a non-braking state where braking is released, the torsion spring 33 of the fail-open mechanism 29 returns to its initial state.

By the way, an electric brake device that does not use a thrust sensor uses electric motor current (Q-axis current) instead of the thrust sensor to estimate the thrust of the electric brake and the pad contact position of the electric brake. For example, Japanese Unexamined Patent Application Publication No. 2012-159134 describes a technique for estimating thrust based on the value of current flowing through an electric motor. Further, for example, Japanese Unexamined Patent Application Publication No. 2008-57643 describes a technique for estimating a pad contact position based on a current value flowing through an electric motor.

For example, the thrust of the electric brake is estimated in the following order (A)-(C).
(A) Subtract currents for acceleration, friction, and viscous torque from the raw data of the current (Q-axis current) applied to the electric motor.
(B) Perform filter processing such as moving average processing using the rotation angle of the electric motor, etc., to remove pulsation and the like specific to the electric motor.
(C) Back-calculate the thrust from the current value (Q-axis current value) under the assumption that the current (Q-axis current) after these processes and the thrust force are in a linear function relationship.

For example, the estimation of the pad contact position of the electric brake is performed in the following order (a) to (c).
(a) Subtract the frictional and viscous torque currents from the raw data of the current (Q-axis current) applied to the electric motor.
(b) Perform filter processing such as moving average processing using the rotation angle of the electric motor and the like to remove pulsation and the like specific to the electric motor.
(c) Obtain the pad contact position from the relationship between the current value (Q-axis current value) after these processes and the motor rotation amount at that time.

Here, the electric brake has a fail-open mechanism consisting of a torsion spring and a ratchet mechanism in order to mechanically release the thrust force in the event of failure. In the ratchet mechanism, when the torque accumulated in the torsion spring exceeds a certain level, one end of the torsion spring climbs over the step (protrusion) of the ratchet mechanism to partially release the torque, and the amount of accumulated torque falls within a certain range. It functions as a torque limiter mechanism that adjusts to fit. Such a fail-open mechanism is essential for electric brakes. However, when one end of the torsion spring of the fail-open mechanism rides over the protrusion of the ratchet mechanism to release the spring force of the torsion spring, the load on the electric motor suddenly drops. As a result, the current (Q-axis current) of the electric motor suddenly changes, which may lead to a decrease in thrust estimation accuracy and a decrease in pad contact position estimation accuracy.

FIG. 10 shows the deviation of the estimated value of the pad contact position due to a sudden change in the Q-axis current. When the thrust increases due to the contact between the brake pads and the disc rotor, the Q-axis current increases. Therefore, the logic for estimating the pad contact position estimates the contact position by searching for the position where the increase starts. A solid characteristic line 51A and a dashed characteristic line 51B in FIG. 10 show changes in the Q-axis current when the pad contact position is accurately estimated. On the other hand, when one end of the torsion spring gets over the step (protrusion) of the ratchet mechanism, the Q-axis current drops sharply. recognize the change in That is, the Q-axis current correctly recognized as the solid line characteristic line 51A and the dashed line characteristic line 51B is recognized as the two-dot chain line characteristic line 52 due to overriding. As a result, an error occurs in the estimated value of the pad contact position.

On the other hand, FIG. 11 shows a thrust estimation deviation due to a sudden change in the Q-axis current. A solid characteristic line 53A and a dashed characteristic line 53B in FIG. 11 indicate changes in the Q-axis current when the thrust is accurately estimated. The thrust is estimated using the Q-axis current. Therefore, when one end of the torsion spring climbs over the step (projection) of the ratchet mechanism and the Q-axis current drops sharply, as indicated by the two-dot chain characteristic line 54, the thrust is generated from the moment the torsion spring climbs over the step (projection) to the steep drop of the Q-axis current. is offset.

As shown in FIGS. 10 and 11, normally (if there is no overriding), the Q-axis current increases with the amount of motor rotation. That is, the change in Q-axis current with respect to the change in motor rotation amount is positive. However, when overriding occurs, the Q-axis current drops sharply because the motor load is reduced. That is, the change in the Q-axis current with respect to the change in the motor rotation amount becomes negative. Therefore, in the embodiment, riding over of the torsion spring is detected using a change in the Q-axis current with respect to a change in the amount of rotation of the motor as a trigger. That is, in the embodiment, the overriding of the torsion spring is detected from the amount of change of the Q-axis current with respect to the amount of rotation of the motor. By estimating the pad contact position and the thrust, the influence of the sudden change in the Q-axis current due to overriding of the torsion spring is eliminated. do. These points will be described below.

The electric brake device 21 includes a brake mechanism 22 as an electric brake, and a rear electric brake ECU 41 and/or a main ECU 10 as a control device. Hereinafter, the rear electric brake ECU 41 and/or the main ECU 10 will be simply referred to as "braking control devices 41, 10". The brake mechanism 22 has an electric motor 26 and a fail-open mechanism 29 . The electric motor 26 is controlled by control units (arithmetic circuits) of the braking control devices 41 and 10 . The fail-open mechanism 29 has a torsion spring 33 and a ratchet mechanism 34 .

The torsion spring 33 stores elastic energy when the electric motor 26 rotates forward to move the brake pad 23 in the direction of pressing the disk rotor D forward. The torsion spring 33 releases elastic energy when the electric motor 26 rotates backward to move the brake pad 23 away from the disk rotor D. The ratchet mechanism 34 has a plurality of projections 34A with which a tip portion 33B, which is one end of the torsion spring 33, engages. The ratchet mechanism 34 is configured such that the tip portion 33B of the torsion spring 33 rides over the projection 34A when the rotational torque acting on the torsion spring 33 exceeds a predetermined value when the electric motor 26 rotates forward. The predetermined value is, for example, a value capable of suppressing excessive elastic energy stored in the torsion spring 33 during braking and releasing the braking force (thrust force of the piston 25) by the brake pad 23 when the electric motor 26 or the like fails. can be set as

Control units (arithmetic circuits) of the braking control devices 41 and 10 control the electric motor 26 . At this time, the braking control devices 41 and 10 estimate the thrust (estimate the thrust in the direction that presses the brake pad 23 against the disk rotor D) based on the value of the electric current supplied to the electric motor 26, and the pad contact Position estimation (estimation of the motor rotation angle at which the brake pad 23 starts pressing the disc rotor D) is performed. In addition, when the electric motor 26 rotates forward, the braking control devices 41 and 10 control the tip portion 33B of the torsion spring 33 based on the decrease in the value of the current supplied to the electric motor 26 with respect to the amount of rotation of the electric motor 26. has climbed over the projection 34A. For the decrease in current value, for example, the positive or negative value of the current change (current change amount) may be used, or the current decrease amount (rapid change amount) may be used. That is, the overriding may be detected based on the fact that the current change (current change amount) has decreased (changed from positive to negative), or the current decrease amount (sudden change amount) has exceeded a threshold value. can be detected based on

FIG. 4 shows the control processing performed by the braking control devices 41 and 10 to detect the overriding of the torsion spring 33. As shown in FIG. The memories of the braking control devices 41 and 10 store a processing program for executing the processing flow shown in FIG. The control process in FIG. 4 is executed, for example, as the process of S15 in FIGS. 6 to 9, which will be described later.

When the control process of FIG. 4 is started, the control units (arithmetic circuits) of the braking control devices 41 and 10 compute the time change of the motor rotation amount and the time change of the Q-axis current in S1. do. "Temporal change" corresponds to, for example, "amount of change per unit time". In S2 subsequent to S1, the change (inclination, amount of change) of the Q-axis current with respect to the amount of rotation of the motor is calculated based on the two time changes calculated in S1. In S3 following S2, it is determined whether or not the change in Q-axis current with respect to the amount of rotation of the motor is 0 or more. If "YES" in S3, that is, if it is determined that the change in Q-axis current with respect to the amount of rotation of the motor is 0 or more, the process proceeds to S4. In S4, it is determined that the tip portion 33B of the torsion spring 33 has not gotten over the projection 34A, and "0" corresponding to the signal "does not get over" is output. When "0" is output in S4, the process is terminated (returned).

On the other hand, if it is determined "NO" in S3, that is, if it is determined that the change in the Q-axis current with respect to the motor rotation amount is less than 0, the process proceeds to S5. In S5, it is determined that the tip portion 33B of the torsion spring 33 has climbed over the projection 34A, and "1" corresponding to the signal "get over" is output. When "1" is output in S5, the process is terminated (returned). Thus, in the control process of FIG. 4, when the change in the Q-axis current with respect to the motor rotation amount is positive, it is determined that the torsion spring 33 has not gotten over the projection 34A of the ratchet mechanism 34, and "0" is output. . On the other hand, when the change in the Q-axis current with respect to the motor rotation amount is negative, it is determined that the torsion spring 33 has gotten over the projection 34A of the ratchet mechanism 34, and "1" is output.

FIG. 5 shows a block diagram of the braking control devices 41 and 10 when the processing of the flowchart of FIG. 4 is incorporated into software. As shown in FIG. 5, the braking control devices 41 and 10 include a current 1/z unit 42, a current subtraction unit 43, a rotation amount 1/z unit 44, a rotation amount subtraction unit 45, and a change amount calculation unit. 46 and an output unit 47 . The Q-axis current from the current sensor 37, that is, the value of the Q-axis current supplied to the electric motor 26 is input to the braking control devices 41 and 10. FIG. Further, the amount of rotation of the motor, that is, the amount of rotation of the electric motor 26 is input from the rotation angle sensor 36 to the braking control devices 41 and 10 . The Q-axis current value input to the braking control devices 41 and 10 is input to the current 1/z section 42 and the current subtraction section 43, and the motor rotation amount input to the braking control devices 41 and 10 is the rotation amount. It is input to the 1/z unit 44 and the rotation amount subtraction unit 45 .

A Q-axis current value is input to the current 1/z section 42 . The current 1/z unit 42 outputs the Q-axis current value before a predetermined number of samplings (that is, before a predetermined time) to the current subtraction unit 43 . The current subtraction unit 43 receives the current Q-axis current value and the Q-axis current value several samplings before (predetermined time ago). The current subtraction unit 43 calculates the difference between the current Q-axis current value and the Q-axis current value several samplings before (predetermined time), that is, the amount of change in the Q-axis current value for a predetermined number of samplings (Δtime). and outputs this calculation result to the change amount calculation unit 46 .

A motor rotation amount is input to the rotation amount 1/z section 44 . The rotation amount 1/z unit 44 outputs the motor rotation amount before a predetermined number of samplings (that is, before a predetermined time) to the rotation amount subtraction unit 45 . The current amount of motor rotation and the amount of motor rotation several samplings before (predetermined time ago) are input to the rotation amount subtraction unit 45 . The rotation amount subtraction unit 45 calculates the difference between the current motor rotation amount and the motor rotation amount several samplings before (predetermined time), that is, the amount of change in the motor rotation amount for a predetermined number of samplings (Δtime), This calculation result is output to the variation calculation unit 46 .

The amount of change (difference) in the Q-axis current value and the amount of change (difference) in the amount of motor rotation during a predetermined number of samplings are input to the amount-of-change calculator 46 . The change amount calculator 46 calculates the change amount of the Q-axis current with respect to the motor rotation amount by dividing the change amount (difference) of the Q-axis current value by the change amount (difference) of the motor rotation amount. Here, the rotation amount subtraction section 45 and the current subtraction section 43 obtain the amount of change in the amount of rotation of the motor and the amount of change in the Q-axis current as the difference between the current value and the value a predetermined number of samplings ago. Originally, if the amount of change over time (the amount of change per unit time) is to be calculated, each value should be divided by a predetermined number of sampling times (Δtime). However, this division is canceled by the next calculation process, that is, the division of the change amount calculator 46 . Therefore, in the embodiment, the rotation amount subtracting section 45 and the current subtracting section 43 obtain the difference between the current value and the value a predetermined number of times before sampling.

The change amount calculation unit 46 divides the amount of change in the Q-axis current value (difference between Δtime) by the amount of change in the motor rotation amount (difference between Δtime) to obtain a reference for determining whether the torsion spring 33 has passed over. The amount of change in the Q-axis current with respect to the amount of motor rotation" is calculated. The change amount calculation unit 46 outputs the calculation result “the change amount of the Q-axis current with respect to the motor rotation amount” to the output unit 47 . The output unit 47 outputs “0” or “1” depending on whether the “change amount of the Q-axis current with respect to the motor rotation amount” calculated by the change amount calculation unit 46 is positive or negative. That is, the output unit 47 outputs "0 (not overcoming)" when the calculation result of the change amount calculation unit 46 is positive (change amount≧0). The output unit 47 outputs “1 (overcame)” when the calculation result of the change amount calculation unit 46 is negative (change amount<0).

Next, the process of estimating the pad contact position will be described with reference to FIG. FIG. 6 shows an example of pad contact position estimation processing performed by the braking control devices 41 and 10 . The memories of the braking control devices 41 and 10 store a processing program for executing the processing flow shown in FIG. 6, that is, a processing program used for estimating the pad contact position.

The control process of FIG. 6 is started, for example, when it is necessary to perform the process of estimating the pad contact position. When the control process of FIG. 6 is started, the controller (arithmetic circuit) of the braking control devices 41 and 10 causes the electric motor 26 to operate according to a predetermined pattern in S11. For example, the braking controllers 41 and 10 drive the electric motor 26 so that the piston 25 moves at a constant speed in order to estimate the pad contact position.

In S12 following S11, the Q-axis current value and motor rotation amount necessary for estimating the pad contact position are accumulated. For example, the Q-axis current value and the motor rotation amount are stored in memory. In S13 following S12, the effects of friction and viscosity are removed from the accumulated Q-axis current. Since the piston 25 is moved at a constant speed, friction and viscosity become factors of variation in the Q-axis current, eliminating the effects of friction and viscosity. In S14 following S13, moving average processing is performed on the Q-axis current from which the effects of friction and viscosity have been removed.

In S15 following S14, a detection process of overcoming of the torsion spring 33 is performed. That is, the above-described processing of FIG. 4 is performed. In S16 following S15, it is determined whether or not the detection result of S15 is "1", that is, whether or not the tip portion 33B of the torsion spring 33 has passed over the projection 34A of the ratchet mechanism 34. If it is determined "NO" in S16, that is, if it is determined that the torsion spring 33 has not gotten over the projection 34A, the process proceeds to S17. In S17, the pad contact position is estimated from the Q-axis current value acquired in the processing of S12 to S14. A specific calculation process for estimating the pad contact position based on the Q-axis current value is described, for example, in Japanese Unexamined Patent Application Publication No. 2008-57643. After estimating the pad contact position in S17, the process ends. That is, it waits until the estimation of the next pad contact position is started.

On the other hand, if it is determined that the torsion spring 33 has climbed over the projection 34A "YES" in S16, the process proceeds to S18. In S18, it is assumed that the pad contact position is not calculated in this operation, the motor rotation amount and the Q-axis current accumulated up to that point are deleted, and the process is terminated. In this manner, the control units (arithmetic circuits) of the braking control devices 41 and 10 delete the current value data when detecting that the tip 33B of the torsion spring 33 has passed over the protrusion 34A of the ratchet mechanism 34. . That is, when the controllers (arithmetic circuits) of the braking control devices 41 and 10 detect the overriding, they detect that the tip portion 33B of the torsion spring 33 has climbed over the protrusion 34A after the electric motor 26 starts rotating forward. Data on the current value (Q-axis current value) applied to the electric motor 26 with respect to the amount of rotation of the electric motor 26 accumulated during the period is deleted.

As shown in FIG. 6, when the controller (arithmetic circuit) of the braking control devices 41 and 10 detects that the tip 33B of the torsion spring 33 has passed over the projection 34A, the electric motor 26 accumulated before detection. is discarded. Then, the control units (arithmetic circuits) of the braking control devices 41 and 10 estimate the pad contact position based on the data of the current value applied to the electric motor 26 with respect to the amount of rotation of the electric motor 26 accumulated after detection. . As a result, it is possible to prevent the estimation from being performed based on the data of the current value when the overriding is detected.

Note that the flow chart of FIG. 6 illustrates a case where data of accumulated current values (Q-axis current values) is deleted when overriding is detected. On the other hand, as shown in FIG. 7, the data of the current value (Q-axis current value) may be interpolated when the overriding is detected. That is, FIG. 7 shows another example of pad contact position estimation processing performed by the braking control devices 41 and 10 . A processing program for executing the processing flow shown in FIG. 7 is stored in the memories of the braking control devices 41 and 10 .

The processing from S11 to S17 in FIG. 7 is the same as the processing in FIG. If it is determined that the torsion spring 33 has climbed over the protrusion 34A, the process proceeds to S21. In S21, the missing portion due to the overriding is complemented. That is, in S21, the overriding portion is interpolated with a curved line. More specifically, in S21, the "broken characteristic line 51B" in FIG. 10 is estimated. In this case, the "broken characteristic line 51B" that is insufficient is estimated from the "solid characteristic line 51A" in FIG. 10, which is the data before riding over. In this case, the degree of rise of the "broken characteristic line 51B" in FIG. 10 can be determined by referring to, for example, the "two-dot chain characteristic line 52" in FIG. In this way, in the process of S21, the curve for the shortage (the dashed characteristic line 51B) is estimated from the data (the solid characteristic line 51A) before the overpass detection. After the crossed-over portion is complemented with a curve in S21, the process proceeds to S17 to estimate the pad contact position using the complemented data.

In this way, when the control units (arithmetic circuits) of the braking control devices 41 and 10 detect that the tip portion 33B of the torsion spring 33 has passed over the projection 34A, the electric motor 26 changes the amount of rotation of the electric motor 26. It is also possible to supplement (correct) the data of the current value to be energized. In this case, the control unit (arithmetic circuit) of the braking control devices 41 and 10 controls the amount of rotation of the electric motor 26 after detecting that the tip 33B of the torsion spring 33 has passed over the projection 34A. Data of current value to be energized” and “the amount of rotation of the electric motor 26 accumulated from the start of forward rotation of the electric motor 26 until it is detected that the tip portion 33B of the torsion spring 33 has passed over the projection 34A. The data of the current value to be energized to the electric motor 26 with respect to the amount of rotation of the electric motor 26 is complemented based on the "data of the current value to be energized to the electric motor 26". At this time, the missing data (broken characteristic line 51B in FIG. 10) is data accumulated from the start of the forward rotation of the electric motor 26 until it is detected that the vehicle has been overridden (the Based on the solid characteristic line 51A), interpolation is performed based on the data (the characteristic line 52 of the two-dot chain line in FIG. 10) after the overcoming is detected.

As shown in FIG. 7, when the controller (arithmetic circuit) of the braking control devices 41 and 10 detects that the tip 33B of the torsion spring 33 has climbed over the projection 34A, the electric motor 26 accumulated before the detection. complements (corrects) the data of the current value energized to the electric motor 26 with respect to the rotation amount of . The control units (arithmetic circuits) of the braking control devices 41 and 10 estimate the pad contact position based on the data of the current value energized to the electric motor 26 with respect to the complemented (corrected) amount of rotation of the electric motor 26. .

Next, thrust estimation processing will be described with reference to FIG. FIG. 8 shows an example of thrust estimation processing performed by the braking control devices 41 and 10 . The memories of the braking control devices 41 and 10 store a processing program for executing the processing flow shown in FIG. 8, that is, a processing program used for thrust estimation processing.

The control process of FIG. 8 is started, for example, when the thrust estimation process needs to be performed. When the control process of FIG. 8 is started, the control section (arithmetic circuit) of the braking control devices 41 and 10 operates the electric motor 26 in a predetermined pattern in S11. In this case, the piston 25 cannot be moved at a constant speed.

In S12 following S11, the Q-axis current value and the motor rotation amount required for thrust estimation are accumulated. For example, the Q-axis current value and the motor rotation amount are stored in memory. In S31 following S12, effects of friction, viscosity and acceleration are removed from the accumulated Q-axis current. Since the piston 25 cannot be moved at a constant speed, acceleration also becomes a factor of variation in the Q-axis current, and the influence of acceleration is also removed. In S14 following S31, moving average processing is performed on the Q-axis current from which the effects of friction, viscosity and acceleration have been removed.

The processing of S15 and the processing of S16 following S14 are the same as the processing of S15 and S16 in FIGS. If it is determined "NO" in S16, that is, if it is determined that the torsion spring 33 has not gotten over the protrusion 34A, the process proceeds to S32. In S32, the thrust is estimated from the Q-axis current value acquired in the processing from S12 to S14. A specific calculation process for estimating the thrust based on the Q-axis current value is described, for example, in Japanese Unexamined Patent Application Publication No. 2012-159134. After estimating the thrust in S32, the process ends. That is, it waits until the next thrust estimation is started.

On the other hand, if "YES" in S16, ie, if it is determined that the torsion spring 33 has climbed over the protrusion 34A, the process proceeds to S17. At S17, it is assumed that the thrust is not calculated in this operation, the motor rotation amount and the Q-axis current accumulated up to that point are deleted, and the process is terminated. As shown in FIG. 8, when the controller (arithmetic circuit) of the braking control devices 41 and 10 detects that the tip 33B of the torsion spring 33 has climbed over the protrusion 34A, the electric motor 26 accumulated before detection. is discarded. Then, the control units (arithmetic circuits) of the braking control devices 41 and 10 estimate the thrust based on the data of the current value applied to the electric motor 26 with respect to the amount of rotation of the electric motor 26 accumulated after detection. As a result, it is possible to prevent the estimation from being performed based on the data of the current value when the overriding is detected.

Note that the flow chart of FIG. 8 illustrates a case where accumulated data is deleted when an overpass is detected. On the other hand, as shown in FIG. 9, the data may be complemented when the overriding is detected. That is, FIG. 9 shows another example of thrust estimation processing performed by the braking control devices 41 and 10 . A processing program for executing the processing flow shown in FIG. 9 is stored in the memories of the braking control devices 41 and 10 .

If it is determined "YES" in S16 in FIG. 9, that is, if it is determined that the torsion spring 33 has climbed over the protrusion 34A, the process proceeds to S21. In S21, the missing portion due to the overriding is complemented. That is, in S21, the overriding portion is interpolated with a curved line. More specifically, in S21, the "broken characteristic line 53B" in FIG. 11 is estimated. In this case, the "broken characteristic line 53B" that is insufficient is estimated from the "solid characteristic line 53A" in FIG. 11, which is the data before riding over. In this case, the degree of rise of the "broken characteristic line 53B" in FIG. 11 can be determined by referring to, for example, the "two-dot chain characteristic line 54" in FIG. In this way, in the process of S21, the curve for the shortage (the dashed characteristic line 53B) is estimated from the data (the solid characteristic line 53A) before the overpass detection. After complementing the overriding portion with a curve in S21, the process proceeds to S32 to estimate the thrust using the complemented data.

As shown in FIG. 9, when the controller (arithmetic circuit) of the braking control devices 41 and 10 detects that the tip 33B of the torsion spring 33 has climbed over the projection 34A, the electric motor 26 accumulated before detection. complements (corrects) the data of the current value energized to the electric motor 26 with respect to the rotation amount of . The control units (arithmetic circuits) of the braking control devices 41 and 10 estimate the thrust based on the data of the current value supplied to the electric motor 26 with respect to the complemented (corrected) amount of rotation of the electric motor 26 .

As described above, according to the embodiment, the control units (arithmetic circuits) of the braking control devices 41 and 10 energize the electric motor 26 corresponding to the amount of rotation of the electric motor 26 when the electric motor 26 rotates forward. It is detected that the tip portion 33B of the torsion spring 33 has climbed over the protrusion 34A based on the decrease in the current value (the amount of change becomes negative). Therefore, it is possible to accurately detect that the tip portion 33B of the torsion spring 33 has climbed over the protrusion 34A based on the decrease in the current value. As a result, deterioration of estimation accuracy based on the current value of the electric motor 26 can be suppressed. That is, when the thrust is estimated based on the current value of the electric motor 26, the accuracy of the thrust (estimated value) can be improved, and deterioration of the thrust estimation accuracy can be suppressed. Further, when estimating the pad contact position based on the current value of the electric motor 26, the accuracy of the pad contact position (estimated value) can be improved, and deterioration of the position estimation accuracy can be suppressed.

According to the embodiment, the controller (arithmetic circuit) of the braking control devices 41 and 10 deletes the accumulated data when detecting that the tip 33B of the torsion spring 33 has passed over the protrusion 34A. Therefore, it is possible to prevent the estimation of the thrust force and the pad contact position from being performed using the data accumulated before overriding the protrusion 34A after detecting that the tip portion 33B of the torsion spring 33 has overridden the protrusion 34A. As a result, deterioration of estimation accuracy (thrust force estimation accuracy, position estimation accuracy) based on the current value of the electric motor 26 can be suppressed.

According to the embodiment, the control units (arithmetic circuits) of the braking control devices 41 and 10 complement the data when detecting that the tip 33B of the torsion spring 33 has passed over the protrusion 34A. Therefore, after detecting that the tip portion 33B of the torsion spring 33 has climbed over the projection 34A, it is possible to estimate the thrust force and the pad contact position based on the supplemented data. As a result, deterioration of estimation accuracy (thrust force estimation accuracy, position estimation accuracy) based on the current value of the electric motor 26 can be suppressed.

In this manner, the embodiment detects a sudden change in the Q-axis current, that is, when the tip 33B of the torsion spring 33 gets over the projection 34A. Therefore, the accuracy of estimating the pad contact position and thrust based on the Q-axis current can be improved. As a result, the excess or deficiency of brake torque can be suppressed, and the stability of brake application can be improved. Further, since the accuracy of estimating the pad contact position is improved, the drag torque can be suppressed and the fuel efficiency can be improved.

In the embodiment, the fail-open mechanism 29 is composed of a torsion spring 33 and a ratchet mechanism 34, the torsion spring 33 is a spiral spring, and the ratchet mechanism 34 is an inner ratchet wheel having wedge-shaped pawls (teeth). (internal gear) has been described as an example. However, the torsion spring is not limited to this, and various configurations (elastic members) can be employed as long as the torsion spring can store elastic energy by forward rotation of the electric motor. Also, the ratchet mechanism can employ various configurations (engagement members) as long as it can be released when the elastic energy (rotational torque) of the torsion spring exceeds a predetermined value.

In the embodiment, as shown in FIGS. 4 and 5, the tip portion 33B of the torsion spring 33 has passed over the protrusion 34A based on the amount of change in the current value (Q-axis current value), that is, whether the amount of change is positive or negative. The case of detection has been described as an example. However, it is not limited to this, and it may be detected that one end of the torsion spring has climbed over the engaging portion of the ratchet mechanism, for example, based on the amount of decrease in the current value (the amount of sudden change in current determined to have crossed over). That is, it can be detected (determined) based on the decrease in the value of the current supplied to the electric motor with respect to the amount of rotation of the electric motor that one end of the torsion spring has passed over the engaging portion of the ratchet mechanism.

In the embodiment, the case where the detection result of getting over (getting over) is used for estimating the pad contact position and estimating the thrust has been described as an example. However, the present invention is not limited to this, and for example, the detection result of overcoming (overcoming) may be used for estimation (determination) of abnormality detection. In this case, it is possible not to determine that the obstacle has been overcome as an abnormality, and the determination accuracy can be improved. That is, the detection result of getting over (getting over) can be used for various estimations (judgments) based on the current value, such as estimation of pad contact position, estimation of thrust, and detection of abnormality.

In the embodiment, the "main ECU 10", the "left rear wheel 5L side rear electric brake ECU 41", and the "right rear wheel 5R side rear electric brake ECU 41" are separate ECUs. A case where the CAN 13, which is a vehicle data bus, is used for connection has been described as an example. That is, the case where the three ECUs, that is, the main ECU 10 and the left and right rear electric brake ECUs 41, 41 are configured as control devices (braking control devices 41, 10) for the electric brake devices 21, 21 will be described as an example. bottom. However, the present invention is not limited to this, and for example, the main ECU and the rear electric brake ECU may be configured by one ECU. That is, the control device that controls the left and right electric motors may be configured by one ECU.

In the embodiment, the case where the brake mechanism 22 and the rear electric brake ECU 41 are configured as one unit (assembly) by attaching the rear electric brake ECU 41 to the brake mechanism 22 has been described as an example. However, the present invention is not limited to this, and for example, the brake mechanism and the rear electric brake ECU may be arranged separately. In this case, the electric brake ECU (rear electric brake ECU) may be provided separately for the left side (left rear wheel side) and the right side (right rear wheel side), or the left side (left rear wheel side) and the right side may be provided separately. (right rear wheel side) may be configured as one (common) electric brake ECU (rear electric brake ECU). In summary, the overriding detection may be performed by the rear electric brake ECU 41 , the main ECU 10 , or both the rear electric brake ECU 41 and the main ECU 10 . That is, the detection of riding over can be performed by at least one of the ECUs (control devices).

In the embodiment, the hydraulic brake devices 4 and 4 are used for the front wheels 3L and 3R, and the electric brake devices 21 and 21 are used for the rear wheels 5L and 5R. However, the present invention is not limited to this, and for example, the electric brake device may be used on the front wheel side and the hydraulic brake device may be used on the rear wheel side. Further, for example, both the front wheel side and the rear wheel side may be electric brake devices.

According to the embodiment described above, the control device (in other words, the control unit that controls the electric motor) determines the current value supplied to the electric motor with respect to the amount of rotation of the electric motor when the electric motor rotates forward. Based on the decrease, it is detected that one end of the torsion spring has passed over the engaging portion. Therefore, it is possible to accurately detect that the one end of the torsion spring has passed over the engaging portion based on the decrease in the current value. As a result, deterioration of estimation accuracy based on the current value of the electric motor can be suppressed. For example, when the thrust is estimated based on the electric current value of the electric motor, the accuracy of the thrust (estimated value) can be improved, and deterioration of the thrust estimation accuracy can be suppressed.

According to the embodiment, the control device (control section) deletes the accumulated data when detecting that one end of the torsion spring has passed over the engaging section. Therefore, after detecting that one end of the torsion spring has climbed over the engaging portion, it is possible to suppress estimation using data accumulated before overcoming. For example, it is possible to prevent the thrust from being estimated using data accumulated before overcoming. As a result, deterioration of the estimation accuracy (for example, thrust estimation accuracy) based on the current value of the electric motor can be suppressed.

According to the embodiment, the control device (control section) complements the data when detecting that one end of the torsion spring has passed over the engaging section. Therefore, after detecting that one end of the torsion spring has passed over the engaging portion, it is possible to estimate based on the complemented data. For example, thrust can be estimated based on the imputed data. As a result, deterioration of the estimation accuracy (for example, thrust estimation accuracy) based on the current value of the electric motor can be suppressed.

10 Main ECU (braking control device, control device)
21 electric brake device 22 brake mechanism (electric brake)
23 brake pad (friction pad)
26 electric motor 33 torsion spring 33B tip (one end)
34 ratchet mechanism 34A projection (engagement portion)
41 Rear electric brake ECU (braking control device, control device)
D disk rotor (disk)

Claims (5)

an electric motor controlled by a control unit;
The forward rotation of the electric motor accumulates elastic energy during forward movement in which the friction pad is pressed against the disk, and the reverse rotation of the electric motor causes the friction pad to move away from the disk in reverse movement. a torsion spring that releases elastic energy;
One end of the torsion spring has a plurality of engaging portions that are engaged with each other. a ratchet mechanism configured to climb over the engaging portion;
An electric brake control device comprising
The control unit
When the electric motor rotates forward, detecting that one end of the torsion spring has passed over the engaging portion based on a decrease in a current value energized to the electric motor with respect to the amount of rotation of the electric motor.
Control device. The control device according to claim 1,
The control unit
When it is detected that one end of the torsion spring has passed over the engaging portion,
Data of current value to be energized to the electric motor with respect to the amount of rotation of the electric motor, which is accumulated from the start of the forward rotation of the electric motor until it is detected that one end of the torsion spring has passed over the engaging portion. to remove the
Control device. The control device according to claim 1,
The control unit
When it is detected that one end of the torsion spring has passed over the engaging portion,
data on the value of current supplied to the electric motor with respect to the amount of rotation of the electric motor after it is detected that one end of the torsion spring has passed over the engaging portion; The amount of rotation of the electric motor based on the data of the current value applied to the electric motor with respect to the amount of rotation of the electric motor accumulated until it is detected that one end of the spring has passed over the engaging portion. Complement the data of the current value energized to the electric motor for
Control device. an electric motor;
The forward rotation of the electric motor accumulates elastic energy during the forward movement in which the friction pad is pressed against the disk, and the reverse rotation of the electric motor causes the friction pad to move away from the disk in the backward movement. a torsion spring that releases elastic energy;
One end of the torsion spring has a plurality of engaging portions that are engaged with each other. a ratchet mechanism configured to climb over the engaging portion;
A control method for an electric brake comprising
A control unit that controls the electric motor,
When the electric motor rotates forward, detecting that one end of the torsion spring has passed over the engaging portion based on a decrease in a current value energized to the electric motor with respect to the amount of rotation of the electric motor;
control method. an electric motor;
The forward rotation of the electric motor accumulates elastic energy during the forward movement in which the friction pad is pressed against the disk, and the reverse rotation of the electric motor causes the friction pad to move away from the disk in the backward movement. a torsion spring that releases elastic energy;
One end of the torsion spring has a plurality of engaging portions that are engaged with each other. a ratchet mechanism configured to climb over the engaging portion;
A control device for detecting that one end of the torsion spring has passed over the engaging portion based on a decrease in the value of the current supplied to the electric motor with respect to the amount of rotation of the electric motor when the electric motor rotates forward. and,
An electric brake device with a

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