JP6513625B2 - Electric brake system - Google Patents

Description

  The present invention relates to an electric brake system provided with a plurality of electric brake devices, and relates to a technology capable of securing a mounting space of an auxiliary power supply and having a redundant function by using a limited auxiliary power supply.

The following techniques have been proposed as an electric brake device.
1. By depressing the brake pedal, the rotational movement of the motor is converted into linear movement via a linear movement mechanism, and a brake pad is pressed against and brought into contact with the brake disc to apply a braking force (Patent Document 1).
2. An electric direct acting actuator using a planetary roller screw mechanism (Patent Document 2).

Unexamined-Japanese-Patent No. 6-327190 Unexamined-Japanese-Patent No. 2006-194356

In the electric brake system using the electric brake device as described in Patent Documents 1 and 2, improvement of the redundancy of the power supply system becomes a major issue. At that time, a method of providing an auxiliary power supply different from the main power supply and a method of multiplexing transmission systems from the main power supply are mainly considered.
With regard to transmission system multiplexing, in general, the harness may become thick when guaranteeing the motor rated current of the electric brake device, and multiplexing of the transmission system is difficult in terms of increase in the number of assembly steps, cost of the harness and wiring space. There is a case.

On the other hand, in the case of providing an auxiliary power supply different from the main power supply, for example, in a disk brake, a complete power supply redundant system on the brake caliper is configured by providing all the motor, control device and auxiliary power in the brake caliper. Can.
In general, the main power supply of a vehicle is often composed of a battery with high energy density, but there are problems such as low resistance to charge and discharge cycles, low current density at charge and discharge, etc. Can be expected to improve the problems described above.
However, when the auxiliary power supply is used, the mounting space of the auxiliary power supply may be limited, and storage of large energy may be difficult.

  An object of the present invention is to provide an electric brake system capable of providing redundancy of a power supply system and increasing the freedom of mounting space of components.

The electric brake system according to the present invention comprises a brake rotor 8, a friction member 9 brought into contact with the brake rotor 8, a friction member operating means 6 bringing the friction member 9 into contact with the brake rotor 8, and the friction member operation means 6. In an electric brake system provided with a plurality of electric brake devices including an electric motor 4 for driving the motor and a control device 2 for controlling the braking force by controlling the electric motor 4,
First and second power supply devices 3 and 18 for supplying electric power to the electric motor 4 in each of the electric brake devices are provided.
The control device 2 of each of the electric brake devices
An abnormality determination unit 26 that determines whether there is an abnormality in the power supply from the first and second power supply devices 3 and 18 to the electric brake device;
When it is determined by the abnormality determination unit 26 that there is an abnormality in the power supply from the first power supply device 3 to the electric brake device, the braking force is applied using the second power supply device 18 according to the defined conditions. A redundant function control unit 27 to control;
Have
The redundant function control unit 27 is a basic condition that a desired braking force can not be obtained only by all the electric brake devices determined to have no abnormality in the power supply at least by the abnormality determination unit 26 as the determined condition. And the second power supply device 18 is used to control the braking force.
The desired braking force is the actual braking force that is output in response to the required braking force by the vehicle operator.
The predetermined condition and the desired braking force are respectively determined by results of tests and simulations.

According to this configuration, the first power supply device 3 normally supplies power to the electric motor 4. In the state where the electric power is supplied, the control device 2 controls the electric motor 4 so as to obtain an appropriate braking force from a command or the like from the upper control device 17, for example.
The abnormality determination unit 26 determines whether there is an abnormality in the power supply from the first power supply device 3 to the electric brake device. When the abnormality determination unit 26 determines that the power supply to the electric brake device is abnormal, the redundant function control unit 27 controls the braking force using the second power supply device 18 according to the determined condition.

  The redundant function control unit 27 satisfies the basic condition that the desired braking force can not be obtained only by all the electric brake devices determined that there is no abnormality in the power supply by at least the abnormality determination unit 26 as the above-mentioned defined condition. The second power supply 18 is used to control the braking force. As described above, by providing the first power supply device 3 and the second power supply device 18 in the electric brake system, the redundant function of the power supply system can be obtained for the electric brake system without the auxiliary power supply.

  Furthermore, in order to use the second power supply device 18 only when the function of the entire electric brake system is lower than a predetermined level, for example, a battery or a capacitor smaller than a battery generally used in vehicles is used. The device 18 can be applied. Since the second power supply device 18 is limitedly used, the second power supply device 18 can be miniaturized, and the degree of freedom of the mounting space of the power supply device 18 on the vehicle can be increased. This can increase the freedom of design.

In addition to satisfying the basic condition that the deceleration in the front-rear direction generated by all the electric brake devices determined to have no abnormality is equal to or less than a threshold value, the redundant function control unit 27 sets The second power supply device 18 may be used so that the turning acceleration of the vehicle equipped with the electric brake system becomes equal to or less than a predetermined value.
The predetermined value and the threshold value are respectively determined by results of tests and simulations.
A request brake by the vehicle operator, such as when the brake pedal 19 is strongly depressed while the abnormality determining unit 26 determines that there is an abnormality in the power supply to the electric brake device corresponding to any of the plurality of wheels. When the power is high, the braking power of only the other electric brake devices may be insufficient. In such a case, by using the second power supply device 18, a desired braking force corresponding to the required braking force can be obtained. In this case, it is preferable to use the second power supply 18 when the turning acceleration of the vehicle becomes equal to or less than a predetermined value, in order to ensure the stability of the vehicle posture.

  The redundant function control unit 27 changes the threshold value of the longitudinal deceleration on the basis of the correlation in which the threshold value of the longitudinal deceleration becomes larger as the required value of the braking force by the driver of the vehicle becomes larger. As well. By changing the threshold value of the longitudinal deceleration in this manner, the frequency of use of the second power supply 18 can be finely limited.

The vehicle speed estimation means 30 is provided to estimate the traveling speed of a vehicle equipped with the electric brake system, and the redundant function control unit 27 may use the vehicle speed estimation means 30 in addition to satisfying the basic condition as the determined condition. The second power supply unit 18 may be used when the vehicle speed estimated in the above condition satisfies the predetermined vehicle speed or more.
The determined vehicle speed is determined by the results of tests, simulations, and the like.
Even when the abnormality determination unit 26 determines that there is an abnormality in the power supply to the electric brake device corresponding to any of the wheels, for example, when the vehicle is in a stopped state, turning acceleration is not generated in the vehicle. For this reason, when the vehicle speed estimated by the vehicle speed estimation means 30 satisfies the predetermined vehicle speed or more, the second power supply 18 is used. By limiting and using the second power supply device 18 as described above, the second power supply device 18 can be miniaturized.
The redundant function control unit 27 of the electric brake device determined to have an abnormality in the power supply uses the electric power of the second power supply unit 18 from the sensing information of all the electric brake devices having no abnormality in the electric power supply. You may decide whether or not.

  The electric brake system according to the present invention comprises a brake rotor, a friction member to be brought into contact with the brake rotor, friction member operating means to bring the friction member into contact with the brake rotor, and an electric motor to drive the friction member operation means. In an electric brake system provided with a plurality of electric brake devices including a control device for controlling a braking force by controlling the electric motor, first and second electric powers are supplied to the electric motors in the respective electric brake devices. Provide a power supply. The control device of each of the electric brake devices determines whether or not there is an abnormality in the power supply from the first and second power supply devices to the electric brake device, and the abnormality determination portion determines the first condition. And a redundant function control unit configured to control the braking force using the second power supply device according to a predetermined condition when it is determined that there is an abnormality in the power supply from the power supply device to the electric brake device. The redundant function control unit satisfies at least a basic condition that a desired braking force can not be obtained only by all the electric brake devices determined by the abnormality judging unit that there is no abnormality in the power supply, as the determined condition. The second power supply device is used to control the braking force. For this reason, it is possible to provide redundancy of the power supply system and to increase the degree of freedom of the mounting space of the components.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the structural example which mounts the electric brake system which concerns on embodiment of this invention in a vehicle by planar view. It is a figure showing roughly each electric brake equipment of the electric brake system. It is a block diagram of the control system of the same electric brake system. It is a figure which shows the usage example of the auxiliary power supply of the same electric brake system. It is a figure which shows the example at the time of the main power supply abnormality of the same electric brake system. It is a figure which shows the operation example of the same electric brake system. It is a figure which shows the other operation example of the same electric brake system. It is a figure which shows the structural example which mounts the electric brake system which concerns on other embodiment of this invention in a vehicle by planar view.

An electric brake system according to an embodiment of the present invention will be described with reference to FIGS. 1 to 7.
As shown in FIG. 1, the electric brake system includes a plurality of electric brake devices FL, FR, RL, RR, a first power supply device 3, and a host ECU 17. Each of the electric brake devices FL, FR, RL, RR has an electric brake actuator 1, a control device 2, and an auxiliary power supply 18 which is a second power supply device. In this example, the control device 2 corresponding to each wheel of the four-wheeled vehicle is provided. First, the electric brake actuator 1 will be described.

  As shown in FIG. 2, the electric brake actuator 1 includes an electric motor 4, a reduction mechanism 5 for decelerating the rotation of the electric motor 4, a direct acting mechanism (friction member operating means) 6, and a parking brake as a parking brake. It has a mechanism 7, a brake rotor 8 and a friction member 9. The electric motor 4, the reduction mechanism 5, and the linear movement mechanism 6 are incorporated into, for example, a housing or the like not shown. The electric motor 4 comprises a three-phase synchronous motor or the like.

  The speed reduction mechanism 5 is a mechanism that transmits the rotation of the electric motor 4 to the tertiary gear 11 fixed to the rotating shaft 10 by decelerating and includes the primary gear 12, the intermediate gear 13, and the tertiary gear 11. In this example, the reduction mechanism 5 reduces the rotation of the primary gear 12 attached to the rotor shaft 4 a of the electric motor 4 by the intermediate gear 13, and the tertiary gear 11 fixed to the end of the rotating shaft 10. Transmission is possible.

  The linear motion mechanism 6, which is a friction member operating means, converts the rotational motion output from the reduction mechanism 5 into a linear motion of the linear motion portion 14 by the feed screw mechanism, and abuts the friction member 9 against the brake rotor 8. It is a mechanism to separate. The linear motion portion 14 is detentated and supported movably in the axial direction indicated by the arrow mark A1. A friction member 9 is provided at the outboard side end of the linear movement portion 14. By transmitting the rotation of the electric motor 4 to the linear motion mechanism 6 via the reduction mechanism 5, the rotational motion is converted into a linear motion, which is converted into the pressing force of the friction member 9 to generate a braking force. . When the electric brake devices FL, FR, RL, and RR (FIG. 1) are mounted on the vehicle, the outside of the vehicle is referred to as the outboard side, and the center side of the vehicle is referred to as the inboard side.

  As an actuator 16 of the parking brake mechanism 7, for example, a linear solenoid is applied. The locking member (solenoid pin) 15 is advanced by the actuator 16 and fitted into a locking hole (not shown) formed in the intermediate gear 13 for locking thereby inhibiting rotation of the intermediate gear 13. , Parking lock state. By disengaging the lock member 15 from the locking hole, the rotation of the intermediate gear 13 is allowed to be in the unlocked state.

  As shown in FIG. 1, the first power supply device 3 and a host ECU 17 which is the upper control means of each control device 2 are connected to the control device 2 of each of the electric brake devices FL, FR, RL, RR. . The host ECU is also referred to as "VCU". For example, an electric control unit that controls the entire vehicle is applied as the host ECU 17. The host ECU 17 also has an integrated control function of each of the electric brake devices FL, FR, RL, RR. The first power supply device 3 supplies power to the electric motor 4 (FIG. 2) and the control device 2 in each of the electric brake devices FL, FR, RL, RR. As this power supply device 3, for example, a 12 V battery mounted on a vehicle is used.

FIG. 3 is a block diagram of a control system of the electric brake system.
The host ECU 17 controls the control device of each of the electric brake devices according to the output of a sensor (not shown) that changes according to the operation amount (request value of the braking force) of the brake pedal 19 (FIG. 1) of the driver of the vehicle. 2 Output the braking force target value to each. The distribution ratio of the brake force target value to each electric brake device may be, for example, a fixed ratio, and is variable based on the motion and posture of the vehicle estimated from information of on-vehicle sensors such as acceleration sensors and It may be a ratio of

  Each control device 2 includes an arithmetic unit 20, a motor driver 21, a switch 22, a backflow prevention mechanism unit 23, and a current sensor 24. The computing unit 20 is, for example, a processor such as a microcomputer or a hardware module such as an ASIC. Arithmetic unit 20 includes control arithmetic function unit 25, abnormality determination unit 26, and redundant function control unit 27.

  Among these, the control calculation function unit 25 controls the electric motor 4 through the motor driver 21 so as to obtain an appropriate braking force from the braking force target value from the host ECU 17 and the sensing information of the electric brake actuator 1. The motor driver 21 converts the DC power of the power supply 3 into three-phase AC power used to drive the electric motor 4. The motor driver 21 may be, for example, a half bridge circuit using a field effect transistor (abbreviated as FET), a snubber capacitor or the like.

  Examples of the sensing information include a motor current value detected by the current or the like detection unit Sa, a motor angle estimated by the rotation angle estimation unit Sb, and the like. The current etc. detection means Sa may be, for example, a current sensor, and the motor current value may be estimated from motor specifications such as inductance value and resistance value measured in advance and motor voltage. The rotation angle estimation means Sb may be, for example, an angle sensor such as a magnetic encoder or resolver, and the motor angle may be estimated from the motor specifications and the motor voltage using a physical equation.

  The abnormality determination unit 26 of the calculation unit 20 determines whether there is an abnormality in the power supply from the power supply device 3 to the electric brake device. The abnormality determination unit 26 determines not only the abnormality of the power supply device itself but also the abnormality such as disconnection of the power supply harness extending from the power supply device 3. A current sensor 24 is provided on the power supply direction upstream side of the power line extending from the first power supply device 3 to each control device 2. Power line 28 is a motor driver from between power supply device 3 to current sensor 24, backflow prevention mechanism 23, switch 22, computing unit 20, and first path 28 a from auxiliary power supply 18, backflow prevention mechanism 23 and switch 22. The second path 28 b is provided to reach 21, and the third path 28 c is provided to reach the electric motor 4 from the motor driver 21.

The backflow prevention mechanism 23 can use, for example, a diode, and is provided to charge the auxiliary power supply 18 without returning the regenerative power of the electric motor 4 to the power supply device 3. When the abnormality determination unit 26 determines that there is no abnormality, the computing unit 20 can supply the regenerative power of the electric motor 4 to the auxiliary power supply 18 by turning on the switch 22.
For example, when judging the presence or absence of an abnormality in the power supply, the abnormality judging unit 26 turns off the switch 22 and judges from the current value detected by the current sensor 24 in the switch-off state.

  When the abnormality determination unit 26 determines that there is an abnormality in the power supply from the power supply device 3 to the electric brake device, the redundant function control unit 27 controls the braking force using the auxiliary power supply 18 according to the defined conditions. The redundant function control unit 27 sets the auxiliary power supply when at least a desired braking force can not be obtained only by all the electric brake devices determined by the abnormality determination unit 26 that there is no abnormality in the power supply, as the above-defined condition. Use 18 to control the braking force. In this case, the operation states of all the other electric brake devices having no abnormality in the power supply are transmitted to the electric brake device whose abnormality determination unit 26 has determined that there is an abnormality. The sensing information can be used as the operation state.

  Arithmetic unit 20 of the electric brake device to which this sensing information has been transmitted determines whether the auxiliary power supply 18 operates the electric brake device having an abnormality in the power supply in redundant function control unit 27 of this arithmetic unit 20. . In this case, the redundant function control unit 27 can determine whether to use the power of the auxiliary power supply 18 while observing the functional state of the entire electric brake system from the operating states of all the other electric brake devices. For example, a capacitor or a battery smaller than a battery generally used in a vehicle can be applied as the auxiliary power supply 18.

  FIG. 4 is a view showing an example of use of the auxiliary power supply 18 of the electric brake system. Hereinafter, description will be made with reference to FIG. 3 as appropriate. In the description in the auxiliary power supply 18 in FIG. 4, “normal” is connected to the power supply 3, “ineffective” is not connected to the power supply 3, and the auxiliary power 18 is from the electric motor 4 (FIG. 3) The disconnected state (switch 22 in FIG. 3 is off) and “valid” indicate a state in which the power supply 3 is not connected and the auxiliary power supply 18 is connected (switch 22 in FIG. 3 is on).

  In FIG. 4A, the power supply harness connected from the power supply device 3 to a part of the electric brake device FL (in this example, the electric brake device FL corresponding to the left front wheel) is disconnected, and the detected current value of the current sensor 24 From the above, the abnormality determination unit 26 determines that an abnormality has occurred in the power supply. However, at this stage, since the predetermined braking force can be obtained using the electric brake devices FR, RL, RR corresponding to the other wheels (in this example, right front wheel, left rear wheel), an abnormality occurs in the electric brake device FL. The redundant function control unit 27 does not use the auxiliary power supply 18.

  As shown in FIG. 4 (b), following the state of FIG. 4 (a), for example, the abnormality of the computing unit 20 is caused to another electric brake device RL (in this example, the electric brake device RL corresponding to the left rear wheel). When an etc. occurs, sensing information which is an operation state of the electric brake device RL and sensing information of other normal electric brake devices FR and RR are transmitted to the partial electric brake device FL. In this case, in the case where braking is performed only by the normal electric brake devices FR and RR, a turning acceleration in the clockwise direction in FIG. For this reason, the redundant function control unit 27 of the electric brake device FL corresponding to the left front wheel enables the auxiliary power supply 18 of the electric brake device FL and brakes using the three electric brake devices FL, FR, RR.

  The driver of the vehicle, for example, when the brake pedal 19 (FIG. 1) is strongly depressed while the power line 28 connected to the electric brake device FL corresponding to the left front wheel is disconnected as shown in FIG. 4A. When the required braking force by the above becomes high, the braking force of only the right front wheel FR and the left and right rear wheels RL and RR may be insufficient. Therefore, the redundant function control unit 27 of the electric brake device FL in which an abnormality has occurred is such that the deceleration in the front-rear direction generated by the electric brake devices FR, RL, RR of the right front wheel and left and right rear wheels determined to be normal In addition to satisfying the basic condition of the following, when the turning acceleration of the vehicle becomes equal to or less than a predetermined value, the auxiliary power supply 18 is enabled to cause the electric brake device FL to generate a braking force.

  The deceleration in each longitudinal direction is calculated by the calculator 20 from the sensing information in the respective electric brake devices FR, RL, RR, and transmitted to the calculator 20 of the electric brake device FL to be controlled via the host ECU 17 Be done. The redundant function control unit 27 of the computing unit 20 sets a threshold value as to whether or not the auxiliary power supply 18 is to be made effective so that the auxiliary power supply 18 of the electric brake device FL becomes effective when the required braking force becomes high. It may be variable according to the required braking force. The correlation in which the threshold value of the deceleration in the front-rear direction becomes larger as the required value of the braking force by the driver of the vehicle becomes larger is stored, for example, in storage means (not shown) in the computing unit 20. The redundant function control unit 27 may change the threshold value of the longitudinal deceleration based on the correlation stored in the storage unit. The frequency of use of the auxiliary power supply 18 can be limited by changing the threshold value of the longitudinal deceleration in this manner.

  As shown in FIG. 5, when an abnormality occurs in the first power supply device 3, all braking forces are lost, so the abnormality judgment unit 26 of each control device 2 of the four-wheeled electric brake devices FL, FR, RL, RR. When it is determined that there is an abnormality in the power supply device 3, the redundant function control unit 27 of each control device 2 immediately activates the respective auxiliary power supplies 18 and brakes them according to the required braking force.

  FIG. 6 is a view showing an operation example of this electric brake system. This figure shows an operation example in the example of FIG. 4 (a) and (b). These FIG. 4 (a), (b) and FIG. 3 are also demonstrated, referring suitably. The control calculation function unit 25 starts the braking by controlling the electric motor 4 from the braking force target value corresponding to the required braking force and the sensing information. After that, for example, it is assumed that a power line abnormality such as a harness disconnection occurs in the electric brake device FL corresponding to the left front wheel.

  At that time, although the electric brake device FL can be driven using the auxiliary power supply 18, the electric brake device FL can be braked by the other electric brake devices FR, RL, RR to which the power supply system is normally connected. Do not use FL. The braking forces of the electric brake devices FR, RL, RR at this time are preferably determined under the constraint that the yaw rate, which is the turning acceleration generated in the vehicle, is less than a predetermined value. The yaw rate is detected by, for example, a yaw rate sensor 29 (FIG. 3).

  Thereafter, it is assumed that, for example, an abnormality or the like of the computing unit 20 occurs in the electric brake device RL corresponding to the left rear wheel. At that time, it is difficult to brake while making the yaw rate equal to or less than the predetermined value only with the electric brake devices FR and RR in the right row in FIG. 4 (b). For this reason, braking is performed by the electric brake devices FL, FR, and RR using the auxiliary power supply 18 of the electric brake device FL on the left front wheel. After that, after the vehicle stops, it is difficult to generate the yaw rate except under conditions such as extreme inclination, so the drive of the electric brake device FL is stopped to conserve the capacity of the auxiliary power supply 18, and the electric brake device in the right row Keep the vehicle stopped at FR and RR.

  FIG. 7 is a view showing another operation example of the electric brake system. This figure shows an operation example under the condition that the required braking force becomes equal to or less than a predetermined value in the example of FIG. 4 (a). If a power line abnormality such as a harness break occurs in the electric brake device FL from the start of braking, the operation is the same as in FIG.

  Thereafter, when the required braking force is increased and it is determined that the braking force is insufficient only with the other electric braking devices FR, RL, RR, the electric power braking device FL is driven using the auxiliary power supply 18. At that time, the motor-driven brake device FL in which an abnormality has occurred can be a brake balance that requires less power as much as possible. Thereafter, after the vehicle is stopped, the drive of the electric brake device FL is stopped to preserve the capacity of the auxiliary power supply 18, and the stopped state is maintained by the other electric brake devices RL, FR, RR.

  According to the electric brake system described above, the first power supply device 3 normally supplies power to the electric motor 4 and the control device 2. The control device 2 controls the electric motor 4 so as to obtain an appropriate braking force from the braking force target value from the host ECU 17 and the sensing information of the electric brake actuator 1. At this time, power is supplied to the auxiliary power supply 18 from the first power supply device 3 and stored. The regenerative power of the electric motor 4 can also be supplied to the auxiliary power supply 18.

  When the abnormality determination unit 26 determines that there is an abnormality in the power supply to the electric brake device, the redundant function control unit 27 controls the braking force using the auxiliary power supply 18 according to the defined conditions. The redundant function control unit 27 uses the auxiliary power supply 18 to apply a braking force when at least a desired braking force can not be obtained only by all the electric brake devices determined to have no abnormality in the power supply as a defined condition. Control. As described above, by providing the first power supply device 3 and the auxiliary power supply 18 in the electric brake system, a redundant function of the power supply system can be provided.

  Furthermore, in order to use the auxiliary power supply 18 only when the function of the entire electric brake system falls below a predetermined level, for example, a battery or a capacitor smaller than a battery generally used in a vehicle is applied as the auxiliary power supply 18 Can. Since the auxiliary power supply 18 is limitedly used, the auxiliary power supply 18 can be miniaturized, and the mounting space of the auxiliary power supply 18 on the vehicle can be increased. This can increase the freedom of design.

Another embodiment will be described.
In the following description, the portions corresponding to the items described in the preceding embodiments are given the same reference numerals, and the redundant description will be omitted. When only a part of the configuration is described, the other parts of the configuration are the same as those described in the preceding embodiment unless otherwise stated. The same function and effect can be obtained from the same configuration. Not only the combination of the portions specifically described in the embodiments but also the embodiments may be partially combined if any problem does not occur in the combination.

  As shown in FIG. 8, one control device 2 and one auxiliary power supply 18 are provided for the two electric brake actuators 1, 1 corresponding to the left and right wheels of the front wheel, and two electric motors corresponding to the left and right wheels of the rear wheel. One controller 2 and one auxiliary power supply 18 may be provided for the brake actuators 1, 1.

  Although the example which provides the auxiliary power supply 18 in all the electrically-driven brake devices is shown also in any structure of FIG. 1, FIG. 8, it is good also as a structure which provides the auxiliary power supply 18 only in a part of electrically-driven brake device. For example, in a four-wheeled vehicle, in general, only the front electric brake device may be redundantly configured by the auxiliary power supply 18 because the front brake exerts a braking force twice or more than that of the rear brake. .

  When determining the presence or absence of an abnormality in the power supply from the power supply device 3 to the electric brake device, the host ECU 17 monitors the power supply state without using the current sensor 24, and the information being monitored is It may be configured to be transmitted to the In this case, the abnormality determination unit 26 of the computing unit 20 can check the information supplied from the host ECU 17 with the defined relationship setting means to determine the presence or absence of the abnormality in the power supply.

For example, since the vehicle does not generate turning acceleration in the stopped state, the auxiliary power supply 18 may be used only when the vehicle speed is equal to or greater than a predetermined vehicle speed. Specifically, as shown in FIG. 3, a vehicle speed estimation means 30 for estimating the traveling speed of a vehicle equipped with an electric brake system is provided, and the redundant function control unit 27 uses the vehicle speed estimation means 30 as a defined condition. The auxiliary power supply 18 may be used when the estimated vehicle speed satisfies the predetermined vehicle speed or more.
Alternatively, processing may be used in which the front-side electric brake device having a larger braking force is used in preference to the rear-side electric brake device.

  As mentioned above, although the form for implementing this invention was demonstrated based on embodiment, embodiment disclosed this time is an illustration and restrictive at no points. The scope of the present invention is indicated not by the above description but by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

2 ... Control device 3 ... First power supply device 4 ... Electric motor 6 ... Linear motion mechanism (friction member operation means)
8 ... brake rotor 9 ... friction member 18 ... auxiliary power supply (second power supply device)
26 ... abnormality determination unit 27 ... redundant function control unit 30 ... vehicle speed estimation means

Claims (5)

A brake rotor, a friction member to be brought into contact with the brake rotor, friction member operating means for bringing the friction member into contact with the brake rotor, an electric motor for driving the friction member operation means, and control of the electric motor In an electric brake system provided with a plurality of electric brake devices including a control device for controlling a braking force,
First and second power supplies for supplying electric power to the electric motor in each of the electric brake devices;
The control device of each of the electric brake devices
An abnormality determination unit that determines presence or absence of an abnormality in power supply from the first and second power supply devices to the electric brake device;
When it is determined by the abnormality determination unit that there is an abnormality in the power supply from the first power supply device to the electric brake device, redundancy for controlling the braking force using the second power supply device according to a defined condition Function control unit,
Have
The redundant function control unit satisfies at least a basic condition that a desired braking force can not be obtained only by all the electric brake devices determined by the abnormality judging unit that there is no abnormality in the power supply, as the determined condition. An electric brake system, comprising: controlling the braking force using the second power supply device.   The electric brake system according to claim 1, further comprising: vehicle speed estimation means for estimating a traveling speed of a vehicle equipped with the electric brake system, wherein the redundant function control unit satisfies the basic condition as the determined condition. In addition to the above, an electric brake system using the second power supply device when the vehicle speed estimated by the vehicle speed estimation means satisfies a condition equal to or higher than a predetermined vehicle speed.   The electric brake system according to claim 1 or 2, wherein the redundant function control unit satisfies the basic condition in which the longitudinal deceleration generated by all the electric brake devices determined to have no abnormality is equal to or less than a threshold. In addition to the above, an electric brake system using the second power supply device when the turning acceleration of the vehicle equipped with the electric brake system becomes equal to or less than a predetermined value as the predetermined condition.   4. The electric brake system according to claim 3, wherein the redundant function control unit is configured to set the threshold value of the longitudinal deceleration larger as the required value of the braking force by the driver of the vehicle increases. An electric brake system that changes the direction deceleration threshold value.   The electric brake system according to any one of claims 1 to 4, wherein the redundant function control unit of the electric brake device determined to have an abnormality in the power supply is all the electric motors having no abnormality in the electric power supply. The electric brake system which determines whether the electric power of said 2nd power supply device is used from the sensing information of a brake device.

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