CN106938644B

CN106938644B - Vehicle and vehicle composite braking system

Info

Publication number: CN106938644B
Application number: CN201710155840.9A
Authority: CN
Inventors: 王舸; 殷德军
Original assignee: Nanjing Aotebo Electromechanical Technology Co ltd
Current assignee: Nanjing Aotebo Electromechanical Technology Co ltd
Priority date: 2017-03-16
Filing date: 2017-03-16
Publication date: 2023-05-02
Anticipated expiration: 2037-03-16
Also published as: CN106938644A

Abstract

The invention provides a vehicle and a vehicle composite braking system, comprising: a first rotary electric machine provided as a brake pedal brake feel feedback mechanism; a second rotary electric machine provided as a brake boosting mechanism; the first rotary motor has a first rotation shaft; the second rotating motor is provided with a second rotating shaft; the brake system further includes a coupler disposed between the first rotating electrical machine and the second rotating electrical machine, the coupler comprising: a first rotating body for connecting to a rotating shaft of the first rotating electric machine; a second rotating body for connecting to a rotating shaft of a second rotating electric machine; the first rotating body and the second rotating body can independently rotate under the drive of the first rotating motor and/or the second rotating motor, and a gap is formed between the first rotating body and the second rotating body in the rotating direction; the void may be reduced or eliminated by adjustment of the operating state of the first rotating electrical machine and/or the second rotating electrical machine. The compound braking system has high reliability and good stability.

Description

Vehicle and vehicle composite braking system

Technical Field

The present invention relates to a vehicle braking system, and more particularly to a compound braking system using a rotary electric machine with feedback and a booster rotary electric machine and using a coupler to achieve mechanical decoupling.

Background

The vehicle braking system is a key for ensuring normal and safe running of the vehicle. The braking system mainly comprises an energy supply device, a control device, a transmission device and a brake four-base plate, wherein a brake master cylinder is a key in the transmission device, is generally arranged at the front part of an automobile and is close to a cab or an engine room, so that the conversion of force and hydraulic pressure is realized, and the brake master cylinder is used as an energy conversion device and is used for realizing the braking of the automobile together with a wheel cylinder under the control of a driver or an automatic driving system/auxiliary driving system. In a general vehicle, a piston is controlled by a brake pedal (or a jack of a booster), and a force generated by the brake pedal and the booster is converted into a corresponding hydraulic pressure, and the hydraulic pressure is pressed into a brake cylinder with a predetermined pressure, thereby generating a braking force for a braking operation.

The electronic hydraulic brake system is improved and developed on the basis of a traditional hydraulic brake system and comprises an electronic brake pedal assembly, compared with a traditional hydraulic brake pedal, the electronic hydraulic brake system can accurately sense the requirement (such as light weight and heavy weight) of a driver for controlling the pedal through a pedal sensor such as a displacement sensor or an angle sensor, or transmit corresponding electric signals to a brake system ECU based on the braking requirement of an upper ECU (electronic control Unit) such as an automatic driving system/auxiliary driving system, and the ECU automatically adjusts the braking pressure of wheels according to different braking requirements, so that the danger that a driver unconsciously reduces braking force due to vibration caused by reaction force of the hydraulic mechanical brake system can be avoided. Meanwhile, the electronic hydraulic system is also more beneficial to realizing the safe risk avoidance of driving, and has less response time.

Disclosure of Invention

The invention aims to provide a vehicle compound brake system, which comprises:

a brake pedal;

a connecting rod connected with the brake pedal, wherein the connecting rod is provided with corresponding travel when the brake pedal moves;

the motion sensor is used for sensing the motion state of the brake pedal when the brake pedal is stepped on;

a brake master cylinder having at least one piston movable within a cylinder body of the brake master cylinder;

a first rotating electric machine provided as a brake pedal braking feel feedback mechanism that is driven to rotate in response to movement of the brake pedal to generate an resisting force that resists further movement of the brake pedal, the connecting rod transmitting the resisting force to the brake pedal;

a second rotary electric machine provided as a brake boosting mechanism driven to rotate to generate a thrust force for pushing a piston of a master cylinder that compresses a liquid to generate a hydraulic pressure in response to the thrust force generated by the brake boosting mechanism;

wherein: the first rotating electric machine has a first rotation shaft; the second rotating motor is provided with a second rotating shaft; the vehicle compound brake system further includes a coupler disposed between the first rotating electric machine and the second rotating electric machine, the coupler including: a first rotating body for being connected to and driven to rotate by a rotating shaft of the first rotating motor; a second rotating body for being connected to and driven to rotate by a rotation shaft of the second rotating motor; the first rotating body and the second rotating body can independently rotate under the drive of the first rotating motor and/or the second rotating motor, and a gap is formed between the first rotating body and the second rotating body in the rotating direction; the void may be reduced or eliminated by an adjustment of the operation state of the first rotating electrical machine and/or the second rotating electrical machine; and, when the gap is maintained, a mechanically decoupled state is maintained between the brake pedal and the brake master cylinder, and when the gap is eliminated, the mechanically decoupled state is released between the brake pedal and the brake master cylinder.

According to the technical scheme, the vehicle composite braking system provided by the invention, in particular to an electronic hydraulic braking system which uses a rotating motor as a braking force feedback motor and a rotating motor as a pressurizing motor, adopts a novel coupler to realize mechanical decoupling between a brake pedal and a piston/booster of a brake master cylinder, and ensures that two rotating parts synchronously rotate along with the pressurizing motor and the feedback motor, and the positions between coupling blocks can be changed along with different working conditions of a vehicle by keeping a certain gap in the rotating direction of the coupler, particularly in a normal braking state, a braking force shortage state and other abnormal states, the control of the abnormal state and the release of braking risks can be realized through the coupler, so that braking safety is ensured. Meanwhile, the coupler can ensure that the whole system does not adopt a hydraulic supercharging device or a vacuum supercharging device any more, and a rotating motor which is simple and mature in technology is directly adopted as a supercharging device and a brake sensory feedback simulator, so that mechanical decoupling is easy to realize, and multifunctionality and stability guarantee are easier to realize in control.

It should be understood that all combinations of the foregoing concepts, as well as additional concepts described in more detail below, may be considered a substrate for the presently disclosed subject matter so long as such concepts are not mutually inconsistent. In addition, all combinations of claimed subject matter are considered a substrate for the inventive subject matter of this disclosure.

The foregoing and other aspects, embodiments, and features of the present teachings will be more fully understood from the following description, taken together with the accompanying drawings. Other additional aspects of the invention, such as features and/or advantages of the exemplary embodiments, will be apparent from the description which follows, or may be learned by practice of the embodiments according to the teachings of the invention.

Drawings

The drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component that is illustrated in various figures may be represented by a like numeral. For clarity, not every component substrate is labeled in every drawing. Embodiments of various aspects of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a schematic illustration of a vehicle braking system according to some embodiments of the invention.

Fig. 2 is a schematic diagram, side view, of a coupler according to some embodiments of the invention.

Fig. 3 is a schematic diagram of a feedback portion (first substrate) of a coupler, according to some embodiments of the invention, in elevation.

Fig. 4 is a schematic diagram of a pressurized portion (second substrate) of a coupler, according to some embodiments of the invention, in elevation.

Fig. 5 is a schematic diagram of a transmission configuration of a booster transmission according to some embodiments of the invention.

Fig. 6 is a schematic diagram of a transmission structure of a booster transmission mechanism according to another embodiment of the present invention.

Detailed Description

For a better understanding of the technical content of the present invention, specific examples are set forth below, along with the accompanying drawings.

Aspects of the invention are described in this disclosure with reference to the drawings, in which are shown a number of illustrative embodiments. The embodiments of the present disclosure are not necessarily intended to include all aspects of the invention. It should be understood that the various concepts and embodiments described above, as well as those described in more detail below, may be implemented in any of a number of ways, as the disclosed concepts and embodiments are not limited to any implementation. Additionally, some aspects of the disclosure may be used alone or in any suitable combination with other aspects of the disclosure.

As shown in fig. 1 and 2, a brake system for a vehicle, particularly an electro-hydraulic brake system 100 in fig. 1, includes a brake pedal 101, a link 102, a return spring 103, an angle sensor 104, a pedal actuator 105, a pedal force feedback motor 106, a coupler 108, a booster motor 110, a booster actuator 111, a master cylinder 112, and a supplemental fluid tank 120, and a brake system ECU (for convenience of description and brief description, hereinafter referred to as ECU) 130 connected to the master cylinder 112, the feedback motor 106, the booster motor 110, and the angle sensor 104. The ECU is used as a control center of the braking system and integrally controls the operation and the realization of the braking system.

In the above and in the embodiments of the present invention to be described below, the feedback motor 106 and the booster motor 110 are both rotary motors.

As shown in fig. 1, the master cylinder 112 has two

supply outlet lines

112a and 112b for outputting hydraulic pressure to a wheel cylinder (not shown) to generate a required braking force to apply braking control to the wheels.

In operation, the master cylinder 112 is supplied with brake fluid via the supply fluid reservoir 120 via the

supply inlet lines

120a and 120b into the cylinder body of the master cylinder 112.

In some typical implementations, when the brake pedal 101 is depressed by the driver, i.e., the driver's intended braking desire (braking demand) is obtained by the brake pedal, rotation occurs through the link 102, the angle sensor 104 collects a pedal movement signal (for example, embodied based on the collected rotation angle of the link) and transmits the pedal movement signal to the ECU 130, which controls the boost assist output of the boost motor 110 and the feedback provided to the pedal by the feedback motor 106 according to the braking demand, and the output of the boost motor 110 transmits a force to the rotating master cylinder via a transmission mechanism such as a guide rod, so that the volume of the master cylinder 112 is changed, thereby causing an output of hydraulic pressure, which is then applied to the wheel cylinder to perform a braking action by a brake such as a disc brake or a drum brake, thereby realizing pedal braking. And the output of the feedback motor 106 is applied to the link 102 and the brake pedal 101 to simulate a brake feel.

As shown in fig. 1, a return spring 103 is provided as a return mechanism between the feedback 106 motor and the brake pedal 101, and has a tendency to return the brake pedal to an initial state. A return spring 103, in particular a torsion spring, may be provided on the link 102, in particular for providing a force that counteracts the movement of the link with the brake pedal, and has a tendency to return the link to an initial state. It is particularly preferred that the spring axis of the torsion spring is parallel or collinear with the axis of the rotary shaft of the feedback motor 106.

In some embodiments, a plurality of the aforementioned return springs 103 may also be provided.

In an alternative example, such a return spring 103 provides, in conjunction with or alone with the feedback motor 106, a resistive force that resists the advancement of the brake pedal 101 to give the driver a brake feel feedback.

In connection with fig. 1, an angle sensor 104 is provided for collecting movement information of the brake pedal 101, thereby obtaining a braking demand and expectation of the driver. Of course, in some embodiments, the acquisition of the movement information of the brake pedal 101 or the acquisition of the braking demand may also be achieved by other means, such as acquisition based on pedal travel variation (by a displacement sensor) or acquisition of the pressure applied to the pedal (by a force sensor), but these examples are not intended to limit the practice of the invention.

The pedal transmission mechanism 105 is disposed between the brake pedal 101 and the feedback motor 106, and is used for transmitting torque between the rotating shaft of the feedback motor and the connecting rod 102 directly connected with the brake pedal, thereby transmitting the torque to the brake pedal 101.

The pedal drive 105 may be, for example, a speed change mechanism (e.g., a planetary gear set, a fixed shaft gear reduction) or a direction change mechanism, or a combination thereof.

In some embodiments, the brake system 100 may also be provided without such a pedal drive 105, such that the shaft of the feedback motor 106 is directly connected (via bearings or the like) to the linkage 102.

Likewise, the booster transmission mechanism 111 is used for torque transmission between the rotating shaft of the booster motor 110 and the piston rod of the brake master cylinder 112.

The booster transmission 111, in particular, employs a variable speed transmission, such as a speed change mechanism or a direction change mechanism, or a combination thereof.

In some embodiments, the brake system 100 may not be provided with such a booster transmission mechanism 111, but the rotation shaft of the booster motor 110 may be directly connected to the piston rod of the brake master cylinder 112 (via a bearing or the like), so as to directly drive the piston rod of the brake master cylinder 112 to move.

The brake master cylinder 112, which is a rotary type master cylinder in the example shown in fig. 1, has a substantially annular cylinder body and a rotating shaft provided in the cylinder body substantially coaxially with the cylinder body center line and rotatable by being driven in the cylinder body, and is provided with an ear portion, and the rotating shaft is rotated by being driven by a rotational force output from an output shaft (rotating shaft) of a booster motor or by being driven to rotate through the booster transmission mechanism 111 as described above, thereby causing a hydraulic pressure change in the annular cylinder body and outputting the hydraulic pressure to a brake cylinder to generate a braking force.

In other examples, such a master cylinder 113 may be configured as a linear type master cylinder, and the rotational force output from the aforementioned booster motor 110 is converted by a force transmission mechanism, for example, from rotational motion to linear motion, so that it pushes a piston rod of a conventional hydraulic cylinder to move the piston, causing a hydraulic pressure change in the brake cylinder, and outputting the hydraulic pressure to the brake cylinder to generate braking force.

As shown in fig. 1 and 2, in the braking function implementation process of the braking system, a coupler 108 is disposed between the pedal braking force feedback motor 106 and the booster motor 110, so as to implement mechanical decoupling.

As shown in fig. 2, the coupler 108 includes a first substrate 108a connected to a rotation shaft of the feedback motor 106 and a second substrate 108b connected to a rotation shaft of the booster motor 110. The first substrate 108a is disposed opposite to the second substrate 108b.

As shown in fig. 2, 3, and 4, the first substrate 108a serves as a rotating body and rotates in synchronization with the rotating shaft 106a of the feedback motor 106.

The second substrate 108b, which is a rotating body, rotates in synchronization with the rotation shaft 110a of the booster motor 110.

At least one coupling block 109 is provided on opposite surfaces of the first and

second substrates

108a, 108b, respectively, and these coupling blocks 109 are provided with a gap in the direction along the rotation so that there is at least one first position in which the first and/or second substrates are rotated independently and at least one second position in which the first and second substrates are rotated together.

As shown in fig. 2, 3 and 4, one of the first substrate 108a and the second substrate 108b can be contacted with the other and driven to rotate together after rotating by a certain angle. That is, the aforementioned backlash in the rotational direction can be reduced or eliminated by the adjustment of the operation state of the booster motor and/or the feedback motor. The brake pedal and the master cylinder are kept mechanically decoupled when the clearance is maintained, and the brake pedal and the master cylinder are decoupled when the clearance is eliminated.

Of course, a plurality of coupling blocks 109 may be provided for each of the aforementioned substrate surfaces (108 a, 108 b).

In some examples, the first substrate 108a and the second substrate 108b are both configured as a disk structure.

Alternatively, the coupling block 109 is configured as a cam or a crank block.

For example, the ECU controls the rotation of the adjustment feedback motor 106 according to the abnormal state of the booster motor 110 and/or the pressure abnormal state of the master cylinder 112, for example, to provide a torque output and/or a rotational speed of the second rotary motor to couple the coupling block on the first substrate 108a of the coupler 108 with the coupling block on the second substrate 108b (at this time, the mechanically decoupled state is released), so that the first substrate 108a rotates the second substrate 108b in unison when driven to rotate.

As shown in fig. 1 and 2, the internal pressure of the brake master cylinder 112 may be monitored in real time by a sensor and transmitted to the ECU, and the ECU determines whether the pressure in the brake master cylinder reaches the demand according to the braking demand and may control the feedback motor 106 to be used as an auxiliary boost motor when the pressure does not reach the demand (abnormal), control the movement speed and direction thereof, and drive the first substrate 108a of the coupler 108 to move so that the coupling blocks are combined, thereby releasing the mechanically decoupled state, and thereby further providing an auxiliary boost driving force to the boost motor 110 (for example, the pressure in the brake master cylinder is abnormal due to insufficient boost driving provided by the boost motor), thereby enhancing the reliability and stability of the brake system.

Meanwhile, for example, when a failure or abnormality of the booster motor 110 is detected, such as insufficient power, no power, line failure, etc., as described above, the ECU controls the feedback motor 106 to be used as an auxiliary booster motor, controls the movement speed and direction thereof, and drives the first substrate 108a of the coupler 108 to move so that the coupling blocks are combined, thereby releasing the mechanically decoupled state and thereby further providing a boost driving force to the booster motor 110, thereby enhancing the reliability and stability of the brake system.

Meanwhile, in other examples, when the booster motor 110 and the feedback motor 106 are failed or abnormal, for example, the driver further steps on the brake pedal 101 to rotate the connecting rod and drive the rotating shaft of the feedback motor 106 to move, it is particularly necessary to set the pedal transmission mechanism 105 in fig. 1, so as to drive the rotating shaft to rotate with smaller force, and further drive the first base plate 108a of the coupler 108 to move, so that the coupling blocks are combined, and the mechanical decoupling state is released, so that the rotating shaft of the booster motor 110 is driven to rotate, thereby realizing braking boosting, avoiding the complete braking system when all 2 motors fail, and reducing the damage caused by braking risks.

When the feedback motor 106 fails or is abnormal, as previously described, some braking feedback may still be achieved by the previously described restoring mechanism, such as the return spring 103.

In some embodiments, to prevent braking risk caused by failure of the feedback motor 106, more than two feedback motors may be provided in series to improve efficiency and provide reliability in failure mode.

Similarly, to prevent the braking risk caused by failure of the booster motor 110, more than two booster motors may be connected in series to improve efficiency and provide reliability in failure mode.

In the embodiment of the present invention, as shown in fig. 5 and 6, it is preferable that the supercharging transmission 111 is implemented by using a planetary gear device 140, and the planetary gear device 140 is disposed coaxially with the rotation shaft of the supercharging motor 110.

As shown in fig. 5, in conjunction with fig. 1, in one example, the direct power input of the planetary gear arrangement 140 is the shaft 110a of the supercharging motor 110. In this example, the planetary gear device has a ring gear 140a, a carrier 140b, a sun gear 140c, and a planetary gear 140d, the ring gear 140a is fixed, the rotating shaft 110a (i.e., an output shaft) of the booster motor 110 is connected to the sun gear 140c, the sun gear is driven to rotate, the carrier 140b is connected to the planetary gear 140d, and the second base plate 108b of the coupler 108 is connected to the rotating shaft 110a of the booster motor, and the carrier 140b provides power output as a power output end to a pushing portion of the brake master cylinder, such as a rotating shaft of the rotary master cylinder or a piston rod of the linear master cylinder (a direction conversion mechanism is required).

In such an embodiment, the coupler is connected to the rotating shaft of the booster motor, and the structure is simple and easy to implement.

As shown in fig. 6, in combination with fig. 1, in another example, the direct power input of the planetary gear device is the rotation shaft of the booster motor 110 and (the second substrate 108b of) the coupler 108.

In this example, the planetary gear device has a ring gear 140a, a carrier 140b, a sun gear 140c and a planetary gear 140d, the carrier 140b is fixed, a rotating shaft (i.e., an output shaft) of the booster motor 110 is connected to the sun gear 140c to drive the sun gear to rotate, the carrier 140b is connected to the planetary gear 140d, and the second base plate 108b of the coupler is connected to the rotating shaft 110a of the booster motor 110, and the ring gear 140a provides power output as a power output end to a pushing part of the brake master cylinder, such as a rotating shaft of the brake master cylinder or a piston rod of the linear master cylinder (a direction conversion mechanism is required to pass through, including but not limited to a cam gear mechanism, a rack-and-pinion mechanism, a crank gear mechanism, etc.). This is done to enhance the coupler-boost motor-boost drive mechanism 111.

While the invention has been described with reference to preferred embodiments, it is not intended to be limiting. Those skilled in the art will appreciate that various modifications and adaptations can be made without departing from the spirit and scope of the present invention. Accordingly, the scope of the invention is defined by the appended claims.

Claims

1. A vehicle compound brake system, comprising:

a brake pedal;

a control unit for controlling operation of the first rotating electrical machine and the second rotating electrical machine in response to a state of motion of the brake pedal;

wherein: the first rotating electric machine has a first rotating shaft configured as an output shaft thereof; the second rotary electric machine has a second rotary shaft configured as an output shaft thereof; the vehicle compound brake system further includes a coupler disposed between the first rotating electric machine and the second rotating electric machine, the coupler including: a first rotating body for being connected to and driven to rotate by a rotating shaft of the first rotating motor; a second rotating body for being connected to and driven to rotate by a rotation shaft of the second rotating motor; the first rotating body and the second rotating body can independently rotate under the drive of the first rotating motor and/or the second rotating motor, and a gap is formed between the first rotating body and the second rotating body in the rotating direction; the void may be reduced or eliminated by an adjustment of the operation state of the first rotating electrical machine and/or the second rotating electrical machine; and, when the gap is maintained, a mechanically decoupled state is maintained between the brake pedal and the brake master cylinder, and when the gap is eliminated, the mechanically decoupled state is released between the brake pedal and the brake master cylinder.

2. The vehicle multiple brake system according to claim 1, wherein the first rotating body and the second rotating body are rotatable independently and contact one another after the other rotates by a certain angle, and are driven to rotate together.

3. The vehicle combination brake system according to claim 1, wherein at least one coupling block is provided on each of the first and second rotating bodies, the coupling blocks having at least one first position in which the first and/or second rotating bodies independently rotate and at least one second position in which the first and second rotating bodies jointly rotate.

4. The vehicle combination brake system of claim 1, further comprising at least one restoring mechanism having a tendency to restore the brake pedal to an initial state.

5. The vehicle compound brake system as defined in claim 4, wherein the at least one restoring mechanism and the first rotating electric machine together or separately provide an impedance force that resists advancement of the brake pedal to give a brake feel feedback to the driver.

6. The vehicle combination brake system according to claim 1, wherein a pedal transmission mechanism is further provided between the pedal and the first rotating electric machine for torque transmission between the rotating shaft of the first rotating electric machine and the connecting rod.

7. The vehicle composite brake system according to claim 1, wherein a booster transmission mechanism is further provided between the output shaft of the second rotary electric machine and the master cylinder for torque transmission between the rotary shaft of the second rotary electric machine and the piston rod of the master cylinder.

8. The vehicle composite brake system according to claim 1, wherein the brake master cylinder comprises one of a linear master cylinder or a rotary master cylinder.

9. The vehicle compound brake system as defined in claim 1, wherein the output shaft of the second rotary electric machine is directly connected with the piston rod of the master cylinder.

10. The vehicle compound brake system as defined in claim 7, wherein the boost transmission includes a planetary gear device coaxially disposed with a rotational axis of the second rotary electric machine.

11. The vehicle compound brake system as defined in claim 10, wherein the planetary gear device has a ring gear, a carrier, a sun gear, and a planetary gear, the ring gear is fixed, the output shaft of the second rotary electric machine is connected to the sun gear, the sun gear is driven to rotate, and the second portion of the coupler is coupled to the shaft of the second rotary electric machine via the coupler, the torque of the first portion of the coupler is transmitted to the shaft of the second rotary electric machine via the coupler and is further transmitted to the sun gear, and the carrier provides the power output to the piston rod of the master cylinder as the power output end.

12. The vehicle compound brake system as defined in claim 10, wherein the planetary gear device has a ring gear, a carrier, a sun gear, and a planet gear, the carrier is fixed, the output shaft of the second rotary electric machine is connected to the sun gear, the sun gear is driven to rotate, and the second portion of the coupler is coupled to the shaft of the second rotary electric machine via the coupler, the torque of the first portion of the coupler is transmitted to the shaft of the second rotary electric machine via the coupler, and is further transmitted to the sun gear, and the ring gear provides a power output to the piston rod of the master cylinder as a power output end.

13. The vehicle compound brake system as defined in claim 10, wherein the boost transmission includes a fixed shaft gear reduction device disposed non-coaxially with the rotational axis of the second rotary electric machine, an output shaft of the second rotary electric machine being connected to an input of the fixed shaft gear reduction device, and the second portion of the coupler being coupled to the rotational axis of the second rotary electric machine via the coupler, torque of the first portion of the coupler being transmitted through the coupler to the rotational axis of the second rotary electric machine and thereby to an input of the reduction device, the output of the fixed shaft gear reduction device providing power to a piston rod of the master cylinder.

14. The vehicle compound brake system as defined in claim 1, wherein at least two of the first rotating electrical machines are provided in series in the compound brake system.

15. The vehicle compound brake system as defined in claim 1, wherein at least two of the second rotating electrical machines are provided in series in the compound brake system.

16. The vehicle composite brake system according to claim 1, further comprising a pressure sensor for detecting an in-cylinder pressure of the master cylinder;

the control unit controls adjustment of rotation of the first rotary electric machine to release the mechanically decoupled state in response to an abnormal state of the second rotary electric machine and/or a pressure abnormal state of a master cylinder.

17. A vehicle having a vehicle compound brake system as claimed in any one of claims 1 to 16.