CN110077378B

CN110077378B - Four-wheel distributed drive electric vehicle braking energy recovery system based on two-way check valve and linear exhaust electromagnetic valve

Info

Publication number: CN110077378B
Application number: CN201910429113.6A
Authority: CN
Inventors: 杨坤; 王杰; 李敏; 苗立东; 陈文刚; 赵义; 肖锦钊
Original assignee: Shandong University of Technology
Current assignee: Shandong University of Technology
Priority date: 2019-05-22
Filing date: 2019-05-22
Publication date: 2022-02-22
Anticipated expiration: 2039-05-22
Also published as: CN110077378A

Abstract

The invention provides a four-wheel distributed drive electric vehicle braking energy recovery system based on a two-way one-way valve and a linear exhaust solenoid valve, which belongs to the technical field of electric vehicle braking energy recovery, and aims at the characteristic that the braking force of a four-wheel motor of a four-wheel distributed drive electric vehicle is independently adjustable, components such as an auxiliary gas storage tank, a switch solenoid valve, a three-way valve, a drive wheel two-way one-way valve, a drive shaft linear exhaust solenoid valve, a drive wheel braking pressure sensor and the like are added in the existing decoupling type braking energy recovery system based on an air pressure ABS solenoid valve, so that each drive wheel braking gas path has a double-loop structure, and when braking energy is recovered, a gas source with high air pressure can be selected to provide high-pressure gas for each drive wheel braking gas chamber, thereby effectively solving the problem that the response speed of the coupling braking force of the drive wheels is slow due to the low gas source pressure in the existing continuous braking in the existing scheme, and lags behind the critical issue of the required braking force.

Description

Four-wheel distributed drive electric vehicle braking energy recovery system based on two-way check valve and linear exhaust electromagnetic valve

Technical Field

The invention belongs to the technical field of electric vehicle braking energy recovery, and particularly relates to a four-wheel distributed drive electric vehicle braking energy recovery system based on a two-way check valve and a linear exhaust electromagnetic valve.

Background

Along with the increasing serious problems of environmental pollution and energy safety, the electric vehicle is more and more emphasized by people, a braking energy recovery system is one of the key means for energy conservation of the electric vehicle, and can recover and utilize energy originally consumed in friction braking through a motor, for example, as described in the research on an EMB-based decoupled braking energy recovery system (Yangkun, Gaussong, Wangjie, and the like), the research on the EMB-based decoupled braking energy recovery system [ J ] in automobile engineering, 2016,38(8):1072 + 1079 ], and the energy of the part can account for about 30% of energy required by driving the whole vehicle.

At present, the braking energy recovery system can be divided into a coupling type and a decoupling type according to the working principle, although the arrangement of the original vehicle braking system is not changed, the coupling type braking energy recovery system has the defects of poor braking feeling and low braking energy recovery rate, and the application is gradually reduced at present.

The decoupling type braking energy recovery system can accurately meet the braking requirement of a driver through the coupling of mechanical braking force and motor braking force, and has the advantages of good braking feeling and high braking energy recovery rate. When the braking force of the motor can completely meet the braking requirement of a driver, the braking force is completely provided by the motor brake, and when the braking force of the motor cannot completely meet the braking requirement of the driver, the braking force of the whole vehicle is provided by the motor brake and the mechanical brake together, so that whether the resultant force of the motor braking force and the mechanical braking force can accurately track the braking force required by the driver becomes the key for influencing the effect of the decoupling type braking energy recovery system.

For an electric commercial vehicle, because the whole vehicle has a heavy weight, the influence of a braking energy recovery effect on the economy of the whole vehicle is very important, and meanwhile, from the perspective of reducing the system cost, the development cost and the system transformation workload, at present, the scheme of a decoupling type braking energy recovery system for the electric commercial vehicle which is researched more is a decoupling type braking energy recovery system based on an air pressure ABS electromagnetic valve, which is mentioned in the document URBS air pressure ABS electromagnetic valve failure analysis and improvement of a new energy passenger vehicle (Yangkun, Ma super, Guo Chi, and the like. the URBS air pressure ABS electromagnetic valve failure analysis and improvement [ J ]. Guangxi university report (natural science version), 2017,42(5): 1647-; this solution has the advantages of low cost and easy implementation, but the following problems are found in the research: the adjusting speed of the pressure of the brake air chamber depends on the difference value of the air pressure of the air storage tank and the air pressure of the brake air chamber, when the continuous braking times are more than two times in the driving process, the pressure in the air storage tank can be obviously reduced, the more the continuous braking times are, the larger the pressure reduction is, the more the adjusting speed of the pressure of the brake air chamber can be obviously reduced, and further the coupling braking force applied to the whole vehicle by the braking energy recovery system can lag behind the required braking force, so that the braking feeling is different from that of a conventional braking system, the braking distance can be prolonged, and other serious problems can be caused.

In addition, the driving mode of the electric vehicle can be divided into a traditional centralized driving mode and a distributed driving mode, compared with the centralized driving mode, the distributed driving mode has the advantages of high transmission efficiency, flexible spatial arrangement, strong dynamic property, good economical efficiency and the like, and simultaneously has the advantage that the motor braking force of the driving wheels has independent adjustability, so that a foundation is provided for further improving the braking energy recovery rate and the braking stability of the four-wheel-drive electric commercial vehicle, and meanwhile, the braking energy can be recovered by the front wheels and the rear wheels, so that a foundation is provided for further improving the braking energy recovery rate, and therefore, the development of the decoupling type braking energy recovery system suitable for the four-wheel-drive electric vehicle has higher practical value.

Disclosure of Invention

Aiming at the problems, the invention provides a four-wheel distributed drive electric vehicle brake energy recovery system based on a two-way one-way valve and a linear exhaust solenoid valve on the basis of the existing decoupling type brake energy recovery system scheme based on a pneumatic ABS solenoid valve, and in the scheme, an auxiliary gas storage tank (3), a rear drive shaft switch solenoid valve (5), a rear drive shaft linear exhaust solenoid valve (7), a first three-way valve (8), a rear drive shaft relay valve (9), a second three-way valve (10), a rear right drive wheel two-way one-way valve (11), a rear right drive wheel brake pressure sensor (17), a rear left drive wheel brake pressure sensor (22), a rear left drive wheel two-way one-way valve (28), a front drive shaft relay valve (32), a front left drive wheel two-way one-way valve (33), a front left drive wheel brake pressure sensor (39) are additionally arranged in a drive wheel brake gas path, The brake system comprises a third three-way valve (42), a front right driving wheel two-way one-way valve (43), a front right driving wheel brake pressure sensor (46), a fourth three-way valve (52), a front driving shaft linear exhaust electromagnetic valve (53), a brake pedal displacement sensor (54), a front driving shaft switch electromagnetic valve (55) and the like, so that each driving wheel brake circuit has two independent high-pressure air sources and a two-circuit structure, and when the brake energy recovery is triggered, one air source with high air pressure can be selected by a control system to provide high-pressure air for each driving wheel brake air chamber, and the problem of reduction of the wheel air pressure brake force adjusting speed caused by low air source pressure during continuous braking is effectively solved.

A four-wheel distributed drive electric vehicle braking energy recovery system based on a two-way one-way valve and a linear exhaust electromagnetic valve comprises a braking pedal (1), a braking valve (2), an auxiliary air storage tank (3), a main air storage tank (4), a rear drive shaft switch electromagnetic valve (5), an air compressor (6), a rear drive shaft linear exhaust electromagnetic valve (7), a first three-way valve (8), a rear drive shaft relay valve (9), a second three-way valve (10), a rear right drive wheel two-way one-way valve (11), a rear right drive wheel speed sensor (14), a rear right drive wheel drive motor and transmission device (15), a rear right drive wheel drive motor controller (16), a rear right drive wheel braking pressure sensor (17), a rear right drive wheel braking air chamber (18), a rear right drive wheel ABS electromagnetic valve (19), a rear left drive wheel ABS electromagnetic valve (20), A rear left driving wheel brake air chamber (21), a rear left driving wheel brake pressure sensor (22), a rear left driving wheel driving motor controller (23), a rear left driving wheel driving motor and transmission device (24), a rear left driving wheel speed sensor (25), a rear left driving wheel two-way one-way valve (28), a battery management system (29), a vehicle control unit (30), a brake controller (31), a front driving shaft relay valve (32), a front left driving wheel two-way one-way valve (33), a front left driving wheel speed sensor (36), a front left driving wheel driving motor and transmission device (37), a front left driving wheel driving motor controller (38), a front left driving wheel brake pressure sensor (39), a front left driving wheel brake air chamber (40), a front left driving wheel ABS electromagnetic valve (41), a third three-way valve (42), The front right driving wheel brake system comprises a front right driving wheel two-way one-way valve (43), a front right driving wheel ABS solenoid valve (44), a front right driving wheel brake air chamber (45), a front right driving wheel brake pressure sensor (46), a front right driving wheel driving motor controller (47), a front right driving wheel driving motor and transmission device (48), a front right driving wheel speed sensor (49), a fourth three-way valve (52), a front driving shaft linear exhaust solenoid valve (53), a brake pedal displacement sensor (54) and a front driving shaft switch solenoid valve (55).

An air outlet port b of the air compressor (6) is connected with an air inlet port a of the main air storage tank (4) through an air path, and an air outlet port a of the air compressor (6) is connected with an air inlet port a of the auxiliary air storage tank (3) through an air path.

An air inlet port a of the brake valve (2) is connected with an air outlet port d of the main air storage tank (4) through an air path, an air inlet port b of the brake valve (2) is connected with an air outlet port c of the main air storage tank (4) through an air path, an air outlet port c of the brake valve (2) is connected with a control port c of the front drive shaft relay valve (32) through an air path, and an air outlet port d of the brake valve (2) is connected with a control port c of the rear drive shaft relay valve (9) through an air path.

An air outlet port b of the auxiliary air storage tank (3) is connected with an air inlet port a of the rear driving shaft switching electromagnetic valve (5) through an air path, an air outlet port b of the rear driving shaft switching electromagnetic valve (5) is connected with an air inlet port a of the rear driving shaft linear exhaust electromagnetic valve (7) through an air path, an air outlet port b of the rear driving shaft linear exhaust electromagnetic valve (7) is connected with an air inlet port a of the first three-way valve (8) through an air path, an air outlet port b of the first three-way valve (8) is connected with an air inlet port b of the rear right driving wheel bi-pass one-way valve (11) through an air path, and an air outlet port c of the first three-way valve (8) is connected with an air inlet port b of the rear left driving wheel bi-pass one-way valve (28) through an air path.

And a port a of the rear drive shaft relay valve (9) is connected with an air outlet port e of the main air storage tank (4) through an air passage, and a port b of the rear drive shaft relay valve (9) is connected with a port b of the second three-way valve (10) through an air passage.

The port a of the second three-way valve (10) is connected with the air inlet port a of the rear right drive wheel two-way one-way valve (11) through an air passage, the air outlet port c of the rear right drive wheel two-way one-way valve (11) is connected with the air inlet port a of the rear right drive wheel ABS electromagnetic valve (19) through an air passage, and the air inlet port b of the rear right drive wheel ABS electromagnetic valve (19) is connected with the rear right drive wheel brake air chamber (18) through an air passage.

And a rear right driving wheel brake pressure sensor (17) is arranged on the rear right driving wheel brake air chamber (18).

And a port c of the second three-way valve (10) is connected with an air inlet port a of a two-way one-way valve (28) of the rear left driving wheel through an air passage, an air outlet port c of the two-way one-way valve (28) of the rear left driving wheel is connected with an air inlet port a of an ABS electromagnetic valve (20) of the rear left driving wheel through an air passage, and an air inlet port b of the ABS electromagnetic valve (20) of the rear left driving wheel is connected with a brake air chamber (21) of the rear left driving wheel through an air passage.

And a rear left driving wheel brake pressure sensor (22) is arranged on the rear left driving wheel brake air chamber (21).

An air outlet port c of the auxiliary air storage tank (3) is connected with an air inlet port a of the front drive shaft switch electromagnetic valve (55) through an air passage, an air outlet port b of the front drive shaft switch electromagnetic valve (55) is connected with an air inlet port a of the front drive shaft linear exhaust electromagnetic valve (53) through an air passage, an air outlet port b of the front drive shaft linear exhaust electromagnetic valve (53) is connected with an air inlet port a of the fourth three-way valve (52) through an air passage, an air outlet port b of the fourth three-way valve (52) is connected with an air inlet port b of the front right drive wheel two-way one-way valve (43) through an air passage, and an air outlet port c of the fourth three-way valve (52) is connected with an air inlet port b of the front left drive wheel two-way one-way valve (33) through an air passage.

The port a of the front drive shaft relay valve (32) is connected with the air outlet port b of the main air storage tank (4) through an air path, and the port b of the front drive shaft relay valve (32) is connected with the port b of the third three-way valve (42) through an air path.

And a port a of the third three-way valve (42) is connected with an air inlet port a of the front right driving wheel two-way one-way valve (43) through an air passage, an air outlet port c of the front right driving wheel two-way one-way valve (43) is connected with an air inlet port a of the front right driving wheel ABS electromagnetic valve (44) through an air passage, and an air inlet port b of the front right driving wheel ABS electromagnetic valve (44) is connected with a front right driving wheel brake air chamber (45) through an air passage.

And a front right driving wheel brake pressure sensor (46) is arranged on the front right driving wheel brake air chamber (45).

And a port c of the third three-way valve (42) is connected with an air inlet port a of the front left driving wheel two-way one-way valve (33) through an air passage, an air outlet port c of the front left driving wheel two-way one-way valve (33) is connected with an air inlet port a of the front left driving wheel ABS electromagnetic valve (41) through an air passage, and an air inlet port b of the front left driving wheel ABS electromagnetic valve (41) is connected with the front left driving wheel brake air chamber (40) through an air passage.

And a front left driving wheel brake pressure sensor (39) is arranged on the front left driving wheel brake air chamber (40).

The rear right driving wheel speed sensor (14), the rear left driving wheel speed sensor (25), the front left driving wheel speed sensor (36) and the front right driving wheel speed sensor (49) are connected with the brake controller (31) through signal lines.

The rear right driving wheel ABS electromagnetic valve (19), the rear left driving wheel ABS electromagnetic valve (20), the front left driving wheel ABS electromagnetic valve (41) and the front right driving wheel ABS electromagnetic valve (44) are connected with the brake controller (31) through signal lines.

The rear driving shaft switch electromagnetic valve (5), the rear driving shaft linear exhaust electromagnetic valve (7), the front driving shaft switch electromagnetic valve (55), the front driving shaft linear exhaust electromagnetic valve (53), the rear right driving wheel brake pressure sensor (17), the front right driving wheel brake pressure sensor (46), the front left driving wheel brake pressure sensor (39), the rear left driving wheel brake pressure sensor (22) and the brake pedal displacement sensor (54) are connected with the whole vehicle controller (30) through signal lines.

The rear right driving wheel driving motor controller (16), the rear left driving wheel driving motor controller (22), the front left driving wheel driving motor controller (38), the front right driving wheel driving motor controller (47), the battery management system (29), the whole vehicle controller (30) and the brake controller (31) are connected through a CAN bus.

Based on the braking energy recovery system of the four-wheel distributed drive electric vehicle based on the two-way one-way valve and the linear exhaust electromagnetic valve, the vehicle controller (30) is based on the vehicle speed output by the brake controller (31) through a CAN bus, the pedal displacement signal output by the brake pedal displacement sensor (54), the maximum charging current allowed by the battery output by the battery management system (29) through the CAN bus, the rear right drive wheel drive motor controller (16) output through the CAN bus and the rear right drive wheel maximum motor braking force provided by the transmission device (15), the rear left drive wheel drive motor controller (23) output through the CAN bus and the rear left drive wheel maximum motor braking force provided by the rear left drive wheel drive motor and the transmission device (24), and the front right drive wheel drive motor controller (47) output through the CAN bus and the front right drive wheel drive motor and the transmission device (48) The maximum motor braking force of the driving wheels is output by a front left driving wheel driving motor controller (38) through a CAN bus, and the maximum motor braking force of the front left driving wheels, which CAN be provided by a front left driving wheel driving motor and a transmission device (37), is output by the front left driving wheel driving motor controller, whether a braking energy recovery function is triggered is judged, and a rear driving shaft switch electromagnetic valve (5), a rear driving shaft linear exhaust electromagnetic valve (7), a front driving shaft switch electromagnetic valve (55) and a front driving shaft linear exhaust electromagnetic valve (53) are controlled according to the braking energy recovery function.

When a brake pedal is stepped on and a braking energy recovery function is triggered, the whole vehicle controller (30) controls the conduction of the rear drive shaft switch electromagnetic valve (5), the gas path between the port b of the auxiliary gas storage tank (3) and the port a of the rear drive shaft linear exhaust electromagnetic valve (7) is conducted, the whole vehicle controller (30) controls the rear drive shaft linear exhaust electromagnetic valve (7) to be in a closed state, and the exhaust port c of the rear drive shaft linear exhaust electromagnetic valve is not communicated with the atmosphere; when a brake pedal is stepped on, but the braking energy recovery function is not triggered, the whole vehicle controller (30) controls the rear drive shaft switching electromagnetic valve (5) to be turned off, an air path between the port b of the auxiliary air storage tank (3) and the port a of the rear drive shaft linear exhaust electromagnetic valve (7) is disconnected, the whole vehicle controller (30) controls the rear drive shaft linear exhaust electromagnetic valve (7) to be in a closed state, and the exhaust port c of the rear drive shaft linear exhaust electromagnetic valve is not communicated with the atmosphere; when a driver releases a brake pedal (1), the vehicle control unit (30) controls the rear drive shaft switching electromagnetic valve (5) to break the gas path connection between the port b of the auxiliary gas storage tank (3) and the port a of the rear drive shaft linear exhaust electromagnetic valve (7), the vehicle control unit (30) controls the rear drive shaft linear exhaust electromagnetic valve (7) to be in an open state, the exhaust port c of the rear drive shaft linear exhaust electromagnetic valve is communicated with the atmosphere, and the opening degree of the rear drive shaft linear exhaust electromagnetic valve is in proportional relation to a pedal displacement signal output by the brake pedal displacement sensor (54) through a signal line.

When a brake pedal is stepped on and a braking energy recovery function is triggered, the whole vehicle controller (30) controls the conduction of a front drive shaft switch electromagnetic valve (55), an air path between a port c of an auxiliary air storage tank (3) and a port a of a front drive shaft linear exhaust electromagnetic valve (53) is conducted, the whole vehicle controller (30) controls the front drive shaft linear exhaust electromagnetic valve (53) to be in a closed state, and an exhaust port c of the front drive shaft linear exhaust electromagnetic valve is not communicated with the atmosphere; when a brake pedal is stepped on, but the braking energy recovery function is not triggered, the whole vehicle controller (30) controls the front drive shaft switch electromagnetic valve (55) to be turned off, an air path between the port c of the auxiliary air storage tank (3) and the port a of the front drive shaft linear exhaust electromagnetic valve (53) is disconnected, the whole vehicle controller (30) controls the front drive shaft linear exhaust electromagnetic valve (53) to be in a closed state, and the exhaust port c of the front drive shaft linear exhaust electromagnetic valve is not communicated with the atmosphere; when a driver releases a brake pedal (1), the vehicle control unit (30) controls the front drive shaft switch electromagnetic valve (55) to disconnect the air path connection between the port c of the auxiliary air storage tank (3) and the port a of the front drive shaft linear exhaust electromagnetic valve (53), the vehicle control unit (30) controls the front drive shaft linear exhaust electromagnetic valve (53) to be in an open state, the exhaust port c of the front drive shaft linear exhaust electromagnetic valve is communicated with the atmosphere, and the opening degree of the front drive shaft linear exhaust electromagnetic valve is in proportional relation to a pedal displacement signal output by the brake pedal displacement sensor (54) through a signal line.

Compared with the prior art, the invention adds an auxiliary air storage tank (3), a rear drive shaft switch electromagnetic valve (5), a rear drive shaft linear exhaust electromagnetic valve (7), a first three-way valve (8), a rear drive shaft relay valve (9), a second three-way valve (10), a rear right drive wheel two-way one-way valve (11), a rear right drive wheel brake pressure sensor (17), a rear left drive wheel brake pressure sensor (22), a rear left drive wheel two-way one-way valve (28), a front drive shaft relay valve (32), a front left drive wheel two-way one-way valve (33), a front left drive wheel brake pressure sensor (39), a third three-way valve (42), a front right drive wheel two-way one-way valve (43), a front right drive wheel brake pressure sensor (46), a fourth three-way valve (52), a front drive shaft linear exhaust electromagnetic valve (53) and a front left drive wheel brake pressure sensor (39), The brake pedal displacement sensor (54), the front drive shaft switch solenoid valve (55) and other components enable each drive wheel brake circuit to be provided with two independent high-pressure air sources and a double-circuit structure, and when the brake energy recovery is triggered, the air source with higher pressure can provide high-pressure air for the drive wheel brake air chamber, so that the key problems that the coupling brake force response speed of the drive wheel is low and the coupling brake force lags behind the required brake force caused by low air source pressure in the continuous braking in the existing scheme are effectively solved.

FIG. 1 is a schematic structural diagram of a braking energy recovery system of a four-wheel distributed drive electric vehicle based on a two-way check valve and a linear exhaust solenoid valve. Wherein: 1. a brake pedal; 2. a brake valve; 3. a secondary gas storage tank; 4. a primary gas storage tank; 5. the rear driving shaft switches the electromagnetic valve; 6. an air compressor; 7. a rear drive shaft linear exhaust solenoid valve; 8. a first three-way valve; 9. a rear drive shaft relay valve; 10. a second three-way valve; 11. a two-way one-way valve of a rear right driving wheel; 12. a rear right drive wheel brake; 13. a rear right drive wheel; 14. a rear right driving wheel speed sensor; 15. a rear right driving wheel driving motor and a transmission device; 16. a rear right drive wheel drive motor controller; 17. a rear right driving wheel brake pressure sensor; 18. a rear right driving wheel brake chamber; 19. the rear right driving wheel ABS electromagnetic valve; 20. the rear left driving wheel ABS electromagnetic valve; 21. a rear left driving wheel brake chamber; 22. a rear left drive wheel brake pressure sensor; 23. a rear left drive wheel drive motor controller; 24. a rear left driving wheel driving motor and a transmission device; 25. a rear left drive wheel speed sensor; 26. a rear left drive wheel; 27. a rear left drive wheel brake; 28. a two-way one-way valve of a rear left driving wheel; 29. a battery management system; 30. a vehicle control unit; 31. a brake controller; 32. a front drive shaft relay valve; 33. a front left driving wheel two-way one-way valve; 34. a front left drive wheel; 35. a front left drive wheel brake; 36. a front left drive wheel speed sensor; 37. a front left driving wheel driving motor and a transmission device; 38. a front left drive wheel drive motor controller; 39. a front left drive wheel brake pressure sensor; 40. a front left drive wheel brake chamber; 41. the front left driving wheel ABS electromagnetic valve; 42. a third three-way valve; 43. a front right driving wheel two-way one-way valve; 44. front right driving wheel ABS electromagnetic valve; 45. front right driving wheel brake chamber; 46. a front right drive wheel brake pressure sensor; 47. a front right drive wheel drive motor controller; 48. a front right driving wheel driving motor and a transmission device; 49. a front right drive wheel speed sensor; 50. a front right drive wheel brake; 51. a front right drive wheel; 52. a fourth three-way valve; 53. a front drive shaft linear exhaust solenoid valve; 54. a brake pedal displacement sensor; 55. the front drive shaft switches the electromagnetic valve.

The following describes in detail embodiments of the present invention.

The invention provides a braking energy recovery system of a four-wheel distributed drive electric vehicle based on a two-way check valve and a linear exhaust electromagnetic valve, and in order to make the technical scheme and the effect of the invention clearer and clearer, the invention is further described in detail by referring to the attached drawings and taking examples; it should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

As shown in figure 1, the four-wheel distributed drive electric vehicle braking energy recovery system based on a two-way one-way valve and a linear exhaust electromagnetic valve comprises a braking pedal (1), a braking valve (2), an auxiliary air storage tank (3), a main air storage tank (4), a rear drive shaft switch electromagnetic valve (5), an air compressor (6), a rear drive shaft linear exhaust electromagnetic valve (7), a first three-way valve (8), a rear drive shaft relay valve (9), a second three-way valve (10), a rear right drive wheel two-way one-way valve (11), a rear right drive wheel speed sensor (14), a rear right drive wheel drive motor and transmission device (15), a rear right drive wheel drive motor controller (16), a rear right drive wheel braking pressure sensor (17), a rear right drive wheel braking air chamber (18), a rear right drive wheel ABS electromagnetic valve (19), a rear left drive wheel ABS electromagnetic valve (20), A rear left driving wheel brake air chamber (21), a rear left driving wheel brake pressure sensor (22), a rear left driving wheel driving motor controller (23), a rear left driving wheel driving motor and transmission device (24), a rear left driving wheel speed sensor (25), a rear left driving wheel two-way one-way valve (28), a battery management system (29), a vehicle control unit (30), a brake controller (31), a front driving shaft relay valve (32), a front left driving wheel two-way one-way valve (33), a front left driving wheel speed sensor (36), a front left driving wheel driving motor and transmission device (37), a front left driving wheel driving motor controller (38), a front left driving wheel brake pressure sensor (39), a front left driving wheel brake air chamber (40), a front left driving wheel ABS electromagnetic valve (41), a third three-way valve (42), a front right driving wheel two-way one-way valve (43), The front right driving wheel ABS electromagnetic valve (44), the front right driving wheel brake air chamber (45), the front right driving wheel brake pressure sensor (46), the front right driving wheel driving motor controller (47), the front right driving wheel driving motor and transmission device (48), the front right driving wheel speed sensor (49), the fourth three-way valve (52), the front driving shaft linear exhaust electromagnetic valve (53), the brake pedal displacement sensor (54) and the front driving shaft switch electromagnetic valve (55).

When braking, the working principle of the braking system is as follows.

During the running process of the automobile, the brake controller (31) receives wheel speed signals output by a rear right driving wheel speed sensor (14), a rear left driving wheel speed sensor (25), a front left driving wheel speed sensor (36) and a front right driving wheel speed sensor (49).

The vehicle controller (30) receives a vehicle speed signal and a vehicle acceleration signal output by the brake controller (31), a pedal displacement signal output by the brake pedal displacement sensor (54), a rear right driving wheel brake pressure value output by the rear right driving wheel brake pressure sensor (17), a rear left driving wheel brake pressure value output by the rear left driving wheel brake pressure sensor (22), a front right driving wheel brake pressure value output by the front right driving wheel brake pressure sensor (46), a front left driving wheel brake pressure value output by the front left driving wheel brake pressure sensor (39), a battery allowed maximum charging current output by the battery management system (29) through a CAN bus, a rear right driving wheel driving motor controller (16) through the CAN bus, and a rear right driving wheel driving motor maximum motor braking force provided by the transmission device (15), the rear left driving wheel driving motor controller (23) outputs the maximum rear left driving wheel motor braking force which CAN be provided by the rear left driving wheel driving motor and transmission device (24) through the CAN bus, the front right driving wheel driving motor controller (47) outputs the maximum front right driving wheel motor braking force which CAN be provided by the front right driving wheel driving motor and transmission device (48) through the CAN bus, and the front left driving wheel driving motor controller (38) outputs the maximum front left driving wheel motor braking force which CAN be provided by the front left driving wheel driving motor and transmission device (37) through the CAN bus.

The maximum motor braking force which CAN be applied to the rear right driving wheel (13) by the rear right driving wheel driving motor and transmission device (15), the maximum motor braking force which CAN be applied to the rear left driving wheel (26) by the rear left driving wheel driving motor and transmission device (24), the maximum motor braking force which CAN be applied to the front right driving wheel driving motor and transmission device (48) and the maximum motor braking force which CAN be applied to the front right driving wheel (51) by the front left driving wheel driving motor and transmission device (37) and the maximum motor braking force which CAN be applied to the front left driving wheel (34) are controlled by the vehicle control unit (30) according to the vehicle speed, the vehicle acceleration, the maximum charging current allowed by the battery output by the battery management system (29) through a CAN bus, and the maximum motor braking force of the rear right driving wheel which CAN be provided by the rear right driving wheel driving motor and transmission device (15) output by the rear right driving wheel driving motor controller (16) through the CAN bus, the rear left driving wheel driving motor controller (23) outputs the maximum rear left driving wheel motor braking force which CAN be provided by the rear left driving wheel driving motor and transmission device (24) through the CAN bus, the front right driving wheel driving motor controller (47) outputs the maximum front right driving wheel motor braking force which CAN be provided by the front right driving wheel driving motor and transmission device (48) through the CAN bus, and the front left driving wheel driving motor controller (38) determines the maximum front left driving wheel motor braking force which CAN be provided by the front left driving wheel driving motor and transmission device (37) through the CAN bus.

The vehicle control unit (30) is based on the vehicle speed output by the brake controller (31) through the CAN bus, the pedal displacement signal output by the brake pedal displacement sensor (54), the maximum charging current allowed by the battery output by the battery management system (29) through the CAN bus, the maximum rear right driving wheel motor braking force provided by the rear right driving wheel driving motor and the transmission device (15) output by the rear right driving wheel driving motor controller (16) through the CAN bus, the maximum rear left driving wheel motor braking force provided by the rear left driving wheel driving motor and the transmission device (24) output by the rear left driving wheel driving motor controller (23) through the CAN bus, and the maximum front right driving wheel motor braking force provided by the front right driving wheel driving motor and the transmission device (48) output by the front right driving wheel driving motor controller (47) through the CAN bus, the front left driving wheel driving motor controller (38) outputs the maximum motor braking force of the front left driving wheel provided by the front left driving wheel driving motor and the transmission device (37) through the CAN bus, and judges whether to trigger the braking energy recovery function according to the following four conditions: according to the first condition, the vehicle speed value output by the brake controller (31) is larger than the minimum vehicle speed threshold value allowing the recovery of the brake energy; under the second condition, a pedal displacement signal output by a brake pedal displacement sensor (54) is larger than a pedal displacement threshold value for triggering braking energy recovery; the third condition is that the maximum allowable battery charging current output by the battery management system (29) is greater than 0; and fourthly, determining that the braking force required by the rear right driving wheel motor, the braking force required by the rear left driving wheel motor, the braking force required by the front right driving wheel motor or the braking force required by the front left bullet train wheel motor is greater than the minimum motor braking force threshold value allowing the braking energy to be recovered by the vehicle control unit (30).

When the four conditions are met simultaneously, the braking energy recovery function is triggered; when any one of the brake energy recovery functions cannot be met, the brake energy recovery function cannot be triggered.

When the brake pedal (1) is stepped on and the braking energy recovery function is triggered.

The vehicle control unit (30) determines a total braking force target value required by a front left driving wheel (34), a front right driving wheel (51), a rear left driving wheel (26) and a rear right driving wheel (13) according to the vehicle speed, the vehicle acceleration and the brake pedal displacement; the vehicle control unit (30) is used for controlling the vehicle according to a total braking force target value required by the front left driving wheel (34), the front right driving wheel (51), the rear left driving wheel (26) and the rear right driving wheel (13), a battery allowable maximum charging current output by the battery management system (29) through a CAN bus, a rear right driving wheel maximum motor braking force provided by a rear right driving wheel driving motor and a transmission device (15) output by the rear right driving wheel driving motor controller (16) through the CAN bus, a rear left driving wheel maximum motor braking force provided by a rear left driving wheel driving motor and a transmission device (24) output by the rear left driving wheel driving motor controller (23) through the CAN bus, and a front right driving wheel maximum motor braking force provided by a front right driving wheel driving motor and a transmission device (48) output by the front right driving wheel driving motor controller (47) through the CAN bus, the front left driving wheel driving motor controller (38) determines motor braking force target values required by the front left driving wheel (34), the front right driving wheel (51), the rear left driving wheel (26) and the rear right driving wheel (13) through the maximum motor braking force of the front left driving wheel, which is output by the CAN bus and CAN be provided by the front left driving wheel driving motor and the transmission device (37).

The vehicle control unit (30) determines a target value of air pressure braking force of the rear left driving wheel (26) according to the target value of total braking force of the rear left driving wheel (26) and a target value of motor braking force required by the rear left driving wheel (26).

The vehicle control unit (30) determines a target value of the air pressure braking force of the rear right driving wheel (13) according to the target value of the total braking force of the rear right driving wheel (13) and the target value of the motor braking force required by the rear right driving wheel (13).

The vehicle control unit (30) determines a target value of air pressure braking force of the front left driving wheel (34) according to a target value of total braking force of the front left driving wheel (34) and a target value of motor braking force required by the front left driving wheel (34).

The vehicle control unit (30) determines a target value of the air pressure braking force of the front right driving wheel (51) according to the target value of the total braking force of the front right driving wheel (51) and the target value of the motor braking force required by the front right driving wheel (51).

The whole vehicle controller (30) outputs a required motor braking force target value of a rear left driving wheel (26) to a rear left driving wheel driving motor controller (23) through a CAN bus, the whole vehicle controller (30) outputs a required motor braking force target value of a rear right driving wheel (13) to a rear right driving wheel driving motor controller (16) through the CAN bus, the whole vehicle controller (30) outputs a required motor braking force target value of a front right driving wheel (51) to a front right driving wheel driving motor controller (47) through the CAN bus, the whole vehicle controller (30) outputs a required motor braking force target value of a front left driving wheel (34) to a front left driving wheel driving motor controller (38) through the CAN bus, and the whole vehicle controller (30) outputs air pressure braking force target values of the front left driving wheel (34), the front right driving wheel (51), the rear left driving wheel (26) and the rear right driving wheel (13), The actual value of the rear right driving wheel air pressure braking force output by the rear right driving wheel braking pressure sensor (17), the actual value of the front right driving wheel air pressure braking force output by the front right driving wheel braking pressure sensor (46), the actual value of the rear left driving wheel air pressure braking force output by the rear left driving wheel braking pressure sensor (22), and the actual value of the front left driving wheel air pressure braking force output by the front left driving wheel braking pressure sensor (39) are sent to the braking controller (31).

When the braking energy recovery function is triggered, the braking is applied to the rear left drive wheel (26) as follows.

The whole vehicle controller (30) controls the conduction of the rear drive shaft switching electromagnetic valve (5), high-pressure gas in the auxiliary gas storage tank (3) sequentially passes through a port b of the auxiliary gas storage tank (3), a port a and a port b of the rear drive shaft switching electromagnetic valve (5), a port a and a port b of the rear drive shaft linear exhaust electromagnetic valve (7) and a port a and a port c of the first three-way valve (8) to reach a port b of the rear left drive wheel two-way check valve (28), and control is not exerted on the rear drive shaft linear exhaust electromagnetic valve (7) in the process;

high-pressure gas in the main gas storage tank (4) enters a control port c of the rear drive shaft relay valve (9) through a port d of the main gas storage tank (4) and ports a and d of the brake valve (2) to enable the port a and the port b of the rear drive shaft relay valve (9) to be communicated, and the high-pressure gas in the main gas storage tank (4) sequentially passes through a port e of the main gas storage tank (4), the ports a and b of the rear drive shaft relay valve (9) and the ports b and c of the second three-way valve (10) to reach the port a of the rear left drive wheel two-way check valve (28).

At this time, the conditions of supplying the braking pressure to the rear left driving wheel brake air chamber (21) are divided into the following two conditions according to the air pressure of the port a of the rear left driving wheel two-way check valve (28) and the air pressure of the port b of the rear left driving wheel two-way check valve (28).

When the air pressure at a port a of the two-way one-way valve (28) of the rear left driving wheel is greater than the air pressure at a port b, the main air storage tank (4) provides high-pressure air for the brake chamber (21) of the rear left driving wheel; at this time, the high-pressure gas in the main gas tank (4) sequentially passes through a port e of the main gas tank (4), a port a and a port b of a rear drive shaft relay valve (9), a port b and a port c of a second three-way valve (10), a port a and a port c of a rear left drive wheel two-way check valve (28), and a port a and a port b of a rear left drive wheel ABS solenoid valve (20) to enter a rear left drive wheel brake chamber (21), so that pneumatic braking force can be applied to a rear left drive wheel (26) through a rear left drive wheel brake (27).

When the air pressure at the port a of the two-way one-way valve (28) of the rear left driving wheel is smaller than the air pressure at the port b, the auxiliary air storage tank (3) provides high-pressure air for the brake chamber (21) of the rear left driving wheel; at this time, high-pressure gas in the auxiliary gas storage tank (3) sequentially passes through a port b of the auxiliary gas storage tank (3), a port a and a port b of a rear drive shaft switching solenoid valve (5), a port a and a port b of a rear drive shaft linear exhaust solenoid valve (7), a port a and a port c of a first three-way valve (8), a port b and a port c of a rear left drive wheel two-way check valve (28) and a port a and a port b of a rear left drive wheel ABS solenoid valve (20) to enter a rear left drive wheel brake chamber (21), so that air pressure brake force can be applied to a rear left drive wheel (26) through a rear left drive wheel brake (27), and the exhaust port c of the rear drive shaft linear exhaust solenoid valve (7) is in a closed state and is not communicated with the atmosphere in the process.

In order to realize the decoupling control of the motor braking force and the air pressure braking force of the rear left driving wheel (26), the air pressure braking force of the rear left driving wheel (26) can be adjusted through the ABS electromagnetic valve (20) of the rear left driving wheel, and the modes of applying the braking force to the rear left driving wheel (26) are divided into the following two modes according to the relation between the maximum motor braking force which can be applied to the rear left driving wheel (26) by the rear left driving wheel driving motor and transmission device (24) and the total braking force target value of the rear left driving wheel (26).

The first mode is as follows: when the maximum motor braking force applied to the rear left driving wheel (26) by the rear left driving wheel driving motor and transmission device (24) is larger than or equal to the total braking force target value of the rear left driving wheel (26), the air pressure braking force target value of the rear left driving wheel (26) is 0, at the moment, the brake controller (31) controls the port a of the rear left driving wheel ABS electromagnetic valve (20) to be closed through signal lines, the port b and the port c are opened, the air path connection between the rear left driving wheel braking air chamber (21) and the port c of the rear left driving wheel two-way one-way valve (28) is disconnected, the rear left driving wheel braking air chamber (21) is communicated with the atmosphere through the port b and the port c of the rear left driving wheel ABS electromagnetic valve (20), and at the moment, the rear left driving wheel driving motor and transmission device (24) applies required braking force to the rear left driving wheel (26).

And a second mode: when the maximum motor braking force which can be applied to the rear left driving wheel (26) by the rear left driving wheel driving motor and transmission device (24) is smaller than the target value of the total braking force of the rear left driving wheel (26), the rear left driving wheel driving motor and transmission device (24) applies the maximum motor braking force to the rear left driving wheel (26).

The target value of the air pressure braking force of the rear left driving wheel (26) is determined by the difference between the target value of the total braking force of the rear left driving wheel (26) and the maximum motor braking force applied to the rear left driving wheel (26) by the rear left driving wheel driving motor and transmission device (24), and the conditions of applying the air pressure braking force to the rear left driving wheel (26) are divided into the following three conditions according to the relationship between the target value of the air pressure braking force of the rear left driving wheel (26) and the actual value of the air pressure braking force.

When the target value of the air pressure braking force of the rear left driving wheel (26) is larger than the actual value of the air pressure braking force, the brake controller (31) controls the opening of the port a and the port b of the ABS electromagnetic valve (20) of the rear left driving wheel to be closed through a signal line, high-pressure air at the port c of the double-way check valve (28) of the rear left driving wheel enters the brake air chamber (21) of the rear left driving wheel through the port a and the port b of the ABS electromagnetic valve (20) of the rear left driving wheel, and therefore the actual air pressure braking force of the rear left driving wheel (26) is increased.

When the target value of the air pressure braking force of the rear left driving wheel (26) is smaller than the actual value of the air pressure braking force, the brake controller (31) controls the port a of the ABS electromagnetic valve (20) of the rear left driving wheel to be closed through signal lines, the port b and the port c are conducted, and high-pressure air at the brake air chamber (21) of the rear left driving wheel is exhausted into the atmosphere through the port b and the port c of the ABS electromagnetic valve (20) of the rear left driving wheel so as to reduce the actual air pressure braking force of the rear left driving wheel (26).

When the target value of the air pressure braking force of the rear left driving wheel (26) is equal to the actual value of the air pressure braking force, the brake controller (31) controls the port b and the port c of the ABS electromagnetic valve (20) of the rear left driving wheel to be closed through a signal line, and the air pressure in the brake air chamber (21) of the rear left driving wheel is kept unchanged so as to realize the maintenance of the actual air pressure braking force of the rear left driving wheel (26).

When the brake pedal (1) is depressed, but the braking energy recovery function is not triggered.

And the rear driving shaft switch electromagnetic valve (5) is closed, the air passage between the port b of the auxiliary air storage tank (3) and the port a of the first three-way valve (8) is disconnected, and the port b of the rear left driving wheel two-way check valve (28) does not contain high-pressure air.

And a port b of the rear left driving wheel two-way check valve (28) is closed, a port a and a port c are communicated, high-pressure gas in the main gas storage tank (4) sequentially passes through a port e of the main gas storage tank (4), a port a and a port b of the rear driving shaft relay valve (9), a port b and a port c of the second three-way valve (10), a port a and a port c of the rear left driving wheel two-way check valve (28), and a port a and a port b of the rear left driving wheel ABS solenoid valve (20) to enter a rear left driving wheel brake chamber (21), so that air pressure braking force can be applied to the rear left driving wheel (26) through a rear left driving wheel brake (27).

The brake release of the rear left driving wheel (26) is divided into the release of the motor braking force and the release of the air pressure power, and the working principle is as follows.

When a driver releases the brake pedal (1), the vehicle control unit (30) controls the motor braking force applied to the rear left driving wheel (26) by the rear left driving wheel driving motor and the transmission device (24) to be reduced through the rear left driving wheel driving motor controller (23) so as to release the motor braking force of the rear left driving wheel.

When a driver releases a brake pedal (1), a brake valve (2) is closed, a rear drive shaft relay valve (9) breaks the air path connection between a port e of a main air storage tank (4) and a port b of a second three-way valve (10), a rear drive shaft switching electromagnetic valve (5) breaks the air path connection between a port b of an auxiliary air storage tank (3) and a port a of a rear drive shaft linear exhaust electromagnetic valve (7), a whole vehicle controller (30) controls the rear drive shaft linear exhaust electromagnetic valve (7) to be opened through signal lines, an exhaust port c of the rear drive shaft linear exhaust electromagnetic valve is communicated with the atmosphere, the opening degree of the rear drive shaft linear exhaust electromagnetic valve (7) is controlled to be in proportional relation with pedal displacement, and the air pressure braking force of a rear left drive wheel (26) is released at the moment.

When the port a of the rear left driving wheel two-way one-way valve (28) is communicated with the port c, high-pressure gas in the rear left driving wheel brake air chamber (21) sequentially passes through the air inlet port b and the air inlet port a of the rear left driving wheel ABS electromagnetic valve (20), the port c and the port a of the rear left driving wheel two-way one-way valve (28), the port c and the port b of the second three-way valve (10) and the port b of the rear driving shaft relay valve (9) to enter the rear driving shaft relay valve (9), and is exhausted to the atmosphere through the rear driving shaft relay valve (9), so that the air pressure brake of the rear left driving wheel (26) can be released, and the rear left driving wheel ABS electromagnetic valve (20) is not controlled in the process.

When the port b of the rear left driving wheel two-way one-way valve (28) is communicated with the port c, high-pressure gas in the rear left driving wheel brake air chamber (21) sequentially passes through the air inlet port b and the air inlet port a of the rear left driving wheel ABS electromagnetic valve (20), the port c and the port b of the rear left driving wheel two-way one-way valve (28), the port c and the port a of the first three-way valve (8) and the port b of the rear driving shaft linear exhaust electromagnetic valve (7) to enter the rear driving shaft linear exhaust electromagnetic valve (7), and is exhausted to the atmosphere through the exhaust port c of the rear driving shaft linear exhaust electromagnetic valve (7), so that air pressure brake of the rear left driving wheel (26) can be relieved, and control is not exerted on the rear left driving wheel ABS electromagnetic valve (20) in the process.

The principle of applying braking to the rear right drive wheel (13) when triggering the braking energy recovery function is as follows.

The whole vehicle controller (30) controls the conduction of the rear drive shaft switching electromagnetic valve (5), high-pressure gas in the auxiliary gas storage tank (3) sequentially passes through a port b of the auxiliary gas storage tank (3), a port a and a port b of the rear drive shaft switching electromagnetic valve (5), a port a and a port b of the rear drive shaft linear exhaust electromagnetic valve (7) and a port a and a port b of the first three-way valve (8) to reach a port b of the rear right drive wheel two-way check valve (11), and control is not exerted on the rear drive shaft linear exhaust electromagnetic valve (7) in the process.

High-pressure gas in the main gas storage tank (4) enters a control port c of the rear drive shaft relay valve (9) through a port d of the main gas storage tank (4) and ports a and d of the brake valve (2) to enable the port a and the port b of the rear drive shaft relay valve (9) to be communicated, and the high-pressure gas in the main gas storage tank (4) sequentially passes through a port e of the main gas storage tank (4), the ports a and b of the rear drive shaft relay valve (9) and the ports b and a of the second three-way valve (10) to reach the port a of the rear right drive wheel two-way one-way valve (11).

At this time, the conditions of supplying the braking pressure to the braking air chamber (18) of the rear right driving wheel are divided into the following two conditions according to the air pressure of the port a of the two-way check valve (11) of the rear right driving wheel and the air pressure of the port b of the two-way check valve (11) of the rear right driving wheel.

When the air pressure at the port a of the two-way one-way valve (11) of the rear right driving wheel is larger than the air pressure at the port b, the main air storage tank (4) provides high-pressure air for the brake air chamber (18) of the rear right driving wheel; at this time, high-pressure gas in the main gas storage tank (4) sequentially passes through a port e of the main gas storage tank (4), a port a and a port b of a rear drive shaft relay valve (9), a port b and a port a of a second three-way valve (10), a port a and a port c of a rear right drive wheel two-way check valve (11), and a port a and a port b of a rear right drive wheel ABS solenoid valve (19) to enter a rear right drive wheel brake chamber (18), so that air pressure braking force can be applied to a rear right drive wheel (13) through a rear right drive wheel brake (12).

When the air pressure at the port a of the two-way one-way valve (11) of the rear right driving wheel is smaller than the air pressure at the port b, the auxiliary air storage tank (3) provides high-pressure air for the brake chamber (18) of the rear right driving wheel; at the moment, high-pressure gas in the auxiliary gas storage tank (3) sequentially passes through a port b of the auxiliary gas storage tank (3), a port a and a port b of a rear drive shaft switching solenoid valve (5), a port a and a port b of a rear drive shaft linear exhaust solenoid valve (7), a port a and a port b of a first three-way valve (8), a port b and a port c of a rear right drive wheel two-way check valve (11) and a port a and a port b of a rear right drive wheel ABS solenoid valve (19) to enter a rear right drive wheel brake chamber (18), so that air pressure brake force can be applied to a rear right drive wheel (13) through a right drive wheel brake (12), and the exhaust port c of the rear drive shaft linear exhaust solenoid valve (7) is in a closed state and is not communicated with the atmosphere in the process.

In order to realize the decoupling control of the motor braking force and the air pressure braking force of the rear right driving wheel (13), the air pressure braking force of the rear right driving wheel (13) can be adjusted through an ABS electromagnetic valve (19) of the rear right driving wheel, and the modes of applying the braking force to the rear right driving wheel (13) are divided into the following two modes according to the relation between the maximum motor braking force which can be applied to the rear right driving wheel (13) by the rear right driving wheel driving motor and a transmission device (15) and the target value of the total braking force of the rear right driving wheel (13).

The first mode is as follows: when the maximum motor braking force applied to the rear right drive wheel (13) by the rear right drive wheel drive motor and transmission device (15) is larger than or equal to the total braking force target value of the rear right drive wheel (13), the air pressure braking force target value of the rear right drive wheel (13) is 0, at the moment, the brake controller (31) controls the port a of the rear right drive wheel ABS electromagnetic valve (19) to be closed through signal lines, the port b and the port c are opened, the air path connection between the rear right drive wheel brake air chamber (18) and the port c of the rear right drive wheel two-way one-way valve (11) is disconnected, the rear right drive wheel brake air chamber (18) is communicated with the atmosphere through the port b and the port c of the rear right drive wheel ABS electromagnetic valve (19), and at the moment, the rear right drive wheel drive motor and transmission device (15) applies required braking force to the rear right drive wheel (13).

And a second mode: when the maximum motor braking force which can be applied to the rear right driving wheel (13) by the rear right driving wheel driving motor and transmission device (15) is smaller than the target value of the total braking force of the rear right driving wheel (13), the rear right driving wheel driving motor and transmission device (15) applies the maximum motor braking force to the rear right driving wheel (13).

The target value of the air pressure braking force of the rear right driving wheel (13) is determined by the difference between the target value of the total braking force of the rear right driving wheel (13) and the maximum motor braking force applied to the rear right driving wheel (13) by the rear right driving wheel driving motor and transmission device (15), and the conditions of applying the air pressure braking force to the rear right driving wheel (13) are divided into the following three conditions according to the relationship between the target value of the air pressure braking force of the rear right driving wheel (13) and the actual value of the air pressure braking force.

When the target value of the air pressure braking force of the rear right driving wheel (13) is larger than the actual value of the air pressure braking force, the brake controller (31) controls the opening of the port a and the port b of the ABS electromagnetic valve (19) of the rear right driving wheel through a signal line, the port c is closed, and high-pressure air at the port c of the double-way check valve (11) of the rear right driving wheel enters the brake air chamber (18) of the rear right driving wheel through the port a and the port b of the ABS electromagnetic valve (19) of the rear right driving wheel so as to realize the increase of the actual air pressure braking force of the rear right driving wheel (13).

When the target value of the air pressure braking force of the rear right driving wheel (13) is smaller than the actual value of the air pressure braking force, the brake controller (31) controls the port a of the ABS electromagnetic valve (19) of the rear right driving wheel to be closed through signal lines, the port b and the port c are conducted, and high-pressure air at the brake air chamber (18) of the rear right driving wheel is exhausted into the atmosphere through the port b and the port c of the ABS electromagnetic valve (19) of the rear right driving wheel so as to reduce the actual air pressure braking force of the rear right driving wheel (13).

When the target value of the air pressure braking force of the rear right driving wheel (13) is equal to the actual value of the air pressure braking force, the brake controller (31) controls the port b and the port c of the ABS electromagnetic valve (19) of the rear right driving wheel to be closed through a signal line, and the air pressure in the brake air chamber (18) of the rear right driving wheel is kept unchanged so as to realize the maintenance of the actual air pressure braking force of the rear right driving wheel (13).

And the rear driving shaft switch electromagnetic valve (5) is closed, the air passage between the port b of the auxiliary air storage tank (3) and the port a of the first three-way valve (8) is disconnected, and the port b of the rear right driving wheel two-way one-way valve (11) has no high-pressure air.

And a port b of the rear right driving wheel two-way check valve (11) is closed, a port a and a port c are communicated, high-pressure gas in the main gas storage tank (4) sequentially passes through a port e of the main gas storage tank (4), a port a and a port b of the rear driving shaft relay valve (9), a port b and a port a of the second three-way valve (10), a port a and a port c of the rear right driving wheel two-way check valve (11) and a port a and a port b of the rear right driving wheel ABS solenoid valve (19) to enter a rear right driving wheel brake chamber (18), so that air pressure braking force can be applied to a rear right driving wheel (13) through the right driving wheel brake (12).

The brake release of the rear right driving wheel (13) is divided into the release of the motor braking force and the release of the air pressure power, and the working principle is as follows.

When a driver releases the brake pedal (1), the vehicle control unit (30) controls the motor braking force applied to the rear right driving wheel (13) by the rear right driving wheel driving motor and the transmission device (15) to be reduced through the rear right driving wheel driving motor controller (16) so as to release the motor braking force of the rear right driving wheel.

When a driver looses the brake pedal (1), the brake valve (2) is closed, the rear drive shaft relay valve (9) breaks the air path connection between the port e of the main air storage tank (4) and the port b of the second three-way valve (10), the rear drive shaft switch electromagnetic valve (5) breaks the air path connection between the port b of the auxiliary air storage tank (3) and the port a of the rear drive shaft linear exhaust electromagnetic valve (7), the whole vehicle controller (30) controls the rear drive shaft linear exhaust electromagnetic valve (7) to be opened through signal lines, the exhaust port c of the rear drive shaft linear exhaust electromagnetic valve (7) is communicated with the atmosphere, the opening degree of the rear drive shaft linear exhaust electromagnetic valve (7) is controlled to be in proportional relation with pedal displacement, and the air pressure braking force of the rear right drive wheel (13) is released at the moment.

When the port a and the port c of the rear right driving wheel two-way one-way valve (11) are communicated, high-pressure gas in the brake air chamber (18) of the rear right driving wheel sequentially passes through the air inlet port b and the air inlet port a of the rear right driving wheel ABS solenoid valve (19), the port c and the port a of the rear right driving wheel two-way one-way valve (11), the port a and the port b of the second three-way valve (10) and the port b of the rear driving wheel relay valve (9) and enters the rear driving wheel relay valve (9), and is exhausted to the atmosphere through the rear driving wheel relay valve (9), so that the air pressure brake of the rear right driving wheel (13) can be released, and the rear right driving wheel ABS solenoid valve (19) is not controlled in the process.

When the port b and the port c of the two-way check valve (11) of the rear right driving wheel are communicated, high-pressure gas in the brake chamber (18) of the rear right driving wheel sequentially passes through the air inlet port b and the air inlet port a of the ABS solenoid valve (19) of the rear right driving wheel, the port c and the port b of the two-way check valve (11) of the rear right driving wheel, the port b and the port a of the first three-way valve (8) and the port b of the linear exhaust solenoid valve (7) of the rear driving shaft to enter the linear exhaust solenoid valve (7) of the rear driving shaft, and is exhausted to the atmosphere through the exhaust port c of the linear exhaust solenoid valve (7) of the rear driving shaft, so that the air pressure brake of the rear right driving wheel (13) can be released, and the ABS solenoid valve (19) of the rear right driving wheel is not controlled in the process.

The principle of applying braking to the front left drive wheel (34) when triggering the braking energy recovery function is as follows.

The whole vehicle controller (30) controls the conduction of the front drive shaft switch electromagnetic valve (55), high-pressure gas in the auxiliary gas storage tank (3) sequentially passes through a port c of the auxiliary gas storage tank (3), a port a and a port b of the front drive shaft switch electromagnetic valve (55), a port a and a port b of the front drive shaft linear exhaust electromagnetic valve (53) and a port a and a port c of the fourth three-way valve (52) to reach a port b of the front left drive wheel two-way one-way valve (33), and control is not exerted on the front drive shaft linear exhaust electromagnetic valve (53) in the process.

High-pressure gas in the main gas storage tank (4) enters a control port c of the front drive shaft relay valve (32) through a port c of the main gas storage tank (4) and a port b and a port c of the brake valve (2) to enable the port a and the port b of the front drive shaft relay valve (32) to be communicated, and the high-pressure gas in the main gas storage tank (4) sequentially passes through the port b of the main gas storage tank (4), the port a and the port b of the front drive shaft relay valve (32) and the port b and the port c of the third three-way valve (42) to reach the port a of the front left drive wheel two-way check valve (33).

At this time, the situation of supplying the braking pressure to the front left driving wheel braking air chamber (40) is divided into the following two situations according to the air pressure of the port a of the front left driving wheel two-way check valve (33) and the air pressure of the port b of the front left driving wheel two-way check valve (33).

When the air pressure at a port a of the two-way one-way valve (33) of the front left driving wheel is larger than the air pressure at a port b, the main air storage tank (4) provides high-pressure air for a brake air chamber (40) of the front left driving wheel; at this time, the high-pressure gas in the main gas tank (4) enters the front left driving wheel brake chamber (40) through the port b of the main gas tank (4), the port a and the port b of the front driving shaft relay valve (32), the port b and the port c of the third three-way valve (42), the port a and the port c of the front left driving wheel two-way check valve (33) and the port a and the port b of the front left driving wheel ABS solenoid valve (41) in sequence, so that the front left driving wheel brake (35) can apply air pressure brake force to the front left driving wheel (34).

When the air pressure at a port a of the two-way one-way valve (33) of the front left driving wheel is smaller than the air pressure at a port b, the auxiliary air storage tank (3) provides high-pressure air for a brake chamber (40) of the front left driving wheel; at this time, high-pressure gas in the auxiliary gas tank (3) sequentially passes through a port c of the auxiliary gas tank (3), a port a and a port b of a front drive shaft switching solenoid valve (55), a port a and a port b of a front drive shaft linear exhaust solenoid valve (53), a port a and a port c of a fourth three-way valve (52), a port b and a port c of a front left drive wheel two-way check valve (33) and a port a and a port b of a front left drive wheel ABS solenoid valve (41) to enter a front left drive wheel brake chamber (40), so that pneumatic braking force can be applied to the front left drive wheel (34) through a front left drive wheel brake (35), and the exhaust port c of the front drive shaft linear exhaust solenoid valve (53) is in a closed state and is not communicated with the atmosphere in the process.

In order to realize the decoupling control of the motor braking force and the air pressure braking force of the front left driving wheel (34), the air pressure braking force of the front left driving wheel (34) can be adjusted through an ABS electromagnetic valve (41) of the front left driving wheel, and the modes of applying the braking force to the front left driving wheel (34) are divided into the following two modes according to the relation between the maximum motor braking force which can be applied to the front left driving wheel (34) by the front left driving wheel driving motor and transmission device (37) and the total braking force target value of the front left driving wheel (34).

The first mode is as follows: when the maximum motor braking force applied to the front left driving wheel (34) by the front left driving wheel driving motor and transmission device (37) is larger than or equal to the total braking force target value of the front left driving wheel (34), the air pressure braking force target value of the front left driving wheel (34) is 0, at the moment, the brake controller (31) controls the port a of the front left driving wheel ABS electromagnetic valve (41) to be closed through a signal line, the port b and the port c are opened, the air path connection between the front left driving wheel braking air chamber (40) and the port c of the front left driving wheel two-way one-way valve (33) is disconnected, the front left driving wheel braking air chamber (40) is communicated with the atmosphere through the port b and the port c of the front left driving wheel ABS electromagnetic valve (41), and at the moment, the front left driving wheel driving motor and transmission device (37) applies required braking force to the front left driving wheel (34).

And a second mode: when the maximum motor braking force which can be applied to the front left driving wheel (34) by the front left driving wheel driving motor and transmission device (37) is smaller than the target value of the total braking force of the front left driving wheel (34), the front left driving wheel driving motor and transmission device (37) applies the maximum motor braking force to the front left driving wheel (34).

The target value of the pneumatic braking force of the front left driving wheel (34) is determined by the difference between the target value of the total braking force of the front left driving wheel (34) and the maximum motor braking force applied to the front left driving wheel (34) by the front left driving wheel driving motor and transmission device (37), and the cases of applying the pneumatic braking force to the front left driving wheel (34) are divided into the following three cases according to the relationship between the target value of the pneumatic braking force of the front left driving wheel (34) and the actual value of the pneumatic braking force.

When the target value of the air pressure braking force of the front left driving wheel (34) is larger than the actual value of the air pressure braking force, the brake controller (31) controls the opening of a port a and a port b of an ABS electromagnetic valve (41) of the front left driving wheel through a signal line, a port c is closed, and high-pressure air at the port c of a two-way check valve (33) of the front left driving wheel enters a brake air chamber (40) of the front left driving wheel through the port a and the port b of the ABS electromagnetic valve (41) of the front left driving wheel so as to realize the increase of the actual air pressure braking force of the front left driving wheel (34).

When the target value of the air pressure braking force of the front left driving wheel (34) is smaller than the actual value of the air pressure braking force, the brake controller (31) controls the port a of the ABS electromagnetic valve (41) of the front left driving wheel to be closed through a signal line, the port b and the port c are conducted, and high-pressure air at the brake air chamber (40) of the front left driving wheel is exhausted into the atmosphere through the port b and the port c of the ABS electromagnetic valve (41) of the front left driving wheel so as to realize the reduction of the actual air pressure braking force of the front left driving wheel (34).

When the target value of the air pressure braking force of the front left driving wheel (34) is equal to the actual value of the air pressure braking force, the brake controller (31) controls the opening b and the opening c of the ABS electromagnetic valve (41) of the front left driving wheel to be closed through a signal line, and the air pressure in the brake air chamber (40) of the front left driving wheel is kept unchanged so as to realize the maintenance of the actual air pressure braking force of the front left driving wheel (34).

And the front drive shaft switching electromagnetic valve (55) is closed, the air passage between the port c of the auxiliary air storage tank (3) and the port a of the fourth three-way valve (52) is disconnected, and the port b of the front left drive wheel two-way one-way valve (33) is free of high-pressure air.

And a port b of the front left driving wheel two-way check valve (33) is closed, a port a and a port c are communicated, high-pressure gas in the main gas storage tank (4) sequentially passes through the port b of the main gas storage tank (4), the port a and the port b of the front driving shaft relay valve (32), the port b and the port c of the third three-way valve (42), the port a and the port c of the front left driving wheel two-way check valve (33) and the port a and the port b of the front left driving wheel ABS solenoid valve (41) to enter a front left driving wheel brake chamber (40), so that air pressure braking force can be applied to the front left driving wheel (34) through the front left driving wheel brake (35).

The brake release of the front left driving wheel (34) is divided into the release of the motor braking force and the release of the air pressure power, and the working principle is as follows.

When a driver releases a brake pedal (1), the vehicle control unit (30) controls the motor braking force applied to the front left driving wheel (34) by the front left driving wheel driving motor controller (38) through the front left driving wheel driving motor and transmission device (37) to be reduced so as to release the motor braking force of the front left driving wheel.

When a driver releases a brake pedal (1), a brake valve (2) is closed, a front drive shaft relay valve (32) breaks the air path connection between a port b of a main air storage tank (4) and a port b of a third three-way valve (42), a front drive shaft switch electromagnetic valve (55) breaks the air path connection between a port c of an auxiliary air storage tank (3) and a port a of a front drive shaft linear exhaust electromagnetic valve (53), a whole vehicle controller (30) controls the front drive shaft linear exhaust electromagnetic valve (53) to be opened through signal lines, the exhaust port c of the front drive shaft linear exhaust electromagnetic valve is communicated with the atmosphere, the opening degree of the front drive shaft linear exhaust electromagnetic valve (53) is controlled to be in proportional relation with pedal displacement, and the air pressure braking force of a front left drive wheel (34) is released at the moment.

When the port a of the front left driving wheel two-way one-way valve (33) is communicated with the port c, high-pressure gas in the front left driving wheel brake air chamber (40) sequentially passes through the air inlet port b and the air inlet port a of the front left driving wheel ABS electromagnetic valve (41), the port c and the port a of the front left driving wheel two-way one-way valve (33), the port c and the port b of the third three-way valve (42) and the port b of the front driving shaft relay valve (32) to enter the front driving shaft relay valve (32), and is exhausted to the atmosphere through the front driving shaft relay valve (32), so that the pneumatic braking of the front left driving wheel (34) can be released, and the front left driving wheel ABS electromagnetic valve (41) is not controlled in the process.

When the port b and the port c of the front left driving wheel two-way check valve (33) are communicated, high-pressure gas in the front left driving wheel brake air chamber (40) sequentially passes through the air inlet port b and the air inlet port a of the front left driving wheel ABS solenoid valve (41), the port c and the port b of the front left driving wheel two-way check valve (33), the port c and the port a of the fourth three-way valve (52) and the port b of the front driving shaft linear exhaust solenoid valve (53) to enter the front driving shaft linear exhaust solenoid valve (53), and is exhausted to the atmosphere through the exhaust port c of the front driving shaft linear exhaust solenoid valve (53), so that the pneumatic brake of the front left driving wheel (34) can be released, and the front left driving wheel ABS solenoid valve (41) is not controlled in the process.

The principle of applying braking to the front right drive wheel (51) when the braking energy recovery function is triggered is as follows.

The whole vehicle controller (30) controls the conduction of the front drive shaft switch electromagnetic valve (55), high-pressure gas in the auxiliary gas storage tank (3) sequentially passes through a port c of the auxiliary gas storage tank (3), a port a and a port b of the front drive shaft switch electromagnetic valve (55), a port a and a port b of the front drive shaft linear exhaust electromagnetic valve (53) and a port a and a port b of the fourth three-way valve (52) to reach a port b of the front right drive wheel two-way one-way valve (43), and control is not exerted on the front drive shaft linear exhaust electromagnetic valve (53) in the process.

High-pressure gas in the main gas storage tank (4) enters a control port c of the front drive shaft relay valve (32) through a port c of the main gas storage tank (4) and a port b and a port c of the brake valve (2) to enable the port a and the port b of the front drive shaft relay valve (32) to be communicated, and the high-pressure gas in the main gas storage tank (4) sequentially passes through the port b of the main gas storage tank (4), the port a and the port b of the front drive shaft relay valve (32), and the port b and the port a of the third three-way valve (42) to reach the port a of the front right drive wheel two-way check valve (43).

At this time, the conditions of supplying the braking pressure to the front right driving wheel brake air chamber (45) are divided into the following two conditions according to the air pressure of the port a of the front right driving wheel two-way check valve (43) and the air pressure of the port b of the front right driving wheel two-way check valve (43).

When the air pressure at a port a of the front right driving wheel two-way check valve (43) is larger than the air pressure at a port b, the main air storage tank (4) provides high-pressure air for a front right driving wheel brake air chamber (45); at this time, the high-pressure gas in the main gas storage tank (4) enters a front right driving wheel brake chamber (45) through a port b of the main gas storage tank (4), a port a and a port b of a front driving shaft relay valve (32), a port b and a port a of a third three-way valve (42), a port a and a port c of a front right driving wheel two-way check valve (43) and a port a and a port b of a front right driving wheel ABS solenoid valve (44) in sequence, so that pneumatic braking force can be applied to a front right driving wheel (51) through a front right driving wheel brake (50).

When the air pressure at the port a of the front right driving wheel two-way one-way valve (43) is smaller than the air pressure at the port b, the auxiliary air storage tank (3) provides high-pressure air for a front right driving wheel brake air chamber (45); at the moment, high-pressure gas in the auxiliary gas storage tank (3) sequentially passes through a port c of the auxiliary gas storage tank (3), a port a and a port b of a front drive shaft switching solenoid valve (55), a port a and a port b of a front drive shaft linear exhaust solenoid valve (53), a port a and a port b of a fourth three-way valve (52), a port b and a port c of a front right drive wheel two-way check valve (43) and a port a and a port b of a front right drive wheel ABS solenoid valve (44) to enter a front right drive wheel brake chamber (45), so that pneumatic brake force can be applied to a front right drive wheel (51) through a front right drive wheel brake (50), and the exhaust port c of the front drive shaft linear exhaust solenoid valve (53) is in a closed state and is not communicated with the atmosphere in the process.

In order to realize the decoupling control of the motor braking force and the air pressure braking force of the front right driving wheel (51), the air pressure braking force of the front right driving wheel (51) can be adjusted through the ABS electromagnetic valve (44) of the front right driving wheel, and the modes of applying the braking force to the front right driving wheel (51) are divided into the following two modes according to the relation between the maximum motor braking force which can be applied to the front right driving wheel (51) by the driving motor and the transmission device (48) of the front right driving wheel and the target value of the total braking force of the front right driving wheel (51).

The first mode is as follows: when the maximum motor braking force applied to the front right driving wheel (51) by the front right driving wheel driving motor and transmission device (48) is larger than or equal to the total braking force target value of the front right driving wheel (51), the air pressure braking force target value of the front right driving wheel (51) is 0, at the moment, the brake controller (31) controls the port a of the front right driving wheel ABS electromagnetic valve (44) to be closed through a signal line, the port b and the port c are opened, the air path connection between the front right driving wheel brake air chamber (45) and the port c of the front right driving wheel two-way one-way valve (43) is disconnected, the front right driving wheel brake air chamber (45) is communicated with the atmosphere through the port b and the port c of the front right driving wheel ABS electromagnetic valve (44), and at the moment, the front right driving wheel driving motor and transmission device (48) applies the required braking force to the front right driving wheel (51).

And a second mode: when the maximum motor braking force which can be applied to the front right driving wheel (51) by the front right driving wheel driving motor and transmission device (48) is smaller than the target value of the total braking force of the front right driving wheel (51), the front right driving wheel driving motor and transmission device (48) applies the maximum motor braking force to the front right driving wheel (51).

The target value of the pneumatic braking force of the front right driving wheel (51) is determined by the difference between the target value of the total braking force of the front right driving wheel (51) and the maximum motor braking force applied to the front right driving wheel (51) by the front right driving wheel driving motor and transmission device (48), and the situations of applying the pneumatic braking force to the front right driving wheel (51) are divided into the following three according to the relation between the target value of the pneumatic braking force of the front right driving wheel (51) and the actual value of the pneumatic braking force.

When the target value of the air pressure braking force of the front right driving wheel (51) is larger than the actual value of the air pressure braking force, the brake controller (31) controls the opening of the port a and the port b of the ABS electromagnetic valve (44) of the front right driving wheel through a signal line, the port c is closed, and high-pressure air at the port c of the double-way check valve (43) of the front right driving wheel enters a brake air chamber (45) of the front right driving wheel through the port a and the port b of the ABS electromagnetic valve (44) of the front right driving wheel so as to realize the increase of the actual air pressure braking force of the front right driving wheel (51).

When the target value of the air pressure braking force of the front right driving wheel (51) is smaller than the actual value of the air pressure braking force, the brake controller (31) controls the port a of the ABS electromagnetic valve (44) of the front right driving wheel to be closed through a signal line, the port b and the port c are conducted, and high-pressure air at the brake air chamber (45) of the front right driving wheel is exhausted into the atmosphere through the port b and the port c of the ABS electromagnetic valve (44) of the front right driving wheel so as to realize the reduction of the actual air pressure braking force of the front right driving wheel (51).

When the target value of the air pressure braking force of the front right driving wheel (51) is equal to the actual value of the air pressure braking force, the brake controller (31) controls the port b and the port c of the ABS electromagnetic valve (44) of the front right driving wheel to be closed through a signal line, and the air pressure in the brake air chamber (45) of the front right driving wheel is kept unchanged so as to realize the maintenance of the actual air pressure braking force of the front right driving wheel (51).

The front drive shaft switch electromagnetic valve (55) is closed, the air passage between the port c of the auxiliary air storage tank (3) and the port a of the fourth three-way valve (52) is disconnected, and the port b of the front right drive wheel two-way one-way valve (43) has no high-pressure air.

The port b of the front right driving wheel two-way check valve (43) is closed, the port a and the port c are communicated, high-pressure gas in the main gas storage tank (4) sequentially passes through the port b of the main gas storage tank (4), the port a and the port b of the front driving shaft relay valve (32), the port b and the port a of the third three-way valve (42), the port a and the port c of the front right driving wheel two-way check valve (43) and the port a and the port b of the front right driving wheel ABS solenoid valve (44) to enter the front right driving wheel brake chamber (45), and accordingly air pressure braking force can be applied to the front right driving wheel (51) through the front right driving wheel brake (50).

The brake release of the front and right driving wheels (51) is divided into the release of the motor braking force and the release of the air pressure power, and the working principle is as follows.

When a driver releases a brake pedal (1), the vehicle control unit (30) controls the motor braking force applied to the front right driving wheel (51) by the front right driving wheel driving motor and the transmission device (48) to be reduced through the front right driving wheel driving motor controller (47) so as to release the motor braking force of the front right driving wheel.

When a driver releases a brake pedal (1), a brake valve (2) is closed, a front drive shaft relay valve (32) breaks the air path connection between a port b of a main air storage tank (4) and a port b of a third three-way valve (42), a front drive shaft switch electromagnetic valve (55) breaks the air path connection between a port c of an auxiliary air storage tank (3) and a port a of a front drive shaft linear exhaust electromagnetic valve (53), a whole vehicle controller (30) controls the front drive shaft linear exhaust electromagnetic valve (53) to be opened through signal lines, the exhaust port c of the front drive shaft linear exhaust electromagnetic valve is communicated with the atmosphere, the opening degree of the front drive shaft linear exhaust electromagnetic valve (53) is controlled to be in proportional relation with pedal displacement, and the air pressure braking force of a front drive wheel (51) and a right drive wheel are released at the moment.

When the port a and the port c of the front right driving wheel two-way check valve (43) are communicated, high-pressure gas in a front right driving wheel brake air chamber (45) sequentially passes through the air inlet port b and the air inlet port a of the front right driving wheel ABS solenoid valve (44), the port c and the port a of the front right driving wheel two-way check valve (43), the port a and the port b of the third three-way valve (42) and the port b of the front driving shaft relay valve (32) and enters the front driving shaft relay valve (32), and is exhausted to the atmosphere through the front driving shaft relay valve (32), so that the pneumatic braking of the front right driving wheel (51) can be released, and the front right driving wheel ABS solenoid valve (44) is not controlled in the process.

When the port b and the port c of the front right driving wheel two-way check valve (43) are communicated, high-pressure gas in the front right driving wheel brake air chamber (45) sequentially passes through the air inlet port b and the air inlet port a of the front right driving wheel ABS solenoid valve (44), the port c and the port b of the front right driving wheel two-way check valve (43), the port b and the port a of the fourth three-way valve (52) and the port b of the front driving shaft linear exhaust solenoid valve (53), enters the front driving shaft linear exhaust solenoid valve (53), and is exhausted to the atmosphere through the exhaust port c of the front driving shaft linear exhaust solenoid valve (53), so that the pneumatic brake of the front right driving wheel (51) can be released, and the front right driving wheel ABS solenoid valve (44) is not controlled in the process.

The working characteristics of a rear drive shaft switch electromagnetic valve (5), a front drive shaft switch electromagnetic valve (55), a rear right drive wheel two-way one-way valve (11), a rear left drive wheel two-way one-way valve (28), a front right drive wheel two-way one-way valve (43), a front left drive wheel two-way one-way valve (33), a rear drive shaft linear exhaust electromagnetic valve (7) and a front drive shaft linear exhaust electromagnetic valve (53) in the four-wheel distributed drive electric vehicle braking energy recovery system based on the two-way one-way valve and the linear exhaust electromagnetic valve are introduced as follows.

When a driver does not step on the brake pedal (1), the rear driving shaft switch electromagnetic valve (5) is in a turn-off state, and high-pressure gas does not exist at the port a of the first three-way valve (8); when a driver steps on the brake pedal (1) but does not trigger the braking energy recovery function, the rear driving shaft switch electromagnetic valve (5) is in a turn-off state, and no high-pressure gas exists at the port a of the first three-way valve (8); when a driver steps on the brake pedal (1) and triggers the braking energy recovery function, the rear driving shaft switch electromagnetic valve (5) is in a conduction state, and high-pressure gas is arranged at the port a of the first three-way valve (8).

When a driver does not step on the brake pedal (1), the front drive shaft switch electromagnetic valve (55) is in a turn-off state, and high-pressure gas does not exist at the port a of the fourth three-way valve (52); when a driver steps on the brake pedal (1) but does not trigger the braking energy recovery function, the front drive shaft switch electromagnetic valve (55) is in a turn-off state, and no high-pressure gas exists at the port a of the fourth three-way valve (52); when a driver steps on the brake pedal (1) and triggers the braking energy recovery function, the front drive shaft switch electromagnetic valve (55) is in a conducting state, and high-pressure gas is arranged at the port a of the fourth three-way valve (52).

The rear right driving wheel two-way check valve (11) has three ports: when the air pressure of the air inlet port a is larger than that of the air inlet port b, air flows in from the air inlet port a and flows out from the air outlet port c, and the air inlet port b is closed; when the air pressure of the air inlet port a is smaller than that of the air inlet port b, air flows in from the air inlet port b and flows out from the air outlet port c, and the air inlet port a is closed.

The rear left drive wheel two-way check valve (28) has three ports: when the air pressure of the air inlet port a is larger than that of the air inlet port b, air flows in from the air inlet port a and flows out from the air outlet port c, and the air inlet port b is closed; when the air pressure of the air inlet port a is smaller than that of the air inlet port b, air flows in from the air inlet port b and flows out from the air outlet port c, and the air inlet port a is closed.

The front right driving wheel two-way one-way valve (43) has three ports: when the air pressure of the air inlet port a is larger than that of the air inlet port b, air flows in from the air inlet port a and flows out from the air outlet port c, and the air inlet port b is closed; when the air pressure of the air inlet port a is smaller than that of the air inlet port b, air flows in from the air inlet port b and flows out from the air outlet port c, and the air inlet port a is closed.

The front left drive wheel two-way check valve (33) has three ports: when the air pressure of the air inlet port a is larger than that of the air inlet port b, air flows in from the air inlet port a and flows out from the air outlet port c, and the air inlet port b is closed; when the air pressure of the air inlet port a is smaller than that of the air inlet port b, air flows in from the air inlet port b and flows out from the air outlet port c, and the air inlet port a is closed.

The rear drive shaft linear exhaust solenoid valve (7) has three ports: the brake pedal device comprises a port a, a port b and an exhaust port c, wherein the port a and the port b are connected with a brake air path and are in a normally-on state, the exhaust port c is not connected with the brake air path, and when the brake pedal (1) is stepped on, the exhaust port c is in a closed state and is not communicated with the atmosphere; when the brake pedal (1) is released, the exhaust port c is opened and communicated with the atmosphere, and the opening degree of the exhaust port c is in proportion to the displacement of the brake pedal (1).

The front drive shaft linear exhaust solenoid valve (53) has three ports: the brake pedal device comprises a port a, a port b and an exhaust port c, wherein the port a and the port b are connected with a brake air path and are in a normally-on state, the exhaust port c is not connected with the brake air path, and when the brake pedal (1) is stepped on, the exhaust port c is in a closed state and is not communicated with the atmosphere; when the brake pedal (1) is released, the exhaust port c is opened and communicated with the atmosphere, and the opening degree of the exhaust port c is in proportion to the displacement of the brake pedal (1).

As can be seen from the above discussion, the auxiliary air storage tank (3), the rear drive shaft switch electromagnetic valve (5), the rear drive shaft linear exhaust electromagnetic valve (7), the first three-way valve (8), the rear drive shaft relay valve (9), the second three-way valve (10), the rear right drive wheel two-way one-way valve (11), the rear right drive wheel brake pressure sensor (17), the rear left drive wheel brake pressure sensor (22), the rear left drive wheel two-way one-way valve (28), the front drive shaft relay valve (32), the front left drive wheel two-way one-way valve (33), the front left drive wheel brake pressure sensor (39), the third three-way valve (42), the front right drive wheel two-way one-way valve (43), the front right drive wheel brake pressure sensor (46), the fourth three-way valve (52), the front drive shaft linear exhaust electromagnetic valve (53) are added in the drive wheel brake air path, The brake system comprises components such as a brake pedal displacement sensor (54), a front drive shaft switch electromagnetic valve (55) and the like, so that each drive wheel brake circuit has two independent high-pressure air sources and a double-circuit structure, and when a driver steps on the brake pedal (1) and does not trigger the brake energy recovery function, high-pressure air required by a rear left drive wheel (26), a rear right drive wheel (13), a front left drive wheel (34) and a front right drive wheel (51) is provided by a main air storage tank (4); when a driver steps on a brake pedal (1) and triggers a braking energy recovery function, high-pressure air required by a rear left driving wheel (26), a rear right driving wheel (13), a front left driving wheel (34) and a front right driving wheel (51) is provided by the air pressure in a main air storage tank (4) and an auxiliary air storage tank (3) to be large, so that the key problems that the response speed of the coupling braking force of the driving wheels is low and the coupling braking force lags behind the required braking force caused by low air source pressure in the continuous braking in the existing scheme can be effectively solved.

Claims

1. The utility model provides a four-wheel distribution drive electric motor car braking energy recovery system based on bi-pass check valve and linear exhaust solenoid valve which characterized in that:

comprises a brake pedal (1), a brake valve (2), an auxiliary gas storage tank (3), a main gas storage tank (4), a rear drive shaft switch solenoid valve (5), an air compressor (6), a rear drive shaft linear exhaust solenoid valve (7), a first three-way valve (8), a rear drive shaft relay valve (9), a second three-way valve (10), a rear right drive wheel two-way one-way valve (11), a rear right drive wheel speed sensor (14), a rear right drive wheel drive motor and transmission device (15), a rear right drive wheel drive motor controller (16), a rear right drive wheel brake pressure sensor (17), a rear right drive wheel brake chamber (18), a rear right drive wheel ABS solenoid valve (19), a rear left drive wheel ABS solenoid valve (20), a rear left drive wheel brake chamber (21), a rear left drive wheel brake pressure sensor (22), a rear left drive wheel drive motor controller (23), A rear left driving wheel driving motor and transmission device (24), a rear left driving wheel speed sensor (25), a rear left driving wheel two-way one-way valve (28), a battery management system (29), a vehicle control unit (30), a brake controller (31), a front driving shaft relay valve (32), a front left driving wheel two-way one-way valve (33), a front left driving wheel speed sensor (36), a front left driving wheel driving motor and transmission device (37), a front left driving wheel driving motor controller (38), a front left driving wheel brake pressure sensor (39), a front left driving wheel brake air chamber (40), a front left driving wheel ABS electromagnetic valve (41), a third three-way valve (42), a front right driving wheel two-way one-way valve (43), a front right driving wheel ABS electromagnetic valve (44), a front right driving wheel brake air chamber (45), a front right driving wheel brake pressure sensor (46), A front right driving wheel driving motor controller (47), a front right driving wheel driving motor and transmission device (48), a front right driving wheel speed sensor (49), a fourth three-way valve (52), a front driving shaft linear exhaust electromagnetic valve (53), a brake pedal displacement sensor (54) and a front driving shaft switch electromagnetic valve (55);

an air outlet port b of the air compressor (6) is connected with an air inlet port a of the main air storage tank (4) through an air path, and an air outlet port a of the air compressor (6) is connected with an air inlet port a of the auxiliary air storage tank (3) through an air path;

an air inlet port a of the brake valve (2) is connected with an air outlet port d of the main air storage tank (4) through an air path, an air inlet port b of the brake valve (2) is connected with an air outlet port c of the main air storage tank (4) through an air path, an air outlet port c of the brake valve (2) is connected with a control port c of the front drive shaft relay valve (32) through an air path, and an air outlet port d of the brake valve (2) is connected with a control port c of the rear drive shaft relay valve (9) through an air path;

an air outlet port b of the auxiliary air storage tank (3) is connected with an air inlet port a of a rear driving shaft switching electromagnetic valve (5) through an air passage, an air outlet port b of the rear driving shaft switching electromagnetic valve (5) is connected with an air inlet port a of a rear driving shaft linear exhaust electromagnetic valve (7) through an air passage, an air outlet port b of the rear driving shaft linear exhaust electromagnetic valve (7) is connected with an air inlet port a of a first three-way valve (8) through an air passage, an air outlet port b of the first three-way valve (8) is connected with an air inlet port b of a rear right driving wheel two-way one-way valve (11) through an air passage, and an air outlet port c of the first three-way valve (8) is connected with an air inlet port b of a rear left driving wheel two-way one-way valve (28) through an air passage;

a port a of the rear drive shaft relay valve (9) is connected with an air outlet port e of the main air storage tank (4) through an air passage, and a port b of the rear drive shaft relay valve (9) is connected with a port b of the second three-way valve (10) through an air passage;

a port a of the second three-way valve (10) is connected with an air inlet port a of the rear right driving wheel two-way one-way valve (11) through an air passage, an air outlet port c of the rear right driving wheel two-way one-way valve (11) is connected with an air inlet port a of the rear right driving wheel ABS electromagnetic valve (19) through the air passage, and an air inlet port b of the rear right driving wheel ABS electromagnetic valve (19) is connected with a rear right driving wheel brake air chamber (18) through the air passage;

a rear right driving wheel brake pressure sensor (17) is arranged on the rear right driving wheel brake air chamber (18);

a port c of the second three-way valve (10) is connected with an air inlet port a of a two-way one-way valve (28) of the rear left driving wheel through an air passage, an air outlet port c of the two-way one-way valve (28) of the rear left driving wheel is connected with an air inlet port a of an ABS electromagnetic valve (20) of the rear left driving wheel through an air passage, and an air inlet port b of the ABS electromagnetic valve (20) of the rear left driving wheel is connected with a brake air chamber (21) of the rear left driving wheel through an air passage;

a rear left driving wheel brake pressure sensor (22) is arranged on the rear left driving wheel brake chamber (21);

an air outlet port c of the auxiliary air storage tank (3) is connected with an air inlet port a of the front drive shaft switch electromagnetic valve (55) through an air passage, an air outlet port b of the front drive shaft switch electromagnetic valve (55) is connected with an air inlet port a of the front drive shaft linear exhaust electromagnetic valve (53) through an air passage, an air outlet port b of the front drive shaft linear exhaust electromagnetic valve (53) is connected with an air inlet port a of a fourth three-way valve (52) through an air passage, an air outlet port b of the fourth three-way valve (52) is connected with an air inlet port b of a front right drive wheel two-way one-way valve (43) through an air passage, and an air outlet port c of the fourth three-way valve (52) is connected with an air inlet port b of a front left drive wheel two-way one-way valve (33) through an air passage;

a port a of the front drive shaft relay valve (32) is connected with an air outlet port b of the main air storage tank (4) through an air path, and a port b of the front drive shaft relay valve (32) is connected with a port b of the third three-way valve (42) through an air path;

a port a of the third three-way valve (42) is connected with an air inlet port a of a front right driving wheel two-way one-way valve (43) through an air passage, an air outlet port c of the front right driving wheel two-way one-way valve (43) is connected with an air inlet port a of a front right driving wheel ABS electromagnetic valve (44) through the air passage, and an air inlet port b of the front right driving wheel ABS electromagnetic valve (44) is connected with a front right driving wheel brake air chamber (45) through the air passage;

a front right driving wheel brake pressure sensor (46) is arranged on the front right driving wheel brake air chamber (45);

a port c of the third three-way valve (42) is connected with an air inlet port a of the front left driving wheel two-way one-way valve (33) through an air passage, an air outlet port c of the front left driving wheel two-way one-way valve (33) is connected with an air inlet port a of the front left driving wheel ABS electromagnetic valve (41) through an air passage, and an air inlet port b of the front left driving wheel ABS electromagnetic valve (41) is connected with a front left driving wheel brake air chamber (40) through an air passage;

a front left driving wheel brake pressure sensor (39) is arranged on the front left driving wheel brake chamber (40);

the rear right driving wheel speed sensor (14), the rear left driving wheel speed sensor (25), the front left driving wheel speed sensor (36) and the front right driving wheel speed sensor (49) are connected with the brake controller (31) through signal lines;

the rear right driving wheel ABS electromagnetic valve (19), the rear left driving wheel ABS electromagnetic valve (20), the front left driving wheel ABS electromagnetic valve (41) and the front right driving wheel ABS electromagnetic valve (44) are connected with the brake controller (31) through signal lines;

a rear driving shaft switch electromagnetic valve (5), a rear driving shaft linear exhaust electromagnetic valve (7), a front driving shaft switch electromagnetic valve (55), a front driving shaft linear exhaust electromagnetic valve (53), a rear right driving wheel brake pressure sensor (17), a front right driving wheel brake pressure sensor (46), a front left driving wheel brake pressure sensor (39), a rear left driving wheel brake pressure sensor (22) and a brake pedal displacement sensor (54) are connected with a whole vehicle controller (30) through signal lines;

2. The braking energy recovery system for four-wheel distributed drive electric vehicle based on two-way check valve and linear exhaust solenoid valve as claimed in claim 1, wherein the vehicle control unit (30) is based on the vehicle speed outputted from the braking controller (31) via the CAN bus, the pedal displacement signal outputted from the brake pedal displacement sensor (54), the maximum charging current allowed by the battery outputted from the battery management system (29) via the CAN bus, the maximum braking force of the rear right drive wheel provided by the rear right drive wheel drive motor and transmission (15) outputted from the rear right drive wheel drive motor controller (16) via the CAN bus, the maximum braking force of the rear left drive wheel provided by the rear left drive wheel drive motor and transmission (24) outputted from the rear left drive wheel drive motor controller (23) via the CAN bus, and the maximum braking force of the rear left drive wheel provided by the front right drive wheel drive motor and transmission (47) via the CAN bus (48) The maximum motor braking force of the front right driving wheel which CAN be provided, the maximum motor braking force of the front left driving wheel which CAN be provided by a front left driving wheel driving motor controller (38) through a front left driving wheel driving motor and a transmission device (37) which are output by a CAN bus, whether a braking energy recovery function is triggered or not is judged, and a rear driving shaft switch electromagnetic valve (5), a rear driving shaft linear exhaust electromagnetic valve (7), a front driving shaft switch electromagnetic valve (55) and a front driving shaft linear exhaust electromagnetic valve (53) are controlled according to the braking energy recovery function, and the braking energy recovery system is characterized in that:

when a brake pedal is stepped on and a braking energy recovery function is triggered, the whole vehicle controller (30) controls the conduction of the rear drive shaft switch electromagnetic valve (5), the gas path between the port b of the auxiliary gas storage tank (3) and the port a of the rear drive shaft linear exhaust electromagnetic valve (7) is conducted, the whole vehicle controller (30) controls the rear drive shaft linear exhaust electromagnetic valve (7) to be in a closed state, and the exhaust port c of the rear drive shaft linear exhaust electromagnetic valve is not communicated with the atmosphere; when a brake pedal is stepped on, but the braking energy recovery function is not triggered, the whole vehicle controller (30) controls the rear drive shaft switching electromagnetic valve (5) to be turned off, an air path between the port b of the auxiliary air storage tank (3) and the port a of the rear drive shaft linear exhaust electromagnetic valve (7) is disconnected, the whole vehicle controller (30) controls the rear drive shaft linear exhaust electromagnetic valve (7) to be in a closed state, and the exhaust port c of the rear drive shaft linear exhaust electromagnetic valve is not communicated with the atmosphere; when a driver looses the brake pedal (1), the vehicle control unit (30) controls the rear drive shaft switching electromagnetic valve (5) to break the gas path connection between the port b of the auxiliary gas storage tank (3) and the port a of the rear drive shaft linear exhaust electromagnetic valve (7), the vehicle control unit (30) controls the rear drive shaft linear exhaust electromagnetic valve (7) to be in an open state, the exhaust port c of the rear drive shaft linear exhaust electromagnetic valve is communicated with the atmosphere, and the opening degree of the rear drive shaft linear exhaust electromagnetic valve is in a proportional relation with a pedal displacement signal output by the brake pedal displacement sensor (54) through a signal line;