Electronic hydraulic braking system with multiple working modes

Abstract

The invention belongs to the technical field of automobile braking systems and discloses an electronic hydraulic braking system with multiple working modes. The electronic hydraulic braking system mainly comprises a braking pedal, a braking pedal displacement sensor, an active control booster, 2 / 2 normally-closed solenoid valves, an active pedal sense simulator, a hydraulic control unit, an electronic control unit, a braking main cylinder and braking wheel cylinders. The electronic hydraulic braking system adopts a double-power source braking system form, so that the fault-tolerant capability of the system can be improved, the relatively steady pedal sense can be guaranteed during the switching of various braking conditions, and furthermore, the relatively high pressurizing response speed of the system can be guaranteed.

Description

Technical field [0001] The invention belongs to the technical field of automobile brake systems, and particularly relates to an electronic hydraulic brake system with multiple working modes. Background technique [0002] The automobile brake system is closely related to the safety of the automobile, and has been receiving extensive attention. At present, the functional requirements for the braking system of automobiles are not only the traditional anti-lock braking (ABS), stability control (ESP), but also the functional requirements of new energy vehicles / smart cars for the braking system. Component suppliers and research institutions have put forward corresponding system schemes. According to the decoupling method of manpower and braking system, it is mainly divided into complete decoupling scheme and partial decoupling scheme. Among them, the complete decoupling scheme is also known as the pure wire control system. , The more typical ones are the electronic hydraulic brake sys...

AI Technical Summary

Problems solved by technology

The high-voltage accumulator in the electronic hydraulic braking system (EHB) is the only high-voltage power source in the system. Once it fails, the system will enter the manual backup circuit. braking deceleration; for the combination of iBooster and ESP-hev, although there are two power sources (iBooster motor and hydraulic pump in ESP-hev), when the iBooster motor fails, the ESP-hev hydraulic pump can provide high pressure, although Larger braking deceleration can be achieved, but due to the constraints of the boosting capacity of the hydraulic pump, it is difficult for the system to meet the needs of boosting response under emergency braking conditions

[0004] For a pure brake-by-wire system, a pedal feel simulator is required to improve the brake feel. The pedal feel simulator in the EHB system uses a simulated spring method. On the one hand, it is difficult to guarantee the traditional nonlinear brake pedal feel by using a simulated spring method. On the other hand, it is impossible to adjust the pedal feel to meet the needs of people with different driving habits; and the combination of iBooster and ESP-hev, although the iBooster can achieve a certain range of adjustable pedal feel, in the braking energy recovery working condition, Then an active pedal feeling simulator (SmartActuator) is additionally required, and its structure is more complicated

[0005] When the system needs to achieve rapid boosting, the combined solution of iBooster and ESP-hev can work together through the iBooster motor and the hydraulic pump, which can shorten the pressure response time, but the iBooster motor is still the main one, which has higher requirements on the motor; while the EHB system The high pressure source is provided by the high pressure accumulator, so the boosting response of the system is fast, but even in the normal braking process (non-failure mode), it still needs the high pressure accumulator to output high pressure. By continuously controlling the solenoid valves of each wheel, To realize the pressure of each wheel cylinder, the high-pressure accumulator is required to have a relatively large fluid storage capacity, which will cause the hydraulic pump to work frequently during continuous braking. Many advantages, in the presence of various factors such as braking process error and control algorithm accuracy, it is difficult to ensure the consistency of the pressure response of each wheel and its steady-state error. For example, when the pressure of the left and right wheel cylinders is inconsistent, the In the case of moving, it is easy to appear the phenomenon of braking deviation

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