Hydraulic braking force control system and method

Abstract

The invention discloses a hydraulic braking force control method, which comprises the following steps that: an EBCU calculates a hydraulic braking force target value according to a braking working condition, carries out impact limiting treatment, and firstly controls the current of a proportional electromagnetic valve in a hydraulic braking system by utilizing inner-layer control of a current closed loop and outer-layer control of a pressure closed loop; pressure is output in a current closed-loop control mode, then the output PWM duty ratio of a proportional electromagnetic valve is finely adjusted according to the difference value between the target pressure and the actual pressure of a brake cylinder, and adjustment of the actual pressure and the target pressure is achieved through an inner-layer current closed-loop and outer-layer pressure closed-loop double-layer control method. The invention further discloses a hydraulic braking force control system corresponding to the hydraulic braking force double-closed-loop control method, the purpose of accurately and stably controlling the braking pressure is achieved, a vehicle runs stably, the impulse is small, and the comfort level of passengers is high.

Description

technical field [0001] The invention relates to the technical field of braking of rail transit vehicles, in particular to a hydraulic braking force control system and method. Background technique [0002] As a new domestic urban rail transit product, low-floor trams have the characteristics of energy saving, environmental protection and high efficiency, and also have the advantages of low floor height, convenient for passengers to get on and off, short stop time, and large lighting area. Passenger capacity, running stability and comfort are better than buses. As an ideal urban public transportation system, it is of great significance to develop low-floor trams in China. However, during the speed regulation process of the low-floor tram, especially in the electro-hydraulic conversion process of the low-speed section, due to the hysteresis of the hydraulic braking force and the problem of the response speed, the precise and stable control of the brake cylinder pressure during ...

AI Technical Summary

Problems solved by technology

However, during the speed regulation process of low-floor trams, especially in the electro-hydraulic conversion process at low speeds, due to the hysteresis and response speed of the hydraulic braking force, the precise and stable pressure control of the brake cylinder during the train stop process directly affects the Vehicle impulse and passenger comfort

[0003] In the braking system that adopts the hydraulic braking method, the transmission path of the braking force is: the hydraulic pump provides high-pressure oil, and various hydraulic control valves control the hydraulic oil according to the control instructions of EBCU (EBCU is the abbreviation of Electronic Brake Control Unit). Adjustment, the adjusted high-pressure oil enters the basic brake unit to generate braking force, but the hydraulic braking system in the prior art has low precision and slow response

[0004] A microcomputer-controlled electromechanical braking system in the prior art (International publication number: WO / 2019 / 047049), the system generates frictional braking force by directly converting electrical energy into mechanical action, although it has the advantages of high precision and fast response , but the system replaces the hydraulic drive mode commonly used in the current rail vehicle braking system with an electric drive mode, and does not have many advantages of hydraulic transmission, such as the inability to control the pressure very accurately and smoothly

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