无压力传感器下的电子液压制动系统轮缸液压力控制

Wheel-Cylinder Hydraulic Pressure Control of Integrated-Electro-Hydraulic Brake System Without Pressure Sensors

摘要:

线控电子液压制动系统作为下一代汽车制动系统的主流解决方案，其轮缸液压力控制是实现车辆稳定性控制等主动安全功能的基础。针对四阀结构的集成式电子液压制动系统的成本与冗余问题，提出一种无轮缸压力传感器下的轮缸液压力控制策略。通过台架测试分析液压调节单元的工作特性，提出基于伯努利方程与轮缸PV(pressure volume)特性相结合的轮缸液压力估计方法，设计电磁阀开闭逻辑及基于减压优先的轮缸液压力均衡控制策略，最后通过台架试验进行对比验证。试验结果表明，所提出方法的液压力控制均方根误差在0.21MPa以内，与有液压力传感器方案的控制精度相当。

Abstract:

The electro-hydraulic brake-by-wire system is the mainstream solution for next-generation automotive brake systems, whose wheel-cylinder hydraulic pressure control is the basis to achieve active safety functions such as vehicle stability control. In view of the cost and redundancy of the integrated-electronic-hydraulic brake system with a four-valve structure, a wheel-cylinder hydraulic pressure control strategy without pressure sensors is proposed. Through the bench test, the working characteristics of the hydraulic control unit were analyzed. A method for estimating the hydraulic pressure of the wheel cylinder is developed based on the combination of Bernoulli equation and PV characteristics. The solenoid-valve control logic and balance control strategy are designed for wheel-cylinder pressure regulation based on depressurization priority. The experimental results show that the root-mean-square error of the pressure control in this method is within 0.21MPa, which is equivalent to the control accuracy of the scheme with a hydraulic pressure sensor.