针对集成式线控制动系统(Integrated Brake-by-Wire System,I-BBW)在轮缸压力控制介入后存在液压系统刚度突变、制动液不足等问题,提出了一种基于电机-电磁阀协同补液逻辑的I-BB W轮缸压力控制策略.首先,分析I-BB W的工作原理并构建其关键子系统的数学模型.随后,设计I-BB W轮缸压力控制策略,电机-电磁阀协同补液逻辑根据伺服缸液压力-活塞位置刚度特性变化动态调节压力调控器内置参数,维持I-BB W制动液充足;伺服缸压力调控器采用基于液压系统变刚度拟合前馈的压力环、鲁棒滑模位置环以及电机电流环,实现对I-BB W高压源压力的精准调控,克服液压系统刚度突变问题;轮缸压力调控器基于测试数据拟合进/出液电磁阀的增/减压特性,将轮缸与电磁阀间复杂的压力调节逻辑转换为结构简洁的特性映射模型,实现轮缸压力精确控制.最后,搭建硬件在环试验台对设计的算法进行测试验证.结果表明:所提出的算法能够实现I-BBW的压力精准控制,伺服缸和轮缸平均压力跟踪误差分别在0.15、0.25 M Pa以内,并且当I-BB W制动液不足时,能够在100 m s内快速响应制动补液需求,保证I-BB W稳定、精确的制动压力调控能力.
Wheel Cylinder Pressure Control Strategy for Integrated Brake-by-wire System Based on Motor-solenoid Valve Coordinated Fluid Replenishment Logic
To address the issues facing the integrated brake-by-wire (I-BBW) system in relation to hydraulic system stiffness mutation and inadequate brake fluid after wheel cylinder pressure control intervention,an I-BBW wheel cylinder pressure control strategy based on motor-solenoid valve coordinated fluid replenishment logic was proposed.First,the working principle of the I-BBW was analyzed.Subsequently,essential mathematical models of the key subsystems were constructed.A strategy for regulating the I-BBW wheel cylinder pressure was then designed.The motor-solenoid valve coordinated replenishment logic dynamically adjusts the integrated parameter status of the pressure regulator according to changes in the servo cylinder fluid pressure-piston position stiffness characteristics to maintain sufficient I-BBW brake fluid. The servo cylinder pressure regulator uses a pressure loop based on the feedforward of the hydraulic system variable stiffness fitting,robust sliding mode position loop,and motor current loop to accurately regulate the pressure of the I-BBW high pressure source and overcome sudden changes in the stiffness of the hydraulic system.The wheel cylinder pressure regulator condenses the pressurization/depressurization characteristics of the inlet/outlet solenoid valve using the test data and converts the complex pressure-regulating logic between the wheel cylinder and solenoid valve into a simple-structured characteristic mapping model to achieve precise control of the wheel cylinder pressure.Finally,a hardware-in-the-loop experimental bench was constructed to verify and test the designed algorithm.The results show that the proposed algorithm can effectively control the I-BBW and accurately respond to a variety of target pressure demands.The average pressure tracking errors of the servo cylinder and wheel cylinders are controlled to within 0.15 and 0.25 Mpa,respectively.Furthermore,should there be a shortage of brake fluid,a quick response is given,demanding brake fluid replenishment within 100 ms,thus ensuring the I-BBW retains stable and accurate brake pressure control capabilities.
万方数据
维普
