基于直驱阀的快速响应线控制动系统液压力精确控制

为突破响应时间与控制精度的性能瓶颈，提出一种基于直驱阀的快速响应线控制动系统，通过基于Halbach永磁阵列的电磁直线执行器直接驱动阀芯，实现制动轮缸液压力的迅速调节。建立线控制动系统电磁、机械和液压子系统模型，设计基于逻辑门限的线控制动系统液压力-直驱阀位置切换控制架构。压力环采用滑模变结构控制，使轮缸液压力迅速逼近目标液压力值；设计结合摩擦补偿自适应控制律、稳定反馈和鲁棒控制的自适应鲁棒控制方法的直驱阀位置环，使直驱阀芯能够迅速通过阀死区；基于李雅普诺夫函数方法证明算法的稳定性。以线控制动系统的响应时间、控制精度等性能参数作为目标函数，通过相关矩阵分析控制参数对性能的影响规律，并通过多目标粒子群算法优化控制器参数。研究结果表明：提出的切换控制方法与PID控制和滑模控制相比，目标压力10 MPa的阶跃响应时间为0.05 s，稳态误差不超过2％；ARTEMIS欧洲循环工况下的均方根误差为0.33 MPa；设计的直驱阀结构与控制方法有利于提高制动系统的响应速度和控制精度。

Precision Control of Hydraulic Pressure in Fast-response Brake-by-wire System Based on Direct-drive Valve

To overcome the performance bottleneck of response time and control accuracy, a fast-response line control system based on a direct-drive valve was proposed, in which an electromagnetic linear actuator based on the Halbach permanent magnet array directly drives the valve core and realizes a rapid adjustment of the hydraulic pressure of the driving-wheel cylinder. The electromagnetic, mechanical, and hydraulic subsystem models of the linear control system were established, and a control architecture for hydraulic pressure-direct drive valve position switching based on logic threshold was designed. Sliding mode variable structure control was adopted in the pressure ring so that the hydraulic pressure of the wheel cylinder may rapidly attain the target value. The position ring of the direct-drive valve was designed by combining the adaptive control law of friction compensation, stable feedback, and robust control so that the direct-drive valve core can pass through the dead zone quickly. The stability of the algorithm was proved using the Lyapunov function method. The response time, control precision, and other performance parameters of the linear control system were used as objective functions, the influence of the control parameters on the performance was analyzed using the correlation matrix, and the controller parameters were optimized by a multi-objective particle swarm optimization algorithm. The results demonstrate that, compared with PID control and sliding mode control, the step response time of the proposed switching control method is 0.05 s and the steady-state error is less than 2% at the target pressure of 10 MPa. The root mean square error of ARTEMIS is 0.33 MPa under European cycle conditions. The structure of the direct-drive valve and the control method can improve the response speed and control accuracy of the braking system.