基于集成式电液制动系统的主动制动压力精确控制方法

智能电动汽车的发展对制动系统的主动制动和再生制动能力提出了更高的要求。配备真空助力器的传统制动系统难以满足智能电动汽车的需求，因此逐渐被线控制动系统所取代。为提高线控制动系统的集成度与解耦能力，提出了一种新型集成式电液制动系统（Integrated Braking Control System，IBC），能够实现主动制动、再生制动、失效备份等功能。作为机-电-液耦合的高集成度系统，IBC具有复杂的非线性特性和动态摩擦特性，对制动系统压力的精确控制提出了挑战。为了提高IBC制动压力动态控制精度，提出了一种基于集成式电液制动系统的主动制动压力精确控制方法。首先，介绍了IBC的结构原理和控制架构。随后针对液压系统的迟滞特性和传动机构的摩擦特性进行建模与测试。然后基于系统的强非线性特性，提出了主动制动三层闭环级联控制器，其中压力控制层采用液压特性前馈与变增益反馈结合的控制策略，伺服层控制器设计考虑了机构惯性补偿与摩擦补偿，电机控制层采用矢量控制并进行了电压前馈解耦。最后，基于dSPACE设备搭建了硬件在环（Hardware-in-the-loop，HiL）试验台对主动压力控制方法进行验证。结果表明：所提出的压力控制方法能控制制动系统压力快速精确跟随期望压力，使动态压力跟随误差控制在0.4 MPa之内，稳态压力误差控制在0.1 MPa之内。

Precise Control Method for Active Brake Pressure Based on an Integrated Braking Control System

The development of intelligent electric vehicles necessitates higher requirements for the braking system's active and regenerative braking capabilities. Traditional braking systems equipped with vacuum boosters are challenged to meet the needs of intelligent electric vehicles, so brake-by-wire (BBW) systems are gradually replacing them. To improve the integration and decoupling capability of BBW systems, this study proposes a novel integrated braking control system (IBC) that can include functions such as active braking, regenerative braking, and failure backup. As a highly integrated system of mechanical-electric-hydraulic coupling, IBC has complex nonlinear and dynamic friction characteristics, which poses a challenge to the precise control of the brake system pressure. To improve the dynamic pressure control accuracy, a precise control method for active brake pressure based on IBC was proposed. First, the structural principle and control architecture of the IBC was introduced. The hydraulic system's hysteresis characteristics and the transmission mechanism's friction characteristics were tested and modeled. Then, based on the strong nonlinear characteristics of the system, a three-layer closed-loop cascade controller for active braking was proposed. The hydraulic characteristic feedforward and variable-gain feedback in the pressure control layer were combined. The servo control layer was designed by considering the mechanism of inertia compensation and friction compensation. Vector control was adopted in the motor control layer, and voltage feedforward decoupling was performed. Finally, a hardware-in-the-loop (HiL) test bench was built based on dSPACE devices to verify the active pressure control method. The results illustrate that the pressure control method can regulate the system pressure to follow the desired pressure quickly and precisely. The dynamic pressure following error is controlled within 0.4 MPa, and the steady-state pressure error is controlled within 0.1 MPa.