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为研究HXD2型电力机车闸瓦间隙调整器在制动时受副风缸压力和轮对椭圆形踏面挤压时的位置控制精度,考虑实际工况中死区输入的非线性和流经细长管路的风压波动、活塞与制动缸内壁非严格配合引起的压力漏损,建立了具有死区输入的制动缸伺服系统的数学模型;针对死区输入未知时变参数的非线性系统,结合阀口游移方向的不确定性,引入Nussbaum类型函数;为改善系统误差面的动态响应,引入虚拟反馈控制函数。理论分析表明,制动缸伺服系统闭环输出有界,跟踪误差半全局一致终结有界并收敛于0。仿真结果表明,误差面动态抖振较小,收敛迅速;Nussbaum函数有界并收敛。具有死区输入的制动缸伺服系统可实现气压存在较大波动及线路上存在激扰时对位置指令输入的近似无偏跟踪,并对参数慢时变漂移具有较强鲁棒性。
In order to study the position control accuracy of HXD2 electric locomotive brake shoe lash adjuster when it is subjected to the auxiliary cylinder pressure and the wheel-to-oval tread during braking, the nonlinearity of the dead zone input and the flow through the slender The wind pressure fluctuation of the pipeline and the pressure loss caused by the non-strict cooperation between the piston and the brake cylinder wall, a mathematical model of brake cylinder servo system with dead-zone input is established. A nonlinear system with unknown time- , The Nussbaum type function is introduced according to the uncertainty of valve port drift direction. In order to improve the dynamic response of system error surface, a virtual feedback control function is introduced. Theoretical analysis shows that the closed-loop output of the servo system of the brake cylinder is bounded, the tracking error is semi-globally uniform and the ending is bounded and converges to zero. The simulation results show that the dynamic chattering of the error surface is small and converges rapidly; the Nussbaum function is bounded and convergent. The brake cylinder servo system with dead-zone input can realize approximate unbiased tracking of the position command input when the air pressure fluctuates greatly and there is disturbance in the line, and has strong robustness to slow time-varying parameters.