“井”字形双驱龙门模型参考自适应控制

Model-Based Adaptive Control for a Dual-drive “Checkerboard” Gantry

为了在大行程范围内实现快速精确定位,研究了一种X-Y双边冗余驱动的“井”字形双驱龙门。分析了同步误差对末端工作头实际精确位置的影响,利用拉格朗日方法推导了其动力学模型。针对两平行轴同步性能易受到由末端工作头运动引起的非对称负载影响的问题,设计了一种模型参考自适应控制方法以用于实时补偿该非对称负载,并利用李亚普诺夫理论证明了该方法的稳定性。在实际龙门平台上的实验表明,相较于传统的主从PID控制,所提控制方法在不增加电机推力负担的情况下,明显减小了轨迹跟踪误差和同步误差,有效提高了龙门平台的精确定位性能。

For fast and precise positioning over large workspace,a dual-drive“checkerboard”gantry system,where both X and Y motion are redundantly driven,is introduced.The effect of synchronization error on the actual position of the end working head is analyzed,and the dynamical model is derived using Lagrangian equation.To address the problem that the synchronization performance of the two parallel axes is easily affected by the asymmetric load caused by the motion of the end working head,a model-based adaptive control strategy is designed for real-time compensation.Then the stability of the proposed method is proved using Lyapunov's theory.Experiments on the actual gantry stage show that,compared with the traditional master-slave PID control,the proposed control method significantly reduces the trajectory tracking error and synchronization error without increasing the motor thrust burden,and effectively improves the precise positioning performance of the gantry stage.