并联机构主模块伺服系统参数辨识与整定

研究一种小型可重构并联机构主模块伺服系统参数辨识与整定方法。首先导出外移动副驱动,含平行四边形支链结构的位置、速度及加速度逆解模型,并利用虚功原理建立其刚体动力学逆解模型。在此基础上,提出辨识该类伺服系统参数的一种方法。该方法采用变频三角波输入,克服了伪随机二位式序列信号幅值变化大,易造成对伺服电动机冲击,引起其速度环开环等问题,且通过附加惯性负载,可将包括伺服系统转动惯量在内的所有参数辨识出来。进而,以超调量和上升时间为优化目标,考虑随位姿变化的极限负载,对伺服系统控制器参数进行了整定,给出了伺服系统控制器参数的范围。最后,试验验证了该方法的有效性和正确性。

PARAMETER IDENTIFICATION AND AUTOMATIC TUNING OF THE ELECTROMECHANIC COUPLING SERVO SYSTEM OF A PARALLEL MANIPULATOR

Aimed at a parallel manipulator with three transla-tional degrees of freedom, a method on parameter identification and automatic tuning of the electromechanical coupling servo system is presented. In parameter identification process, the triangle shape input with variable frequency is adopted to overcome the disadvantages of pseudo-random number sequence, i.e. making the change of vibration amplitude of the motor dramatically, easy to impact motor and result in its velocity loop open and so on. Moreover, the rotary inertia can also be identified by the additive mass, and by the simulation and experiments in which a step input is adopted, this identified model is proved general and validated. Based on the above, the overshoot and rise time are acted as optimum goals, and the range of PID controller parameters of the servo system is given. At last, a series of the experiments are done to prove its correctness.