直线超声电机驱动的并联微夹持器的振动控制

Vibration Control of a Parallel Microgripper Driven by Linear Ultrasonic Motors

针对直线超声电机驱动的并联微夹持器手指的振动问题,提出了一种基于状态反馈的主动控制方法来抑制微夹持器手指的振动,提高了微夹持器的稳定性。首先,利用有限单元法建立了微夹持器系统中圆盘与活动手指的动力学模型,并推导其状态方程;其次,分析该振动系统的能控性和稳定性,采用极点配置法得到状态反馈矩阵,设计了振动反馈控制律,通过Simulink对该反馈系统进行仿真分析,验证了主动控制对手指振动的抑制效果;最后,利用该控制系统分别对微米级的钢珠以及茶花花粉细胞进行夹取实验。结果表明,该主动控制策略下微夹持器的夹持性能及稳定性能够满足微纳定位精度的要求。

This paper proposes an active control mothed based on the state feedback to suppress the vibration of the parallel microgripper finger driven by linear ultrasonic motors,to improve the stability of the microgripper.First,the dynamic model of the disk and the moving finger in microgripper system is established by finite ele⁃ment method,and the state equation is derived.Then,the controllability and stability of the vibration system are analyzed.The state feedback matrix is obtained by pole assignment method,and the vibration feedback con⁃trol law is designed.The feedback system is simulated and analyzed by Simulink to verify the vibration suppres⁃sion effect of the active control on the finger.Finally,the experiments of clamping steel ball and camellia pollen cell in micron scale are carried out by using the designed control system.The results indicate that the clamping performance and stability of the microgripper under the active control strategy can meet the requirements of mi⁃cro-nano positioning accuracy.