一种具有力传感的微夹持器设计与标定

Design and calibration of a micro-gripper with force sensing

为了避免微夹持器在夹持微小对象过程中对其造成损伤或脱落,要求对夹持力进行预测和控制。提出了一种将电阻式应变片集成于微夹持器结构实现结构-传感一体化设计。以夹持力产生的应变最大、压电陶瓷驱动力产生的应变最小为目标对传感单元的尺寸参数进行优化设计。采用最小二乘方法分别标定压电驱动器输入电压、夹持力与力传感单元应变之间的关系。结果表明,描述驱动电压与传感单元应变的关系为3阶多项式,力传感单元应变与夹持力之间的关系为线性关系。可得出夹持力与驱动电压之间的关系为3阶多项式,利用该关系式可实现预测和控制夹持力。所提出的设计思路和标定方法为微夹持器设计提供一种新思路。

In order to avoid the injury or loss of small objects when micro gripper operating the small objects,the gripper force needs to be predicted and controlled. A structure-sensing integration design idea is presented,in which the structure of micro gripper is integrated with resistance strain. The optimization design of the structural parameters of the sensing unit was carried out by taking the maximum of the strain caused by gripping force and the minimum of the strain caused by piezoelectric ceramic driving force. The least square method is applied to calibrate the relationship between the input voltages of piezoelectric actuator,the gripping force and the strains of the force sensing unit respectively. The results show that the relationship between the driving voltage and the strain of sensing unit is three-order polynomial and the relationship between the strains of the force sensing unit and the gripping force is linear. The relationship between gripping force and driving voltage can be obtained,and the relationship is three-order polynomial in order to forecast and control gripping force. The proposed design idea and calibration method provides a novel thought for micro gripper.