分流式柔性铰六维力传感器刚度分析与结构优化

Stiffness Analysis and Structure Optimization of Shunted Sensor with Flexure Hinge

摘要:

针对目前已有六维力传感器的不足，基于并联机构设计了一种分流式柔性铰六维力传感器。阐述了传感器的结构，通过等效法和微元法建立了其静力和刚度模型，对刚度模型进行了有限元仿真验证。基于遗传算法进行了结构优化设计，得到了传感器各向同性最优时的结构参数。最后对传感器进行标定实验。实验结果验证了静力模型的有效性，得到了传感器测量精度。传感器测量误差在1.05%以内，能够精确测量未知外载的六维分量。

Abstract:

For the disadvantages of existing six-dimensional force sensor, a new shunted sensor with three rigid compliant hybrid limbs and six standard force sensors was designed and manufactured based on parallel structure for measuring the heavy six-component force/torque. Firstly, a prototype of the developed parallel sensor was built up and its merits were analyzed. A 3D model of the robot hybrid hands with parallel sensor was constructed. A statics equation among the forces of the six standard force sensors and the external workload was established, and a mapped matrix from the workload to forces of the six standard force sensors was derived based on its equivalent parallel mechanism. The theoretical solutions of the parallel sensor stiffness were obtained and verified by the simulation solutions of a FE model. Secondly, structural optimum design of the sensor was carried out based on the genetic algorithm. The best structural parameters of sensor were obtained by analyzing isotropy. Finally, an experiment was performed to obtain the accuracy in each direction by loading weights. The forces of the six standard force sensors of the prototype of parallel sensor were measured by adding different workload components onto the prototype loading platform. The results indicated that the maximun error in each direction of sensor was 1.05% in full scale. The theoretical analysis was verified by finite element method simulating and experimental results. The force/torque of the parallel sensor can be accurately measured under the given external load.