Sequential and concurrent design of linkages mechanism with hybrid actuators

Abstract

The design of a linkage with hybrid actuators involves three aspects.They are kinematic design,dynamic design and control design.On one hand,each of the aspects affects and relates to others.They are strongly coupled.On the other hand,they are different in design criteria and decision objective as well.In sequential design,the kinematic design is completed firstly,then the dynamic design,and finally the control design.Whereas in concurrent design,the optimizations of the three aspects are considered simultaneously.The sequential and concurrent designs of five-bar mechanism with hybrid actuators are developed.Even though the differential evolution algorithm is employed as the optimization tool in all cases,the results from the sequential and concurrent designs are different.It is shown that the sequential design leads to more accuracy in kinematics,but the control design is more difficult and the performance of control system is not good.By contrast, the concurrent design enables the control design to be easy and the performance is improved apparently at the expense of more complex design model and the loss of accuracy in kinematics.