Research On The Design And Control Of A Flexible Pneumatic Spherical Joint

A new type of pneumatic actuator, pneumatic spherical joint is studied in this thesis. Compared with conventional actuators, it has many advantages such as high safety and reliability, flexibility and simple structure. First, the progress of research work on new-type pneumatic actuators is introduced. Then the principles of this actuator are presented, on which the static and dynamic mathematical models are constructed and analyzed. In order to measure the deformations of the joint, a posture sensor system is presented. A prototype of the model is manufactured, and an experiment system built up, and then a series of static and dynamic experiments are carried out. We compare the results of the experiments with those of simulations, and reach conclusions as follow: the static model matches well with the experiment; the pose sensor system works well. The open loop response of the joint has the apparent characteristic of non-overshot and slow rising. Under the algorithms of digital PID, fuzzy,fuzzy PID control, the joint has a satisfactory close loop response. Limited by immature manufacturing technology, the movement of this joint is constrained to little range of deformation ( bending angle no more than 20) . Further research can be performed on large deformation of this joint based on structure optimization, improvement on manufacturing technology, posture sensor system and control algorithms.