This thesis deals with the study on the position control of a pneumatic SCARA manipulator using low cost on-off valves. The manipulator which consists of a pneumatic rotary actuator and a rodless cylinder with on-off valves is constructed.
The state-feedback control with valve control band(VCB) is proposed to get fast response, and to prevent solenoid valves from unnecessary switching at the beginning of response. It is shown experimentally that the proposed algorithm can be used to obtain fast response and low steady-state error.
Describing function analysis is made to investigate the stability of the on-off system. The predicted critical value of the velocity gain satisfactorily agrees with the experiment.
It is also shown in the experiment that the voltage-current relationship of a pneumatic on-off valve may be expressed as a first order differential equation with a time constant.
The effects of loads and feedback gains on the control performance are discussed, and computer simulation on the dynamic performance of the pneumatic system is presented.
