Authors

Abstract

In a previous study, speed-controlled hydraulic motor system has
employed a DC motor for changing the swashplate angle of a variable
displacement piston pump. However, the speed control has been performed by a flow modulation valve which is permitted to bypassing the flow of the hydraulic motor when the speed exceeds the set value. In the present work, another speed control configuration has been proposed with the pump and hydraulic motor are permitted to perform reversal actions. The conventional proportional, integral and derivative (PID) controller has been introduced to manipulate the speed error such
that it could achieve the required performance. The specification required by the PID controller is to reach the command speed as fast as possible with minimum peak overshoot. Also, the effectiveness of the suggested controller against changing of system parameters is considered. The modeling of the speed control system components is detailedly presented, including the dynamic of swashplate,
and one can easily see that the system is of a nonlinear nature. The state space representation of the complete system has been developed and the program codes are listed inside an m-file, which is instantaneously called by an s-function within SIMULINK library.

Keywords