Trajectory Control of Hydraulic Servo Robot Arm
In industry, hydraulic servo robotic arms with precise movements are desired. Controlling the movements of such a robot can be difficult due to the complexity of a multi-linked system. It can be achieved by a hydraulic valve control system that regulates the position of the hydraulic valves resulting in the movement of the linear actuators. This allows for trajectory control. Due to the nonlinearities of the hydraulic- and mechanical system, and the fact that each link affects each other’s dynamics, a nonlinear control system must be implemented. Utilizing inverse kinematics in addition to Euler-Lagrange mechanics it was possible to set up a trajectory control for the hydraulic robot system. By using trajectory control it became possible to program the robotic arm with Cartesian coordinates instead of hydraulic actuator displacement. Where the dynamic of the robot was calculated with Lagrangian mechanics. This procedure can be used for controlling a wide variety of mechanical systems actuated by hydraulics or electrics. The control system makes the implementation of the robot in new tasks simpler as any movement can be described with Cartesian coordinates. Therefore, any other task simply requires another trajectory plan.