Inverse servo hydraulic pendulum
The inverse servohydraulic pendulum is used to test new control strategies and components. In addition, this is used in the servohydraulics course to teach control engineering content to students.
Overview
The pendulum is mounted on a carriage which is moved laterally by a cylinder. This cylinder is actuated by a valve and an accumulator charging circuit. The pendulum and cylinder movements and the hydraulic pressures are recorded in the test rig.
With a suitable control strategy, the pendulum is swung up and held at the top. The challenge here is to achieve stability at top dead center and to compensate for sensor errors.
Controller
The following controllers are tested on the test bench:
- Model-based linear control technology
- State based controller
- Machine learning based controllers
The overview of a model-based linear controller is shown in the adjacent diagram. It directly controls the pendulum angular velocity. The setpoint is based on the current pendulum angle, the carriage speed and position.