Bond Graph Modeling of a Hydraulic Vibration System: Simulation and Control

Electro hydraulic drives are often used where the dynamic response requirements of the driven load in terms of speed, cycling, accuracy and stability are particularly severe. One such application is the control and drive system associated with a high frequency hydraulic vibrator. A hydraulic shaker controls a valve which directs high pressure hydraulic fluid to generate controlled vibration. Hydraulic shakers typically have long stroke and large force and are useful up to many hundreds of Hertz vibration frequency. In this paper, bond graph modeling is used to study and simulate the effect of various components in a hydraulic circuit on a shaker performance. The intention is that the electrohydraulic system vibrates at a specified force or displacement amplitude and frequency for the controlled vibration of a load attached to the rod. This paper describes the simulation and control of such system. Feedforward PID control scheme is utilized in the simulations to control the system and to track a variable reference signal.