In this work modern robust control systems are designed and compared to standard techniques for a hydraulic implement system. The system includes a four orifice metering valve in an H-bridge configuration and a variable displacement pump. The four valve orifices are coupled so that there is only one input for the valves. There are two control inputs, one for the valve and one for the pump displacement. The complexity of the system makes classic control methods difficult to design. Parameter variations and unmodeled dynamics can cause sluggish performance and instability in some cases. By applying modern control, robustness can be improved relative to classical and single-input/single-output (SISO) control design techniques. Techniques such as H∞ control have been proven effective in many multiple-input/multiple-output (MIMO) applications. Linear analysis shows improvement in robustness characteristics of the system over a conventional PID control scheme. Nonlinear simulations show favorable system response and similarly positive robustness traits for the modern control design.
Practical modern control design techniques for power systems