H∞ controller design for speed control of a natural gas engine

In this paper the design of a robust H
_infin
controller for the speed control of a natural gas engine is presented. The gas engine is an internal combustion engine, has multi input - single output structure, is open loop unstable and has nonlinear behavior. In order to obtain proper performance at any operating point of the power range of the engine, a robust H
_infin
controller was utilized for speed control. One requirement is integral action of the controller, thus, due to physical limitations of the controlled inputs, an anti-windup technique is presented. Simulations as well as test bench runs were performed, and the results are also compared with a state of the art gain scheduled PID controller.