Hybrid Control in Automotive Applications

Abstract

Hybrid systems have captured the attention of the research community because of their intrinsic power and of the challenging mathematical problems they pose. We believe that much needs to be done to understand how to use effectively this mathematical formalism for important applications. We have embarked on an ambitious project aiming at the complete redesign of an automotive engine control unit for the next generation automobiles equipped with complex devices such as drive-by-wire and electronic valve control. The design problem has been formulated in an innovative way and makes extensive use of hybrid system technology. We present first the overall methodology and its basic components. Then we focus on the highest levels of abstraction that involve the formulation of the control problem and its solution. A hybrid model which describes the torque generation mechanism and the powertrain dynamics is developed. Then, two particular control sub-problems (cut-off and fast positive force tracking) are formulated as hybrid optimal control problems, whose solutions are obtained by relaxing the problems to the continuous domain and mapping their solutions back into the hybrid domain. A formal analysis as well as experimental results demonstrate the properties and the quality of the control laws.