14.1 Introduction

The items under study in this chapter embrace four issues: automotive alternators, combustion engines AFR (air-fuel ratio), diesel engines NOx and ABS (anti-lock brake system) control. First, the automotive alternator is governed by nonlinear equations and back EMF (Electromotive Force) should be estimated to optimise rectifier performance. For the sake of cost reduction, it should be done only with readily available battery current instead of generator angular position measurement.

Next, the desired AFR in a combustion engine depends on fuelling rate, air flow rate and the mass of fuel in the fuel film. The mass can be measured under no conditions. Information from the AFR sensor, governed by a 1 st-order equation, is obtained with certain delay. A sliding mode observer is designed to get the quantity of mass in the fuel film based on this information. The estimation result then may be utilised for fuel injector diagnosis.

The third issue covers diesel engine NOx control. New technology applied to contemporary diesel engines is to append the VG (Variable Geometry) turbocharger. It enables us to control exhaust gas recirculation and compressor air flow rate simultaneously. The system exhibits unstable zero dynamics so that the feedback control is designed to stabilise the system. A regular form approach from the sliding mode control methodology [1] is employed here for controller design.

Finally, an important issue, automobile ABS, is discussed. The tyre traction force depends on the road conditions and is always an unknown function.