Comparison of control methods for Electric Vehicle Antilock Braking / Traction Control Systems 2001-01-0596

The alleviation of environmental problems associated with personal, public and commercial transport in urban areas has become an important issue for both policy makers and the automotive industry. Future legislation in Europe and the USA is expected to introduce strict limits in vehicle emissions, and both electric and hybrid vehicles are considered to be strong contenders for meeting low / zero emissions targets. As a result, research into electrically driven powertrains, which have similar performance attributes as ICE (Internal Combustion Engine) vehicles, has led to the development of electrically actuated wheel technologies, with increasing attention being focused on research into novel antilock braking / traction control (ABS / TCS) strategies.

This paper describes a comparison of traction control schemes using real - time observer based estimates of μ-slip characteristics. In particular, a ‘bang-bang’ type strategy will be evaluated against fuzzy based control schemes to facilitate torque production from the powertrain to produce optimal traction.

Simulation studies and experimental trials on a laboratory test facility and simulation studies on a prototype electric vehicle will be used to evaluate and compare the response of the proposed techniques in real driving situations.

Furthermore, the paper will demonstrate that the application of observer techniques are appropriate for the on-line determination of the peak adhesion coefficient for different tyre-road surface conditions, and the fuzzy based techniques offer substantial potential for optimal control of wheel traction.