A Robust Traction Control for Electric Vehicles Without Chassis Velocity

Abstract

As the rapid development of technology, the control technology and daily livings are interrelated. However, unanticipated breakdowns can happen in any control system due to the internal malfunctions or external distractions. Since the prices in most of the home electronic appliances are reasonable and affordable, malfunctions can simply be solved by purchasing new ones, however, for complex control systems with high social costs, the consequences of these passive solutions result in paying more prices. For example, systems such as aircrafts, ships, satellites, nuclear power plants, space shuttles, high speed rails are all extremely high in manufacturing costs, and if malfunction happens and is not able to eliminate or repair, the price paying afterward is tremendous. Traction control is an example. For passenger involved in electric automobile systems, traction control is a core for stabilizing the movements of automobiles. In addition to guarantee the safety of automobile system in any driving conditions, one must also has adequate ability of fault-tolerant. Under a slippery, a muddy, and a flat tire conditions, wheel inertia changes, and results in deteriorating of controllability in traction control. Hence, researches have been focusing on adopting robust control theory, which can endow electric vehicles with fault-tolerant performance. Fully electric vehicles powered by batteries can achieve quieter and pollution-free operation, which has offered a solution to next generation vehicles. Unlike internal combustion engine vehicles, electric vehicles use independently equipped motors to drive each wheel. The independently equipped motors provide higher power/weight density, higher reliability for safety and better dynamic performance. These aspects make it easy to estimate the driving or braking forces between tires and road surfaces in real time, which contributes a great deal to the application of new traction control strategies based on road condition estimation (Hori, 2004; He & Hori, 2006; Yang & Lo, 2008). For advanced vehicles today, many technologies embedded in the micro controller unit (MCU) that enhance the vehicle stability and handling performance in critically dynamic situations. For example, the antilock braking system (ABS) (Schinkel & Hunt, 2002; Patil et al., 2003), electronic differential (ED) (Urakubo et al., 2001; Tsai & Hu, 2007), direct yaw-