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Dry clutch control is one of the main components of both conventional and advanced automotive powertrain systems. In this paper, a robust control strategy is proposed which is suitable for the precise and accurate control of a clutch-by-wire actuator in automotive applications. A parallel connection of a sliding mode controller to a proportional integral derivative (PID) controller collectively forms the proposed robust controller. The sliding mode controller alone ensures robust control against system nonlinearities by providing a high feedback gain, but it also induces a control chattering phenomenon which could be harmful for the clutch-by-wire actuator. Instead of viewing chattering as an undesirable yet inevitable feature, the chattering signals are used as natural excitation signals for identifying an equivalent PID controller using the recursive least squares algorithm. Analysis is provided on the robustness properties of the control scheme.

In this paper, an optimal control tracking strategy for a brake-by-wire system is developed and tested on a laboratory setup consisting of a driving motor, clutch and gearbox system, rotating inertia and an electro-mechanical brake actuator. The presented brake by wire system consists of a brake pedal sub-system connected to the electro-mechanical brake actuator through an electronic control module handling the optimal control logic. A mathematical model of the proposed brake-by-wire control system is presented. The presented mathematical model is simulated and validated against the experimental data. The good agreement between both simulation results and experimental validates the mathematical model. The validated mathematical model is then used to test the proposed optimal control tracking strategy against different levels of disturbances that are difficult to emulate in the laboratory.

A vehicle braking system is used to provide acceptable drivability of the vehicle and ensure safety in different emergency situations that the vehicle may encounter. The braking system is used also as an integrated sub-system in many other important vehicle driving systems such as traction control, adaptive cruise control, accident avoidance and other vehicle systems in which the braking system plays an important role. This paper is dedicated to provide an accurate and at the same time simple enough hydro-mechanical braking system mathematical model that takes brake pad wear impact on the system pressure dynamics into consideration. A wear simulation procedure based on the concept of Archard's wear law is used and integrated in the nonlinear braking system model with flow compressibility taken into consideration. The presented model simulation results and the experimental tests results show good agreement and validate the confidence in the proposed model.