The ABS (Anti-lock Braking System) is an active safety system that is designed for emergency braking situations. In an emergency braking scenario, the ABS instructs the disk-pad braking force to achieve the maximum available tyre-road braking force without locking the wheels. The maximum available tyre-road braking force helps to achieve the optimal braking distance, while the rotating wheels allow the vehicle to retain directional control capability, which allows the driver to avoid dangerous obstacles during an emergency braking scenario. This research has delivered a new and novel approach to ABS design, which could be developed at a low cost in a way which will benefit specialist and niche vehicle manufacturers alike. The proposed ABS control method combines the control logic from both theory-based ABS and commercialised ABS. Therefore, it is more practical compared to the theory-based ABS and less complex compared to a commercialised ABS. The control method only has two control phases with simple decrease, hold, and increase control actions. The proposed ABS control method uses representable tyre-road braking force data from an in-wheel-hub force measurement sensor as well as wheel angular acceleration data from a wheel angular speed sensor as control references. It uses the detected peak tyre-road braking force and its relative predefined drop percentage as control activation and control phase alternation triggers. It uses wheel angular acceleration to identify the control phase and implement the correct control actions. Zero wheel angular acceleration is used to trigger the hold control action in the first control phase, while wheel angular acceleration is used as an aid to increase the accuracy of the in-wheel-hub force sensor. An ADAMS full vehicle model based on a Subaru Impreza and a Simulink ABS control logic model have been used to establish a co-simulation environment to test the performance of the proposed ABS control method using high, low friction and split-mu road surfaces. The co-simulation results demonstrate that the proposed novel ABS control method satisfies the ABS control target, and its control results are similar to commercialised ABS.
|Date of Award||2017|
|Supervisor||Mike Blundell (Supervisor), Yuri Vershinin (Supervisor) & Gary Wood (Supervisor)|