Outlier Treatment and Adaptive Signal Conditioning of Wheel Speed Measurement for Antilock Brake System.

Wheel speed is an important physical quantity used to implement an Antilock Brake System (ABS) in vehicles. This study uses a Variable Reluctance - Wheel Speed Sensor (VR - WSS) for wheel speed measurement, which is commonly used in Heavy Commercial Road Vehicles (HCRVs). However, wheel speed measurement from in-vehicle experiment results was affected by various time-varying attributes such as noise and outliers. The abovementioned physical measurement considerations are characterized through statistical measures to analyze the consequences on ABS performance. Further, these have been programmed in IPG TruckMaker ^® , a vehicle dynamics simulation software and experimentally demonstrated using an HCRV Hardware-in-the-Loop (HiL) setup with ABS algorithm. The experimental results showed that the ABS performance is degraded in terms of braking distance and braking efficiency due to these practical considerations. Therefore, this study proposes an adaptive signal conditioning algorithm to address these physical considerations. It consists of an outlier treatment to handle non-synchronized arbitrary data points and an adaptive filter to handle time-varying noise signals in the measurement. The outcomes of the closed-loop HiL evaluation of the ABS algorithm integrated with the signal conditioning algorithm confirmed that the proposed method retained the ABS performance while addressing practical measurement considerations.