Co-relating Subjective and Objective Brake Performance: A Case Study

Over the years the brake system of a passenger car was considered satisfactory if it met regulatory requirements. Meeting stopping distance at specified pedal efforts would declare the vehicle to be safe on roads. But beyond meeting safety requirements, the brake system response to pedal input is also important.

This paper presents a case study where in the brake system met the regulatory norms, but subjective pedal feel and response was poor. This anomaly of subjective behavior was analyzed and correlated to the objective performance on the vehicle. Subsequent to this, the contribution of controllable parameters for good pedal feel was investigated. The investigations have led to identification of parameters that are critical in achieving optimal balance of performance and subjective feel. The results presented highlight the order of merit of the various components