Evaluation and optimization of vehicle pedal comfort based on biomechanics

Abstract

Existing research on the manipulation comfort of the cab pedal generally focuses on the completion of the pedal movement when a vehicle is at rest, with certain data collected for analysis. This paper, by taking passenger vehicles in China as the study object and in view of the actual road conditions in China and the Chinese body size, attempts to solve the problem of muscle redundancy through the maximum/minimum optimization model of muscle activation. The road test was carried out on a typical pavement in a Chinese city. The parameters of pedal stroke, pedal force, and typical Electromyography signal (EMG) signal of drivers’ lower limbs during driving were obtained, from which muscle activation degree was calculated. The obtained experimental data were used as external driving one to simulate and analyze the pedal comfort under the layout of different human percentile and different pedal parameters in an aim to obtain the optimal value. The results indicate that the difference in pedal strokes, pedal preload, pedal resistance coefficients, seat heights, and H-point distances can have a noticeable effect on muscle activation. Taking a 95th-percentile accelerator pedal as an example, with the optimal values of each parameter selected (pedal preload: 8.2 N, pedal resistance coefficient: 2.55, seat height: 0.45 m and H-point distance: 0.86 m), as the pedal strokes increase, muscle activation shows a trend of increase after initial decrease. In the common stroke of a pedal after optimization, the degree of muscle activation is significantly lower than that before optimization, indicating a decrease in muscle fatigue.