Variable Assist Characteristics and Control Strategies for ECHPS in Terms of Maneuverability and Energy Efficiency

Abstract

Abstract: The design and control of assist characteristics have a significant impact on handling stability and energy efficiency for Heavy-duty vehicles. The establishment of electronically controlled hydraulic power steering system(ECHPS) is built in Matlab/Simulink, which contains proportional valve sub-models, child models of mechanical systems, hydraulic systems and three degrees of freedom steering dynamics system. Based on the principle of energy flow, the impact on the energy saving of the assist characteristics is analysed. A design method of variable assist characteristics aiming at maneuverability and energy saving is developed. The bypass flow is variable with speed by using fuzzy proportional integral derivative(PID) control strategy for proportional valve spool displacement control. ECHPS performance platform is built, and characteristics at different speeds are tested. The test results are consistent with the designed variable assist characteristics, which can not only meet the requirements of steering handiness but also assure proper road feeling, while improving energy efficiency.

Key words: energy efficiency, heavy-duty vehicle, maneuverability, variable assist characteristic

JIANG Haobin, ZHOU Zelei, QIAN Yang, LIU Hai. Variable Assist Characteristics and Control Strategies for ECHPS in Terms of Maneuverability and Energy Efficiency[J]. Journal of Mechanical Engineering, 2015, 51(22): 88-97.

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