Abstract：To improve the steering feeling at high speed and reduce the energy consumption of power steering system for heavyduty commercial vehicles, a novel electronically controlled hybrid power steering system (ECHBPS) with assist torque coupling device was proposed based on the electrohydraulic steering system. The structures and working principles of ECHBPS were introduced, and the parameters of hydraulic subsystem were reset to reduce the steering system energy consumption. The assist characteristic curves of the electrical and hydraulic subsystems were designed according to driver preferred manoeuvring torque at different speeds, and the model of ECHBPS energy wastage was established. The cosimulation of Matlab/Simulink and Trucksim was conducted. The results show that compared with the hydraulic power steering system(HPS), the steering portability of ECHBPS is improved by 21.3% under the parking manoeuvring condition, and the steering feeling under the oncenter steering condition is improved by 108.96%. The energy consumption values are reduced by 15.74% under the steering condition and by 62.61% under the straightdriving condition, respectively.
2019, Vol. 40 
