Suspension design and posture control for a novel by-wire chassis based on integrated electric wheel module

• Published in: Journal of mechanical science and technology 2022, 36(6), , pp.2669-2683
• Main Authors: Du, Qiuyue, Chen, Song, Cheng, Shuo, Du, Fengshan, Li, Liang, Li, Quantong, Zhang, Limei
• Format: Article
• Language: English
• Subjects: Active control; Chassis; Control; Controllers; Deflection; Degrees of freedom; Dynamic loads; Dynamical Systems; Engineering; Genetic algorithms; Industrial and Production Engineering; Maneuverability; Mechanical Engineering; Mechanical systems; Modules; Multiple objective analysis; Optimization; Original Article; Passenger comfort; Performance evaluation; Performance indices; Posture; Seats; Steering; Suspension systems; Vehicle safety; Vibration; 기계공학
• ISSN: 1738-494X; 1976-3824
• DOI: 10.1007/s12206-022-0501-3

The integrated electric wheel module (IEWM) with large-angle steering capability is blooming which greatly alters the conventional chassis structure over recent years. The IEWM brings challenges to the suspension system due to higher requirements, which includes 360 degrees steering, active adjustment of chassis height and posture, superior ride comfort, and compact mechanical structure. Hence, a novel double trailing arm suspension mechanical system for the aforementioned IEWM and its control strategy are studied to get better driving maneuverability, ride comfort, driving safety, and posture stability of automobiles in this paper. The 6 degree of freedom (DOF) roll model of active suspension vibration with seats and multi-objective optimization controller are constructed for vehicle posture active control to solve the difficult trade-off between suspension dynamic deflection, roll angle, and seat vertical acceleration. The controller weight coefficients are optimized by an improved genetic algorithm (IGA) method, and the fitness function in piecewise form is adopted to reduce the search range. The simulation analysis shows that the combination of IGA and a multi-objective controller can defuse the conflict of goals between different suspension performance evaluation indexes, which also improves the overall suspension performances compared with the experience adjustment method and passive suspension system. In detail, this simple optimization control strategy can reduce the vertical acceleration root mean square value (RMSV) of the left and right seat by 45 % and 11 %, respectively; the left and right tire dynamic load decreased by 13 % and 2 %, respectively; and 25 % reduction in roll angle. These performance improvements only sacrifice part of suspension dynamic deflection RMSV increase, but do not affect driving safety.