Robust H∞ control design of an electromagnetic actuated active suspension considering the structure non-linearity

2018 ◽  
Vol 233 (4) ◽  
pp. 1008-1022 ◽  
Author(s):  
Xinbo Chen ◽  
Lixin Wu ◽  
Jun Yin ◽  
Jianqin Li ◽  
Jie Luo
Keyword(s):  
Active Control ◽  
Control Design ◽  
Active Suspension ◽  
Random Excitation ◽  
Multi Objective Optimization ◽  
Robust Controller ◽  
Output Torque ◽  
Wheel Side ◽  
Equivalent Mass ◽  
Unsprung Mass

Electromagnetic actuated active suspension (EAAS) benefits energy harvesting while providing active control. However, the inertia of the actuator introduces an equivalent mass coupled with the sprung and unsprung mass. In addition, the specific structure of the suspension features structure non-linearity, which results in the perturbation of the equivalent mass of the actuator, the variation of the transmission ratio of the actuator output torque to the actuator force at the wheel side and an extra force to be compensated with. A dynamic model of active control considering the equivalent mass and the structure non-linearity is proposed. Based on a gearbox type EAAS, respective non-linearity is studied. For multi-objective optimization, a robust controller is designed with proper weighting functions. A virtual prototype of the EAAS is built and simulated with a bump/pothole and random excitation road profiles. Results show that neglecting the structure non-linearity effects influences the accuracy of active control. The investigation of this paper provides a fundamental methodology for the control design of actual applications of EAASs.

Research on design and numerical optimization of bowed-twisted-swept cascade of low aspect ratio hydraulic turbine

2021 ◽  
pp. 095440622110303
Author(s):  
Yan Gong ◽  
Cong Wang ◽  
Meng Lin ◽  
Zhiguang Gao ◽  
Xiaodong Zhang
Keyword(s):  
Pressure Drop ◽  
Optimization Design ◽  
Three Dimensional ◽  
Hydraulic Turbine ◽  
Multi Objective Optimization ◽  
Modeling Technology ◽  
Low Aspect Ratio ◽  
Turbine Performance ◽  
Output Torque ◽  
Twisted Blade

The bowed-twisted-swept modeling technology of three-dimensional blade has been widely used in the gas impeller machinery and achieved good results. This paper introduces the two-dimensional flow theory and the bowed-twisted-swept modeling ideology into hydraulic turbine design. Simultaneously combined with the popular NSGA-II multi-objective optimization algorithm, a complete set of hydraulic turbine cascade design method was proposed. Taking the last-stage low aspect ratio hydraulic cascade of Ф175 type turbine as an example, the parametric model of this cascade was reconstructed by a high-precision automatic bridge coordinate measuring machine. The multi-objective optimization design of three-dimensional modeling of cascade was completed with the single-stage turbine output torque, efficiency and pressure drop as the objective targets. Finally the influence of the bowed-twisted-swept modeling technology on the hydraulic turbine performance was explored in detail by a professional rotating machinery CFD software. Numerical analysis shows that the twisted blade design achieves a 1.5 times increase in torque and 2 to 4 times increase in pressure diff at same working condition. Moreover, when bowing optimization design and sweeping optimization design are applied on the twisted blade individually, the output torque and the stage efficiency of the hydraulic turbine are respectively improved, and when both two methods are simultaneously applied on the twisted blade, it is beneficial to reduce the pressure drop loss. However, it is noticeable that when the bowed-swept modeling technology used in a straight blade using almost have no effect on the turbine performance.

On-line estimation of road profile in semi-active suspension based on unsprung mass acceleration

2020 ◽  
Vol 135 ◽  
pp. 106370 ◽  
Author(s):  
Wei Liu ◽  
Ruochen Wang ◽  
Renkai Ding ◽  
Xiangpeng Meng ◽  
Lin Yang
Keyword(s):  
Active Suspension ◽  
Road Profile ◽  
On Line ◽  
Unsprung Mass

Multiobjective Weighting Selection for Optimization-Based Control Design

1997 ◽  
Vol 122 (3) ◽  
pp. 567-569 ◽  
Author(s):  
Ricardo H. C. Takahashi ◽  
Juan F. Camino and ◽  
Douglas E. Zampieri ◽  
Pedro L. D. Peres
Keyword(s):  
Control Design ◽  
Active Suspension ◽  
Pareto Optimal ◽  
Pareto Optimal Solutions ◽  
Optimal Solutions ◽  
Cost Functional ◽  
Design Variables ◽  
Optimal Controllers ◽  
Selection For ◽  
Multiobjective Design

A methodology for the multiobjective design of controllers is presented, motivated by the problem of designing an active suspension controller. This problem has, as a particular feature, the possibility of being defined with two design variables only. The multiobjective controller is searched inside the space of “optimal controllers” defined by a weighted cost functional. The weightings are taken as the optimization variables for the multiobjective design. The method leads to (local) Pareto-optimal solutions and allows the direct specification of controller constraints in terms of some primary objectives which are taken into account in the multiobjective search. [S0022-0434(00)01403-9]

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