【作者】 王悦；

【导师】 陈长征；

【作者基本信息】 沈阳工业大学 ， 机械电子工程， 2018， 博士

【摘要】 汽车已成为当今社会最重要的交通工具之一。近年来随着汽车产量和保有量的迅速增长,人类面临严峻的能源、环境和气候挑战。以电动汽车为代表的新能源汽车是实现交通可持续发展的最佳选择。轮毂驱动具有电机转矩响应比内燃机快速精确、并可通过线控技术直接实现各轮驱动力和制动力的独立控制等特点,已被视为电动汽车的最终驱动形式。但由于其一方面增加了整车的非簧载质量,另一方面轮毂电机的直接承受地面激励,二者均影响了电动汽车的振动特性。本文针对轮毂驱动电动汽车悬架系统振动问题,进行了如下研究:首先,建立1/4电动汽车线性悬架系统动力学模型,分析其动力学特性;分别在簧载质量和非簧载质量上附加线性动力吸振器,建立悬架-线性吸振系统微分方程并求解,得到悬架-吸振系统的动态特性并进行参数影响分析,结果表明线性吸振器能够有效地抑制簧载质量和非簧载质量在其固有频率附近的振动。接下来,在簧载质量上附加立方刚度非线性动力吸振器(非线性能量阱,NES),建立电动汽车悬架-NES系统微分方程,采用复变量-平均法对方程进行求解,分析悬架-NES系统的分岔特性及平衡点的稳定性,得到系统可能出现强调制响应的参数区间,并得到悬架-非线性吸振系统的动态特性,结果表明,非线性吸振器能够降低簧载质量在其共振区附近的振动。然后,将控制作用施加在线性动力吸振器上,建立电动汽车悬架-主动吸振系统微分方程,获得控制系统的状态方程,基于二次线性最优控制理论,设计主动动力吸振器,分别在路面正弦激励和随机激励条件下,对悬架-主动吸振系统的动态特性进行分析,并讨论悬架系统相关参数对悬架-主动吸振系统的影响。最后,将控制作用直接施加在悬架系统上,建立电动汽车主动悬架系统的微分方程,获得控制系统的状态方程,基于二次线性最优控制理论,设计主动悬架系统,分别在路面正弦激励和随机激励条件下,对主动悬架系统的动态特性进行分析,并讨论悬架系统相关参数对主动悬架系统的影响,并进行了实验验证。更多还原

【Abstract】 Vehicle has become one of the most important modes of transportation in today’s society.In recent years,mankind is faced with severe energy,environment and climate challenges with the rapid growth of automobile production and possession.New energy vehicles represented by electric vehicles are the best choices for sustainable traffic development.In-wheel motor has characteristics that the torque response of the motor is faster than the internal combustion engine,and can realize the independent control of the driving and braking force of each wheel directly through the wire control technology.It has been regarded as the ultimate drive form of electric vehicle.However,on the one hand,unsprung mass of the vehicle is increased,and on the other hand,ground excitation is acted on in-wheel motor directly,both of which affect dynamic characteristics of electric vehicle.In this paper,this research includes as follows:Fristly,the dynamic model of 1/4 the electric vehicle linear suspension system is established and dynamic characteristics of the system are analyzed.Linear dynamic vibration absorber is attached to sprung and unsprung mass separately,and differential equations of suspension-linear vibration absorber system are established and solved.Dynamic characteristics of the suspension-absorber system are obtained and parameter influence analysis is carried out.The results show that the linear vibration absorber can effectively suppress the vibration of the sprung and unsprung masses near their natural frequencies.Moreover,the nonlinear dynamic vibration absorber(NES)with cubic stiffness is added to sprung mass.Differential equations of the electric vehicle suspension-nonlinear dynamic vibration absorber system are established.The Complexification-averaging method is used to solve the equations,and bifurcation and stability of the equilibrium point are analyzed.The parameter interval of strongly modulated responses can be obtained,and dynamic characteristics of the suspension-nonlinear dynamic vibration absorber system are obtained.The results show that the nonlinear vibration absorber can reduce the vibration of the sprung mass near its resonance region.Additionally,introducing the control action into the electric vehicle linear dynamic absorber,the differential equation of the suspension-active vibration absorption system is established.The state equation of the control system is obtained.Based on the quadratic linear optimal control theory,the active dynamic vibration absorber is designed.The dynamic characteristics of the suspension-active vibration absorption system are analyzed under the sine and stochastic excitations.The influences of the system parameters are discussed.Finally,introducing the control effect directly on the suspension system,the differential equation of the electric vehicle active suspension system is established.The state equation of the control system is obtained.The active suspension system is designed based on the quadratic linear optimal control theory.The dynamic characteristics and the influences of the system parameters are analyzed under the sine and stochastic excitations.Additionally,some experiments are conducted to verify the designed controller.更多还原