考虑油液黏温特性的电静液作动器流量死区动态逆补偿方法

Dynamic Inverse Compensation Method of Flow Rate Dead-zone of Electro-hydrostatic Actuator Considering Viscosity-temperature Characteristics of Oil

高集成电静液作动器(EHA)在减小体积和质量的同时,带来散热能力差、系统油温上升快等问题,导致油液黏度降低而使EHA的流量死区具有时变特性,给EHA的精确控制增加了难度。针对上述问题,考虑油液黏温特性,建立了EHA流量死区的数学模型,分析了流量死区的变化规律,提出了基于系统模型信息的流量死区动态逆补偿方法,对比分析了不同转速和负载下所提方法的补偿效果,并进行了实验验证。结果表明,EHA的流量死区随温度升高而增大,所提出的动态逆补偿方法在轻载条件下能够较好地补偿EHA的流量死区,有利于提高系统的控制性能。

The highly integrated electro-hydrostatic actuator(EHA)has been reduced in size and weight,but the poor heat dissipation and rapid increase in system oil temperature have been brought,thus leading to the time-varying characteristics of flow rate dead-zone of EHA resulting from the reduction of oil viscosity.This makes accurate control of EHA more difficult.For the above problems,a mathematical model of EHA flow rate dead-zone is established,in which the viscosity-temperature characteristics of the oil are considered,and the variation law of flow rate dead-zone is analyzed.Furthermore,a dead-zone dynamic inverse compensation method for flow rate based on the system model information is proposed.The compensation effects of proposed method at different speeds and loads are compared and analyzed,and verified through experiment.The results show that the flow rate dead-zone of EHA increases with the rise in temperature,and the proposed dynamic inverse compensation method can compensate the flow rate dead-zone of EHA under light load conditions,which is conducive to improving the control performance of the system.