伺服阀多场耦合分布参数数学模型的建模及自激振荡控制关键技术研究

Caused by self-excited oscillations, the problems of instability and failure happened in servovalves are the most terrible potential hazards of high quality electro-hydraulic servo systems in the applications of aerospace, aircraft, national defense and military. The unreasonable coordination of the interaction and coupling among electromagnetic, mechanical and hydraulic sources inside the electro-hydraulic servovalve is an essential cause of the self-excited oscillation in the servovalve. Classic lumped parameter mathematical model and single physical field FE model for the servovalve cannot reflect the distribution parameters and couplings characteristics of the physical fields inside the servovalve. Therefore, both of the models cannot be used to predict and control the self - excited oscillations in the servovalves. Based on the multi-field coupled distributed parameter model of the servovalves, this project presented a control method for the self–excited oscillation in the servovalve. It will also work on the order reduction of the distributed parameter mathematical models based on the Galerkin method and mode interception, explain the modelling mechanism of the multi-field coupled distributed parameter and study the key technology for the on-line detection and controller design of the self-excited oscillations. Based on the multi-field coupled distributed parameter model, the stable regions of the self-excited oscillations in the servovalve will be predicted by simulation. The performance of self-excited oscillation controller will be verified through experiments of the servovalves. By this study, the intention to predict and control the self-excited oscillation in the servovalve will be achieved and consequently the stability as well as the reliability of the servovalve can be improved. The results of this project will promote the progress of electro-hydraulic servo technology in all kinds of application areas and lay the foundation for the study of distributed-parameter modeling and control of self-excited oscillations in hydro-mechatronic components and systems.

自激振荡引起的伺服阀不稳定和失效问题是航空航天、国防、军工等领域高性能电液伺服系统的严重隐患之一，伺服阀内部电磁、机械和流体之间多物理场耦合的不协调是引起伺服阀自激振荡的重要因素。伺服阀传统集中参数数学模型和单一物理场有限元模型无法同时体现伺服阀中各物理场的分布参数特性和相互耦合关系，因而难以用于伺服阀自激振荡预测和控制。本项目提出了基于伺服阀多场耦合分布参数数学模型的伺服阀自激振荡预测和控制方法，研究基于Galerkin截断和模态截取的伺服阀分布参数数学模型降阶方法，基于多场耦合分布参数模型对伺服阀自激振荡进行稳定域的仿真预测及试验验证，研究伺服阀自激振荡在线检测方法和控制器设计等关键技术，以达到预测和控制伺服阀自激振荡的目的。本项目的研究不仅能够提高伺服阀的稳定性及可靠性，促进我国各领域电液伺服技术的发展，而且能够为机电液一体化元件和系统分布参数建模及自激振荡研究奠定理论基础。

针对自激振荡引起的伺服阀不稳定和失效这一问题，为在伺服阀设计和使用阶段消除航空航天、国防、军工等领域高性能电液伺服系统中由伺服阀自激引起的这一严重隐患，本项目基于伺服阀内部电磁、机械和流体之间多物理场耦合的协调性机理，开展了伺服阀多场耦合分布参数数学模型的建模方法研究，伺服阀多场耦合分布参数数学模型的有限元仿真及试验验证，基于多场耦合分布参数数学模型预测了伺服阀自激振荡稳定域，并通过控制方法抑制了的伺服阀的自激振荡现象。.基于哈密顿原理及衔铁组件模态信息推导了伺服阀前置级衔铁组件分布参数模型，通过衔铁组件模态的有限元仿真和试验测试方法，验证了基于弹簧管切向变形的衔铁组件分布参数模型。给出了不同阶数分布参数模型的精度，从而对分布参数模型进行了优化。.根据伺服阀前置级流场的流固耦合流动特性及分布参数特性，利用有限元仿真结果和半经验公式方法建立了射流力分布参数模型，基于射流力流固耦合模型和衔铁组件分布参数模型，建立了包含射流力的衔铁组件分布参数流固耦合模型。.针对不同工作条件和不同结构参数，通过伺服阀前置级和整体分布参数模型，对伺服阀前置级压力脉动和伺服阀整体自激振荡特性进行了仿真预测及试验验证，给出了稳定工作条件。.基于伺服阀前置级分布参数数学模型，开展了伺服阀前置级自激振荡的前馈控制方法、速度/微小位移反馈控制方法和磁流体抑制方法研究，仿真及试验证明了磁流体和亥姆霍兹消振器可通过增加阻尼或吸收脉动的方式减小自激振荡幅值，而通过改变控制器参数，可降低衔铁组件振动幅值或消除衔铁组件振动。.本项目伺服阀多场耦合分布参数模型和自激振荡抑制关键技术的研究，为伺服阀使用过程中通过合理的控制消除伺服阀的自激振荡，提高稳定性和可靠性，提供了理论依据，能够促进我国各领域电液伺服系统的可靠应用，此外伺服阀多场耦合分布参数模型的建立，对于机电液一体化元件和系统分布参数建模及自激振荡的研究具有重要的借鉴意义。