基于阻尼/刚度协同优化的气动伺服动态负载模拟系统控制方法研究

Based on the requirement of dynamic load simulation test for actuator system of instantaneous deployment mechanism, aiming at the bottleneck problem of improving system performance caused by friction and nonlinearity uncertainty, a new type of valve-controlled combination structure, which breaks through the mutual restriction of frequency response and flow rate of pneumatic valve control system, is discussed to enable the system to adjust quickly and accurately. HHT transformation is used to capture the nonlinearity of friction and establish completed friction model. Analysis the effect of dynamic response on friction compensation, and a friction compensation control method based on combination of predictive model and active regulation of dynamic response of the system is proposed to effectively improve the adverse effects of friction. Aiming at the uncertainty, low stiffness, weak damping and uncertain nonlinear characteristics of the working environment, the relationship between dynamic damping and dynamic response of the system is analyzed, the relationship between state stiffness and energy dissipation of the system is discussed, parallel cooperative control based on real-time optimal adjustment of dynamic damping and stiffness and nonlinear adaptive robust method is proposed to improve the transient and steady performance of the system. In this study, through deep analysis of the nonlinearity and uncertainty of the pneumatic servo system, a control strategy is put forward, which combines the internal dynamic performance optimization regulation with the external control method organically and coordinates the optimization, and a high-performance control method with adaptability and robustness to the nonlinearity and uncertainty of the parameter change and the external environment change is designed.

基于瞬时展开机构舵机系统动态负载模拟测试需求，针对摩擦及不确定性非线性导致系统性能提升瓶颈问题，探讨突破气动阀控系统频响与流量相互制约的新型阀控组合结构，使系统具有快速与精准调节的能力；采用HHT变换捕捉摩擦非线性特征并建立完善的摩擦非线性预测模型，分析动态响应对摩擦补偿效果的影响规律，提出基于预测模型与系统动态响应主动调节相结合的摩擦补偿控制方法，有效改善摩擦不利影响；针对系统所处工作环境未知、低刚度、弱阻尼以及不确定性非线性特征，分析系统动态阻尼与动态响应，动态刚度与系统能量耗散的关系，提出系统动态阻尼、刚度实时优化调节与非线性自适应鲁棒方法并行协同控制，提高系统的暂态和稳态水平。本研究通过对气动伺服系统非线性、不确定性进行深入分析，提出内部动态性能优化调节与外部控制方法有机结合、协调优化的控制策略，设计出对参数变化及外界环境变化的非线性及不确定性具有自适应及鲁棒性的高性能控制器。

本项目分析了系统自身存在的非线性、不确定性影响因素以及各因素之间的相互耦合机理，系统中存在的可描述非线性、不确定性及不可描述部分，结合流体力学、热力学 及动力学理论，建立了气动伺服动态负载模拟系统的非线性数学模型。进行了摩擦力测试，建立了摩擦模型；探讨了系统动态响应对摩擦补偿效果的影响规律，设计了动态响应调节与预测模型相结合的摩擦补偿控制方法，进行了摩擦力补偿控制实验，有效改善了摩擦导致的台阶及滞后现象。揭示了系统动态刚度影响因素以及系统能量消耗之间的关系，闭环系统动态阻尼影响因素以及与系统动态响应之间的关系，结合非线性自适应鲁棒控制理论，考虑外界环境不确定、系统非线性、不确定性以及低阻尼、弱刚度特征，研究闭环系统刚度、阻尼优化调节与非线性自适应鲁棒相结合的并行协调控制机理，设计相应的控制结构和方法。通过实验和仿真相结合的方法，进行了气动伺服动态负载模拟系统静动态性能测试与分析，提出的NARCSR控制方法提高了系统的动态性能。