高压气动伺服阀零区特性对伺服系统高精度控制影响及补偿方法研究

High-pressure pneumatic system is the key element of motion control for some weapon equipment. For the precision control requirement of the high speed dynamics of the equipment, the high-pressure pneumatic servosystem is investigated based on the current research. The influence and compensation of the high-pressure pneumatic servo valve characteristics at null position on the control performance of the servosystem are focused in the program. Firstly, The flow characteristic is one of important performance of the servo valve. The internal leakage at the null position of the HESV with high-pressure gas is great. The leakage flow rate are strong nonlinear with the valve openings. Both of them are important factors to the control accuracy and dynamic characteristics of the high-pressure pneumatic servo system. For the HESV, firstly, the computational model of multi-scale complex flow field is established, considering the annular clearance and round edge between the valve spool and sleeve. The mapping relation between leakage flow at null position with high-pressure gas and micro-scaled designed parameters, manufactured errors is numerically investigated with CFD method. The accurate mathematical model of leakage flow at null position of HESV is researched. And then, the jet flow behavior of valve orifice is studied. The nonlinear change law of flow rate for the HESV is clarified. Secondly, the high-efficiency and high-accuracy determination method of the flow characterized parameters of HESV is researched based on pneumatic bridge principle. Finally, the influence mechanism of the null position characteristics on the high precision control of the high-pressure pneumatic servo system is investigated. The results are beneficial to providing the theoretical guide for the optimum design and precision manufacture of high-performance HESV. As also provide a basis to the high-accuracy control of the high-pressure pneumatic servo system. It is of importance for improving the performance of national defense equipment.

高压气动系统是某武器装备运动控制的核心部分。本项目面向该装备高速动力学精确控制的迫切需求，在现有研究基础上，开展高压气动伺服系统研究，重点研究伺服阀零区特性对系统高精度控制影响规律及补偿方法。首先，针对高压气体属性与伺服阀结构特征造成伺服阀零区特性非线性增强等问题，研究伺服阀零区高压气体跨尺度复杂流动机理，揭示伺服阀微米级设计参数及加工误差与零区泄漏间映射关系，建立伺服阀零区流量特性精确数学模型，为系统高精度控制提供理论依据。其次，基于阀口串联桥路原理，提出通过改变气路方向实现伺服阀流量特性表征参数高效精确测量的方法。在此基础上，结合理论与实验方法阐明伺服阀零区特性多参数耦合变化关系，揭示零区特性多参数耦合对系统性能影响规律，并提出补偿方法。项目旨在高压气动伺服系统的高精度控制方面取得一定成果，为解决某武器装备高速动力学精确控制难题及国防装备快速发展提供理论基础与关键技术。

高压气动伺服阀是高压气动伺服系统的核心部件，其零位特性为伺服阀重要性能指标，对伺服系统的高精度控制和稳定性具有重要影响。由于高压气体属性与伺服阀结构特征的原因，伺服阀零位难以保证绝对密封，导致伺服阀零位产生较大气体泄漏。. 为完善伺服阀零区特性及提高伺服系统控制精度，项目开展了以下4个方面的研究工作：（1）伺服阀零区高压气体跨尺度复杂流动机理研究；（2）气浮式伺服阀阀芯阀套滑动副结构优化及流场特性研究；（3）伺服阀零区流量特性及其表征参数高效精确测量方法研究；（4）伺服阀零区特性对高压气动伺服系统性能影响及补偿方法研究。揭示了伺服阀微米级设计参数及加工误差与高压气体零区泄漏量之间的关系，建立高压气体状态下伺服阀零区流量特性精确数学模型，提出高灵敏度高压气动伺服阀的优化设计方法，发明了一种带有气浮式滑动副的气动伺服阀、阀芯阀套配合副及其液/气动力补偿方法；基于阀口串联桥路音速排气原理，发明了一种通过改变气路方向实现高压气动伺服阀质量流量特性表征参数高效精确测量的方法，实验测试结果表明，高压气动伺服阀有效通流面积与临界压力比均随阀口开度变化而变化，临界压力比介于0.3-0.52之间，为高压气动伺服系统的精确化设计与分析、高精度控制提供实验数据；阐明了伺服阀零区特性对高压气动伺服系统高精度控制的影响，并提出基于零区泄漏模型的高压气动伺服系统高精度控制补偿方法，结果表明补偿后压力伺服系统精度可达到0.05%。. 项目相关研究成果已发表论文10篇，其中SCI收录3篇；授权发明专利3项；举办国际学术会议1次，参加国际国内学术会议5次；获得2019年度国家技术发明二等奖1项、国际国内学术会议最佳论文奖2项；培养研究生7名，其中已毕业5名。项目在高压气动伺服阀优化设计与伺服系统高精度控制方面取得了一定的成果，为高压气动伺服系统的应用及某武器装备高速动力学的精确控制提供理论基础，具有重要的应用价值。