空载流量特性死区的颤振补偿  

Dither Compensation for Dead Zone of Zero Load Flow of Characteristics

作　　者：李胜[1] 阮健[1] 孟彬[1] 朱何[1] 

机构地区：[1]浙江工业大学特种装备制造与先进加工技术教育部重点实验,室杭州310014

出　　处：《机械工程学报》2014年第18期186-192,共7页Journal of Mechanical Engineering

基　　金：国家自然科学基金(51375445,50975258);浙江省自然科学基金(LZ13E050002)资助项目

摘　　要：为对电液伺服阀死区非线性进行补偿,提出在阀芯位移信号上叠加一高频颤振信号从而减小甚至消除其死区的颤振补偿技术。阐述电液伺服阀死区颤振补偿原理。根据颤振补偿原理求解颤振补偿后的空载流量特性表达式,并对补偿后的空载流量特性的死区进行仿真分析,理论分析表明,随着颤振幅值的增加,死区变小,当颤振幅值的大于死区量时,死区完全消除。对补偿后的空载流量特性的线性度进行理论分析,分析表明,随着颤振幅值的增加,空载流量特性的线性度也提高了。搭建专门的试验平台对所设计的样阀进行试验研究,结果表明,采用颤振补偿技术,当颤振幅值为50%、100%、480%死区量时空载流量特性死区由3.8%分别降为2%、0.4%、0,并且空载流量特性的线性度也得到改善,由4.38%分别提高到4.25%、4.09%、3.56%,试验结果和理论分析是吻合的。为进一步提高空载流量特性的线性度,提出流量特性的线性规划,试验表明,规划后流量特性的线性度得到了明显的改善,并且流量线性规划不受系统压力的影响。In order to compensate dead zone nonlinearity of electro-hydraulic servo valve, a dither compensation technology is presented, which is realized by superimposing high frequency dither signal to the control signal of spool movement to reduce and even eliminate dead zone. The principle of dither compensation is introduced. The analytical equation of zero load flow characteristics with dither compensation is derived and simulation analysis is performed. The simulated results illustrate with the increase of dither amplitude the dead zone width reduces and when dither amplitude is large than dead zone width, the dead zone can be totally eliminated. Besides, the linearity of zero load flow characteristics is also analyzed whose results show that with the increase of dither amplitude the linearity is also reduced. Then a special test rig is built and experiment for prototype valve is carried out. The experimental results revealed that when the dither amplitude is 50%, 100%and 480%of dead zone magnitude respectively, the dead zone width of zero load flow characteristics is accordingly reduced from 3.8% to 2%, 0.4% and 0 respectively. And the linearity of zero load flow characteristics are also improved, which is reduced from 4.38%to 4.25%, 4.09%and 3.56%respectively. The experimental results coincide with simulated results. In order to further improve linearity of zero load flow, a linear programming approach of flow characteristics is presented. The experimental results show that with linear programming linearity of zero load flow is improved obviously, and flow linear programming is not influenced by system pressure.

关 键 词：死区 线性度 颤振 线性规划 

分 类 号：TH137[机械工程—机械制造及自动化]