液压作动器力伺服系统参数灵敏度研究

发布时间：2018-01-26 22:41

本文关键词： 液压作动器力伺服系统灵敏度分析方法灵敏度衡量方法　出处：《哈尔滨理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：高集成度高性能的液压作动器已成为足式机器人关节驱动研究的新思路。支撑相的关节力控制己成为提高机器人运动柔顺性、环境适应性和地形适应性的迫切需求。但液压作动器输出力控制是液压系统的难点,输出力控制系统本身稳定裕度小、输出力变化快的特点极大限制了控制系统的增益;同时输出力对系统参数变化敏感,且在外界干扰作用下极易使多余力湮没目标力。这些因素导致了力伺服响应慢、振荡较大而且力跟踪精度较差等后果,远远不能满足足式机器人的要求。因此,针对足式机器人的关节驱动液压作动器力伺服系统的参数进行灵敏度研究,将灵敏度分析理论引入到液压作动器力伺服非线性系统中,能够定量分析系统时变参数,了解系统中各参数灵敏度对系统动态性能的影响,为系统参数优化及控制方法的研究奠定基础,对提高机器人整体性能具有重大意义。本文对液压作动器力伺服系统的参数进行灵敏度研究,采用轨迹灵敏度和矩阵灵敏度两种灵敏度分析方法定量分析系统参数变化对系统输出的影响。首先,针对足式机器人的关节驱动液压作动器力伺服系统建立数学模型,得出其状态空间方程,推导出轨迹灵敏度方程和矩阵灵敏度方程,确定系统参数与系统输出间的关系式。其次,针对系统空载与加载工况,分别对轨迹灵敏度方程和矩阵灵敏度方程编程求解,得到两种灵敏度分析方法的时程曲线,并提出百分比灵敏度衡量法和积分灵敏度衡量法两种灵敏度衡量方法,采用柱形图显示两种衡量方法的数值,用来对比衡量系统采样时间内系统中各参数对系统动态性能的影响,确定出对动态性能产生影响的主要参数的次要参数。最后,根据液压作动器力伺服系统的半物理仿真实验台,采用比较类推法,通过改变系统中积分系数、比例系数、微分系数、伺服阀流量增益、负载质量和负载刚度等可控参数,计算出这些参数在两种灵敏度衡量方法的数值,与灵敏度仿真分析结果对比,验证灵敏度分析方法的可行性与准确性,确定系统各参数对系统动态性能影响大小。
[Abstract]:The hydraulic actuator with high integration and high performance has become a new way to study the joint drive of the foot robot. The joint force control of the supporting phase has become to improve the flexibility of the robot movement. Environmental adaptability and terrain adaptability are urgent needs, but the output force control of hydraulic actuator is the difficult point of hydraulic system, and the output force control system has little stability margin. The fast change of output force greatly limits the gain of the control system. At the same time, the output force is sensitive to the change of system parameters, and it is easy to make many Yu Li annihilate the target force under the external interference. These factors lead to the result that the force servo response is slow, the oscillation is large and the precision of force tracking is poor. It is far from satisfying the requirements of the foot robot. Therefore, the sensitivity of the parameters of the hydraulic actuator force servo system driven by the joint of the foot robot is studied. The sensitivity analysis theory is introduced into the hydraulic actuator force servo nonlinear system, which can quantitatively analyze the time-varying parameters of the system and understand the influence of the sensitivity of each parameter in the system on the dynamic performance of the system. It is of great significance to improve the overall performance of the robot. The sensitivity of the parameters of the hydraulic actuator force servo system is studied in this paper. Two sensitivity analysis methods, locus sensitivity and matrix sensitivity, are used to quantitatively analyze the effect of system parameters on the output of the system. A mathematical model is established for the force servo system of the joint driven hydraulic actuator of the foot robot. The state space equation is obtained and the trajectory sensitivity equation and the matrix sensitivity equation are derived. The relationship between the system parameters and the system output is determined. Secondly, the trajectory sensitivity equation and the matrix sensitivity equation are solved by programming for the no-load and loading conditions of the system. The time history curves of two sensitivity analysis methods are obtained, and two sensitivity measurement methods, the percentage sensitivity measurement method and the integral sensitivity measurement method, are proposed, and the values of the two methods are displayed by using the column diagram. It is used to compare and measure the influence of the system parameters on the dynamic performance of the system during the sampling time, and to determine the secondary parameters of the main parameters that affect the dynamic performance. Finally. According to the semi-physical simulation test bench of the hydraulic actuator force servo system, by changing the integral coefficient, proportional coefficient, differential coefficient and flow gain of servo valve, the method of comparison and analogy is used to change the integral coefficient, the proportion coefficient, the differential coefficient and the flow gain of servo valve. The controllable parameters such as load mass and load stiffness are calculated and compared with the sensitivity simulation results to verify the feasibility and accuracy of the sensitivity analysis method. Determine the impact of system parameters on the dynamic performance of the system.
【学位授予单位】：哈尔滨理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH137

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