面向FAST工程主动反射面系统的液压促动器研制及性能分析

发布时间：2018-03-30 07:22

本文选题：液压促动器　切入点：键合图　出处：《天津大学》2016年硕士论文

【摘要】：本文针对应用于500米口径球面射电望远镜主动反射面系统中的促动器特性不完善的问题,以实现机电液系统集成化、轻量化、自动化、智能化为目的,研制了一种新型的液压促动器。为了满足主动反射面索网节点位置和速度控制的要求,提高主动反射面系统在天文观测时的控制精度,重点对液压促动器的功能实现过程、动态特性、控制策略和调节机制等进行了研究,并将所研制的液压促动器应用于工程实际。液压促动器的动态特性受到机械、液压、电气系统等多个物理过程相互作用的影响。因此,该系统数学模型的建立需要借助一个统一的方法来描述系统中所存在的非线性特征。功率键合图方法非常适用于多个物理过程相互作用的非线性系统建模。本文利用功率键合图方法建立了液压促动器的非线性数学模型,将整个系统分解成若干个进行能量交换的子系统,将泵控差动缸机液系统与电机的电气系统相结合,对闭环系统的动态响应进行分析。推导了系统的状态空间表达式,着重研究几个影响系统性能的主要因素,并将闭环系统的数学模型进一步简化,为后续计算机处理仿真模型提供了保障和理论基础。针对传统PID控制策略对该液压促动器进行控制难以获得理想控制精度的问题,本文将灰色预测模型应用到传统PID控制中,并在前人经验的基础上进行改进,提出一种新型的步长调整机制,在简化以往调整机制复杂性、不确定性和耗时性的同时,很好地解决了促动器在换源和扫描跟踪等天文观测时的控制精度,满足FAST工程主动反射面索网节点位置控制精度和响应速度的要求。最后,对液压促动器进行了计算机仿真和实验分析,对比了传统PID控制策略和引入新调节机制的灰色预测PID控制策略的控制效果,进一步评估和验证所提出的控制方法的有效性,具有明显的工程实际意义。
[Abstract]:In order to realize the integration, lightweight, automatization and intelligentization of electromechanical hydraulic system, this paper aims at solving the problem that the actuators used in the active reflector system of the 500m spherical radio telescope are imperfect, and the aim is to realize the integration, lightweight, automation and intelligence of the electrohydraulic system. A new type of hydraulic actuator is developed. In order to meet the requirements of the position and speed control of the cable network node of the active reflector, and to improve the control accuracy of the active reflector system in astronomical observation, the emphasis is placed on the realization of the function of the hydraulic actuator. The dynamic characteristics, control strategy and regulation mechanism are studied, and the developed hydraulic actuators are applied to engineering practice. The dynamic characteristics of the hydraulic actuators are subjected to mechanical, hydraulic, hydraulic, The interaction of multiple physical processes, such as electrical systems. The mathematical model of the system needs a unified method to describe the nonlinear characteristics of the system. The power bond graph method is very suitable for modeling nonlinear systems with multiple physical processes. The nonlinear mathematical model of the hydraulic actuator is established by using the power bond graph method. The whole system is decomposed into several subsystems for energy exchange. The dynamic response of the closed loop system is analyzed by combining the pump controlled differential cylinder machine hydraulic system with the electrical system of the motor. The state space expression of the system is derived. Several main factors affecting the performance of the system are studied, and the mathematical model of the closed-loop system is further simplified. This paper provides a guarantee and theoretical basis for the subsequent computer simulation model. Aiming at the problem that it is difficult for the traditional PID control strategy to control the hydraulic actuator, it is difficult to obtain the ideal control precision. In this paper, the grey prediction model is applied to the traditional PID control. Based on the previous experience, a new step size adjustment mechanism is proposed, which simplifies the complexity, uncertainty and time consuming of the previous adjustment mechanism. The control accuracy of actuators in astronomical observation such as source changing and scanning tracking is well solved, and the position control accuracy and response speed of cable network nodes on active reflector of FAST engineering are satisfied. Finally, The computer simulation and experimental analysis of hydraulic actuator are carried out. The control effects of traditional PID control strategy and grey predictive PID control strategy with new regulation mechanism are compared, and the effectiveness of the proposed control method is further evaluated and verified. It has obvious practical significance in engineering.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TH751;TH137

【相似文献】