负载试验电液张力控制系统研究

【作者】 刘昊天；

【导师】 王庆丰；

【作者基本信息】 浙江大学 ， 机械控制电子工程， 2004， 硕士

【摘要】 张力绞车应用在绞车负载试验系统中，通过对缆绳上张力的控制来模拟被试绞车的负载，测试被试绞车的负载能力。本文针对张力绞车的实际应用情况，结合液压系统的特点，提出了张力控制过程与速度调整过程相分离的混合控制方法。并根据两控制过程中不同的控制要求，有针对性的设计不同的控制器，主控制器则根据缆绳上张力的变化趋势区分不同的控制过程，选择适当的控制器控制系统的运转。在张力控制过程中，通过增加非线性转速-转矩反馈环节的放大系数，增加电液系统的阻尼，改善系统的动态特性。针对非线性转速-转矩反馈环节对张力稳态精度的影响，提出基于压差反馈的输出转矩控制方法，兼顾系统的动态与稳定性能。在速度调整过程中，根据被试绞车的转速变化调节比例方向阀的阀口开度，在实现卷筒转速快速跟随的同时，进一步抑制非线性转速-转矩反馈引起的稳态误差。最后，考虑到转盘的引入对于系统控制精度的影响，设计基于张力反馈的PID控制器，并通过各种试验方法对该PID控制器进行整定。实验结果表明，上述将多种控制与补偿算法相结合的张力绞车电液控制系统能够稳定、可靠的工作，并满足负载试验系统的要求。 论文内容如下： 第一章绪概述了卷绕张力控制系统的一般结构形式，分析几种常见张力控制方法及其结构形式。简要介绍负载试验系统的具体应用情况，并提出了本文的选题意义与研究内容。 第二章介绍了张力绞车液压系统的工作原理，并在对各液压器件静特性进行分析的基础上，结合实际应用情况，提出了系统的改进方案。 第三章由最简结构下的张力控制系统入手，根据张力绞车卷筒的动力学微分方程与液压系统的静特性方程，建立了张力控制的数学模型，并针对系统中的非线性反馈环节进行了初步分析。 第四章根据最简结构下张力控制系统模型的仿真结果，分析系统的稳态与动态特性。在此基础上，利用仿真研究非线性转速-转矩反馈对于系统控制特性的改善作用。提出基于压差反馈的输出转矩控制方法，抑制非线性反馈对系统稳态精度的影响。考虑到被试绞车转速变化对于张力控制的影响，提出分离张力控制过程与速度调整过程的混合控制方法。 第五章介绍了绞车负载试验系统的构成以及控制系统的结构，分析缆绳张力信号的采集与处理方法，并针对第四章中论述的多种控制方法与补偿算法，分别进行了实验研究。 第六章结论与展望，总结了张力绞车电液控制系统的结论，提出了应用前景和展望。更多还原

【Abstract】 The tension windlass is applied to the windlass load experiment system to test the load function of windlass by controlling the tension of cordage to imitate the windlass load. According to the windlass practice condition and the feature of hydraulic system, the article puts forward the mingling control theory by separating the tension control and the speed control. Meanwhile, the author has designed different controller based on the different control request of two control processes. The main controller selects the proper controller to control the system by testing the changing tendency of tension. The dynamic character is improved by increasing the amplified coefficient of feedback link of nonlinear rotational speed-rotation torque and resistance of hydraulic system. To the influence of the link of nonlinear rotational speed-rotational torque, the author also puts forward the control method of outputting the rotational torque on the basis of the feedback of pressure difference, which improves the system character of static state and dynamic state in the same time. In the process of adjusting speed, according to the changing of the windlass speed, the proportional directional valve is adjusted to realize the rapid following of the windlass speed and control the static error leaded by the feedback of nonlinear rotational speed-rotational torque. At last, considering of the influence caused by the winch, the author designs the PID controller on the basis of the feedback of tension and adjusts the PID controller by many experiments. The experiments show that the above-mentioned method is able to maintain the tension windlass control system stability and meet the request of the load experiment system.The Main Content:The first chapter is a preface. It summarizes some kinds of structures of windlass load experiment system and methods of tension control. It introduces briefly the applicability of load experiment system, the article’s content and significance.The second chapter is a design of hydraulic system. It introduces the principles of the tension windlass hydraulic system. On the basis of the analyzing the system static state and combining the factual conditions, it puts forward the improved plan of the system.The third chapter is a design of the matrix the control system. On the basis of the simplified structure of the system, according to the static equation of hydraulic system and the dynamic derivative equation, it establishes the matrix of the tension control system and analyses preliminarily the nonlinear feedback link of the system.The fourth chapter is a design of algorithm and simulation. According to the request of simulation of the simplified tension control system matrix, it analyses the static and dynamic system features, in the same time, using simulation to observe the function, which is improved by the nonlinear feedback of rotational speed-rotational torque. It puts forward a method that is on the basis of feedback of pressure difference, which can restrain the static state influence that is made by nonlinear feedback. Because the windlass speed changing has a great influence to the tension control, it also puts forward the mingling control theory by separating the tension control and speed control.The fifth chapter is a result of experiment. It analyses the method of collecting and handling the cordage tension signals, illustrates the results of many control methods.The sixth chapter is a conclusion and prospects. It summaries the conclusion of tension windlass hydraulic control system and puts forward its prospects.更多还原