分类号: 密级: U D C : 编号: 工学硕士学位论文 低重力模拟系统控制方法研究 硕士研究生 :陈力恒 指 导 教 师 :朱齐丹 教授 学科、专业 :控制理论与控制工程 论文主审人 :陆 军 教授 哈尔滨工程大学 2014 年 6 月万方数据 万方数据 分类号: 密级: U D C : 编号: 工学硕士学位论文 低重力模拟系统控制方法研究 硕 士 研 究 生硕 士 研 究 生 :陈力恒 指 导 教 师指 导 教 师 :朱齐丹 教授 学 位 级 别学 位 级 别 :工学硕士 学 科 、 专 业学 科 、 专 业 :控制理论与控制工程 所 在 单 位所 在 单 位 :自动化学院 论文提交日期论文提交日期 :2014 年 5 月 论文答辩日期论文答辩日期 :2014 年 6 月 学位授予单位学位授予单位 :哈尔滨工程大学 万方数据 万方数据 Classified Index: U.D.C: A Dissertation for the Degree of M. Eng Research on Control Method of Low Gravity Simulating System Candidate: Chen Liheng Supervisor: Prof. Zhu Qidan Academic Degree Applied for: Master of Engineering Specialty: Control Theory and Control Engineering Date of Submission: May.2014 Date of Oral Examination: Jun.2014 University: Harbin Engineering University 万方数据 万方数据 哈尔滨工程大学 学位论文原创性声明 本人郑重声明:本论文的所有工作,是在导师的指导下,由作者本人独立完成的。有关观点、方法、数据和文献的引用已在文中指出,并与参考文献相对应。除文中已注明引用的内容外,本论文不包含任何其他个人或集体已经公开发表的作品成果。对本文的研究做出重要贡献的个人和集体,均已在文中以明确方式标明。本人完全意识到本声明的法律结果由本人承担。 作者(签字): 日期: 年 月 日 哈尔滨工程大学 学位论文授权使用声明 本人完全了解学校保护知识产权的有关规定,即研究生在校攻读学位期间论文工作的知识产权属于哈尔滨工程大学。哈尔滨工程大学有权保留并向国家有关部门或机构送交论文的复印件。本人允许哈尔滨工程大学将论文的部分或全部内容编入有关数据库进行检索,可采用影印、缩印或扫描等复制手段保存和汇编本学位论文,可以公布论文的全部内容。同时本人保证毕业后结合学位论文研究课题再撰写的论文一律注明作者第一署名单位为哈尔滨工程大学。涉密学位论文待解密后适用本声明。 本论文(□在授予学位后即可 □在授予学位12个月后 □解密后)由哈尔滨工程大学送交有关部门进行保存、汇编等。 作者(签字): 导师(签字): 日期: 年 月 日 年 月 日 万方数据 万方数据 低重力模拟系统控制方法研究 摘 要 为了保证星球巡视车能够在某星球的低重力环境中顺利完成勘探任务,需要在地球表面模拟低重力环境来对巡视车的动力性能等方面进行调节与测试。当巡视车处于复杂的路面测试时,上下颠簸等恶劣的路况会对低重力模拟系统的稳定性与精度带来很大的干扰,并且模拟系统中内部的一些不确定性也对低重力模拟系统的鲁棒稳定性产生不利影响。因此为了保证低重力模拟系统具有良好的鲁棒性,并且能够为巡视车提供稳定而精确的低重力环境,本文将从以下几个方面展开低重力模拟系统控制方法的研究。 首先,本文在对于低重力模拟系统缓冲机构与电机主动控制相结合的工作原理进行了详细的阐述;通过建立摆杆坐标与大地坐标以及相互的转化关系,并利用力学知识,对于起到缓冲作用的缓冲机构建立动态的数学模型;对起到主动控制作用的电机在速率模式下的模型进行了最小二乘的参数辨识,通过实验对比验证了模型的输入输出关系的准确性;利用系统工作时吊索的伸缩与缓冲机构以及电机的关系建立了低重力模拟系统的标称模型。 其次,为了保证控制器设计能够更加具有针对性,本文结合低重力模拟系统的数学模型对各关键部件展开特性分析。通过频域分析的角度,讨论了缓冲机构在系统中起到对于巡视车竖直方向高频加速度良好的吸收作用以及存在的等效弹性系数不确定问题;对于电机部分存在的机械谐振,详细分析了机械谐振的产生原因以及抑制机械谐振常用的办法;对于没有建立在模型中的吊索部分,通过有限元模型讨论了它的纵向谐振问题及影响,并分析了相关的抑制方法。 再次,根据低重力模拟系统在工作时受到巡视车竖直方向加速度干扰,以及系统特性分析过程中得到的各部件存在的问题,选用了具有较强鲁棒性优势的H控制方法来对系统综合。在控制器设计过程中对于H控制解决鲁棒稳定性与鲁棒性能的相关方法及步骤进行了讨论,针对低重力模拟系统设计了广义控制对象与加权函数,并利用Matlab 鲁棒工具箱得到H控制器。控制器使得闭环系统满足小增益定理保证了系统鲁棒稳定,并且在开环 bode 图中验证了控制器的可实现性。在仿真检验过程中,对于巡视车加速度频率不断增加的较强干扰,以及系统参数剧烈变化的情况下,控制器均保证了系统的稳定,并得到较高的控制精度。 最后,为了保证控制器在实际系统中具有较好工作效果,在 xPC-Target 环境下搭建了低重力模拟系统的简易实验平台,实验平台可以实现了硬件在环的检测,实时曲线的绘制与数据的存储,方便了操作者的调试。在实验过程中,为了保证了对低重力模拟方案检验同时可以将实验在实验室现有条件下展开, 根据系统建模过程中的结论对于系统平衡工作点进行了转移。在建立好实验平台上完成了给定吊索拉力的阶跃信号实验,模万方数据 哈尔滨工程大学硕士学位论文 拟巡视车爬坡越障实验与模拟巡视车处于路面颠簸情况下实验,在三组实验过程中,控制器均有效保证了系统的稳定性与控制精度, 以上结果将为低重力模拟系统的进一步完善与改进提供理论指导与实践参考。 关键词:低重力模拟;恒张力;主动悬吊方法;H控制;xPC-Target 万方数据 低重力模拟系统控制方法研究 ABSTRACT In order to ensure the patrol car to complete the exploration task successfully in low gravity environment of the planet, it is necessary to simulate the low gravity environment on earth where the dynamic performances of the patrol car can be adjusted and tested before it is sent to the planet. When the patrol car is tested in complex road conditions such as bumps up and down, it will cause the large disturbance. At the same time, the uncertainty of parameters aroused by modeling exists inevitable. These problems will have an adverse impact on the robust stability and precision of the low gravity simulation system. Therefore, to guarantee the good robustness of the low gravity simulation system and to supply the patrol car with the stable and accurate low-gravity environment, in the paper, the research of the control methods of the low gravity simulation system will be carried out as following. Firstly, the operational principle of combination of the buffer mechanism and the motor active control is described in detail. By establishing the pendulum coordinates system, geodetic coordinates system and the transforming relationship between them, applying the knowledge of the mechanical, the dynamic model of the buffer mechanism is obtained. Next, the motor is set in the rate mode and the method of parameter identification of least squares is used to identify the model of the motor. Then the experiment is carried out to verify the accuracy of the relationship between input and output. On the basis of the above models of the buffer mechanism and the motor, the nominal model of the low gravity simulation system is obtained. Secondly, in order to make the controller design targeted, combined with the mathematical model of the low gravity simulation system, the paper conducts the characteristic analysis of the key components. Through frequency domain analysis, it is proved that the buffer mechanism can absorb the high-frequency acceleration well in the vertical direction of the patrol car and the problem of the equivalent elastic coefficient uncertainty also exists. For the existence of the mechanical resonant of the motor, the causes of the mechanical resonant are analyzed in details, and common approaches of suppressing the mechanical resonance are given. As the sling which model is not established in the simulation system, its longitudinal resonance problem is discussed by the finite element mode, and the related suppression method is also analyzed. Thirdly, According to the vertical interference by the patrol car in the work and the characteristics of the system components, H-infinite control method which has strong robustness advantage to the system is chosen. In the design of the controller, the method and the steps to solve the robust stability and robust performance are discussed. The generalized control object and the weighted functions of the low gravity simulating system are designed. By using the robust tool box of Matlab, the controller is got easily. The controller satisfies the small gain theorem and guarantees the robust stability. The Bode diagram shows that the open loop of the system verifies the realization. In the simulating process, although the interference 万方数据 哈尔滨工程大学硕士学位论文 of the patrol car acceleration is strong with the increasing frequency and the change of system parameters is dramatic, the controller can also guarantee the system stability and control precision of the system is high. Finally, in order to ensure that the controller has good effect in the actual system, the simple experimental platform for low gravity simulation system is built in the xPC-Target environment, the experimental platform can achieve the detection of hardware in the loop, the curve drawing and the data storage, it’s convenient for the operator. In order to complete the experiment under the current condition in the laboratory, the balance working point of the system is transferred. In the experimental platform, the experiments such as the step signal of force, simulation of the patrol car climbing obstacle experiment and the patrol car in bumps experiment are complete. The experiment result shows that the controller is effective to guarantee the stability and control accuracy of the system and provides the theoretical and practical value to improve the low gravity simulating system. Keywords: low gravity simulating system; constant tension; active suspension; H-infinite control; xPC-Target 万方数据 低重力模拟系统控制方法研究 目 录 第1章 绪论 .............................................................................................................................. 1 1.1课题研究的目的和意义 ............................................................................................... 1 1.1.1课题的背景 ........................................................................................................ 1 1.1.2课题的意义 ........................................................................................................ 1 1.2国内外研究现状及分析 ............................................................................................... 3 1.3H控制的概述 ............................................................................................................ 5 1.4主要研究内...