110m大射电望远镜的两自由度复合控制器设计
|
摘要
针对110m大射电望远镜结构柔性大、固有频率低的特点,本文在传统伺服控制的基础上进一步考虑副反射面支撑结构对指向精度的影响,提出了一种两自由度复合控制器.该控制器由内外两环构成,外环是基于广义比例积分(Generalized Proportional Integral,GPI)的鲁棒控制器,其以副反射面支撑结构的振动量为输入,确定伺服的参考指令;内环利用线性二次型高斯(Linear Quadratic Gaussian,LQG)控制器以外环输出为参考,对天线伺服驱动部分进行控制.与目前已有的大口径天线控制方法相比,该控制器既可以有效抑制驱动部分的柔性振动,又能抑制副反射面的振动,进而提高大口径天线的指向精度.本文以等效天线模型为控制对象.通过数值仿真验证了该方法的可行性.
Considering that the 110 m large radio telescope has the characteristics of big structural flexibility and low fundamental frequency,a two degree of freedom compound controller is proposed basing on the traditional servo control and considering the influence of subreflector's support structure for pointing accuracy.The controller consists of both inner and outer loop.The outer loop is based on the GPI(Generalized Proportional Integral) robust controller to determine the servo reference instruction by the vibration of subreflector;the inner loop uses the output of outer loop as its reference to control the drive part through the LQG controller.With this scheme,the flexible vibration of the drive part and the subreflector's support structure can be effectively suppressed simultaneously,thus improving the antenna's pointing accuracy.The validity of proposed algorithm is verified by numerical simulation on the equivalent antenna model.
Considering that the 110 m large radio telescope has the characteristics of big structural flexibility and low fundamental frequency,a two degree of freedom compound controller is proposed basing on the traditional servo control and considering the influence of subreflector's support structure for pointing accuracy.The controller consists of both inner and outer loop.The outer loop is based on the GPI(Generalized Proportional Integral) robust controller to determine the servo reference instruction by the vibration of subreflector;the inner loop uses the output of outer loop as its reference to control the drive part through the LQG controller.With this scheme,the flexible vibration of the drive part and the subreflector's support structure can be effectively suppressed simultaneously,thus improving the antenna's pointing accuracy.The validity of proposed algorithm is verified by numerical simulation on the equivalent antenna model.
引文
1 Wang N.Xinjiang Qitai 110 m radio telescope(in Chinese).Sci Sin-Phys Mech Astron,2014,44:783-794[王娜.新疆奇台110米射电望远镜.中国科学:物理学力学天文学,2014,44:783-794]
2 Li TR,Guo C L.Simulation of radio telescope PID control system(in Chinese).Comput Simul,2009,26:85-88[李天睿,郭从良.射电望远镜PID控制系统仿真.计算机仿真,2009,26:85-88]
3 Wan Z.Notch filter application in servo system of weather radar(in Chinese).Radio Eng,2004,34:40-42[万泽.凹口滤波器技术在天气雷达伺服系统中的应用.无线电工程,2004,34:40-42]
4 He GL,Li GM,Huang Y,et al.Design of feed forward controller for the servo system of large dish deep space antennas(in Chinese).J Spacecraft TT&C Tech,2010,29:25-28[何国龙,李国民,黄英,等.深空大口径天线前向反馈型伺服系统设计.飞行器测控学报,2010,29:25-28]
5 Gawronski W K,Racho C S,Mellstrom J A.Application of the LQG and feedforward controllers to the deep space network antennas.IEEE Trans Contr Syst Tech,1995,3:417-421
6 Gawronski W.Antenna control systems:From PI to H_∞.IEEE Antennas Propag Mag,2001,43:52-60
7 Gawronski W,Souccar K.Control systems of the large millimeter telescope.IEEE Antennas Propag Mag,2005,47:41-49
8 Gawronski W.Control and pointing challenges of large antennas and telescopes.IEEE Trans Contr Syst Tech,2007,15:276-289
9 You W Q,Chen H H,He X D,et al.H∞mixed sensitivity method for vibration tracking control on flexible structures(in Chinese).J Vib Meas Diagnosis,2011,31:562-566[游伟倩,陈怀海,贺旭东,等.柔性结构振动跟踪控制H_∞混合灵敏度法.振动、测试与诊断,2011,31:562-566]
10 Qiu D,Sun M,Wang Z,et al.Practical wind-disturbance rejection for large deep space observatory antenna.IEEE Trans Contr Syst Tech,2014,22:1983-1990
11 Morales R,Sira-Ramirez H.Trajectory tracking for the magnetic ball levitation system via exact feedforward linearisation and GPI control.Int J Control,2010,83:1155-1166
12 Gawronski W.Modeling and Control of Antennas An Telescopes.New York:Springer,2008
13 Feliu V,Castillo F J,Ramos F,et al.Robust tip trajectory tracking of a very lightweight single-link flexible arm in presence of large payload changes.Mechatronics,2012,22:594-613
14 Ren Y H.A Study of Robust Control Method of Large Radio Telescope Servo System(in Chinese).Dissertation for Master Degree.Xi'an:Xidian University,2015[任元昊.大型射电望远镜伺服系统的鲁棒控制方法研究.硕士学位论文.西安:西安电子科技大学,2015]
2 Li TR,Guo C L.Simulation of radio telescope PID control system(in Chinese).Comput Simul,2009,26:85-88[李天睿,郭从良.射电望远镜PID控制系统仿真.计算机仿真,2009,26:85-88]
3 Wan Z.Notch filter application in servo system of weather radar(in Chinese).Radio Eng,2004,34:40-42[万泽.凹口滤波器技术在天气雷达伺服系统中的应用.无线电工程,2004,34:40-42]
4 He GL,Li GM,Huang Y,et al.Design of feed forward controller for the servo system of large dish deep space antennas(in Chinese).J Spacecraft TT&C Tech,2010,29:25-28[何国龙,李国民,黄英,等.深空大口径天线前向反馈型伺服系统设计.飞行器测控学报,2010,29:25-28]
5 Gawronski W K,Racho C S,Mellstrom J A.Application of the LQG and feedforward controllers to the deep space network antennas.IEEE Trans Contr Syst Tech,1995,3:417-421
6 Gawronski W.Antenna control systems:From PI to H_∞.IEEE Antennas Propag Mag,2001,43:52-60
7 Gawronski W,Souccar K.Control systems of the large millimeter telescope.IEEE Antennas Propag Mag,2005,47:41-49
8 Gawronski W.Control and pointing challenges of large antennas and telescopes.IEEE Trans Contr Syst Tech,2007,15:276-289
9 You W Q,Chen H H,He X D,et al.H∞mixed sensitivity method for vibration tracking control on flexible structures(in Chinese).J Vib Meas Diagnosis,2011,31:562-566[游伟倩,陈怀海,贺旭东,等.柔性结构振动跟踪控制H_∞混合灵敏度法.振动、测试与诊断,2011,31:562-566]
10 Qiu D,Sun M,Wang Z,et al.Practical wind-disturbance rejection for large deep space observatory antenna.IEEE Trans Contr Syst Tech,2014,22:1983-1990
11 Morales R,Sira-Ramirez H.Trajectory tracking for the magnetic ball levitation system via exact feedforward linearisation and GPI control.Int J Control,2010,83:1155-1166
12 Gawronski W.Modeling and Control of Antennas An Telescopes.New York:Springer,2008
13 Feliu V,Castillo F J,Ramos F,et al.Robust tip trajectory tracking of a very lightweight single-link flexible arm in presence of large payload changes.Mechatronics,2012,22:594-613
14 Ren Y H.A Study of Robust Control Method of Large Radio Telescope Servo System(in Chinese).Dissertation for Master Degree.Xi'an:Xidian University,2015[任元昊.大型射电望远镜伺服系统的鲁棒控制方法研究.硕士学位论文.西安:西安电子科技大学,2015]