摘要
为了满足2.5 m大视场望远镜的跟踪要求,提出了望远镜主轴伺服三闭环控制设计方法。在整定好的电流环输入端注入正弦信号,扫频测试主轴伺服速度环的开环频率特性。根据谐振频率设计结构滤波器抑制机械谐振,从而达到更高的闭环带宽。最后,依据辨识得到的控制模型,设计速度环线性自抗扰控制器和位置环比例控制器。速度环基于线性扩张状态观测器估计扰动并补偿其影响,可以达到更高的低速跟踪精度。为解决快速搜索问题,根据设备允许的最大速度、加速度,基于离散最速跟踪微分器安排过渡过程。实验结果表明:线性自抗扰控制相比PI控制,2.5 m大视场望远镜进行1.24°视场角快速步进搜索的时间由1.6 s降低为1.0 s;以速度为2(°)/s,加速度为1(°)/s2作为等效正弦引导的误差均方根值由1.08″降低为0.60″;低速跟踪斜率为0.0001(°)/s的位置斜坡曲线时,位置跟踪稳态误差均方根值由0.0158″降低为0.0106″。线性自抗扰控制能够满足大视场角天文望远镜高效率快速搜索和低速精密跟踪的要求。
To meet the requirements of fast search and high precision tracking at ultra-low speed for a 2.5 m wide field telescope,the design method of the three closed-loop control system of position,velocity,and current of telescope main axes AC servo is introduced.Firstly,a sinusoidal signal is injected into the set current closed-loop reference input end,and the speed open-loop frequency characteristic curve of the main axes servo system for the telescope is measured using a frequency sweep.Then,the structural filter is designed according to the resonant frequency to suppress the mechanical resonance so as to achieve a higher closed-loop bandwidth.Finally,according to the identified control model,the speed loop linear ac⁃tive disturbance rejection(LADRC)controller and position loop proportional controller are designed.The velocity loop estimates the disturbance and compensates for its effects based on the linear extended state observer,which achieves higher low-speed tracking accuracy.To solve the fast search problem,the posi⁃tion loop arranges the transition process according to the maximum allowable velocity and acceleration of the device and based on the discrete maximum velocity tracking differentiator.The experimental results show that,compared with the PI control,LADRC reduces the fast step search time of 1.24°FOV for a 2.5 m wide field telescope from 1.6 s to 1.0 s.The equivalent sinusoidal guidance error RMS value de⁃creases from 1.08″to 0.60″when tracking the sine curve with a velocity of 2(°)/s and acceleration of 1(°)/s2,The steady-state error RMS of position decreases from 0.0158″to 0.0106"when tracking the slope of position at 0.0001(°)/s.The experimental results indicate that LADRC can meet the require⁃ments of high efficiency,fast search,and precise tracking at low speed for large field angle telescopes.
作者
刘洋
李洪文
邓永停
王帅
费强
杨晓霞
曹玉岩
LIU Yang;LI Hongwen;DENG Yongting;WANG Shuai;FEI Qiang;YANG Xiaoxia;CAO Yuyan(Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun 130033,China;University of Chinese Academy of Sciences,Beijing 100049,China;Ji Hua Laboratory,Foshan 528000,China)
出处
《光学精密工程》
EI
CAS
CSCD
北大核心
2022年第23期3058-3069,共12页
Optics and Precision Engineering
基金
国家自然科学基金资助项目(No.11973041,No.12122304)
中国科学院青年创新促进会会员项目(No.2019218)
天文联合基金资助项目(No.U2031126)。
关键词
大视场望远镜
线性自抗扰
频率特性
结构滤波器
最速跟踪微分器
wide field telescope
linear active disturbance rejection control
frequency characteristics
structural filters
fastest tracking differentiator
