Disturbance Observer-based Pointing Control of Leighton Chajnantor Telescope

Chen, Weirui; Wang, Zheng

doi:10.1088/1674-4527/ad0826

Cited by 2 publications

(1 citation statement)

References 37 publications

(51 reference statements)

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“…However, standard ADRC is limited to integral chain systems [19], and the extended state observer (ESO) can only tackle slowly varying disturbances [20]. A disturbance observer-based composite position controller (DOB-CPC) is designed to enhance antidisturbance capability of Leighton Chajnantor telescope [21]. A cascade acceleration feedback control (AFC) enhanced by disturbance observation and compensation is proposed to improve the tracking precision of telescope systems [22].…”

Section: Introductionmentioning

confidence: 99%

Tracking and Disturbance Suppression of the Radio Telescope Servo System Based on the Equivalent-Input-Disturbance Approach

Yang,

Wang,

Liu

et al. 2024

Advances in Astronomy

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This paper presents a composite control algorithm for the radio telescope servo control system to address the target tracking and matched/mismatched disturbance suppression problems. The algorithm consists of the equivalent-input-disturbance (EID) approach and the optimal control method. An EID estimator is developed using the difference between the estimated output of the state observer and the measurement output and then the estimate of the EID is fed forward into the control input to reject the disturbance. A cost function with clear physical meaning is selected and the weighting parameters are adjusted for the optimal controller to improve tracking performance. Considering the nonminimum phase characteristics of the radio telescope system, the state observer gain is computed using the linear matrix inequality (LMI) method. The system stability is analyzed using the small gain theorem, and the linear quadratic regulator (LQR) control method is utilized to determine the state feedback gain. Finally, the composite controller is designed for an identified telescope model. Simulation results show that for the tracking performance, the settling time of proposed method is 1.13 s and reduces by about 0.32 s and 0.87 s than that of the ADRC controller and PI controller, respectively. For the antidisturbance performance, the RMS value and the maximum error of the proposed method are 0.0039 and 0.0128, which are 42.86% and 40.38% of the ADRC controller and 30.71% and 27.77% of the PI controller, respectively, which indicates that the proposed method has better control performance. In addition, the proposed controller has certain robustness to systematic parameter perturbations.

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Section: Introductionmentioning

confidence: 99%

Tracking and Disturbance Suppression of the Radio Telescope Servo System Based on the Equivalent-Input-Disturbance Approach

Yang,

Wang,

Liu

et al. 2024

Advances in Astronomy

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A feedforward/feedback pointing control policy for Leighton Chajnantor Telescope against wind disturbance and beam offset

Chen,

Wang

2024

Modeling, Systems Engineering, and Project Management for Astronomy XI

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Leighton Chajnantor Telescope (LCT) will be moved to the new site at Chajnantor Plateau, Chile in 2024. The new site has high wind speed and large temperature difference, which leads to strong wind disturbance and beam offset for LCT due to the deformation of the primary reflector. To achieve a high pointing control accuracy, we propose a composite feedforward/feedback control policy (CFFCP), which integrates disturbance observer-based feedforward control policy (DOB-FFCP) and the robust feedback control policy (RFBCP) to compensate the wind disturbance and the beam offset compensation strategy (BOCS) to reduce the negative effect caused by the beam offset respectively. The results of simulation on the synthesized model of LCT's pointing control system reveal that the proposed CFFCP can signific antly reduce the pointing error during the observations.

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Disturbance Observer-based Pointing Control of Leighton Chajnantor Telescope

Cited by 2 publications

References 37 publications

Tracking and Disturbance Suppression of the Radio Telescope Servo System Based on the Equivalent-Input-Disturbance Approach

Tracking and Disturbance Suppression of the Radio Telescope Servo System Based on the Equivalent-Input-Disturbance Approach

A feedforward/feedback pointing control policy for Leighton Chajnantor Telescope against wind disturbance and beam offset

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