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

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.