Controller Design and Experiment for Tracking Mount of Movable SLR, ARGO-M
Cheol Hoon Park, Young Su Son, Sang Yong Ham, Byung In Kim, Sung Whee Lee, Hyung Chul Lim
Controller design procedure for prototype tracking mount of
Movable SLR (Satellite Laser Ranging), ARGO-M is presented.
Tracking mount of ARGO-M is altitude-azimuth type and it
has two axes of elevation and azimuth to control its position.
Controller consists of velocity and acceleration feed-forward
controller, position controller at outer loop, velocity controller
at inner loop. There are two kinds of position control modes.
One is the pointing mode to move from one position to the
other position as fast as possible and the other one is tracking
mode to follow SLR trajectory as precise as possible. Because
the requirement of tracking accuracy is less than 5 arcsec and it
is very tight error budget, a sophisticated controller needs to be
prepared to meet the accuracy. Especially, ARGO-M is using
the cross-roller bearing at each axis to increase the mechanical
accuracy, which requires add-on controller DOB (Disturbance
observer) to suppress friction load and low frequency
disturbances. The pointing and tracking performance of the
designed controller is simulated and visualized using
MATLAB/ Simulink & SimMechanics and the experimental
results using test are presented as well.