The Investigation of PID and Lag-Lead Controller for Positioning Controller of the Shape Memory Alloy Spring Gripper
University of Bangka Belitung, ID
shape memory alloy (SMA) spring, PID, lag-lead, PWM
This paper presents the investigation of positioning control performance of SMA spring by PID and Lag-Lead Controller. Several experiments of the gripper performance were conducted by employed the PWM with 12Hz, 25Hz, 125Hz, 250Hz and 1150Hz frequency signals. The optimal performance signal was 125Hz and then has been used for testings on closed-loop control. The closed-loop controllers used are PID controller and lag-lead compensators. The optimal gain has been obtained by experimentaly tuning. By introducing the closed-loop controllers, the rise time of gripper system was increased approximately 6 times than the open-loop controller. The steady state error of the gripper system was also decreased up to 0% by using the PID controller. The PID controllers generated a shorter rise time and a smaller steady state error than the lag-lead compensators. The important consideration for positioning controller for SMA spring is the speed and steady state error when reaching the position and then how long the position can be sustained. The reability and accuracy of controller and sensor employed determines those problems.
Nanotech 2008 Conference Program Abstract