Control of Pan-tilt Mechanism Angle using Position Matrix Method

Abstract

Control of a Pan-Tilt Mechanism (PTM) angle for the bomb disposal robot Morolipi-V2 using inertial sensor measurement unit, x-IMU, has been done. The PTM has to be able to be actively controlled both manually and automatically in order to correct the orientation of the moving Morolipi-V2 platform. The x-IMU detects the platform orientation and sends the result in order to automatically control the PTM. The orientation is calculated using the quaternion combined with Madwick and Mahony f ilter methods. The orientation data that consists of angles of roll ( α ), pitch ( β ), and yaw ( γ ) from the x-IMU are then being sent to the camera for controlling the PTM motion (pan 8 tilt angles) after calculating the reverse angle using position matrix method. Experiment results using Madwick and Mahony methods show that the x-IMU can be used to find the robot platform orientation. Acceleration data from accelerometer and flux from magneto meter produce noise with standard deviation of 0.015 g and 0.006 G, respectively. Maximum ab solute errors caused by Madgwick and Mahony method with respect to X- axis are 48.45º and 33.91º, respectively. The x-IMU im plementation as inertia sensor to control the Pan-Tilt Mechanism shows a good result, which the probability of pan angle tends to be the same with yaw and tilt angle equal to the pitch angle, except a very small angle shift due to the influence of roll angle.