Open-loop velocity control of the troweling robot

The 2-trowel type concrete floor finishing robot can move in any direction and rotate without any mechanism such as wheels by adjusting the posture of trowels. It utilizes the unbalanced friction forces occurring between the rotary trowels and the floor. Since the quality of the smoothed and polished concrete floor is determined by plastering speed, we need to control the velocity of the robot. However, we cannot use the typical velocity control method because it is very difficult to measure the velocity of the robot, in contrast to the mobile robots with wheels. To overcome this difficulty, the following are studied in the paper. We found that the robot dynamics has disturbance depending on its velocity, and showed that there exists the saturated velocity of the robot which is set by the posture of the trowels, and obtained the relationship between the saturated velocity and the posture in the translation and the rotation. These enable us to control the velocity of the robot only by adjusting the posture of trowels. We built the trowelling robot and are experimenting its performance with the proposed velocity control method