Control of mobile robots for the push-a-box operation

We consider the situation where an intelligent mobile robot goes through a corridor-like path pushing a box. During the mission, we assume the robot is off the course, and comes very near to a wall. To avoid the collision, the robot must, first, stop the operation, examines the surrounding situation, and does some adjusting operations if necessary, and finally rebuild a new plan to return to the previous trajectory. This is a scenario which we dealt with in this paper. First, we derive the combined equation of motion for a mobile robot and an object, which is a good model for the computer simulation. We define the motion where a robot is controlled to run on a straight line. Using this controlled linear motion we prove that an object can be rotated without any significant translational movement. After an object is rotated to an appropriate position, the robot enters the continuous pushing operation to return to the former path. We have written a simulation program for a workstation, and built an experimental mobile robot. The proposed algorithms are programmed in the control computer of the robot. The feasibility of our algorithm has been proven by the actual experiments and also by the computer simulations