EFFICIENT DISTRIBUTION OF TRACTION FORCES BETWEEN ROBOTS DURING COOPERATIVE CARGO TRANSPORTATION

Abstract

The task of collective movement of load by wheeled robots has kinematic redundancy of drives. It allows distributing traction forces without changing the trajectory and velocity of the system. In this way, it is possible to define additional traffic quality criteria which the traction control system should strive to achieve. In addition, efficient distribution will allow the robots to move without wheel slip at a higher speed than classical control methods. Robots and cargo combined into one system mechanically and informationally, form a variable configuration transport cell (VCTC). The following transportation quality criteria are considered: no wheel slippage, maintaining a given speed, no soft bumps, minimizing work in the generator mode, maintaining the desired final charge levels of the robot batteries after transportation. The proposed methods for the efficient distribution of traction forces are based on the finding local minimum and on the Hebbian learning principle. Tests are carried out in the Simulink using the dynamic mathematical model of the VCTC. In the case under consideration, new distribution methods made it possible to increase the maximum allowable turn entry speed by 27% compared with classical control approaches. At a lower speed new method of distribution showed good results on additional transportation quality criteria. The presented material can also be used for multi-wheeled robots with steerable drive wheels.