Traction Control System For Sumo Class Robot

This report describes the technique to estimate friction limits of the driven surfaceof a ring on which sumo class robot wrestling contests takes place. The estimation isbased on laser optical sensor as robot’s motion sensor. Before the contest, number ofsemi-automatic experiments have to be conducted in which robot is attempting toaccelerate in different patterns to achieve highest levels of traction forces and thehighest momentum before the impact with opponent. Also a Direction CorrectionStability Controller was developed to maintain initial heading angle when robotaccelerates. This system was necessary as the vehicle is driven by relatively powerfulmotors and due to the fact that it is very easy to turn when traction forces of bothtracks differ. Robot used in the study is a small tracked vehicle.During this research, an attempt was made to build a Traction Control Systemthat is based on longitudinal slip control. This technique is intended to maintain theconstant and optimum value of longitudinal slip of the continuous tracks that allowsachieving highest longitudinal traction forces. This system was also designed and fullyimplemented into the robot’s MCU. The constant desired value of the slip is controlledby PID controller. However results of the operation of this system are not satisfyingsince it requires highly precise feedback signals and the employed laser displacementsensor was unable to provide such data.Furthermore a number of other algorithms and systems have been developed.Several different modes of decision-making have been designed and implementedduring this study. In one of the operation modes vehicle is streaming all the data to thePC computer where new decisions and motion orders for motors are calculated. In thisapproach vehicle can be considered as remote-brained robot. Another mode is based onthe opposite principle in which decision is entirely calculated in MCU without theneed to communication to the human operator or PC computer. Another operationmode allowed for semi-automatic operation and only evaluation of it is performed onPC computer.