Fuzzy Logic SystemforPosition Control and Current Stabilization ofaRobotManipulator
Thispaperproposes theusageofthefuzzy logic forbothposition control andstabilization ofcurrent pulsations. Theaimistoensureprecise control ofthejoint motionposition withveryquickly joints movements. The blockdiagramofa control systeminvolves controller, actuator, robotandappropriate sensors. Eachofthese componentsis described. The dynamicmodelof a manipulator isbasedontheNewton-Euler formulation that provides adescription oftherelationship between thejoint actuator torques andthemotionofthestructure. Thefuzzy logic controller Mamdanitypecontains twocontrol inputs: position errorand armaturecurrent.Inputvariable fuzzification, inference basedonfuzzy rules andoutputset defuzzification are described. The same fuzzycontrol algorithm isusedinalljoint servoloops, requiring only multiplexing andproperscaling ofthefuzzy controller inputs andoutputs. Theelectric dc(direct-drive) servomotors used foractuating thejoints ofa manipulator. Theinfluence of nonlinear loads, gravitation-dependent load, viscous friction torque, Coulomb's friction andtorqueduebyreducer on position tracking performance wasalsoconsidered.