DevelopmentofaTwo-Wheels CasterTypeof Odometer with a Dual Shaft for Omnidirectional Mobile Robots

Thispaper proposesaTwoWheelsCaster(TW-Caster)typeof odometerfordeadreckoningof Omni-DirectionalMobileRobots (ODMRs). The proposed TW-Caster is composed of two passive wheels and one passive rotational axis with a dual shaft. The two wheels rotate independently, and the rotational axis changes orientation of the TW-Caster as the ODMR motion. Angular velocitiesofthetwo wheelsand rotationalaxisare measuredbythreerotary encodersusingagear train.Amechanismofthegear train is proposed to prevent the encoder from being entangled with itself. Using measured values of the three encoders, the current velocityvectorof the ODMRis calculatedby kinematicsof theTW-Caster. The current position and orientationof the ODMR are estimated by the dead reckoning of the TW-Caster.