Control and kinematic design of multi-degree-of freedom mobile robots with compliant linkage

Mobile robots (unlike automated guided vehicles) usually rely on dead-reckoning between periodic absolute position updates and their performance is diminished by excessive wheel slippage. This paper introduces compliant linkage, a new concept in the control and kinematic design of multi-degree-of-freedom (MDOF) mobile robots. As the name implies, compliant linkage provides compliance between the drive wheels or drive axles of a vehicle, to accommodate control errors which would otherwise cause wheel slippage. The concept of compliant linkage was implemented and tested on a 4-DOF vehicle built at the University of Michigan´s Mobile Robotics Lab. Experimental results show that control errors are effectively absorbed by the linkage, resulting in smooth and precise motion. The dead-reckoning accuracy of the compliant linkage vehicle is substantially better than that reported in the literature for other MDOF vehicles; it was found equal to, or even better than that of comparable 2-DOF vehicles