This book introduces a new framework for non-linear analysis and control of intelligent machines such as robot arms, mechanical hands, and other advanced mechatronic systems. It clarifies the physical and mathematical prinicples underlying the complicated dynamics of non-linear mechanical systems and deals with the design of controllers that enable sophisticated tasks to be executed. A new concept called `non-linear position-dependent circuits' plays a crucial role, together with passivity analysis as a generalization of the impedance concept. Adaptability and learnability of robot arms and hands as intelligent machines are aLso analysed through visible expressions of their dynamics via corresponding non-linear circuits and generalized impedance concepts.This approach may mark a milestone not only in development of a control theory for advanced mechatronics systems but also in the long path toward understanding the mysteries of motor control in the human central nervous system.