This monograph analyzes the design of nonlinear filters and nonlinear adaptive controllers, using exact linearization methods which are based on the theory of flatness and the methods of differential geometry. The filters obtained outperform other nonlinear filters in terms of accuracy of estimation and computation speed and the adaptive controllers can be applied to a wide class of nonlinear systems with unknown dynamics and assure reliable functioning of the control loop under uncertainty and varying operating conditions. In addition, the book analyzes differential-flatness-theory-based control and filtering methods for distributed-parameter systems. The book demonstrates the efficiency of the proposed control and filtering schemes showing how they may be applied in various simulated electromechanical systems. These include: industrial robotic manipulators with multiple degrees of freedom; mobile robots and vehicles; electrical power generators and power electronics; electric motors and actuators; digital and spark-ignited internal combustion engines; distributed parameter systems including fault diagnosis in sensor networks; and communication systems including compensation for delays and packet drops.§Differential Flatness Approaches to Nonlinear Control and Filtering will be of interest to academic researchers exploring methods of treating nonlinear systems and to workers studying electromechanical systems.