%0 Book %A J. R. Leigh %+ Polytechnic of Central London %T Essentials of Non-linear Control Theory %D 1983 %I Institution of Engineering and Technology %S Control, Robotics and Sensors %K envelope methods %K system decomposition %K nonlinearity %K phase plane portrait %K nonlinear second-order system linearisation %K relaxation oscillations %K Limit cycles %K gradient systems %K Lienard's equation %K dynamic systems %K describing function method %U https://digital-library.theiet.org/;jsessionid=t6u96akq12ee.x-iet-live-01content/books/ce/pbsp006e