George Ellis 
Control System Design Guide: [PDF ebook] 
Using your Computer to Develop and Diagnose Feedback Controllers

This is a practical approach to control techniques. The author covers background material on analog controllers, digital controllers, and filters. Commonly used controllers are presented. Extended use of PSpice (a popular circuit simulation program) is used in problem solving. The book is also documented with 50 computer programs that circuit designers can use. Explains integration of control systems with a personal computer Compares numerous control algorithms in digital and analog form Details the use of SPICE in problem solving Presents modeling concepts for linear and nonlinear systems Examines commonly used controllers