Control theory

The concept of the feedback loop to control the dynamic behavior of the system: this is negative feedback, because the sensed value is subtracted from the desired value to create the error signal which is amplified by the controller.

Control theory is an interdisciplinary branch of engineering and mathematics, that deals with the behavior of dynamical systems. The desired output of a system is called the reference. When one or more output variables of a system need to follow a certain reference over time, a controller manipulates the inputs to a system to obtain the desired effect on the output of the system.

Contents

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• 1 Overview
  • 1.1 An example
• 2 History
• 3 People in systems and control
• 4 Classical control theory
  • 4.1 Closed-loop transfer function
  • 4.2 PID controller
• 5 Modern control theory
• 6 Topics in control theory
  • 6.1 Stability
  • 6.2 Controllability and observability
  • 6.3 Control specifications
  • 6.4 Model identification and robustness
• 7 System classifications
  • 7.1 Linear control
  • 7.2 Nonlinear control
• 8 Main control strategies
• 9 See also
• 10 References
• 11 Further reading
• 12 External links