文档介绍：Topic #1
Feedback Control Systems
• Motivation
• Basic Linear System Response
Cite as: Jonathan How, course materials for Feedback Control Systems, Fall 2007. MIT OpenCourseWare
(), Massachusetts Institute of Technology. Downloaded on [DD Month YYYY].
Fall 2007 1–1
: Introduction
d(t)
r(t) e(t) y(t)
Gc(s) G(s)
– u(t)
• Goal: Design a controller Gc(s) so that the system has some
desired characteristics. Typical objectives:
– Stabilize the system (Stabilization)
– Regulate the system about some design point (Regulation)
– Follow a given class mand signals (Tracking)
– Reduce response to disturbances. (Disturbance Rejection)
• Typically think of closed-loop control → so we would analyze the
closed-loop dynamics.
– Open-loop control also possible (called “feedforward”) – more
prone to modeling errors since inputs not changed as a result
of measured error.
• Note that a typical control system includes the sensors, actuators,
and the control law.
– The sensors and actuators need not always be physical devices
(., economic systems).
– A good selection of the sensor and actuator can greatly simplify
the control design process.
– Course concentrates on the design of the control law given the
rest of the system (although we will need to model the system).
September 2, 2007
Cite as: Jonathan How, course materials for Feedback Control Systems, Fall 2007. MIT OpenCourseWare
(), Massachusetts Institute of Technology. Downloaded on [DD Month YYYY].
Fall 2007 1–2
Why Use Control
• Typically easy question to answer for aerospace because many vehi-
cles (spacecraft, aircraft, rockets) and aerospace processes (propul-
sion) need to be controlled just to function
– Example: the F-117 does not even fly puter con-
trol, and the X-29 is unstable
• But there are also many stable systems that simply require better
performance in some sen