Closed-loop control method and apparatus
AssigneeMax-Planck-Gesellschaft zur Foerderung der Wissenschaften e.V.
InventorFrank Schneider
Life of this patent
Estimating the term…
Abstract
Method and apparatus for closed-loop control of a variable in which an analog manipulated signal is produced for discrete time intervals in response to an error signal. The effect of the manipulated signal is confined to a predetermined manipulating range. The response to the error signal is distributed among a plurality of subsequent discrete time intervals when it tends to exceed the manipulating range of the control, so that the entire rate action becomes effective. The control according to the invention allows to deal with delays up to the third order with high accuracy and extraordinary speed. Special correcting means allow to apply this type of control also to line-commutated converters and choppers.
Claims29
Controlling apparatus comprising
- a) an input for receiving an error signal representing a deviation of an actual value of a variable from a desired value of said variable,
- b) an output (U) for providing a manipulated signal in response to said error signal, said manipulated signal being effective in a predetermined manipulating range,
- c) first controller means (100) having a first output (D) for providing a signal which a function of the rate of change of the error signal, and a second output (P) for providing a proportional signal which is a function of the magnitude of said error,
- d) means (150) for combining the signals from said first and second outputs of said first controller means, and to produce said manipulated signal and to apply it to the output of said apparatus, and further characterized by
- e) clock means (300) for producing clock signals defining subsequent time intervals,
- f) limiting means (105) for limiting in each time interval a manipulated signal that has a portion exceeding said manipulating range to prevent exceeding said manipulating range, and
- g) transfer means (103, 104) for combining the portion of the manipulating signal which exceeds said manipulating range with the manipulated signal of the next following time interval.
Control apparatus comprising
- a) an input for receiving an error signal representing a deviation of an actual value of a variable from a desired value of said variable said error signal having a magnitude which is subject to vary with a rate of change,
- b) an output (U) for providing a manipulated signal in response to said error signal,
- c) first controller means (100) having a first output (D) for providing a first output signal which a function of the rate of change of the error signal, and a second output (P) for providing a second output signal which is a function of the magnitude of said error,
- d) means (150) for combining said first and second output signals to produce a combined signal,
- characterized by correcting means (200) having an input terminal and an output terminal, said input terminal being connected to receive said combined signal, said correcting means being adapted to provide a corrected manipulated signal at the output terminal, said corrected manipulated signal including a first portion of said combined signal and a delayed second portion of said combined signal.
A method of closed-loop control in which a manipulated signal is produced {n response to an error signal (X), said error signal being subject to change with a rate of change, said manipulated signal being a function at least of a derivative signal corresponding to the rate of change of said error signal, and a proportional signal which is a function of the magnitude of said error signal;
- said manipulated signal having a predetermined manipulating range and controlling a repetitive signal consisting cf a series of subsequent cycles, each cycle containing a positive going signal transition and a negative going signal transition;
- said controlling including varying the time of occurrence of one of said signal transitions in the respective cycle, said method further comprising the steps
- a) dividing said manipulated signal (U) of at least some cycles into a first signal part (U.sub.i and a second signal part (U.sub.K),
- b) delaying said second signal part (U.sub.K) by at least one cycle (T.sub.i) to produce a delayed signal part, and
- c) combining a first signal part (U.sub.i) and a delayed signal part (U.sub.k) to produce a corrected manipulated signal.
A method for closed-loop control in which a manipulated signal is produced in response to an error signal (S.sub.d) and applied to manipulating means, said error signal being subject to change with a rate of change, said manipulated signal being a function of at least a signal (derivative signal D.sub.i) depending on the rate of change of said error signal, and a signal (proportional signal P.sub.i) proportional to the magnitude of said error signal, and said manipulated signal having a predetermined manipulating range (U.sub.h), said method further comprising
- a) defining a plurality of successive time intervals (i) with a clock time (T.sub.i) by a clock signal;
- b) producing an error signal in each time interval,
- c) if the error signal has a magnitude which would result in a manipulated signal which includes a portion exceeding that manipulating range in a given time interval, using in said given time interval for generating said manipulated signal only a portion of said error signal which results in a manipulated signal not exceeding said manipulating range;
- d) in the time interval following said given time interval generating a manipulated signal on the basis of a momentary error signal existing during said following time interval and said exceeding portion of the preceding time interval, and
- e) repeating steps c) and d) if step d) results in a manipulated signal exceeding said manipulating range.
Dependencies are inferred from the claim text.