The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 02, 1985
Filed:
Mar. 31, 1983
Hugo S Ferguson, Averill Park, NY (US);
Duffers Scientific, Inc., Troy, NY (US);
Abstract
Apparatus, for use in a servo-control system and which provides a smooth 'bumpless' transition while switching from one transducer feedback signal to another, is described. Specifically, with this apparatus, a plurality of tracking signals are first produced in which each signal has a value which, in response to the value of a corresponding select signal, either tracks the feedback signal produced by a corresponding one of a plurality of transducers or remains constant. Each of these tracking signals is then subtractively summed with the feedback signal produced by the corresponding transducer in order to produce an output signal. Each of the output signals is then fed-back and subtractively summed with a command signal and the resulting difference, in turn, is applied as an error signal to a servo-amplifier. The values of all the select signals are set, by illustratively a process computer, in accordance with the particular transducers being switched. Since values of all the fed-back output signals are equal to zero, at the instant any transducer is switched, a 'bumpless' transition advantageously results regardless of which transducer is switched, when it is switched and any difference occurring between the values of the feedback signals of the transducers being switched.