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:
Jun. 13, 1978
Filed:
Sep. 07, 1976
John G Klauser, Holliston, MA (US);
Boston Digital Corporation, Hopkinton, MA (US);
Abstract
A digital control system is provided for regulating the position and velocity of a load. Within the control system, both commanded and actual motion of the load are represented by a bi-directional pulse train in which each pulse represents an increment of movement, so that the pulse repetition rate represents the speed of the load. A bi-directional pulse generator is provided in which the polarity and repetition rate of the output signal are dependent respectively on the sign and magnitude of the differential pulse accumulation between the commanded and actual motion signals. In one embodiment, a pulse-actuated incremental stepping motor is used to move the load, so that the bi-directional pulse train from the pulse generator can be applied directly to the stepping motor through a pulse conditioner, and is also fed back through a single feedback connection as the actual motion signal. In a second embodiment of the system, a motor requiring an analog drive signal is used and the system has two feedback paths for a bi-directional pulse signal produced by a transducer in response to the actual movement of the load. In the first path, there is accumulated the difference between the number of pulses in the transducer signal and the number of pulses in an externally applied command signal to produce a positional error signal. The positional error signal is applied to a pulse generator to control the polarity and repetition rate of bi-directional output pulses produced by the pulse generator. The output pulses from the pulse generator are used as the command signal for the second feedback path in which there is accumulated the difference between the number of pulses in the pulse generator signal and the transducer signal to produce a second error signal. The second error signal is applied to a digital-to-analog converter which provides an analog signal for controlling the speed of the motor that moves the load. In a third embodiment, a plurality of subsystems, each of the type described above, are combined to form a system for controlling the position and motion of the load along a plurality of coordinates.