DIGITAL CONTROL DEVICE

• US 3,622,855 A
• Filed: 08/03/1970
• Issued: 11/23/1971
• Est. Priority Date: 08/03/1970
• Status: Expired due to Term

• Current Assignee: David M. Hodgin, Ferman L. Walker, Leonard J. Petska, Robert H. Pool
• Original Assignee: David M. Hodgin, Ferman L. Walker, Leonard J. Petska, Robert H. Pool
• Inventors: Walker, Ferman L., Pool, Robert H., Hodgin, David M., Petska, Leonard J.
• Primary Examiner(s): Dobeck, Benjamin
• Application Number:
  US05/060,470
• Time in Patent Office: 477 Days
• Field of Search: 318/603,601,571,602
• US Class Current: 318/603
• CPC Class Codes: G05B 19/23 for point-to-point control
• CPC Class Codes: G05B 2219/43183 Speed control, input is the reference, but no feedback
• CPC Class Codes: G05D 16/2013 using throttling means as controlling means
• CPC Class Codes: G05D 3/121 using synchromachines (selsyns)

Abstract

This invention relates to control means for accurately controlling the amount and rate of change of a device to be controlled. The invention contemplates a digital input device which receives a digital command, either manually or from a computer; compares the command with a signal from a position sensing mechanism; and generates an '"'"''"'"''"'"''"'"'error'"'"''"'"''"'"''"'"' signal which is applied to correctly position the controlled device.

Claims

1. A digital control device comprising:

drive means for driving a device to be controlled, encoder means coupled to said drive means and operative to generate a digital signal indicative of the position of said controlled device, digital input means for supplying a digital command signal indicative of a desired position and a desired rate of change, comparison means for comparing said command signal with said signal from said encoder and generating a drive signal to actuate said drive means, said comparison means comprising;

a command register connected to receive the position control portion of said command signal, an UP-DOWN counter connected to receive said signal from said encoder means, a comparator circuit connected to compare the signal held by said command register with the signal held by said counter and operative to generate an appropriate difference signal, a rate register connected to receive the rate-of-change portion of said command signal, a variable rate pulse generator operative to generate pulses at a rate determined by the signal held by said rate register, motor driver means operable to drive said stepping motor, and pulse control means connected to receive said difference signal and responsive thereto to control passage of pulses from said pulse generator to said motor driver means.

2. The device of claim 1 further comprising:

an increment register connected to receive that portion of said command signal indicative of increment of rate adjustment with time and serving to appropriately adjust the value held by said rate register.