Programmable positioning apparatus and acceleration control system particularly useful therein

A programmable positioning system for supplying motion command pulses to a drive to move an article a programmed distance, comprising:

• data input means for inputting the programmed distance data "D," acceleration data rlating to a predetermined rate of acceleration, velocity data relating to a predetermined maximum velocity, and for establishing th value "B" corresponding to the distance to be traversed by the article when accelerated at said predetermined rate of acceleration from zero velocity to said predetermined maximum velocity;
• acceleration control means for generating a first series of electrical pulses at a repetition rate corresponding to said predetermined rate of acceleration;
• a velocity generator generating a second series of electrical pulses at a repetition rate corresponding to said predetermined maximum velocity;
• means for continuously computing the distance "d" corresponding to the remaining distance-to-go for the article to reach the programmed distance;
• and drive control means normally enabling said acceleration generator to generate said first series of electrical pulses to be supplied to the drive as motion command pulses, but enabling instead said velocity generator to generate said second series of electrical pulses to be supplied to the drive as motion command pulses whenever the programmed distance "D" is more than twice "B", and the computed distance "d" is more than "B" but less than "D" minus "B."

An acceleration control system, comprising:

• a pulse generator producing pulses at a predetermined pulse repetition rate;
• a summing register;
• means adding into said latter register during acceleration, and subtracting from said latter register during deceleration, the pulse produced by the pulse generator;
• an error register;
• means clearing the error register at the start of the acceleration operation;
• means incrementing the error register according to one sign by a quantity relating to a predetermined rate of acceleration;
• means incrementing the error register according to the opposite sign by the quantity in said summing register whenever a pulse is generated by the pulse generator;
• a sign detector detecting the sign of the error register;
• and means effective each time the error register is of said opposite sign to produce a motion command pulse and to increment the error register according to said one sign by said acceleration quantity until the error register becomes zero or of said one sign.

A system for coordinating a first quantity to a second quantity and a third quantity so that the first quatity varies according to the square of the second quantity at a rate according to the third quantity, comprising:

• a pulse generator producing pulses at a rate corresponding to said second quantity;
• a summing register;
• means incrementing said latter register, according to the sign of said third quantity, by the pulses produced by the pulse generator;
• an error register;
• means clearing the error register at the start of the coordinating operation;
• means incrementing the error register according to one sign by a quantity corresponding to said thire quantity;
• means incrementing the error register according to the opposite sign by the quantity in said summing register whenever a pulse is generated by the pulse generator;
• a sign detector detecting the sign of the error register;
• and means effective each time the error register is of said opposite sign to produce a pulse representing said first quantity and to increment said error register according to said one sign by said third quantity until the error register becomes zero or of said one sign.