US3589474A
Expired / Lapsed
US
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Digital pattern generator for motor speed control
Assignee: Westinghouse Electric Corp
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Filing: 1969-05-07
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Granted: 1971-06-29
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Expires: 1989-05-07
Abstract
Abstract A speed reference signal for an elevator speed control is generated by a nonlinear digital to analog converter as a function of the accumulated count in a first reversible digital counter of pulses representative of increments of displacement between the car and the hatchway. The accumulated count is limited to a predetermined maximum corresponding to a desired maximum speed. A second reversible counter maintains a running count proportional to the position of the car in the hatchway. The counts in the two counters are totalized to give an advance car position and when this total count equals the desired stopping point, as determined by a bit-by-bit comparator, deceleration is begun by causing subsequent pulses to reduce the count in the first counter. Alternatively the advance car position is generated directly in the second counter by directing pulses to this counter at twice the normal rate while pulses are being accumulated in the first counter and then at the normal rate during the constant speed phase when no pulses are being accumulated in the first counter. No pulses are directed to the second counter in the alternate configuration during deceleration while pulses are being subtracted in the first counter.
Inventors
- 👤 Andre Wavre
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:06
CPC Classifications
B; B66; B66B; B66B1/00; B66B1/34; B66B1/3492; B66B5/00; B66B5/02; B66B5/08; B66B5/10
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
164 words
In a speed control system, a structure, a movable member mounted for movement relative to the structure, a speed regulator operative to control the speed of the movable member with respect to the structure in accordance with a speed reference signal, and a speed reference signal generator comprising first counting means for accumulating a count proportional to the incremental displacement of the movable member as it moves with respect to the structure, converter means responsive to the accumulated count in the first counting means for generating the speed reference signal as a continuous function of the accumulated count and control means responsive to the counting means for initiating a decrease in the accumulated count in said first counting means for each increment of displacement between the movable member and the structure when the accumulated count in the counting means is equal to the increments of displacement between the movable member and a desired stopping point for the movable member with respect to the structure.
Claim 2
Dependent Claim
164 words
In a speed control system, a structure, a movable member mounted for movement relative to the structure, a speed regulator operative to control the speed of the movable member with respect to the structure in accordance with a speed reference signal, and a speed reference signal generator comprising first counting means for accumulating a count proportional to the incremental displacement of the movable member as it moves with respect to the structure, converter means responsive to the accumulated count in the first counting means for generating the speed reference signal as a continuous function of the accumulated count and control means responsive to the counting means for initiating a decrease in the accumulated count in said first counting means for each increment of displacement between the movable member and the structure when the accumulated count in the counting means is equal to the increments of displacement between the movable member and a desired stopping point for the movable member with respect to the structure.
Claim 3
Dependent Claim
53 words
The system of claim 1 wherein the speed reference signal generator includes limit means operable to discontinue the further accumulation of increments of displacement between the movable member and the structure when the accumulated count in the first counting means reaches a value corresponding to a predetermined maximum speed desired for the system.
Claim 4
Dependent Claim
35 words
The system of claim 2 including starting means operable to apply a bias to said converter for generating a speed reference signal adequate to initiate movement of said movable member with respect to the structure.
Claim 5
Dependent Claim
135 words
The system of claim 3 wherein said speed reference signal generator includes second counting means operable to accumulate a second count proportional to the incremental position with respect to the structure at which said movable member could be brought to a stop from the speed called for by the speed reference signal, encoder means operative to register a count proportional to the incremental position with respect to the structure at which it is desired that said movable member be brought to a stop, and comparator means responsive to the count in the second counting means and the count in the encoder and operative to trigger the control means to initiate the decrease in the accumulated count in the first counting means when the count in the second counting means equals the count in the encoder.
Claim 6
Dependent Claim
113 words
The system of claim 4 wherein the second counting means includes a counter operative to count increments of displacement as the movable member moves with respect to the structure, the count so accumulated being representative of the actual position of the movable member with respect to the structure, said second counting means also including totalizing means operative to continuously combine the accumulated count in the counter and the accumulated count in the first counting means whereby the resultant count in the totalizing means represents the incremental position with respect to the structure at which the movable member could be brought to a stop from the speed called for by the speed reference signal.
Claim 7
Dependent Claim
127 words
The system of claim 5 wherein the counter is a reversible counter operative to increase the count in the counter for each increment of displacement between the movable member and the structure when the movable member moves in a first direction with respect to the structure and operative to decrease the count in the counter for each of sAid increments of displacement when the movable member moves in a second direction with respect to the structure, said totalizing means being operative to add the counts in the counter and the first counting means when said member is moving in the first direction and to subtract the count in the first counting means from the count in the counter when said movable member moves in the second direction.
Claim 8
Dependent Claim
135 words
The system of claim 4 including pulse generating means operative to generate pulses at a first output for each increment of displacement as the movable member moves with respect to the structure and operative to generate pulses at a second output for alternate of said increments of displacement, said first counting means being responsive only to the pulses generated at the second output of said pulse generator, said second counting means including a counter operable to count pulses received from the first output of said pulse generator when pulses are being accumulated in the first counting means, to receive pulses from the second output of the pulse generator when no pulses are being accumulated in said first counting means and to receive no pulses while the count is being reduced in said first counting means.
Claim 9
Dependent Claim
203 words
In a speed control for controlling the speed of an elevator car with respect to a structure having a plurality of landings, a speed reference pattern generator comprising pulse generating means for generating pulses indicative of incremental movement of the elevator car with respect to the structure, reversible counting means for counting pulses generated by the pulse generator, said counting means having a first input for counting in a first direction to increase the count in said counter and a second input for counting in a second direction to decrease the count in said counter, converter means operable for generating a speed reference pattern signal as a function of the accumulated count in said counting means, control means operative to a first condition to direct the pulses generated by said pulse generator into the first input of said counter to effect an increase in the pattern signal and operative to a second condition to direct the pulses generated by the pulse generator into the second input of said counter to effect a decrease in the pattern signal, and means to apply the speed pattern signal to the speed control in the proper sense to cause the car to move in the desired direction.
Claim 10
Dependent Claim
203 words
In a speed control for controlling the speed of an elevator car with respect to a structure having a plurality of landings, a speed reference pattern generator comprising pulse generating means for generating pulses indicative of incremental movement of the elevator car with respect to the structure, reversible counting means for counting pulses generated by the pulse generator, said counting means having a first input for counting in a first direction to increase the count in said counter and a second input for counting in a second direction to decrease the count in said counter, converter means operable for generating a speed reference pattern signal as a function of the accumulated count in said counting means, control means operative to a first condition to direct the pulses generated by said pulse generator into the first input of said counter to effect an increase in the pattern signal and operative to a second condition to direct the pulses generated by the pulse generator into the second input of said counter to effect a decrease in the pattern signal, and means to apply the speed pattern signal to the speed control in the proper sense to cause the car to move in the desired direction.
Claim 11
Dependent Claim
56 words
The system of claim 8 wherein the speed reference pattern generator includes limit means responsive to the accumulated count in the counter and effective to operate the control means to a third condition wherein no pulses from the pulse generator are directed into either input of the counter when said accumulated count reaches a predetermined value.
Claim 12
Dependent Claim
38 words
The pattern generator of claim 8 wherein the converter means comprises a nonlinear digital to analog converter which produces the speed reference pattern signal as a function of the square root of the accumulated count in said counter.
Claim 13
Dependent Claim
33 words
The pattern generator of claim 8 including first bias means operative to cause said converter means to generate an initial output independent of the count in said counter to start the car moving.
Claim 14
Dependent Claim
108 words
The system of claim 11 including precision landing control means for generating the speed reference pattern signal during the final landing phase to bring the car into precise registry with the landing, and transfer means for transferring the response of the speed control from the pattern generator to the precision landing control when the count in the counter reaches a predetermined value while the counter is counting in the second direction, the magnitude of said first bias signal being so determined that the speed reference pattern signal generator by the converter substantially matches the speed reference signal generated by the precision landing control means when transfer is effected.
Claim 15
Dependent Claim
72 words
The system of claim 11 including second bias means operative to apply a second Bias to the converter for increasing the output of the converter when the control means is in the first condition and for decreasing the output of the converter when the control means is in the second condition to compensate for the lag in the response of the system to the speed reference pattern signal during acceleration and deceleration.
Claim 16
Dependent Claim
84 words
The speed reference pattern generator of claim 9 including second reversible counting means responsive to the pulses generated by the pulse generator and the number of pulses accumulated in said first counter for accumulating a count representative of the advance position of the elevator car with respect to the structure, said pattern generator also including stopping means responsive when the count in the second counting means represents the desired stopping point of the elevator car to operate the control means to the second condition.
Claim 17
Dependent Claim
143 words
The speed reference pattern generator of claim 14 wherein the stopping means includes encoder means for storing a count representative of the desired stopping point of the elevator car relative to the structure and a comparator responsive to the count in the encoder and the accumulated count in the second counting means, said comparator having a first output when the count in the encoder exceeds the count in the second counting means, a second output when the count in the second counting means, a second output when the count in the second counting means exceeds the count in the encoder and a third output when the count in the encoder and the count in the second counting means are equal, said stopping means being effective to operate the control means to the second condition in response to the third output from the comparator.
Claim 18
Dependent Claim
140 words
The system of claim 14 wherein the second counting means includes a second reversible counter responsive to pulses generated by the pulse generator and operative to accumulate a count representative of the actual position of the elevator car relative to the structure by counting in a first direction when the elevator car moves in a first direction and counting in the second direction when the elevator car moves in the second direction, said second counting means also including an adder-subtracter operative to accumulate a count representative of the elevator car advance position by summing the count in said first and second reversible counters when the second counter is counting in the first direction and subtracting the count in the first reversible counter from that in the second reversible counter when the second reversible counter is counting in the second direction.
Claim 19
Dependent Claim
128 words
The speed reference pattern generator of claim 14 wherein the pulse generator includes means for generating pulses at a first rate and at a second rate which is twice the first rate, wherein the second counting means includes a second reversible counter for counting pulses generated by the pulse generator and wherein said control means is effective to direct pulses to said first reversible counter only at said first rate while being effective to direct pulses to said second reversible counter at said second rate when the control means is in the first condition, at said first rate when the control means is in the third condition and to block pulses from being directed to the second reversible counter when the control means is in the second condition.
Claim 20
Dependent Claim
133 words
A floor selector adaptable for use in an elevator system including a structure having a plurality of floors, a car mounted for movement relative to the structure to serve the floors, and supervisory means for supervising said movement, said floor selector comprising pulse generating means operative to generate pulses for each standard increment of displacement of the car relative to the structure, reversible counting means responsive to the pulse generating means and operative to accumulate a count representative of the position of the car relative to the structure and decoder means responsive to the accumulated standard count in the counting mEans and to the position of the various floors in terms of said standard increments of displacement for transforming the accumulated count into floor position signals to be utilized by the supervisory means.
Claim 21
Dependent Claim
133 words
A floor selector adaptable for use in an elevator system including a structure having a plurality of floors, a car mounted for movement relative to the structure to serve the floors, and supervisory means for supervising said movement, said floor selector comprising pulse generating means operative to generate pulses for each standard increment of displacement of the car relative to the structure, reversible counting means responsive to the pulse generating means and operative to accumulate a count representative of the position of the car relative to the structure and decoder means responsive to the accumulated standard count in the counting mEans and to the position of the various floors in terms of said standard increments of displacement for transforming the accumulated count into floor position signals to be utilized by the supervisory means.
Claim 22
Dependent Claim
58 words
The floor selector of claim 18 wherein the counting means of the floor selector includes means for adjusting the accumulated count in accordance with the velocity of the car so that the floor position signals generated by the decoder reflect the floor at which the car could be brought to a stop according to a predetermined deceleration schedule.
Claim 23
Dependent Claim
38 words
The floor selector of claim 19 wherein the counting means also includes means for generating a speed reference signal and wherein said mounting means is responsive to said speed reference signal for controlling the speed of the car.
Claim 24
Dependent Claim
67 words
The floor selector of claim 19, wherein the means for adjusting the accumulated count in accordance with the velocity of the car includes auxiliary counting means for accumulating a count of standard increments of displacement during the interval while the car is being accelerated, and totalizing means operative to totalize the accumulated count in the auxiliary counting means and the accumulated count in the reversible counting means.
Claim 25
Dependent Claim
66 words
The floor selector of claim 19, wherein the means for adjusting the accumulated count in accordance with the velocity of the car includes means within said pulse generating means for delivering pulses to said reversible counting means during the period that the car is accelerating at twice the rate that pulses are delivered to the reversible counting means while the car is traveling at constant speed.
Claim 26
Dependent Claim
48 words
The floor selector of claim 22 wherein the means for adjusting the accumulated count in accordance with the velocity of the car includes means within said pulse generating means for discontinuing the delivery of pulses to said reversible counting means during the period that the car is decelerating.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-06-28 | 1974-12-28 | 1975-06-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-28 | 1978-12-28 | 1979-06-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-28 | 1982-12-28 | 1983-06-29 | $7700.00 | Window Closed / Lapsed |