Motor control system

Claim 2

A variable voltage system comprising a direct current motor, a direct current generator, connections for energizing the motor in accordance with the voltage output of the generator, and a source of field excitation for said generator including a pattern generator for generating a signal representative of the desired speed of said motor, said signal having a first polarity and a second polarity, deriving means for generating an error signal representative of the difference between the desired speed and the actual speed of the motor, a source of alternating potential selectively operable at different elevated magnitudes for providing an alternating current, control means for delivering half cycles of said alternating current while said source is at a first elevated magnitude to the generator field with a proper polarity to drive the motor in the direction called for by the polarity of the error signal, said control means being further operative to block the delivery of the portion of each half cycle of the alternating current to the generator field in accordance with the magnitude of the error signal, and limiting means operative to reduce the magnitude of the alternating potential to an elevated magnitude which is less than the first elevated magnitude upon the occurrence of predetermined abnormal conditions.

Claim 3

The system of claim 1 including means for producing a feedback signal proportional to the voltage across the motor and means for applying said feedback signal to the control means in opposition to the error signal.

Claim 4

The system of claim 1 including monitoring means operative upon the detection of armature current above a predetermined value after the motor has been brought to a stop to prevent the restarting of the system.

Claim 5

A variable voltage system comprising a direct current motor, a direct current generator, connections for energizing the motor in accordance with the voltage output of the generator, a source of field excitation for said generator including a pattern generator for generating a signal representative of the desired speed of said motor, said signal having a first polarity and a second polarity, deriving means for generating an error signal representative of the difference between the desired speed and the actual speed of the motor, a source of alternating current, control means for delivering half cycles of said alternating current to the generator field with a proper polarity to drive the motor in the direction called for by the polarity of the error signal, said control means being further operative to block the delivery of a portion of each half cycle of the alternating current to the generator field in accordance with the magnitude of the error signal, limiting means operative to reduce the potential of the alternating current supply upon the occurrence of predetermined conditions, monitoring means operative upon the detection of armature current above a predetermined value after the motor has been brought to a stop to prevent the restarting of the system, and delay means operative to prevent the operation of the monitoring means until a predetermined time after the motor has been brought to a stop.

Claim 6

A variable voltage system comprising a direct current motor, a direct current generator, connections for energizing the motor in accordance with the voltage output of the generator, a source of field excitation for said generator including a pattern generator for generating a signal representative of the desired speed of said motor, said signal having a first polarity and a second polarity, deriving means for generating an error signal representative of the difference between the desired speed and the actual speed of the motor, a source of alternating current, control means for delivering half cycles of said alternating current to the generator field with a proper polarity to drive the motor in the direction called for by the polarity of the error signal, said control means being further operative to block the delivery of a portion of each half cycle of the alternating current to the generator field in accordance with the magnitude of the error signal, limiting means operative to reduce the potential of the alternating current supply upon the occurrence of predetermined conditions, monitoring means operative upon the detection of armature current above a predetermined value after the motor has been brought to a stop to prevent the restarting of the system, and delay means operative to prevent the operation of the monitoring means until a predetermined time after the motor has been brought to a stop.

Claim 7

A variable voltage system comprising a direct current motor, a direct current generator, connections for energizing the motor in accordance with the voltage output of the generator, and a source of field excitation for said generator including a pattern generator for generating a signal representative of the desired speed of said motor, said signal having a first polarity and a second polarity, deriving means for generating an error signal representative of the difference between the desired speed and the actual speed of the motor, a source of alternating current, control means for delivering half cycles of said alternating current to the generator field with a proper Polarity to drive the motor in the direction called for by the polarity of the error signal, said control means being further operative to block the delivery of a portion of each half cycle of the alternating current to the generator field in accordance with the magnitude of the error signal, limiting means operative to reduce the potential of the alternating current supply upon the occurrence of predetermined conditions, said limiting means being biased to its operative condition, and means responsive to the limiting means to prevent starting of the motor when the limiting means is not in its operative condition, said limiting means being operated to its inoperative condition after the motor starts in the absence of said predetermined conditions.

Claim 8

A variable voltage system comprising a direct current motor, a direct current generator, connections for energizing the motor in accordance with the voltage output of the generator, and a source of field excitation for said generator including a pattern generator for generating a signal representative of the desired speed of said motor, said signal having a first polarity and a second polarity, deriving means for generating an error signal representative of the difference between the desired speed and the actual speed of the motor, a source of alternating current, control means for delivering half cycles of said alternating current to the generator field with a proper Polarity to drive the motor in the direction called for by the polarity of the error signal, said control means being further operative to block the delivery of a portion of each half cycle of the alternating current to the generator field in accordance with the magnitude of the error signal, limiting means operative to reduce the potential of the alternating current supply upon the occurrence of predetermined conditions, said limiting means being biased to its operative condition, and means responsive to the limiting means to prevent starting of the motor when the limiting means is not in its operative condition, said limiting means being operated to its inoperative condition after the motor starts in the absence of said predetermined conditions.

Claim 9

An elevator system comprising a structure having a plurality of landings, a vehicle, motive means for effecting movement of the vehicle relative to the structure to serve the landings, a pattern generator for generating a pattern signal as a function of the displacement of the vehicle relative to the landing from which it started and relative to the landing at which a stop is to be made, deriving means for deriving an error signal representative of the difference between the speed called for by the pattern generator and the actual speed of the vehicle, control means connected to the deriving means and the motive means for variable energizing said motive means in accordance with the error signal, and bias means operative to apply a bias signal of predetermined magnitude to the control means to compensate for the difference in the effect of the lag in the response of the vehicle to the speed called for by the pattern generator during acceleration and deceleration whereby substantially similar response is obtained during acceleration and deceleration using the single pattern.

Claim 10

An elevator system comprising a structure having a plurality of landings, a vehicle, motive means for effecting movement of the vehicle relative to the structure to serve the landings, a pattern generator for generating a pattern signal as a function of the displacement of the vehicle relative to the landing from which it started and relative to the landing at which a stop is to be made, deriving means for deriving an error signal representative of the difference between the speed called for by the pattern generator and the actual speed of the vehicle, control means connected to the deriving means and the motive means for variable energizing said motive means in accordance with the error signal, and bias means operative to apply a bias signal of predetermined magnitude to the control means to compensate for the difference in the effect of the lag in the response of the vehicle to the speed called for by the pattern generator during acceleration and deceleration whereby substantially similar response is obtained during acceleration and deceleration using the single pattern.

Claim 11

An elevator system comprising a structure having a plurality of landings, a vehicle, motive means for effecting movement of the vehicle relative to the structure to serve the landings, a pattern generator for generating a pattern signal as a function of the displacement of the vehicle relative to the landing from which it started and relative to the landing at which a stop is to be made, deriving means for deriving an error signal representative of the difference between the speed called for by the pattern generator and the actual speed of the vehicle, control means connected to the deriving means and the motive means for variably energizing said motive means in accordance with the error signal, and bias means operative to apply a bias signal to the control means to compensate for the difference in the effect of the lag in the response of the vehicle to the speed called for by the pattern generator during acceleration and deceleration whereby substantially similar response is obtained during acceleration and deceleration using the single pattern, said bias means generating a first bias signal during acceleration and a second bias means during deceleration, with the application of said first bias signal being utilized to initiate movement of said vehicle.

Claim 12

An elevator system comprising a structure having a plurality of landings, a vehicle, motive means for effecting movement of the vehicle relative to the structure to serve the landings, a pattern generator for generating a pattern signal as a function of the displacement of the vehicle relative to the landing from which it started and relative to the landing at which a stop is to be made, deriving means for deriving an error signal representative of the difference between the speed called for by the pattern generator and the actual speed of the vehicle, control means connected to the deriving means and the motive means for variably energizing said motive means in accordance with the error signal, and bias means operative to apply a bias signal to the control means to compensate for the difference in the effect of the lag in the response of the vehicle to the speed called for by the pattern generator during acceleration and deceleration whereby substantially similar response is obtained during acceleration and deceleration using the single pattern, said bias means generating a first bias signal during acceleration and a second bias means during deceleration, with the application of said first bias signal being utilized to initiate movement of said vehicle.

Claim 13

The system of claim 7 wherein said pattern generator generates a pattern signal as a continuous function of said displacement throughout the range of travel of said vehicle.

Claim 14

An elevator system comprising a structure having a plurality of landings, a vehicle, motive means for effecting movement of the vehicle relative to the structure to serve the landings, a pattern generator for generating a pattern signal as a function of the displacement of the vehicle relative to the landing from which it started and relative to the landing at which a stop is to be made, deriving means for deriving an error signal representative of the difference between the speed called for by the pattern generator and the actual speed of the vehicle, control means connected to the deriving means and the motive means for variably energizing said motive means in accordance with the error signal, bias means operative to apply a bias signal to the control means to compensate for the difference in the effect of the lag in the response of the vehicle to the speed called for by the pattern generator during acceleration and deceleration whereby substantially similar response is obtained during acceleration and deceleration using the single pattern, leveling means operative when the vehicle does not come to rest level with the landing to re-energize the motive means in accordance with the error signal to bring the car to exact registry with the landing, and means responsive to the operation of the leveling means to render the bias means inoperative.

Claim 15

An elevator system comprising a structure having a plurality of landings, a vehicle, motive means for effecting movement of the vehicle relative to the structure to serve the landings, a pattern generator for generating a pattern signal as a function of the displacement of the vehicle relative to the landing from which it started and relative to the landing at which a stop is to be made, deriving means for deriving an error signal representative of the difference between the speed called for by the pattern generator and the actual speed of the vehicle, control means connected to the deriving means and the motive means for variably energizing said motive means in accordance with the error signal, bias means operative to apply a bias signal to the control means to compensate for the difference in the effect of the lag in the response of the vehicle to the speed called for by the pattern generator during acceleration and deceleration whereby substantially similar response is obtained during acceleration and deceleration using the single pattern, leveling means operative when the vehicle does not come to rest level with the landing to re-energize the motive means in accordance with the error signal to bring the car to exact registry with the landing, and means responsive to the operation of the leveling means to render the bias means inoperative.

Claim 16

An elevator system including a structure having a plurality of landings, an elevator car, motive means for moving the car relative to the structure to serve the landings, and control means for controlling the operation of said motive means, said control means including, a pattern generator for producing a speed reference signal as a function of the displacement of the car relative to a landing from which the car is started and relative to a landing at which a stop can be made, a power supply for supplying power to the motive means, a speed regulator for regulating the power supplied to the motive means by the power supply as a function of the speed reference signal, limiting means biased to an operative condition wherein it is effective to restrict the power supplied to the motive means by the speed regulator, means operative to prevent the starting of the motive means when the limiting means is not in the operative condition, and means responsive to the starting of the car within a leveling zone adjacent a landing for transferring the limiting means from the operative to an inoperative condition wherein it is ineffective to restrict the power supplied to the motive means by the speed regulator.

Claim 17

An elevator system including a structure having a plurality of landings, an elevator car, motive means for moving the car relative to the structure to serve the landings, and control means for controlling the operation of said motive means, said control means including, a pattern generator for producing a speed reference signal as a function of the displacement of the car relative to a landing from which the car is started and relative to a landing at which a stop can be made, a power supply for supplying power to the motive means, a speed regulator for regulating the power supplied to the motive means by the power supply as a function of the speed reference signal, limiting means biased to an operative condition wherein it is effective to restrict the power supplied to the motive means by the speed regulator, means operative to prevent the starting of the motive means when the limiting means is not in the operative condition, and means responsive to the starting of the car within a leveling zone adjacent a landing for transferring the limiting means from the operative to an inoperative condition wherein it is ineffective to restrict the power supplied to the motive means by the speed regulator.

Claim 18

The system of claim 10, wherein the power supply is an alternating current source, wherein the speed regulator includes deriving means for deriving an error signal as a function of the difference between the speed reference signal and a signal representative of the actual speed of the car and gating means for gating half cycles of the alternating current source to the motive means, said gating means varying the gating time in each half cycle in accordance with the magnitude of the error signal and wherein said limiting means is effective in its operative condition to limit the potential of the alternating current source thereby effecting a positive limit on the maximum speed of the car.

Claim 19

The system of claim 11 wherein said motive means includes a generator, a motor, and connections for energizing the motor in accordance with the voltage output of the generator, wherein the speed regulator controls the operation of said motive means by controlling the power delivered to the generator field by the power supply, and wherein the limiting means also includes a negative feed back loop operative to combine in opposition with the error signal a signal representative of the potential drop across said motor thereby further limiting the speed of the motor when said limiting means is in the operative condition.

Claim 20

An elevator system comprising: a structure having a plurality of landings, an elevator car having at least one door, means for moving the car relative to the structure to serve the landings, means defining a leveling zone adjacent each landing, means initiating the opening of the door of said car as the car approaches a landing at which it is to stop, means for monitoring the speed of the car, means for rendering the means for monitoring the speed of the car effective a predetermined period of time after the door starts to open, to slow the car if the car is exceeding a predetermined speed.

Claim 21

An elevator system comprising: a structure having a plurality of landings, an elevator car having at least one door, means for moving the car relative to the structure to serve the landings, means defining a leveling zone adjacent each landing, means initiating the opening of the door of said car as the car approaches a landing at which it is to stop, means for monitoring the speed of the car, means for rendering the means for monitoring the speed of the car effective a predetermined period of time after the door starts to open, to slow the car if the car is exceeding a predetermined speed.

Claim 22

The elevator system of claim 13 including means for defining a landing zone adjacent each landing, which is within the leveling zone associated with each landing, and means responsive to car being within the landing zone For a predetermined period of time for stopping the car.

Claim 23

In a transportation system, a structure having a plurality of landings, a vehicle, means mounting the vehicle for movement relative to the structure in a path bringing the vehicle adjacent each of the landings, and control means for moving the vehicle along said path and stopping the vehicle in registry with a selected one of the landings, said control means comprising motive means effective when actuated from a power source for moving the vehicle along said path, brake means operable between a set condition wherein said brake means restrains said vehicle against movement by the motive means and a released condition wherein the motive means is free of such restraint by the brake means, said vehicle having a predetermined landing zone adjacent each of the landings wherein the position of the vehicle is acceptable for load transfer for the associated landing, said control means comprising means for actuating the motive means from a power source for moving the vehicle from a first one of the landing to a second one of the landings and initiating a stopping operation for stopping the vehicle at the second one of the landings, and timing means responsive to the presence of the vehicle in the landing zone for the second one of the landings for a predetermined period of time for actuating the brake means to the set condition.

Claim 24

In a transportation system, a structure having a plurality of landings, a vehicle, means mounting the vehicle for movement relative to the structure in a path bringing the vehicle adjacent each of the landings, and control means for moving the vehicle along said path and stopping the vehicle in registry with a selected one of the landings, said control means comprising motive means effective when actuated from a power source for moving the vehicle along said path, brake means operable between a set condition wherein said brake means restrains said vehicle against movement by the motive means and a released condition wherein the motive means is free of such restraint by the brake means, said vehicle having a predetermined landing zone adjacent each of the landings wherein the position of the vehicle is acceptable for load transfer for the associated landing, said control means comprising means for actuating the motive means from a power source for moving the vehicle from a first one of the landing to a second one of the landings and initiating a stopping operation for stopping the vehicle at the second one of the landings, and timing means responsive to the presence of the vehicle in the landing zone for the second one of the landings for a predetermined period of time for actuating the brake means to the set condition.

Claim 25

A system as claimed in claim 15 wherein said vehicle has door means operable between a first condition representing an open door and a second condition representing a closed door, said control means comprising limiting means for operating the vehicle at a speed below a predetermined value as the vehicle nears a selected landing at which the vehicle is to stop, and monitoring timing means effective a predetermined period of time after operation of the door means from the second condition to the first condition if the vehicle is traveling at a speed in excess of said predetermined value for initiating a slowing of said vehicle, said monitoring timing means being ineffective for initiating a slowing of the vehicle if the vehicle is traveling at a speed below said predetermined value.

Claim 26

A system as claimed in claim 15 in combination with door means for said vehicle operable between a first condition representing an open door and a second condition representing a closed door, said control means comprising leveling means establishing a leveling zone for each of the landings within which the vehicle levels into the landing zone for the associated landing, and monitoring timing means effective a predetermined period of time after operation of the door means from the second condition to the first condition for effecting a modification in the speed of the vehicle.

Claim 27

A system as claimed in claim 17 wherein in response to presence of the vehicle in a location outside of the leveling zone for the selected landing at which the vehicle is intended to stop when said predetermined period of time expires, said modification comprises the stopping of the vehicle at a position displaced from the landing zone for such selected landing.

Claim 28

In a transportation system, a structure having a plurality of landings, a vehicle, means mounting the vehicle for movement relative to the structure in a path bringing the vehicle adjacent each of the landings, and control means for moving the vehicle along said path and stopping the vehicle in registry with a selected one of the landings, said control means comprising motive means effective when actuated from a power source for moving the vehicle along said path, brake means operable between a set condition wherein said brake means restrains said vehicle against movement of the motive means and a released condition wherein the motive means is free of such restraint by the brake means, said vehicle having a predetermined landing zone adjacent each of the landings wherein the position of the vehicle is acceptable for load transfer for the associated landing, said cOntrol means comprising means for actuating the motive means from a power source for moving the vehicle from a first one of the landing to a second one of the landings and initiating a stopping operation for stopping the vehicle at the second one of the landings, said control means comprising leveling means establishing a leveling zone for each of the landings within which the vehicle levels into the landing zone for the associated landing, and monitoring timing means operating in response to expiration of a predetermined period of time measured from a predetermined event occurring during the approach of the vehicle to a selected landing at which the vehicle is to stop for effecting a modification in the speed of the vehicle.

Claim 29

In a transportation system, a structure having a plurality of landings, a vehicle, means mounting the vehicle for movement relative to the structure in a path bringing the vehicle adjacent each of the landings, and control means for moving the vehicle along said path and stopping the vehicle in registry with a selected one of the landings, said control means comprising motive means effective when actuated from a power source for moving the vehicle along said path, brake means operable between a set condition wherein said brake means restrains said vehicle against movement of the motive means and a released condition wherein the motive means is free of such restraint by the brake means, said vehicle having a predetermined landing zone adjacent each of the landings wherein the position of the vehicle is acceptable for load transfer for the associated landing, said cOntrol means comprising means for actuating the motive means from a power source for moving the vehicle from a first one of the landing to a second one of the landings and initiating a stopping operation for stopping the vehicle at the second one of the landings, said control means comprising leveling means establishing a leveling zone for each of the landings within which the vehicle levels into the landing zone for the associated landing, and monitoring timing means operating in response to expiration of a predetermined period of time measured from a predetermined event occurring during the approach of the vehicle to a selected landing at which the vehicle is to stop for effecting a modification in the speed of the vehicle.

Claim 30

A system as claimed in claim 19 wherein said monitoring timing means comprise means effective upon operation of the monitoring timing means for reducing power supplied to the motive means by a power source.

Claim 31

A system as claimed in claim 19 wherein said control means comprises first limiting means for limiting the speed of the motive means to a first maximum speed prior to said modification, said monitoring timing means being effective upon operation for establishing a second maximum speed for the motive means which is less than said first maximum speed.

Claim 32

A system as claimed in claim 19 wherein said vehicle has door means operable from a second condition representing a closed door to a first condition representing an open door as the vehicle approaches a selected landing at which the vehicle is to stop, said predetermined event comprising operation of the door means from the second condition to the first condition.

Claim 33

A system as claimed in claim 22 wherein the control means comprises means responsive to the door means being in the first condition with the vehicle displaced from a selected landing at which it is to stop by a distance which is outside of the leveling zone for stopping the vehicle in a position displaced from the registry range for such landing.

Claim 34

A system as claimed in claim 19 wherein said control means comprises timing means responsive to the continued supply of power to said motive means for a substantial period of time after the stopping of the vehicle at a landing for interrupting the connection of the motive means to a source of power.

Claim 35

A system as claimed in claim 15 wherein said control means comprises timing means responsive to the continued supply of power to said motive means for a substantial period of time after the stopping of the vehicle at a landing for interrupting the connection of the motive means to a source of power, said substantial period of time being longer than said predetermined period of time.