Distance slowdown control for elevator systems

Claim 2

Control means providing distance dependent speed pattern signals for controlling at least a portion of the slowdown phase of an elevator car with respect to a structure having a plurality of landings, comprising: output terminal means, first means providing a first distance dependent speed pattern speed signal responsive to the distance to go to the landing at which the car is to stop, second means providing a second distance dependent speed pattern signal when the car nears said landing, means initially connecting said first means to said output terminal means at a predetermined point in the slowdown phase of the elevator car, and then switching from said first means to said second means at a predetermined transfer distance from said landing, and calibration means automatically calibrating said first means prior to the connection of said first means to said output terminal means.

Claim 3

The Control means of claim 1 wherein the calibration means calibrates the first means at the predetermined transfer distance.

Claim 4

The control means of claim 1 including counting means providing a count representative of the distance to go to a landing at which the car is to stop, the first distance dependent speed pattern signal provided by the first means is responsive to the magnitude of a count applied to its input, and wherein the calibration means applies a count to the input of the first means representing the predetermined transfer distance, to calibrate the first means to provide an accurate signal magnitude at this count, and including means effectively connecting the counting means to the input of the first means at a predetermined point in the slowdown phase of the elevator car.

Claim 5

The control means of claim 1 wherein the first distance dependent speed pattern signal is responsive to the square-root of the distance to go to the landing at which the car is to stop.

Claim 6

The control means of claim 1 including pulse generating means generating pulses in response to incremental movement of the elevator car relative to the structure, counting means responsive to said pulse generating means, counting the pulses in a first direction until reaching the count which corresponds to the distance required to stop the elevator car according to a predetermined deceleration schedule, and counting the pulses in a second direction when the car is requested to stop, and means connecting the counting means to the first means at a predetermined point in the slowdown phase of the elevator car.

Claim 7

The control means of claim 5 wherein the calibration means applies a count to the first means corresponding to the predetermined transfer distance, prior to the count of the counting means being applied to the first means, to provide an accurate first speed pattern signal at the transfer point.

Claim 8

The control means of claim 5 including auxiliary means responsive to the count of the counting means when the counting means is counting in the second direction, for applying a first predetermined count to the first means when the counting means reaches a second predetermined count.

Claim 9

The control means of claim 7 wherein the auxiliary means applies the first predetermined count to the first means when the counting means reaches a count having a magnitude less than the count representing the transfer distance.

Claim 10

The control means of claim 7 wherein the first predetermined count applied to the first means by the auxiliary means is that count which represents the predetermined transfer distance.

Claim 11

The control means of claim 1 wherein the first means includes a linear digital-to-analog converter and square-root means providing a signal responsive to the square-root of the output of the digital-to-analog converter, and including counting means connected to the input of the digital-to-analog converter during a predetermined point of the slowdown phase which provides a count representative of the distance to go to te landing at which the elevator car is to stop.

Claim 12

The control means of claim 10 wherein the calibration means applies a calibration count to the input of the digital-to-analog converter which corresponds to the predetermined transfer distance.

Claim 13

Speed control means for providing a first distance dependent speed pattern signal for controlling the slowdown speed of an elevator car with respect to a structure having a plurality of landings, comprising: pulse generating means generating pulses in response to incremental movement of the elevator car relative to the structure, counting means responsive to said pulse generating means, said counting means counting the pulses provided by said pulse generating means in a first direction until the count represents the distance required to stop the elevator car according to a predetermined deceleration schedule, and in a second direction when the car is requested to stop, converter means having an input and an output, operable for generating a speed reference pattern at its output in response to a count applied to its input, calibrating means calibrating said converter means during each run of the elevator car, prior to the counting of said counting means in the second direction, said calibrating means applying a calibration count to the input of said converter means which represents a predetermined distance, and adjusting the output of said converter means to the correct magnitude for the specific input count, and means rendering the input of said converter means responsive to the output of said counting means when said counting means initiates counting in the second direction, to provide a speed pattern signal at its output calibrated for a specific distance.

Claim 14

Speed control means for providing a first distance dependent speed pattern signal for controlling the slowdown speed of an elevator car with respect to a structure having a plurality of landings, comprising: pulse generating means generating pulses in response to incremental movement of the elevator car relative to the structure, counting means responsive to said pulse generating means, said counting means counting the pulses provided by said pulse generating means in a first direction until the count represents the distance required to stop the elevator car according to a predetermined deceleration schedule, and in a second direction when the car is requested to stop, converter means having an input and an output, operable for generating a speed reference pattern at its output in response to a count applied to its input, calibrating means calibrating said converter means during each run of the elevator car, prior to the counting of said counting means in the second direction, said calibrating means applying a calibration count to the input of said converter means which represents a predetermined distance, and adjusting the output of said converter means to the correct magnitude for the specific input count, and means rendering the input of said converter means responsive to the output of said counting means when said counting means initiates counting in the second direction, to provide a speed pattern signal at its output calibrated for a specific distance.

Claim 15

The control means of claim 12 including auxiliary means responsive to the count of the counting means when said counting means is counting pulses in the second direction, for applying a first predetermined count to the input of the converter means when the counting means reaches a second predetermined count.

Claim 16

The control means of claim 13 wherein the auxiliary means applies its first predetermined count to the input of the converter means when the counting means reaches the count of zero.

Claim 17

The control means of claim 13 wherein the first predetermined count applied to the input of the converter means by the auxiliary means is the calibration count.

Claim 18

The control means of claim 13 wherein the auxiliary means applies its first predetermined count to the input of the converter means when the count of the counting means is less than the first predetermined count of the auxiliary means.

Claim 19

The control means of claim 12 including means for providing a second distance dependent speed pattern signal, and means for switching from the first to the second distance dependent speed pattern signal at a predetermined transfer distance from a floor at which the elevator car is to stop, and wherein the calibration count represents the predetermined transfer distance, insuring accuracy of the first speed pattern signal at the transfer point.

Claim 20

The control means of claim 17 including auxiliary means responsive to the count of the counting means when said counting means is counting pulses in the second direction, for applying a first predetermined count to the input of the converter means when the counting means reaches a count less than the count representing the predetermined transfer distance.

Claim 21

The control means of claim 18 wherein the first predetermined count of the auxiliary means is the count representing the predetermined transfer distance.

Claim 22

The control means of claim 12 wherein the converter means includes a linear digital-to-analog converter and square-root means providing a signal responsive to the square-root of the output of the digital-to-analog converter.

Claim 23

The control means of claim 20 wherein the square-root means includes an operational amplifier having an analog multiplier in its feedback circuit.

Claim 24

The control means of claim 12 wherein the calibration means includes sample and hold means for sampling the output of the converter means while the calibrating count is being applied to the input of the converter means, and holding a signal responsive to any correction required while the converter means is responsive to the output of the counting means.

Claim 25

The control means of claim 22 including means providing a deceleration request signal, with the sample and hold means switching from its sampling to its holding function in response to said deceleration request signal.

Claim 26

The control means of claim 23 including delay means, said delay means being responsive to the deceleration request signal to remove the calibration count and render the input of the converter means responsive to the output of the counter means, a predetermined period of time after initiation of the deceleration request, enabling the sample and hold means to switch to its hold mode prioR to the removal of the calibration count from the converter means.