Method for the position detection of an elevator car using an accelerometer and a door sensor

Patent metadata

Field	Value
Publication number	US-10315885-B2
Application number	US-201615089065-A
Country	US
Kind code	B2
Filing date	Apr 1, 2016
Priority date	Apr 16, 2015
Publication date	Jun 11, 2019
Grant date	Jun 11, 2019

Abstract

The invention concerns a method and a software program for determining the position of an elevator car moved in an elevator shaft, wherein an acceleration is measured and combined with measured open/closed states of the car door. The open-states of the door are used to identify floor-levels and a moving run sequence, wherein the car position estimate is then compared with allocated floor-levels from which the destination floor-level is calculated to extract the exact position of the car within the elevator shaft.

First claim

The invention claimed is:

1. A method for determining the position of an elevator car moved in an elevator shaft by the operation of a drive motor, said method comprising the steps of:
measuring an acceleration by means of an accelerometer for a moving run sequence of the car;
processing the acceleration in a processing unit to determine a distance-value the car moved;
using the distance-value the car has moved to update a car position estimate;
measuring open/closed states of a car door by means of a door sensor, wherein open-states of the door are used to identify floor-levels and the moving run sequence; and
comparing the car position estimate with said allocated floor-levels and determining therefrom the destination floor-level,
wherein only the accelerometer and the door sensor are used to determine the destination floor-level.

2. The method according to claim 1 , wherein the measured acceleration over the time is low-pass filtered in order to reduce noise.

3. The method according to claim 1 , wherein the measured acceleration over the time is high-pass filtered in order to remove the effect of gravity on the acceleration measurement.

4. The method according to claim 1 , wherein said distance-value is determined by a mathematical integration of said acceleration value over said time period of the car run.

5. The method according to claim 1 , wherein a computed list of floor-levels to be served is compiled by attributing an appertaining floor indication to one of the floor-levels, respectively, wherein a specific real floor number can be directly obtained from a list index of the landing.

6. The method according to claim 5 , wherein the list is periodically actualized by combining a previous level-value and the current distance-value by comparing by statistical weighing means using for example a moving average.

7. The method according to claim 1 , wherein the accelerometer is installed at the car site measuring the derivation of its movement.

8. The method according to claim 1 , wherein an error in accelerometer signal is corrected by setting it to zero when the door sensor indicates an open door state by means of the formula:

z
corrected

=

z
-

1
2

⁢
vt

,

wherein v is being calculated when the car door is open.

9. The method according to claim 1 , wherein at least one further trigger point in the elevator shaft is set triggering a signal to the car when being bypassed, wherein the signal is used to enhance a calibration of the velocity data with the formula:

v
corrected

=

v
-

2
⁢

z
-

z
ref

t

,

where v and z are the calculated velocity and position, and t the integration time.

10. The method according to claim 9 , wherein multiple trigger points are set, and wherein succeeding trigger points differ in their signal, respectively.

11. The method according to claim 10 , wherein the signals differ in polarity of magnet poles.

12. A software program embodied on a non-transitory computer readable medium and realizing the method according to claim 1 when being run on a computer controller for an elevator.

13. The method according to claim 2 , wherein the measured acceleration over the time is high-pass filtered in order to remove the effect of gravity on the acceleration measurement.

14. The method according to claim 2 , wherein said distance-value is determined by a mathematical integration of said acceleration value over said time period of the car run.

15. The method according to claim 3 , wherein said distance-value is determined by a mathematical integration of said acceleration value over said time period of the car run.

16. The method according to claim 2 , wherein a computed list of floor-levels to be served is compiled by attributing an appertaining floor indication to one of the floor-levels, respectively, wherein a specific real floor number can be directly obtained from a list index of the landing.

17. The method according to claim 3 , wherein a computed list of floor-levels to be served is compiled by attributing an appertaining floor indication to one of the floor-levels, respectively, wherein a specific real floor number can be directly obtained from a list index of the landing.

18. The method according to claim 4 , wherein a computed list of floor-levels to be served is compiled by attributing an appertaining floor indication to one of the floor-levels, respectively, wherein a specific real floor number can be directly obtained from a list index of the landing.

19. The method according to claim 2 , wherein the accelerometer is installed at the car site measuring the derivation of its movement.

20. The method according to claim 3 , wherein the accelerometer is installed at the car site measuring the derivation of its movement.

Assignees

• Kone Corp

Inventors

• Kinnari Jouko
• Laakso Matti

Classifications

• B66B1/3492

  Position or motion detectors or driving means for the detector (B66B1/40, B66B1/50 take precedence; length measuring G01B; speed measuring G01P) · CPC title

• B66B5/00 Primary

  Applications of checking, fault-correcting, or safety devices in elevators · CPC title

• B66B5/0025

  for maintenance or repair · CPC title

• B66B5/0018 Primary

  Devices monitoring the operating condition of the elevator system · CPC title

• B66B19/007 Primary

  method for modernisation of elevators · CPC title