Elevator hitch load weighing tare compensation
First Claim
Patent Images
1. A method of moving an elevator car, comprising the steps:
- a) providing an analog load signal indicative of weight on a car hitch;
b) providing an analog tare compensation signal;
c) providing a compensated analog load signal in response to a difference between said analog tare compensation signal and said analog load signal;
d) converting said compensated analog load signal into a digital load signal;
e) providing a digital stored load signal in response to said digital load signal;
f) providing a payload signal in response to a difference between said digital stored load signal and said digital load signal; and
g) moving an elevator car in response to said payload signal.
1 Assignment
0 Petitions
Accused Products
Abstract
In an elevator hitch load weighing assembly, a load cell provides an analog load signal to a summer 12, where an analog tare compensation signal is subtracted from the load signal prior to a compensated load signal being provided to an analog-to-digital converter (ADC) 20; the digital load signal is provided to a remaining tare subtractor 26 where tare remaining in the digital load signal is subtracted and a payload provided.
19 Citations
9 Claims
-
1. A method of moving an elevator car, comprising the steps:
-
a) providing an analog load signal indicative of weight on a car hitch; b) providing an analog tare compensation signal; c) providing a compensated analog load signal in response to a difference between said analog tare compensation signal and said analog load signal; d) converting said compensated analog load signal into a digital load signal; e) providing a digital stored load signal in response to said digital load signal; f) providing a payload signal in response to a difference between said digital stored load signal and said digital load signal; and g) moving an elevator car in response to said payload signal. - View Dependent Claims (2)
-
-
3. A method of compensation tare in an elevator load weight signal, comprising the steps of:
-
providing an analog load signal indicative of weight on a car hitch; providing an analog tare compensation signal wherein said step of providing an analog tare compensation signal includes; measuring a static tare; providing a slope describing a relationship between elevator position and tare; multiplying said slope by said static tare for providing a product; and summing said product with said elevator position for providing said analog tare compensation signal; and providing a compensated analog load signal in response to a difference between said analog tare compensation signal and said analog load signal. - View Dependent Claims (4)
-
-
5. A method of compensating tare in an elevator load weight signal, comprising the steps of:
-
providing an analog load signal indicative of weight on a car hitch; providing an analog tare compensation signal including; measuring a static tare; obtaining a slope describing a linear relationship between elevator position and tare including; moving an empty car to a first floor of a hoistway; measuring said digital load signal; comparing said digital load signal with an estimated remaining tare and adjusting a magnitude of a digital tare compensation signal until a magnitude of said digital load signal is less than said estimated remaining tare; measuring and storing a first floor digital tare compensation signal; moving said empty elevator to a second floor in said hoistway; measuring said digital load signal while said car is at a top of said hoistway; comparing said digital load signal with an estimated remaining tare and adjusting the magnitude of a digital tare compensation signal until the magnitude of said digital load signal is less than said estimated remaining tare while the car is at the top of said hoistway; measuring and storing a second floor digital tare compensation signal; and dividing a hoistway length by a difference between said first floor digital tare compensation signal and said second floor digital tare compensation signal ; multiplying said slope by said elevator position for obtaining a product; summing said product with said elevator position for providing said analog tare compensation signal; and providing a compensated analog load signal in response to a difference between said analog tare compensation signal and said analog load signal.
-
-
6. A method of compensating tare in an elevator load weight signal, comprising the steps of:
-
providing an analog load signal indicative of weight on a car hitch; providing an analog tare compensation signal; and providing a compensated analog load signal in response to a difference between said analog tare compensation signal and said analog load signal; converting said compensated analog load signal into a digital load signal; providing a digital stored load signal including; moving said empty elevator from one end of said hoistway to another in response to said analog tare compensation signal; and measuring a magnitude of said digital load signal at each floor in said hoistway and storing said digital load signal in a remaining tare table and providing a digital stored load signal whose value comes from the remaining tare table; providing a payload signal in response to a difference between said digital stored load signal from said digital load signal.
-
-
7. An elevator load weighing apparatus, comprising:
-
a summer, responsive to an analog load signal indicative of weight on a car hitch and an analog tare compensation signal, which provides a compensated load signal; an analog-to-digital converter, responsive to said compensated load signal, which provides a digital load signal; a tare compensator, responsive to said digital load signal and an elevator position signal, which provides a digital tare compensation signal; and a digital-to-analog converter, responsive to said digital tare compensation signal, which provides an analog tare compensation signal. - View Dependent Claims (8, 9)
-
Specification