Claims

1. Method for determining the mass of a car and counterweight of an elevator, running in an elevator shaft along their traveling paths driven by an elevator motor, in which method at least one test run is performed preferably as complete round trip of the elevator car and counterweight, in which test run

a) the hoisting system balance m_{B},

b) the hoisting system friction F_{mS}, and

c) optionally the hoisting system compensation ΔΒ

is calculated from constant speed data, and in which test run

d) the hoisting system inertia mass mi

is calculated from constant acceleration/deceleration data in the following way,

- the hoisting system balance m_{Bi} which is the difference between the weight of the car and the counterweight, is calculated from the power difference of the motor power when driving the car in both running directions with a constant velocity at a point when the elevator car is in the middle of its travelling length in the elevator shaft in line with the teachi ng of EP 2774 885 B2,

- the hoisting system friction F_{mS} is calculated from the addition of the motor power in both running directions in the middle of the shaft, divided by the car velocity of the test run, and in which method the hoisting system inertia mass m_{r} is calculated from the motor power

with

"mean" being the arithmetic mean value,

C being a constant, which between 2/5 and 4/5, particularly 2/3 for most elevators, PME being the motor power at constant speed,

g being the gravitational force

v being the nominal car velocity

h being the actual height position of the car along its traveling length,

hnom being the nominal travel length of the elevator in the shaft,

whereby the parameters a, v h and P_{M}E are obtained during test runs with constant acceleration/deceleration,

in which method the system inertia mass mi represents the moving masses of all moved components of the elevator,

whereafter finally the car mass m_{car} is calculated according to following formula :

and the counterweight mass m_{cwt} is calculated according to following formula :

^{m}cwt = η,→η_{Β} ^{~}∑ι I_{c}. ) (5 ,4)

with I, I_{ci} being the sum of inertia masses of the relevant linearly moving elevator components , preferably of all linearly moving elevator components (except car and counterweight).

2. Method according to claim 1, wherein ∑, I_{ci} also comprises the sum of the inertia masses of the relevant rotating elevator components, preferably of all rotating elevator components, whereby the inertia moment Jc of a rotating component is transformed into a corresponding linear value I_{c} by following equation :

whereby r_{c} is the radius of the rotating component (where ropes touch) and K is a factor depending on the elevator component and roping ratio.

3. Method according to claim 1 or 2, wherein the hoisting system compensation ΔΒ is calculated from the unit masses of the suspension rope under consideration of the roping ratio, of the compensation rope - if present, and of the travelling cable according to followi formula :

ΔΒ = am_{™}— R^{■} w.m_{™}— -um_{T} .

4. Method according to claim 1 or 2, wherein the hoisting system compensation ΔΒ is calculated from constant speed portions of a test run of the elevator car preferably over a complete movement cycle as follows

__ ^{CBg}(^{J}jlfi,gp'^{h}ap)

ΔΒ = (ΔΒ_{Μρ} + ΔΒ_{ά} )

with var{) being the variance and

covQ being the covariance.

5. Method according to claim 4, wherein the variance and covariance are calculated one-pass algorithms.

6. Method according to one of the preceding claims, wherein the hoisting system balance m_{B} is calculated according to following formula :

with "mean (P_{M}E_{UP})" being the value of the motor power P_{M E} in up-direction in the middle of the travelling length of the elevator car, and

with "mean (P_{M}Edn) " being the value of the motor power P_{M E} in down-direction in the middle of the travelling length of the elevator car.

7. Method according to one of the preceding claims, wherein the hoisting system friction F_{mS} is calculated from the friction over a round trip of the elevator car via following equation

with "mean (P_{M}E_{UP})" being the value of the motor power P_{M E} in up-direction in the middle of the travelling length of the elevator car, and

with "mean (P_{M}Edn) " being the value of the motor power P_{M E} in down-direction in the middle of the travelling length of the elevator car,

Vtest being the velocity of the elevator car during the test run.

8. Method according to one of the preceding claims, wherein the parameter data m_{B}, mi, ΔΒ and F_{M}s are calculated in the elevator control during the test runs and are outputted on an output device.

9. Method according to one of the preceding claims, wherein the parameters m_{car} and m_{cwt} are calculated in a mobile device from the parameter data of the output device of the elevator control .

10. Method according to one of the preceding claims, wherein the power P_{M E} of the elevator motor is determined by a power measuring circuit.

11. Method according claim 10, wherein the elevator comprises an electronic weight calculating unit, which is connected to a position reading means of the elevator car and/or counterweight and which initiates the power measuring circuit to determine the actual power consumption P_{ME} of the elevator motor when the position reading means indicates the position of the elevator car or counterweight being in the middle of its traveling length in the elevator shaft.

12. Method according to one of the preceding claims, wherein the calculated hoisting system friction F_{mS} is used to check an overall shaft alignment and lubrication condition.

13. Elevator system comprising at least one elevator car traveling in an elevator shaft along its traveling length driven by an elevator motor controlled by an elevator control,

characterized in that the elevator control comprises an electronic weight calculating unit, which is connected with

- a car/counterweight position reading means of the elevator control, and

- a power measuring circuit of the elevator control, which is configured to measure the actual power consumption of the elevator motor,

whereby the electronic weight calculating unit is configured to perform the method according to one of the preceding claims.

14. Elevator according to claim 13, wherein the electronic weigh calculating unit is configured to calculate from a test run of the elevator, preferably over a complete round trip of the elevator car the

a) the hoisting system balance m_{B},

b) the hoisting system friction F_{mS}, and

c) the hoisting system compensation ΔΒ

from constant speed data, and

d) the hoisting system inertia mass mi

from constant acceleration/deceleration data of the test run, whereby the electronic weight calculation unit is connected to an output device of the elevator to output the above mentioned calculated parameters m_{B}, F_{mS}, ΔΒ and m^ and which elevator system comprises a terminal unit which is configured to receive the parameters m_{B}, F_{mS}, ΔΒ and mi and to calculate the car weight m_{car} and counterweight weight m_{ctw} therefrom.