Self-checking device and method for braking device and elevator system

1 . A self-checking device for a braking device, the braking device comprising a static plate, a movable plate movably connected to the static plate, and a friction lining provided on a side of the movable plate facing away from the static plate, and an electromagnetic brake coil moving the movable plate relative to the static plate, wherein, the self-checking device comprises:

an inductance testing module configured to measure an electromagnetic brake coil inductance L of the braking device; and

a processing module electrically connected to the inductance testing module, and storing a mathematical model of an air gap a between the movable plate and the static plate with respect to the electromagnetic brake coil inductance L in a brake state;

wherein, the processing module is configured to execute a checking mode in the brake state of the braking device, and in the checking mode, the processing module receives a current inductance Lo measured by the inductance testing module,

calculates a current air gap ao based on the mathematical model stored, and determines a wear degree of the friction lining based on the current air gap ao calculated;

wherein the mathematical model is a=f(L), and the mathematical model is trained by at least two sets of data of corresponding air gaps and electromagnetic brake coil inductances (allla 2 , L 2 ) received in a testing mode of the braking device.

2 . The self-checking device according to claim 1 , wherein the processing module is configured to repeatedly execute the checking mode at specific time intervals.

3 . The self-checking device according to claim 1 , wherein the processing module is configured to send an alarm message or perform a shutdown operation when the current air gap a 0 monitored is greater than a threshold.

4 . The self-checking device according to claim 1 , wherein the mathematical model is also related to number of turns N of the brake coil, and total magnetic resistance R_IRON of the static plate and the movable plate.

5 . The self-checking device according to claim 1 , wherein the mathematical model is

a

=

k

1

L

-

k

2

,

wherein, coefficients k 1 and k 2 are determined based on at least two sets of data of corresponding air gaps and brake coil inductances (a 1 , L 1 , a 2 , L 2 ).

6 . The self-checking device according to claim 1 , wherein the at least two sets of data of corresponding air gaps and brake coil inductances (a 1 , L 1 , a 2 , L 2 ) are obtained in the testing mode, wherein, the air gap a 1 and the brake coil inductance L 1 are measured in the brake state, and the air gap a 2 and the brake coil inductance L 2 are measured in another brake state entered by lifting the movable plate to insert an object with a specific thickness D between the movable plate and the brake component, and then releasing the movable plate.

7 . The self-checking device according to claim 6 , wherein the processing module is further configured to train the mathematical model a=f(L) based on additional data of corresponding air gap and brake coil inductance (a 3 , L 3 ) obtained during maintenance.

8 . The self-checking device according to claim 1 , wherein the inductance testing module is a PWM circuit.

9 . An elevator system, wherein the elevator system comprises the self-checking device according to claim 1 .

10 . A self-checking method for a braking device of an elevator system, the braking device comprising a static plate, a movable plate movably connected to the static plate, and a friction lining provided on a side of the movable plate facing away from the static plate, and an electromagnetic brake coil moving controlling movement of the movable plate relative to the static plate t, wherein, the method comprises:

establishing a mathematical model of an air gap a between the movable plate and the static plate with respect to a brake coil inductance L in a brake state;

executing a checking mode in the brake state of the braking device to measure a current inductance Lo; and

calculating a current air gap ao based on the mathematical model, and determining a wear degree of the friction lining based on the current air gap ao calculated;

wherein the method further comprises at least one of (i) sending an alarm message to an operator when the current air gap ao monitored is greater than a threshold or (ii) performing a shutdown operation of the elevator system when the current air gap ao monitored is greater than a threshold;

wherein the mathematical model is a=f(L), and the method further comprises: obtaining, in a testing mode, at least two sets of data of corresponding air gaps and brake coil inductances (alLa 2 L) to train the mathematical model a=f(L).

11 . The self-checking method according to claim 10 , wherein the method further comprises repeatedly executing the checking mode at specific time intervals.

12 . The self-checking method according to claim 10 , wherein the mathematical model is also related to number of turns N of the brake coil and total magnetic resistance R_IRON of the static plate and the movable plate.

13 . The self-checking method according to claim 10 , wherein the mathematical model is

a

=

k

1

L

-

k

2

,

wherein, coefficients k 1 and k 2 are determined based on at least two sets of data of corresponding air gaps and brake coil inductances (a 1 , L 1 , a 2 , L 2 ).

14 . The self-checking method according to claim 10 , wherein the method further comprises obtaining, in the testing mode, the at least two sets of data of corresponding air gaps and brake coil inductances (a 1 , L 1 , a 2 , L 2 ), wherein, the air gap a 1 and the brake coil inductance L 1 are measured in the brake state, and the air gap a 2 and the brake coil inductance L 2 are measured in another brake state entered by lifting the movable plate to insert an object with a specific thickness D between the movable plate and the brake component, and then releasing the movable plate.

15 . The self-checking method according to claim 10 , further comprising training the mathematical model a=f(L) based on additional data of corresponding air gap and brake coil inductance (a 3 , L 3 ) obtained during maintenance.

16 . The self-checking method according to claim 10 , wherein the method further comprises measuring the brake coil inductance using a PWM circuit to produce a sinusoidal voltage input to the electromagnetic brake coil.