Beam climber friction monitoring system

1 . An elevator system comprising:

an elevator car configured to travel through an elevator shaft;

a first guide beam extending vertically through the elevator shaft, the first guide beam comprising a first surface and a second surface opposite the first surface;

a beam climber system configured to move the elevator car through the elevator shaft, the beam climber system comprising:

a first wheel in contact with the first surface; and

a first electric motor configured to rotate the first wheel; and

a controller configured to determine wheel slippage in a low friction area along the first guide beam;

a sensor configured to detect a rotational wheel speed of the first wheel, wherein the controller is configured to determine wheel slippage in response to the rotational wheel speed is outside of a rotational wheel speed tolerance range;

a position reference system configured to detect a location of the elevator car in response to detection of wheel slippage.

2 . The elevator system of claim 1 , further comprising:

an accelerometer configured to detect a speed of the elevator car or the beam climber system, wherein the controller is configured to determine wheel slippage when the speed is greater than an expected speed.

3 . The elevator system of claim 1 , further comprising:

a sensor configured to detect a torque of the first electric motor, wherein the controller is configured to determine wheel slippage when the torque is outside of a torque tolerance range.

4 . The elevator system of claim 1 , further comprising:

a sensor configured to detect a rotational wheel speed of the first wheel; and

a sensor configured to detect a torque of the first electric motor,

wherein the controller is configured to determine wheel slippage when the rotational wheel speed is outside of a rotational wheel speed tolerance range and the torque is outside of a torque tolerance range.

5 . The elevator system of claim 1 , further comprising:

a first motor brake mechanically connected to the first electric motor, wherein the controller is configured to activate the first motor brake when the first wheel is at or proximate the low friction area.

6 . The elevator system of claim 5 , wherein the controller is configured to pulsate the first motor brake when the first wheel is at or proximate the low friction area.

7 . The elevator system of claim 1 , further comprising;

a first guide rail extending vertically through the elevator shaft; and

a first guide rail brake operably connected to the first guide rail, wherein the controller is configured to activate the first guide rail brake when the first wheel is at or proximate the low friction area.

8 . The elevator system of claim 1 , further comprising;

a first guide rail extending vertically through the elevator shaft; and

a first guide rail brake operably connected to the first guide rail, wherein the controller is configured to pulsate the first guide rail brake when the first wheel is at or proximate the low friction area.

9 . The elevator system of claim 1 , further comprising;

a compression mechanism, configured to compress the first wheel against the first surface of the guide beam.

10 . The elevator system of claim 9 , wherein the controller is configured to increase compression of the first wheel against the first surface of the guide beam when the first wheel is at or proximate the low friction area.

11 . A method of operating an elevator system, the method comprising:

rotating, using a first electric motor of a beam climber system, a first wheel, the first wheel being in contact with a first surface of a first guide beam that extends vertically through an elevator shaft;

moving, using the beam climber system, an elevator car through the elevator shaft when the first wheel of the beam climber system rotates along the first surface of the first guide beam; and

determining, using a controller, wheel slippage in a low friction area along the first guide beam;

detecting, using a sensor, a rotational wheel speed of the first wheel, wherein the controller is configured to determine wheel slippage in response to the rotational wheel speed being outside of a rotational wheel speed tolerance range;

detecting, using a position reference system, a location of the elevator car in response to detection of wheel slippage.

12 . The method of claim 11 , further comprising:

detecting, using an accelerometer, a speed of the elevator car or the beam climber system, wherein the controller is configured to determine wheel slippage when the speed is greater than an expected speed.

13 . The method of claim 11 , further comprising:

detecting, using a sensor, a torque of the first electric motor, wherein the controller is configured to determine wheel slippage when the torque is outside of a torque tolerance range.

14 . The method of claim 11 , further comprising:

detecting, using a sensor, a rotational wheel speed of the first wheel; and

detecting, using a sensor, a torque of the first electric motor,

wherein the controller is configured to determine wheel slippage when the rotational wheel speed is outside of a rotational wheel speed tolerance range and the torque is outside of a torque tolerance range.

15 . The method of claim 11 , further comprising:

activating, using the controller, a first motor brake when the first wheel is at or proximate the low friction area, the first motor brake being mechanically connected to the first electric motor.

16 . The method of claim 11 , further comprising:

activating, using the controller, a first guide rail brake when the first wheel is at or proximate the low friction area, the first guide rail brake being operably connected to a first guide rail that extends vertically through the elevator shaft.

17 . The method of claim 11 , further comprising:

compressing, using a compression mechanism, the first wheel against the first surface of the first guide beam.