Real-time belt tension sensing system

1 . A belt tension sensing system comprising:

an engagement assembly operable to contact a belt while the belt is being driven in a drive direction, said engagement assembly is urged by the belt to move in a slack direction that is substantially perpendicular to the drive direction;

a sensor coupled to said engagement assembly; and

a control circuit in electronic communication with said sensor;

said sensor adapted to produce a slack position signal based on a current position of said engagement assembly in the slack direction and to transmit said slack position signal to said control circuit; and

wherein said control circuit is adapted to interpret said slack position signal to produce a tension measurement representative of the tension in the belt, and wherein said engagement assembly comprises a stationary fixed end and an idle roller configured to contact the belt, said idle roller coupled to a roller link, and wherein said idle roller and said roller link are constrained by said fixed end to only move in the slack direction.

2 . The belt tension sensing system of claim 1 , wherein said sensor comprises a tension sensor.

3 . The belt tension sensing system of claim 1 , wherein said sensor comprises a Hall Effect sensor.

4 . The belt tension sensing system of claim 1 , wherein said sensor comprises an infrared sensor.

5 . The belt tension sensing system of claim 1 , wherein said sensor comprises an optical sensor.

6 . The belt tension sensing system of claim 1 , wherein said engagement assembly comprises a fixed end configured to be coupled to a non-moving object such that the fixed end remains stationary.

7 . The belt tension sensing system of claim 1 , wherein said idle roller is configured to remain in contact with the belt while the belt is being driven.

8 . The belt tension sensing system of claim 1 , wherein said sensor is configured to bias said engagement assembly towards the belt in said slack direction.

9 . The belt tension sensing system of claim 8 , wherein said sensor comprises a pressure sensor.

10 . The belt tension sensing system of claim 9 , wherein said pressure sensor comprises a resilient member coupled between a moving end and a fixed end of said pressure sensor, wherein said moving end is configured to move synchronously with said roller link and said fixed end remains substantially stationary.

11 . The belt tension sensing system of claim 10 , wherein said resilient member is configured to bias said idle roller towards the belt in said slack direction.

12 . The belt tension sensing system of claim 1 , wherein said sensor is adapted to produce a plurality of said slack position signals and transmit said plurality of slack position signals to said control circuit, said control circuit adapted to interpret said plurality of slack position signals to produce said tension measurement.

13 . The belt tension sensing system of claim 12 , wherein said sensor is adapted to produce a continuous slack data string comprising a plurality of said slack position signals that are continuously transmitted to said control circuit, said control circuit adapted to interpret said slack data string to produce a continuous tension measurement data string comprising a plurality of said tension measurements.

14 . The belt tension sensing system of claim 13 , wherein said tension measurement data string is produced by calculating a rolling average based on a subset of said slack position signals of said slack data string.

15 . A belt tension sensing system comprising:

a pressure sensor;

a control circuit in electronic communication with said pressure sensor; and

an engagement assembly comprising:

an idle roller configured to remain in contact with a belt while the belt is being driven in a drive direction; and

a roller link comprising a proximal end coupled to said idle roller, and a distal end coupled to said pressure sensor;

wherein while the belt is being driven in the drive direction, said idle roller and said roller link are urged by the belt to move in a slack direction that is substantially perpendicular to said drive direction;

wherein said pressure sensor is configured to bias said engagement assembly towards the belt in the slack direction;

wherein said pressure sensor is adapted to produce a continuous slack data string comprising a plurality of slack position signals, each of said slack position signals based on a position of a portion of said engagement assembly in the slack direction;

wherein said slack data string is continuously transmitted by said pressure sensor to said control circuit; and

wherein said control circuit is adapted to continuously interpret said slack data string to produce a continuous tension measurement data string comprising a plurality of tension measurements.

16 . The belt tension sensing system of claim 15 , wherein said tension measurement data string is produced by calculating a rolling average based on a subset of said slack position signals of said slack data string.

17 . The belt tension sensing system of claim 15 , wherein said pressure sensor comprises a resilient member coupled between a moving end and a fixed end of said pressure sensor, wherein said moving end is configured to move synchronously with said roller link and said fixed end remains substantially stationary.

18 . The belt tension sensing system of claim 17 , wherein said resilient member is configured to bias said roller link and said idle roller towards the belt in the slack direction.

19 . The belt tension sensing system of any one of claim 17 , wherein said pressure sensor further comprises a variable resistor having an electrical resistance that varies according to the distance between said fixed end and said moving end.

20 . A method for sensing tension in a belt while the belt is being driven in a conveyance system, said method comprising:

positioning an engagement assembly in relation to the belt such that an idle roller of the engagement assembly remains in contact with the belt as the belt is driven in a drive direction, wherein the engagement assembly further comprises a stationary fixed end and a roller link coupled to said idle roller, and wherein said idle roller and said roller link are constrained by said fixed end to only move in a slack direction that is substantially perpendicular to the drive direction;

producing a plurality of slack position signals with a pressure sensor that is coupled to the idle roller, the slack position signals based on a position of a portion of the engagement assembly in the slack direction, the belt urging the portion of the engagement assembly to change position in the slack direction as the belt is driven;

transmitting the slack position signals to a control circuit;

calculating the tension of the belt with the control circuit based on the slack position signals; and

using a resilient member to bias the idle roller towards the belt in the slack direction.