Assembly, system, and method for cable tension measurement

Abstract

A tension measurement assembly, for measuring and monitoring a tension force in a cable being deployed from a spooling device on which the cable is spooled, comprises at least one force sensor disposed adjacent the spooling device for sensing a force applied to the spooling device and generating a force signal representing the sensed force, and a processor responsive to the force signal for calculating and monitoring a tension force present in the cable. A cable sensor engages the deployed cable for sensing a spooling/unspooling rate and a length of the cable moving past the cable sensor in a pre-determined time period and generating a spooling signal representing the sensed rate and length to the processor for use in the calculating and monitoring of the tension force.

1 . A tension measurement assembly for measuring and monitoring a tension force in a cable being deployed from a spooling device on which the cable is spooled, comprising:
 at least one force sensor disposed adjacent the spooling device for sensing a force applied to the spooling device and generating a force signal representing the sensed force; and   a processor responsive to the force signal for calculating and monitoring a tension force present in the cable.   
     
     
         2 . The assembly according to  claim 1 , wherein said at least one force sensor is a multi-axis force sensor. 
     
     
         3 . The assembly according to  claim 1 , wherein said at least one force sensor comprises a multi-axis transducer for measuring forces along a pre-determined coordinate system. 
     
     
         4 . The assembly according to  claim 1 , further comprising a chassis for supporting the spooling device, wherein said at least one force sensor is disposed adjacent said chassis. 
     
     
         5 . The assembly according to  claim 1 , further comprising a cable sensor disposed to engage the cable and measure a spooling/unspooling characteristic of the cable. 
     
     
         6 . The assembly according to  claim 5 , wherein said cable sensor comprises a measuring wheel to engage the cable and an encoder to measure a rotation of the measuring wheel due to a movement of the cable. 
     
     
         7 . The assembly according to  claim 5 , wherein the spooling/unspooling characteristic of the cable comprises at least one of a spooling/unspooling rate and a length of the cable moving past said cable sensor in a pre-determined time period. 
     
     
         8 . A system for measuring and monitoring a tension force in a cable, comprising:
 a spooling device for deploying and retrieving the cable spooled thereon, wherein said spooling device includes a support member;   a force sensor disposed adjacent the support member of said spooling device for sensing a force on said support member and generating a force signal representing the sensed force;   a cable sensor disposed to measure spooling/unspooling characteristics of the cable and generate a spooling signal representing the measured spooling/unspooling characteristics; and   a processor for computing and monitoring the tension force in the cable in response to the force signal and the spooling signal.   
     
     
         9 . The system according to  claim 8 , wherein said force sensor comprises a multi-axis force sensor. 
     
     
         10 . The system according to  claim 8 , wherein said force sensor comprises a multi-axis transducer for measuring forces along a pre-determined coordinate system. 
     
     
         11 . The system according to  claim 8 , wherein said spooling device comprises a drum having the cable spooled thereon and said support member comprises a shaft rotatably supporting said drum. 
     
     
         12 . The system according to  claim 8 , further comprising a chassis for engaging said support member of said spooling device, wherein said force sensor is disposed adjacent said chassis to measure a force between said support member and said chassis. 
     
     
         13 . The system according to  claim 12 , further comprising a bearing mounted to said chassis for receiving said support member, wherein said bearing allows said support member to rotate. 
     
     
         14 . The system according to  claim 8 , further comprising a cable sensor disposed to engage the cable and measure a spooling/unspooling characteristic of the cable. 
     
     
         15 . The system according to  claim 14 , wherein said cable sensor comprises a measuring wheel to engage the cable and an encoder to measure a rotation of said measuring wheel due to a movement of the cable. 
     
     
         16 . The system according to  claim 14 , wherein the spooling/unspooling characteristic of the cable is at least one of a spooling/unspooling rate and a length of the cable moving past said cable sensor in a pre-determined time period. 
     
     
         17 . A method for measuring and monitoring a tension force in a spoolable device, comprising:
 providing a spooling device for deploying and retrieving the spoolable device;   directing the spoolable device from the spooling device to and from a downstream point;   providing at least one force sensor disposed adjacent the spooling device for sensing a force applied to the spooling device and generating a force signal representing the sensed force;   providing a spoolable device sensor disposed to measure spooling/unspooling characteristics of the spoolable device and generate a spooling signal representing the measured spooling/unspooling characteristics; and   calculating the tension force in the spoolable device based on the force signal from the at least one force sensor and the spooling signal from the spoolable device sensor.   
     
     
         18 . The method according to  claim 17 , wherein the at least one force sensor is a multi-axis force sensor. 
     
     
         19 . The method according to  claim 17 , wherein the spooling/unspooling characteristic of the spoolable device is at least one of a spooling/unspooling rate and a length of the spoolable device moving past the spoolable device sensor in a pre-determined time period. 
     
     
         20 . The method according to  claim 17 , further comprising a step of calculating a drum weight, wherein the step of calculating the tension force in the spoolable device is based on the force signal from the force sensor, the spooling signal from the spoolable device sensor, and the drum weight. 
     
     
         21 . The method according to  claim 17 , wherein the spoolable device comprises a wireline cable.