Determing an activity of a mobile machine

Abstract

Disclosed herein is a method for determining an activity associated with a mobile machine in an underground mine, and a system ( 30 ) configured to perform the method. The method comprises communicating by a radio-frequency communication between a first ranging device ( 34 ) at a known location ( 35 ) within the mine and a second ranging device ( 36 ) located on the mobile machine ( 10 ). The method further comprises determining a position of the mobile machine ( 10 ) based at least on a time-based characteristic associated with the radio-frequency communication. The method further comprises identifying an activity of the mobile machine ( 10 ) based on the determined position in the mine ( 20 ).

What is claimed is: 
     
         1 . A method for determining an activity associated with a mobile machine in an underground mine, the method comprising:
 communicating by a radio-frequency communication between a first ranging device at a known location within the mine and a second ranging device located on the mobile machine;   determining a position of the mobile machine based at least on a time-based characteristic associated with the radio-frequency communication; and   identifying an activity of the mobile machine based on the determined position in the mine.   
     
     
         2 . A method according to  claim 1 , wherein
 identifying the activity is based on a positional correlation between the determined position and an activity identifier from a plurality of activity identifiers associated with respective positions in the mine.   
     
     
         3 . A method according to  claim 2 , wherein
 the determined position of the machine is a position of a portion of the mobile machine for carrying earth material; and   determining the position of said portion of the mobile machine is based on said time-based characteristic and on orientation information associated with said portion, the orientation information being derived from at least one orientation sensing device located on the mobile machine.   
     
     
         4 . A method according to  claim 2 , wherein the plurality of activity identifiers comprise:
 one or more first activity identifiers corresponding to respective positions in the mine which are designated for loading earth material; and   wherein in the event that said determined position of the mobile machine positionally correlates with a first activity identifier, the activity is determined to be loading of the earth material.   
     
     
         5 . A method according to  claim 4 , wherein the method further comprises tracking movement of the mobile machine based on a time-based characteristic associated with subsequent radio frequency communications between the first and second signal devices; and
 wherein the plurality of activity identifiers further comprise one or more second activity identifiers corresponding to respective positions in the mine which are designated for dumping the earth material; and in the event that a determined position of the mobile machine positionally correlates with a second activity identifier, the determined activity is dumping of the earth material.   
     
     
         6 . A method according to  claim 5 , wherein in the event that the mobile machine is stationary for longer than a predetermined time-period while said position of the mobile machine is not positionally correlated with a first or second position identifier, the mobile machine is determined to be inactive. 
     
     
         7 . A method according to  claim 1 ,
 wherein the radio frequency communication comprises at least one round trip, each of the at least one round trips comprising:
 transmitting a first radio frequency signal from one of first and second ranging devices, the first ranging device being at a known location in the mine and the second ranging device being on the mobile machine; and 
 receiving a radio frequency response signal from the other of the first and second ranging devices; 
   wherein the characteristic is a two-way time-of-flight.   
     
     
         8 . A method according to  claim 7 , transmitting a first signal and transmitting a response signal each comprise transmitting data multiple times, wherein the data is coherently processed to determine the time of flight. 
     
     
         9 . A method according to  claim 7 , wherein the method comprises determining the position from a plurality of determined two-way time-of-flights, for respective round-trip communications, using a Kalman filter. 
     
     
         10 . A method according to  claim 1 , wherein determining the position of the mobile machine is further based on information derived from a motion sensor. 
     
     
         11 . The method of  claim 7 , wherein determining the position of the mobile machine is further based on information derived from a motion sensor, and wherein the position is determined from a plurality of determined time-of-flights, wherein the position is derived using a particle filter. 
     
     
         12 . The method of  claim 1 , wherein the radio-frequency communication is an ultra-wideband radio-frequency communication. 
     
     
         13 . The method of  claim 1 , wherein the method further comprises:
 performing a radio-frequency communication between the second ranging device and a third ranging device, the third ranging device being at another known location in the mine; and   determining the position of the mobile machine is additionally based on a time-based characteristic associated with the radio frequency communication between the second and third ranging devices.   
     
     
         14 . A system for determining an activity associated with a mobile machine in an underground mine, the system comprising:
 a first ranging device for positioning at a known location in the mine and a second ranging device for attaching to the mobile machine, the first and second ranging devices being configured to perform a radio-frequency communication therebetween;   a memory system for storing data defining a geographic frame of reference; and   a processing system configured to:
 determine a position of the mobile machine based at least on a time-based characteristic associated with the radio-frequency communication; and 
 identify an activity of the mobile machine based on the determined position in the mine by determining a positional correlation between the determined position of the mobile machine and an activity identifier from a plurality of activity identifiers associated with respective positions in the mine, the positional correlation being determined with respect to the stored data defining a geographic frame of reference. 
   
     
     
         15 . A system according to  claim 14 , wherein
 identifying the activity comprises is based on a positional correlation between the determined position of the mobile machine and said activity identifier from a plurality of activity identifiers.   
     
     
         16 . A system according to  claim 14 , wherein:
 the system further comprises an orientation sensing device located on the mobile machine for determining orientation information associated with a portion of the mobile machine for carrying the earth material;   the determined position of the machine is a determined position of said portion of the mobile machine; and   the processing system is configured to determine the position of said portion of the mobile machine based on said time-based characteristic and on the orientation information associated with said portion of the mobile machine.   
     
     
         17 . A system according to  claim 15 , wherein the plurality of activity identifiers comprise:
 one or more first activity identifiers corresponding to respective positions in the mine which are designated for loading earth material; and   wherein in the event that said determined position of the mobile machine positionally correlates with a first activity identifier, the activity is determined to be loading of the earth material.   
     
     
         18 . A system according to  claim 17 , wherein the plurality of activity identifiers further comprise one or more second activity identifiers corresponding to respective positions in the mine which are designated for dumping the earth material; and
 the processing system is further configured to track movement of the mobile machine based at least a time-based characteristic associated with subsequent radio frequency communications between the first and second signal devices;   wherein in the event that a determined position of the mobile machine positionally correlates with a second activity identifier, the activity is determined to be dumping of the earth material.   
     
     
         19 . A system according to  claim 14 , wherein the first ranging device and second ranging device are ultra-wideband ranging devices, and the characteristic is a two-way time-of-flight. 
     
     
         20 . A method for determining a plurality of activities associated with a mobile machine in an underground mine, the method comprising:
 performing a first radio-frequency communication comprising at least one round trip communication, each of the at least one round-trips comprising:
 transmitting a first radio frequency signal from one of first and second ranging devices, the first ranging device being at a known location in the mine and the second ranging device being on the mobile machine; 
 receiving a radio frequency response signal from the other of the first and second ranging devices; 
   determining a first position of the second ranging device based at least on a time-of-flight associated the first radio-frequency communication;   receiving first orientation information associated with a bucket portion of the mobile machine from an orientation sensing device located on the mobile machine;   determining a first activity based on the determined position and the received first orientation information; and   performing a second first radio-frequency communication comprising at least one round trip communication, each of the at one least round-trips comprising:
 transmitting a second radio frequency signal from one of second and third ranging devices, the third ranging device being at another known location in the mine; 
 receiving a second ultra-wideband radio frequency response signal from the other of the second and third ranging devices; 
   determining a second position of the second ranging device based at least on a time-of-flight associated with the second radio-frequency communication;   receiving second orientation information associated with the bucket from the orientation sensing device located on the mobile machine;   determining a second activity based on the second determined position and the received second orientation information.