Method and system for monitoring operations of a mining shovel

Abstract

A method and system for monitoring a mining shovel having a boom supported by a plurality of suspension cables is disclosed. The method involves receiving accelerometer signals from a plurality of accelerometers, each accelerometer being mounted on one of the plurality of suspension cables. The method also involves processing the accelerometer signals to extract a fundamental frequency associated with vibration of each suspension cable, the fundamental frequency being proportional to a tension in the suspension cable. The method further involves determining changes in the fundamental frequency as a function of time, the changes being indicative of an operating state of the mining shovel.

1 . A method for monitoring a mining shovel having a boom supported by a plurality of suspension cables, the method comprising:
 receiving accelerometer signals from a plurality of accelerometers, each accelerometer being mounted on one of the plurality of suspension cables;   processing the accelerometer signals to extract a fundamental frequency associated with vibrations in each suspension cable, the fundamental frequency being proportional to a tension in the suspension cable; and   determining changes in the fundamental frequency as a function of time, the changes facilitating a determination of an operating state of the mining shovel.   
     
     
         2 . The method of  claim 1  wherein receiving the accelerometer signals comprises receiving accelerometer signals from an accelerometer mounted on the suspension cable at a distance of at least one-third of the length from an end of the suspension cable. 
     
     
         3 . The method of  claim 1  wherein determining changes in the fundamental frequency comprises detecting changes in fundamental frequency that are indicative of a boom jacking event associated with an excavation being performed by the rope shovel. 
     
     
         4 . The method of  claim 1  wherein determining changes in the fundamental frequency comprises determining changes in fundamental frequency that are indicative of a potential failure of one of the plurality of suspension cables. 
     
     
         5 . The method of  claim 4  further comprising determining a tension in each of the plurality of suspension cables based on the respective fundamental frequencies relating the fundamental frequency to tension. 
     
     
         6 . The method of  claim 1  further comprising estimating forces on components of the mining shovel by:
 receiving orientation signals from one or more attitude sensors associated with the components, the orientation signals defining an orientation of the components; 
 determining a kinematic condition defining the position and orientation of the components based on the orientation signals and kinematic calibration data; and 
 determining forces acting on the components of the mining shovel based on the kinematic condition, the orientation signals, and the fundamental frequency tension in each of the plurality of suspension cables. 
 
     
     
         7 . The method of  claim 6  wherein estimating the forces on components of the mining shovel comprises estimating a weight of a payload in a payload container component of the mining shovel. 
     
     
         8 . The method of  claim 6  further comprising performing a kinematic calibration to establish the kinematic calibration data by:
 controlling the mining shovel to cause one of the components of the shovel to be successively located in each of a plurality of known positions and orientations with respect to the mining shovel; and 
 processing the orientation signals based on the plurality of known positions and orientations to determine the kinematic calibration data for the mining shovel. 
 
     
     
         9 . The method of  claim 6 , wherein determining forces acting on the components of the mining shovel further includes performing a dynamic calibration to establish dynamic calibration data by:
 causing an unloaded payload container component of the mining shovel to maneuver through a trajectory while receiving the orientation signals and determining the changes in the fundamental frequency; and   determining forces on the components of the mining shovel under unloaded conditions based on the changes in fundamental frequency.   
     
     
         10 . The method of  claim 9  wherein the trajectory is selected to emulate a digging operation of the mining shovel. 
     
     
         11 . A monitoring system for monitoring a mining shovel having a boom supported by a plurality of suspension cables, the system comprising:
 an accelerometer being mounted on one of the plurality of suspension cables at a distance of at least one-third of the length from an end of the suspension cable; and   a processor in communication with the accelerometer includes programmable logic to process the accelerometer signals to extract a fundamental frequency associated with vibrations in the suspension cable, the fundamental frequency being proportional to a tension in the suspension cable; and determine changes in the fundamental frequency as a function of time, the changes facilitating a determination of an operating state of the mining shovel.   
     
     
         12 . The monitoring system of  claim 11 , wherein the processor includes programmable logic to detect changes in fundamental frequency that are indicative of a boom jacking event associated with an excavation being performed by the rope shovel. 
     
     
         13 . The monitoring system of  claim 11 , wherein the processor includes programmable logic to detect changes in fundamental frequency that are indicative of a potential failure of one of the plurality of suspension cables. 
     
     
         14 . The monitoring system of  claims 11 , further comprising
 one or more attitude sensors associated with the boom and other components of the mining shovel, the one or more attitude sensors sending orientation signals defining an orientation of the components;   the processor having programmable logic to determine a kinematic condition defining the position and orientation of the components based on the orientation signals; and   the processor having programmable logic to determine forces acting on the components of the mining shovel based on the kinematic condition, the orientation signals, and the fundamental frequency tension in each of the plurality of suspension cables.   
     
     
         15 . The monitoring system of  claim 11 , wherein estimating the forces on components of the mining shovel comprises estimating a weight of a payload in a payload container component of the mining shovel.