Rotary drill head position measurement system

Abstract

A blast hole drill machine ( 100 ) including a deck frame ( 102 ), and a mast ( 106 ) mounted on the deck frame ( 102 ) is provided. A feed cylinder ( 120 ) supported on the mast ( 106 ) and configured to move in proportion to movement of a rotary drill head ( 114 ) along the mast ( 106 ). A position magnet ( 202 ) is moveably disposed on the feed cylinder ( 120 ). A linear transducer ( 204 ) extends along the mast ( 106 ) and configured to detect a movement of the position magnet ( 202 ) indicative of a change in a position of the rotary drill head ( 114 ).

What is claimed is: 
     
         1 . A blast hole drill machine comprising:
 a deck frame;   a mast mounted on the deck frame;   a feed cylinder supported on the mast and configured to move in proportion to movement of a rotary drill head along the mast;   a position magnet moveably disposed on the feed cylinder; and   a linear transducer extending along the mast and configured to detect a movement of the position magnet indicative of a change in a position of the rotary drill head.   
     
     
         2 . The blast hole drill machine of  claim 1 , wherein the feed cylinder is a dual rod, single piston type feed cylinder having a cylinder body. 
     
     
         3 . The blast hole drill machine of  claim 2 , wherein the position magnet is attached to the cylinder body. 
     
     
         4 . The blast hole drill machine of  claim 1 , wherein the linear transducer is a magnetostrictive position sensor. 
     
     
         5 . The blast hole drill machine of  claim 4 , wherein the magnetostrictive position sensor includes a magnetostrictive waveguide extending up to half a length of the mast. 
     
     
         6 . The blast hole drill machine of  claim 5 , wherein the magnetostrictive position sensor includes a piezoceramic element operatively coupled to the magnetostrictive waveguide. 
     
     
         7 . A rotary drill head position measurement system for a blast hole drill machine, the rotary drill head position measurement system comprising:
 a position magnet moveably disposed on a feed cylinder and configured to move with the feed cylinder and in proportion to movement of a rotary drill head along a mast of the blast hole drill machine; and   a linear transducer extending along on the mast and configured to detect a movement of the position magnet indicative of a change in a position of the rotary drill head.   
     
     
         8 . The rotary drill head position measurement system of  claim 7 , wherein the position magnet is attached to a cylinder body of the feed cylinder. 
     
     
         9 . The rotary drill head position measurement system of  claim 7  is configured to determine a change in a linear position of a drill bit of the blast hole drill machine based on the change in the position of the rotary drill head. 
     
     
         10 . The rotary drill head position measurement system of  claim 7 , wherein the linear transducer is a magnetostrictive position sensor. 
     
     
         11 . The rotary drill head position measurement system of  claim 10 , wherein the magnetostrictive position sensor includes a magnetostrictive waveguide extending up to half a length of the mast. 
     
     
         12 . The rotary drill head position measurement system of  claim 11 , wherein the magnetostrictive position sensor includes a piezoceramic element operatively coupled to the magnetostrictive waveguide. 
     
     
         13 . A method for determining a rotary drill head position in the blast hole drill machine, the method comprising:
 moving a position magnet corresponding to a movement of a rotary drill head of the blast hole drill machine;   detecting a strain pulse using a magnetostrictive waveguide based on the movement of the position magnet; and   generating an electrical signal based on the strain pulse indicative of a position of the position magnet.   
     
     
         14 . The method of  claim 13  further comprises receiving an electrical excitation signal along a magnetostrictive waveguide extending up to half a length of a mast of the blast hole drill machine. 
     
     
         15 . The method of  claim 14 , wherein detecting the strain pulse comprises generating a first magnetic field by the position magnet. 
     
     
         16 . The method of  claim 15 , wherein detecting the strain pulse further comprises generating a second magnetic field by a magnetostrictive waveguide in response to the electrical excitation signal. 
     
     
         17 . The method of  claim 16  further comprises generating the strain pulse in response to an intersection of the first magnetic field and the second magnetic field. 
     
     
         18 . The method of  claim 17  further comprises generating a first output signal in response to receiving the strain pulse by using a piezoceramic element operatively coupled to the magnetostrictive waveguide, the first output signal indicative of a position of the position magnet. 
     
     
         19 . The method of  claim 18  further comprises determining a time lapse between the electrical excitation signal and receiving of the strain pulse by using the piezoceramic element. 
     
     
         20 . The method of  claim 19  further comprises generating a second output signal indicative of the change in the linear position of a drill bit