System, method and apparatus for accurately measuring haptic forces

Abstract

A low-cost sensor and apparatus comprising same, and a system for measuring force, comprising an end-effector having a first end and a second end on opposing sides of the end-effector; a first sensor located at the first end of the end-effector; and a second sensor located at the second end of the end-effector.

What is claimed is: 
     
         1 . A system for measuring force, comprising:
 an end-effector having a first end and a second end on opposing sides of the end-effector;   a first sensor located at the first end of the end-effector; and   a second sensor located at the second end of the end-effector.   
     
     
         2 . The system of  claim 1 , wherein the end-effector comprises a handle for grasping by a user. 
     
     
         3 . The system of  claim 2 , wherein each of the first and second sensors comprises a plate, a first strain gage mounted on the plate, and a probe configured to receive a force from the end-effector and to exert a force upon the plate. 
     
     
         4 . The system of  claim 3 , wherein each place plate comprises a PCB (printed circuit board) having mounted thereon at least one strain gage for measuring force exerted by the probe. 
     
     
         5 . The system of  claim 4 , wherein the at least one strain gage comprises a Wheatstone bridge. 
     
     
         6 . The system of  claim 5 , further comprising a motion restrictor configured to restrict the range of motion of the probe. 
     
     
         7 . The system of  claim 6 , wherein a length of the probe is from 15 mm to 35 mm. 
     
     
         8 . The system of  claim 6 , wherein the plate comprises four beams substantially forming an X-shape, each of the four beams having a length from 10 mm to 30 mm. 
     
     
         9 . The system of  claim 8 , wherein a thickness of each of the four beams is from 1 mm to 3 mm. 
     
     
         10 . The system of  claim 8 , wherein a width of each of the four beams is from 0.5 mm to 10 mm. 
     
     
         11 . The system of  claim 10 , wherein the width of each of the four beams is from 2.5 mm to 7.5 mm. 
     
     
         12 . The system of  claim 8  wherein a radius of the plate is from 0.5 mm to 10 mm. 
     
     
         13 . The system of  claim 12 , wherein the radius of the plate is from 3 mm to 6 mm. 
     
     
         14 . The system of  claim 8 , wherein a first strain gage is mounted on a first beam of the four beams, a second strain gage is mounted on a second beam of the four beams, a third strain gage is mounted on a third beam of the four beams, and a fourth strain gage of a fourth beam of the four beams. 
     
     
         15 . The system of  claim 14 , wherein the first strain gage and the second strain gage are located substantially on the same plane and substantially in line and the third strain gage and fourth strain gage are substantially on the same plane and substantially in line. 
     
     
         16 . The system of  claim 15 , further comprising a fifth strain gage mounted on a side of the first beam of the four beams and located on a plane substantially perpendicular to the plane on which the first strain gage is located and a sixth strain gage mounted on side of the second beam of the four beams and located on a plane substantially perpendicular to the plane on which the second strain gage is located. 
     
     
         17 . A sensor, comprising a PCB (printed circuit board), a probe and a plurality of strain gages, wherein the strain gages are mounted on the PCB, and wherein the probe exerts a force on the strain gages by exerting a force on the PCB; wherein the PCB has a radius of at least 3 mm. 
     
     
         18 . The sensor of  claim 17 , wherein four strain gages are mounted on said PCB in a X shaped structure and a plurality of strain gages are mounted on inserts cut into at least one side of said X shaped structure. 
     
     
         19 . A sensor apparatus, comprising the sensors of  claim 18 , and further comprising a top cover and a bottom cover, such that said sensor is located between said top cover and said bottom cover, and said probe is inserted through one of said top cover or said bottom cover. 
     
     
         20 . The sensor apparatus of  claim 19 , further comprising a motion restrictor for restricting a range of motion of said probe, said motion restrictor being located between a cover through which said probe is inserted and said sensor. 
     
     
         21 . A method for measuring force in a haptic robot system, comprising:
 receiving an at least one vector of a force by a first probe for a first sensor located on a first end of an end-effector;   receiving an at least one vector of the force by a second probe of a second sensor at a second end opposing the first end of the end-effector;   contacting, by the first probe and in response to the receiving the at least one vector of the force by the first probe, a plate of the first sensor, the plate of the first sensor having at least one strain gauge mounted thereon;   measuring the at least one vector of the force using the at least one strain gauge mounted on the plate of the first sensor;   contacting, by the second probe and in response to the receiving the at least one vector of the force by the second probe, a plate of the second sensor, the plate of the second sensor having at least one strain gauge mounted thereon; and   measuring the at least one vector of the force using the at least one strain gauge mounted on the plate of the second sensor.   
     
     
         22 . The method of  claim 21 , further comprising:
 restricting the range of motion of the first probe by a motion restrictor.