Machine sensor calibration system

Abstract

A sensor calibration system for a mobile machine is disclosed. The sensor calibration system may have a first machine mounted sensor configured to sense a characteristic of an offboard object and to generate a corresponding signal, and a second machine mounted sensor configured to sense the characteristic of the offboard object and to generate a corresponding signal. The sensor calibration system may also have a controller in communication with the first and second machine mounted sensors. The controller may be configured to compare the characteristic of the offboard object as sensed by the first machine mounted sensor to the characteristic of the offboard object as sensed by the second machine mounted sensor, and to correct subsequent signals received from the first machine mounted sensor based on the comparison.

1 . A sensor calibration system, comprising:
 a first machine mounted sensor configured to sense a characteristic of an offboard object and to generate a corresponding signal;   a second machine mounted sensor configured to sense the characteristic of the offboard object and to generate a corresponding signal; and   a controller in communication with the first and second machine mounted sensors, the controller being configured to:
 compare the characteristic of the offboard object as sensed by the first machine mounted sensor to the characteristic of the offboard object as sensed by the second machine mounted sensor; and 
 correct subsequent signals received from the first machine mounted sensor based on the comparison. 
   
   
   
       2 . The sensor calibration system of  claim 1 , wherein the first and second machine mounted sensors are mounted on a common mobile machine. 
   
   
       3 . The sensor calibration system of  claim 2 , further including a third machine mounted sensor configured to sense the characteristic of the offboard object and generate a corresponding signal, wherein the controller is in further communication with the third machine mounted sensor and configured to:
 compare the characteristic of the offboard object as sensed by the first machine mounted sensor to the characteristic of the offboard object as sensed by the second and third machine mounted sensors; and   correct subsequent signals received from the first machine mounted sensor only when the characteristic of the offboard object as sensed by the first machine mounted sensor differs substantially from the characteristic of the offboard object as sensed by the second and third machine mounted sensors.   
   
   
       4 . The sensor calibration system of  claim 3 , wherein the first, second, and third machine mounted sensors have substantially identical scan directions with overlapping scan ranges. 
   
   
       5 . The sensor calibration system of  claim 4 , wherein one of the first, second, and third machine mounted sensors is a short range forward-looking sensor, another of the first, second, and third machine mounted sensors is a medium range forward-looking sensor, and the remaining of the first, second, and third machine mounted sensors is a long range forward-looking sensor. 
   
   
       6 . The sensor calibration system of  claim 1 , wherein the offboard object is a stationary object. 
   
   
       7 . The sensor calibration system of  claim 6 , wherein a mobile machine upon which the first and second machine mounted sensors are mounted remains substantially stationary during the characteristic sensing of the first and second sensors. 
   
   
       8 . The sensor calibration system of  claim 6 , wherein a mobile machine upon which the first and second machine mounted sensors are mounted is moving during the characteristic sensing of the first and second sensors. 
   
   
       9 . The sensor calibration system of  claim 8 , further including a machine mounted positioning device configured to determine a machine heading during the characteristic sensing of the first and second machine mounted sensors, wherein the characteristic of the offboard object is a position of the offboard object with respect to the machine heading. 
   
   
       10 . The sensor calibration system of  claim 1 , wherein:
 the first machine mounted sensor is mounted on the first mobile machine; and   the second machine mounted sensor is mounted on a second mobile machine.   
   
   
       11 . The sensor calibration system of  claim 10 , wherein the first machine mounted sensor is the only sensor mounted on the first mobile machine that is configured to sense the characteristic of the offboard object within an environment of the first mobile machine. 
   
   
       12 . The sensor calibration system of  claim 1 , wherein the controller is further configured to generate a map having stored therein the characteristic of the offboard object as sensed by the first and second machine mounted sensors. 
   
   
       13 . A sensor calibration system, comprising:
 a first sensor mounted on a first mobile machine and configured to sense a characteristic of an object at a worksite;   a first positioning device configured to indicate a position of the first mobile machine at the worksite;   a second sensor mounted on a second mobile machine and configured to sense the characteristic of the object;   a second positioning device configured to indicate a position of the second mobile machine at the worksite; and   a controller in communication with the first sensor, the second sensor, the first positioning device, and the second positioning device, the controller being configured to:
 compare the characteristic of the object as sensed by the first sensor when the first positioning device indicates the first mobile machine is at a first worksite location to the characteristic of the object as sensed by the second sensor when the second positioning device indicates the second mobile machine is at the first worksite location; and 
 correct subsequent signals received from the first sensor based on the comparison. 
   
   
   
       14 . The sensor calibration system of  claim 13 , wherein the object remains substantially stationary during the characteristic sensing of the first and second sensors. 
   
   
       15 . The sensor calibration system of  claim 14 , wherein the first and second mobile machines remain stationary during the characteristic sensing of the first and second sensors. 
   
   
       16 . The sensor calibration system of  claim 14 , wherein the first and second mobile machines are moving during the characteristic sensing of the first and second sensors. 
   
   
       17 . The sensor calibration system of  claim 16 , wherein the first and second positioning devices are configured to determine a heading of the first and second mobile machines during the characteristic sensing of the first and second sensors, and the characteristic of the object is a position of the object with respect to the heading. 
   
   
       18 . A method of calibrating object sensing, the method comprising:
 sensing from a first mobile machine a characteristic of an object;   sensing from a second mobile machine the characteristic of the object;   comparing the characteristic of the object as sensed from the first mobile machine to the characteristic of the object as sensed from the second mobile machine; and   correcting subsequent characteristics sensed from the first mobile machine based on the comparison.   
   
   
       19 . The method of  claim 18 , wherein the object, the first mobile machine, and the second mobile machine remain substantially stationary during the characteristic sensing. 
   
   
       20 . The method of  claim 18 , wherein the first and second mobile machines are moving during the characteristic sensing, and the method further includes determining a heading of the first and second mobile machines during the characteristic sensing, the characteristic of the object being a position of the object relative to the headings of the first and second mobile machines.