Yaw estimation

Abstract

Methods and systems are described for estimating yaw of an implement relative to a machine. The yaw is estimated using gyro signals. The gyro signals may be provided by gyro sensors such as IMUs that are coupled to the implement and machine.

What is claimed is: 
     
         1 . A method of estimating a yaw of an implement coupled to a machine, the method comprising:
 receiving gyro signals of a first gyro sensor coupled to the implement, wherein the implement is rotatable to change the yaw of the implement relative to the machine, wherein at least some of the gyro signals of the first gyro sensor include signals obtained while at least a portion of the machine is moving and the yaw of the implement is substantially static;   receiving gyro signals of a second gyro sensor coupled to the machine, wherein the machine is configured so that movement of at least the portion of the machine simultaneously changes at least one of a pitch of the first gyro sensor and a pitch of the second gyro sensor or a roll of the first gyro sensor and a roll of the second gyro sensor, wherein at least some of the gyro signals of the second gyro sensor include signals obtained while at least the portion of the machine is moving; and   estimating the yaw of the implement relative to the machine based on the gyro signals of the first gyro sensor and the gyro signals of the second gyro sensor.   
     
     
         2 . The method of  claim 1 , further comprising:
 estimating a pitch and roll of the implement based on the gyro signals of the first gyro sensor; and   estimating a pitch and roll of the machine based on the gyro signals of the second gyro sensor.   
     
     
         3 . The method of  claim 1 , further comprising:
 reducing effects of an estimated pitch and roll of the implement on the gyro signals of the first gyro sensor to provide first corrected gyro signals; and   reducing effects of an estimated pitch and roll of the machine on the gyro signals of the second gyro sensor to provide second corrected gyro signals, wherein the gyro signals of the first gyro sensor used to estimate the yaw of the implement relative to the machine are the first corrected gyro signals, and the gyro signals of the second gyro sensor used to estimate the yaw of the implement relative to the machine are the second corrected gyro signals.   
     
     
         4 . The method of  claim 1 , wherein the implement is a dozer blade and the machine is a dozer that includes a c-frame coupled to the dozer blade, and wherein the second gyro sensor is coupled to the c-frame. 
     
     
         5 . The method of  claim 1 , wherein measurement axes of the first gyro sensor and measurement axes of the second gyro sensor are approximately aligned. 
     
     
         6 . The method of  claim 1 , wherein the first gyro sensor is coupled to the implement at a known orientation relative to the second gyro sensor coupled to the machine. 
     
     
         7 . A system for estimating a yaw of an implement coupled to a machine, wherein the implement is rotatable to change the yaw of the implement relative to the machine, the system comprising:
 a first gyro sensor coupled to the implement;   a second gyro sensor coupled to the machine, wherein the machine is configured so that movement of at least a portion of the machine simultaneously changes at least one of a pitch of the first gyro sensor and a pitch of the second gyro sensor or a roll of the first gyro sensor and a roll of the second gyro sensor; and   a computer system communicatively coupled to the first gyro sensor and to the second gyro sensor, the computer system configured to:
 receive gyro signals of the first gyro sensor, wherein at least some of the gyro signals of the first gyro sensor include signals obtained while at least the portion of the machine is moving and the yaw of the implement is substantially static; 
 receive gyro signals of the second gyro sensor, wherein at least some of the gyro signals of the second gyro sensor include signals obtained while at least the portion of the machine is moving; and 
 estimate the yaw of the implement relative to the machine based on the gyro signals of the first gyro sensor and the gyro signals of the second gyro sensor. 
   
     
     
         8 . The system of  claim 7 , wherein the computer system is further configured to:
 estimate a pitch and roll of the implement based on the gyro signals of the first gyro sensor; and   estimate a pitch and roll of the machine based on the gyro signals of the second gyro sensor.   
     
     
         9 . The system of  claim 7  wherein the computer system is further configured to:
 reduce effects of an estimated pitch and roll of the implement on the gyro signals of the first gyro sensor to provide first corrected gyro signals; and 
 reduce effects of an estimated pitch and roll of the machine on the gyro signals of the second gyro sensor to provide second corrected gyro signals, wherein the gyro signals of the first gyro sensor used to estimate the yaw of the implement relative to the machine are the first corrected gyro signals, and the gyro signals of the second gyro sensor used to estimate the yaw of the implement relative to the machine are the second corrected gyro signals. 
 
     
     
         10 . The system of  claim 7 , wherein the implement is a dozer blade and the machine is a dozer that includes a c-frame coupled to the dozer blade, and wherein the second gyro sensor is coupled to the c-frame. 
     
     
         11 . The system of  claim 7 , wherein measurement axes of the first gyro sensor and measurement axes of the second gyro sensor are approximately aligned. 
     
     
         12 . The system of  claim 7 , wherein the first gyro sensor is coupled to the implement at a known orientation relative to the second gyro sensor coupled to the machine. 
     
     
         13 . A non-transitory computer-readable medium comprising instructions that, when executed by one or more processors, cause the one or more processors to perform operations for estimating a yaw of an implement coupled to a machine, the operations comprising:
 receiving gyro signals of a first gyro sensor coupled to the implement, wherein the implement is rotatable to change the yaw of the implement relative to the machine, wherein at least some of the gyro signals of the first gyro sensor include signals obtained while at least a portion of the machine is moving and the yaw of the implement is substantially static;   receiving gyro signals of a second gyro sensor coupled to the machine, wherein the machine is configured so that movement of at least the portion of the machine simultaneously changes at least one of a pitch of the first gyro sensor and a pitch of the second gyro sensor or a roll of the first gyro sensor and a roll of the second gyro sensor; wherein at least some of the gyro signals of the second gyro sensor include signals obtained while at least the portion of the machine is moving; and   estimating the yaw of the implement relative to the machine based on the gyro signals of the first gyro sensor and the gyro signals of the second gyro sensor.   
     
     
         14 . The non-transitory computer-readable medium of  claim 13 , wherein the operations further comprise:
 estimating a pitch and roll of the implement based on the gyro signals of the first gyro sensor; and   estimating a pitch and roll of the machine based on the gyro signals of the second gyro sensor.   
     
     
         15 . The non-transitory computer-readable medium of  claim 13 , wherein the operations further comprise:
 reducing effects of an estimated pitch and roll of the implement on the gyro signals of the first gyro sensor to provide first corrected gyro signals; and   reducing effects of an estimated pitch and roll of the machine on the gyro signals of the second gyro sensor to provide second corrected gyro signals, wherein the gyro signals of the first gyro sensor used to estimate the yaw of the implement relative to the machine are the first corrected gyro signals, and the gyro signals of the second gyro sensor used to estimate the yaw of the implement relative to the machine are the second corrected gyro signals.   
     
     
         16 . The non-transitory computer-readable medium of  claim 13 , wherein the implement is a dozer blade and the machine is a dozer that includes a c-frame coupled to the dozer blade, and wherein the second gyro sensor is coupled to the c-frame. 
     
     
         17 . The non-transitory computer-readable medium of  claim 13 , wherein measurement axes of the first gyro sensor and measurement axes of the second gyro sensor are approximately aligned. 
     
     
         18 . The non-transitory computer-readable medium of  claim 13 , wherein the first gyro sensor is coupled to the implement at a known orientation relative to the second gyro sensor coupled to the machine.