System and method for rotational motion capture of a solid

Abstract

A capture device of the orientation of a solid comprising a sensor of angular position, capable of being affixed to the solid and supplying a measuring datum related to a real orientation of the solid, wherein the sensor is sensitive to gravity/magnetic field; calculation means for generating test data independent of any measuring datum and related to an estimated orientation of the solid; and means for modifying the estimated orientation by confrontation of the measuring datum and test data. A process including capturing a measuring datum related to a real orientation of the solid, the measuring datum originating from an angular position sensor sensitive to gravity/a magnetic field; establishing test data independent of any measuring datum and related to an estimated orientation of the solid; confronting the test data and the measuring datum; and establishing a new estimated orientation of the solid based on the result of the confrontation.

1 . A capture device of the orientation of a solid comprising: 
 a sensor of angular position, capable of being affixed to the solid and of supplying at least a measuring datum related to a real orientation of the solid, wherein the sensor of angular position being sensitive to at least one of gravity or a magnetic field;    calculation means for generating test data independent of any measuring datum and related to an estimated orientation of the solid; and    means for modifying the estimated orientation of the solid by confrontation of the measuring datum and the test data.    
     
     
         2 . Device as claimed in  claim 1 , wherein said means for modifying the estimated orientation of the solid comprise a first comparator connected to said sensor and to said calculation means, the first comparator configured to receive the measuring datum and at least a test datum, wherein the first comparator is configured to establish at least a difference between the test datum and the measuring datum.  
     
     
         3 . Device as claimed in  claim 2 , further comprising a second comparator with a threshold for comparing the difference established by the first comparator to a threshold value and to validate the estimated orientation of the solid, when the difference established by the first comparator is less than the threshold value.  
     
     
         4 . Device as claimed in  claim 1 , wherein the sensor is sensitive to gravity, the sensor comprises at least an accelerometer.  
     
     
         5 . Device as claimed in  claim 1 , wherein the sensor sensitive to a magnetic field and comprises at least a magnetometer.  
     
     
         6 . Device as claimed in  claim 1 , wherein the sensor further comprises two sensors each having three axes of sensitivity.  
     
     
         7 . Device as claimed in  claim 1 , wherein said calculation means comprises a calculator configured to calculate test data as a function of parameters characteristic of a response of the angular position sensor.  
     
     
         8 . Device as claimed in  claim 7 , wherein the calculator is localized on the solid.  
     
     
         9 . Device as claimed in  claim 1 , wherein said means for modifying the estimated orientation of the solid further comprises a calculator for establishing a new estimated orientation of the solid according to an error gradient descent method.  
     
     
         10 . Device as claimed in  claim 1 , wherein said calculation means comprises a calculator for establishing a new test datum according to an error gradient descent method.  
     
     
         11 . Device as claimed in  claim 10 , wherein the calculator is localized on the solid.  
     
     
         12 . Device as claimed in  claim 1 , further comprising means for registering successive estimated orientations of the solid.  
     
     
         13 . Device as claimed in  claim 12 , wherein said means for registering is localized on the solid.  
     
     
         14 . Device as claimed in  claim 13 , comprising a timer configured to rate registration of the successive estimated orientations of the solid.  
     
     
         15 . A process for estimation of the orientation of a solid comprising: 
 capturing at least a measuring datum related to a real orientation of the solid, the measuring datum originating from at least one angular position sensor sensitive to at least one of gravity or a magnetic field;    establishing test data independent of any measuring datum and related to an estimated orientation of the solid;    confronting the test data and the measuring datum; and    establishing a new estimated orientation of the solid based on the result of the confrontation.    
     
     
         16 . Process as claimed in  claim 15 , wherein said capture and said confrontation are repeated until said confrontation reveals a difference between test data and the measuring datum less than a determined threshold.  
     
     
         17 . Process as claimed in  claim 15 , wherein a correction calculation is made according to an error gradient descent method during the establishment of the new estimated orientation of the solid.