Six-way blade orientation determination from lifting movement

Abstract

Embodiments are directed to determining at least one orientation parameter of a six-way blade coupled to a vehicle via an attachment member. The at least one orientation parameter is determined based on a pure lifting movement of the blade and the attachment member. Rotation rate measurements of the attachment member and/or the blade are taken during the pure lifting movement and used to derive orientation parameters such as the swing angle of the blade and the relative heading between the blade and the attachment member.

What is claimed is: 
     
         1 . A system, comprising:
 at least one first sensor mounted on a vehicle, wherein the vehicle includes a body, a blade, and an attachment member that couples the blade to the body, wherein at least one of the at least one first sensor is coupled to the blade,   wherein the attachment member is configured for lift movement, wherein the lift movement is defined as a rotation along a horizontal axis with respect to the body,   wherein the blade is configured for swing movement, wherein the swing movement is defined as a rotation along an axis orthogonal to an axis of the lift movement with respect to the attachment member,   wherein the at least one first sensor is configured to determine rotation rate measurements with respect to movement of the blade about at least one axis of rotation, wherein the movement of the blade includes lift movement synchronized with the lift movement of the attachment member; and   at least one processor integrated in or coupled to the at least one first sensor, wherein the at least one processor is configured to:   determine a lift rotation rate of at least one of: the blade or the attachment member, the lift rotation rate associated with a pure lifting movement of the blade and the attachment member performed simultaneously,   determine at least one orientation parameter of the blade with respect to the attachment member based on the lift rotation rate and the rotation rate measurements.   
     
     
         2 . The system of  claim 1 , wherein the at least one orientation parameter of the blade includes a swing angle of the blade with respect to the attachment member, wherein the at least one first sensor is physically coupled to the blade. 
     
     
         3 . The system of  claim 2 , wherein the at least one processor uses the rotation rate measurements from the at least one first sensor physically coupled to the blade to determine a rotation rate of the attachment member. 
     
     
         4 . The system of  claim 2 , comprising at least one second sensor physically coupled to the attachment member, wherein the at least one second sensor is configured to determine rotation rate measurements of the attachment member. 
     
     
         5 . The system of  claim 4 , wherein the at least one processor is configured to determine the swing angle of the blade with respect to the attachment member based on the rotation rate measurements of the attachment member and the blade. 
     
     
         6 . The system of  claim 1 , comprising at least one second sensor physically coupled to the attachment member, wherein the at least one first sensor is configured to determine an attitude of the blade and the at least one second sensor is configured to determine an attitude of the attachment member,
 wherein the at least one orientation parameter of the blade includes a relative heading between the blade and the attachment member, wherein the at least one processor is configured to determine the relative heading based on the attitude of the blade and the attitude of the attachment member.   
     
     
         7 . The system of  claim 6 , wherein to determine the relative heading, the at least one processor is configured to:
 determine a first quaternion characterizing an extent of rotation of the attachment member relative to an inertial reference frame;   determine a second quaternion characterizing an extent of rotation corresponding to a swing movement of the blade relative to the inertial reference frame;   determine a third quaternion characterizing an extent of rotation of the blade from the first and the second quaternions;   determine a heading of the blade based on the third quaternion; and   determine the relative heading from the heading of the blade.   
     
     
         8 . The system of  claim 6 , wherein the at least one orientation parameter includes a swing angle of the blade relative to the attachment member, wherein the at least one processor is configured to determine the relative heading based on the swing angle. 
     
     
         9 . The system of  claim 1 , wherein the at least one orientation parameter includes a swing angle of the blade relative to the attachment member and a relative heading between the blade and the attachment member, wherein the at least one processor is configured to generate a smoothed swing angle from raw swing angle measurements, wherein the at least one processor is configured to determine the relative heading based on the smoothed swing angle. 
     
     
         10 . A method for determining at least one orientation parameter of a blade attached to a vehicle, wherein the vehicle includes a body and an attachment member that couples the blade to the body, wherein movement of the blade is defined orthogonal to an axis of motion with respect to the attachment member, wherein the attachment member is configured for lift movement, wherein the lift movement is defined as a rotation along a horizontal axis with respect to the body, wherein the blade is configured for swing movement, wherein the swing movement is defined as a rotation along an axis orthogonal to an axis of the lift movement with respect to the attachment member, the method comprising:
 determining rotation rate measurements with respect to movement of the blade about at least one axis of rotation; and   determining a lift rotation rate of at least one of: the blade or the attachment member, the lift rotation rate associated with a pure lifting movement of the blade and the attachment member performed simultaneously,   determining at least one orientation parameter of the blade with respect to the attachment member based on the lift rotation rate and the rotation rate measurements.   
     
     
         11 . The method of  claim 10 , comprising: determining a rotation rate of the attachment member from the rotation rate measurements with respect to movement of the blade. 
     
     
         12 . The method of  claim 10 , comprising:
 determining rotation rate measurements of the attachment member; and   determining a swing angle of the blade with respect to the attachment member based on the rotation rate measurements of the attachment member and the blade.   
     
     
         13 . The method of  claim 10 , comprising:
 determining an attitude of the blade;   determining an attitude of the attachment member; and   determining a relative heading between the blade and the attachment member based on the attitude of the blade and the attitude of the attachment member.   
     
     
         14 . The method of  claim 10 , comprising:
 determining a swing angle of the blade with respect to the attachment member based on the lift rotation rate and the rotation rate measurements; and   determining a relative heading between the blade and the attachment member based on the swing angle.   
     
     
         15 . The method of  claim 10 , comprising:
 determining a smoothed swing angle from raw swing angle measurements; and   determining a relative heading between the blade and the attachment member from the smoothed swing angle.   
     
     
         16 . The method of  claim 10 , comprising:
 determining a first quaternion characterizing an extent of rotation of the attachment member relative to an inertial reference frame;   determining a second quaternion characterizing an extent of rotation corresponding to a swing movement of the blade relative to the inertial reference frame;   determining a third quaternion characterizing an extent of rotation of the blade from the first and the second quaternions;   determining a heading of the blade based on the third quaternion; and   determining a relative heading between the blade and the attachment member from the heading of the blade.   
     
     
         17 . A program product comprising a non-transitory processor-readable medium on which program instructions configured to be executed by at least one processor are embodied, wherein by executing the program instructions, the at least one processor is configured to:
 determine rotation rate measurements with respect to movement of a blade about at least one axis of rotation, wherein the blade is coupled to a body of a vehicle by an attachment member, wherein movement of the blade is defined orthogonal to an axis of motion with respect to the attachment member, wherein the attachment member is configured for lift movement, wherein the lift movement is defined as a rotation along a horizontal axis with respect to the body, wherein the blade is configured for swing movement, wherein the swing movement is defined as a rotation along an axis orthogonal to an axis of the lift movement with respect to the attachment member; and   determine a lift rotation rate of at least one of: the blade or the attachment member, the lift rotation rate associated with a pure lifting movement of the blade and the attachment member performed simultaneously, and   determine at least one orientation parameter of the blade with respect to the attachment member based on the lift rotation rate and the rotation rate measurements.   
     
     
         18 . The program product of  claim 17 , wherein by executing the program instructions the at least one processor uses the rotation rate measurements received from at least one sensor physically coupled to the blade to determine a rotation rate of the attachment member. 
     
     
         19 . The program product of  claim 17 , wherein by executing the program instructions the at least one processor is configured to receive rotation rate measurements from at least one sensor physically coupled to the attachment member, and to determine a swing angle based on rotation rate measurements from the at least one sensor. 
     
     
         20 . The program product of  claim 17 , wherein by executing the program instructions, the at least one processor is configured to:
 determine an attitude of the blade;   determine an attitude of the attachment member;   determine a relative heading between the blade and the attachment member based on the attitude of the blade and the attitude of the attachment member.