Velocity biased laser velocimeter

Claim 1

An apparatus for measuring the relative three-dimensional vectorial velocity in a coordinate system between a moving object mounted thereto and an adjAcent surface, said apparatus comprising: illuminating means developing a plurality of coherent beams of light for illuminating separate portions of said surface with light energy; means for receiving light energy reflected from said surface at three different angles of reflection, said last-mentioned receiving means having three functionally separate signal processing channels; three optical gratings disposed between said surface and said receiving means with each functionally separate grating modulating the reflected light energy processed by a corresponding one of said separate channels, a first one of said optical gratings effectively located at a different point in the coordinate system from said second and third ones of said optical gratings, said second and third gratings having a different orientation with respect to one another in the coordinate system, each said optical grating having alternate transparent and opaque lines extending in a direction normal to a corresponding velocity component Va, Vb, and Vc to be measured in predetermined directions a, b, and c, said opaque lines interrupting the reflected light energy points so that said receiving means detects the resulting motion of each of the interrupted energy points and converts the energy points into pulses for a signal representative of the relative velocity components Va, Vb, and Vc between the moving object and the adjacent surface, each said optical grating adapted for continuous motion parallel to the direction of the velocity component at an effective velocity Vg relative to said receiving means; Vg being selectively adjusted when said object has zero relative velocity with respect to said surface so that Va > OR = 0, Vb > OR = 0, and Vc > OR = 0; and means coupled to said receiving means for deriving signals representative of the three-dimensional vectorial velocity between said moving object and said surface in a predetermined coordinate system.

Claim 2

An apparatus for measuring the relative three-dimensional vectorial velocity in a coordinate system between a moving object mounted thereto and an adjAcent surface, said apparatus comprising: illuminating means developing a plurality of coherent beams of light for illuminating separate portions of said surface with light energy; means for receiving light energy reflected from said surface at three different angles of reflection, said last-mentioned receiving means having three functionally separate signal processing channels; three optical gratings disposed between said surface and said receiving means with each functionally separate grating modulating the reflected light energy processed by a corresponding one of said separate channels, a first one of said optical gratings effectively located at a different point in the coordinate system from said second and third ones of said optical gratings, said second and third gratings having a different orientation with respect to one another in the coordinate system, each said optical grating having alternate transparent and opaque lines extending in a direction normal to a corresponding velocity component Va, Vb, and Vc to be measured in predetermined directions a, b, and c, said opaque lines interrupting the reflected light energy points so that said receiving means detects the resulting motion of each of the interrupted energy points and converts the energy points into pulses for a signal representative of the relative velocity components Va, Vb, and Vc between the moving object and the adjacent surface, each said optical grating adapted for continuous motion parallel to the direction of the velocity component at an effective velocity Vg relative to said receiving means; Vg being selectively adjusted when said object has zero relative velocity with respect to said surface so that Va > OR = 0, Vb > OR = 0, and Vc > OR = 0; and means coupled to said receiving means for deriving signals representative of the three-dimensional vectorial velocity between said moving object and said surface in a predetermined coordinate system.

Claim 11

An apparatus for measuring the relative three-dimensional vectorial velocity in a coordinate system between a moving object mounted thereto and an adjacent surface, said apparatus comprising: illuminating means developing a plurality of coherent beams of light for illuminating separate portions of said surface with light energy; means for receiving light energy reflected from said surface at three different angles of reflection, said last-mentioned receiving means having three functionally separate signal processing channels; three coplanar optical gratings disposed between said surface and said receiving means with each functionally separate grating modulating the reflected light energy processed by a corresponding one of said separaTe channels, a first one of said optical gratings effectively located at a different point in the coordinate system from said second and third ones of said optical gratings, said second and third gratings having a different orientation with respect to one another in the coordinate system, each said optical grating having alternate transparent and opaque lines extending in a direction normal to a corresponding velocity component Va, Vb, and Vc to be measured in predetermined directions a, b, and c, said opaque lines interrupting the reflected light energy points so that said receiving means detects the resulting motion of each of the interrupted energy points and converts the energy points into pulses for a signal representative of the relative velocity components Va, Vb, and Vc and between the moving object and the adjacent surface, each said optical grating adapted for continuous motion parallel to the direction of the corresponding velocity component at an effective velocity Vg relative to said receiving means; Vg being selectively adjusted so that Va 24 0, Vb > or = 0, and Vc > or = 0; and means coupled to said receiving means for deriving signals representative of the three-dimensional vectorial velocity between said moving object and said surface in a predetermined coordinate system having three orthogonal coordinates x, y and z, the relative velocity components Vx, Vy and Vz being derived by the moving object referenced velocity formulae Vx (Va + Vc + 2Vg)/2 cos psi y Vy (Va - Vb)/2 sin psi y Vz (Vc -Vb)/2 tan theta L cos psi y where the x and y axes are in the plane of said optical gratings, where psi y is equal to the angle between the a and x coordinates and between the b and the x coordinates and where each line segment depicting the outer of one of a selected pair of coherent beams forms an angle psi L with the z axis, the angle theta L lying in the xz plane.

Claim 12

An apparatus for measuring the relative three-dimensional vectorial velocity in a coordinate system between a moving object mounted thereto and an adjacent surface, said apparatus comprising: illuminating means developing a plurality of coherent beams of light for illuminating separate portions of said surface with light energy; means for receiving light energy reflected from said surface at three different angles of reflection, said last-mentioned receiving means having three functionally separate signal processing channels; three coplanar optical gratings disposed between said surface and said receiving means with each functionally separate grating modulating the reflected light energy processed by a corresponding one of said separaTe channels, a first one of said optical gratings effectively located at a different point in the coordinate system from said second and third ones of said optical gratings, said second and third gratings having a different orientation with respect to one another in the coordinate system, each said optical grating having alternate transparent and opaque lines extending in a direction normal to a corresponding velocity component Va, Vb, and Vc to be measured in predetermined directions a, b, and c, said opaque lines interrupting the reflected light energy points so that said receiving means detects the resulting motion of each of the interrupted energy points and converts the energy points into pulses for a signal representative of the relative velocity components Va, Vb, and Vc and between the moving object and the adjacent surface, each said optical grating adapted for continuous motion parallel to the direction of the corresponding velocity component at an effective velocity Vg relative to said receiving means; Vg being selectively adjusted so that Va 24 0, Vb > or = 0, and Vc > or = 0; and means coupled to said receiving means for deriving signals representative of the three-dimensional vectorial velocity between said moving object and said surface in a predetermined coordinate system having three orthogonal coordinates x, y and z, the relative velocity components Vx, Vy and Vz being derived by the moving object referenced velocity formulae Vx (Va + Vc + 2Vg)/2 cos psi y Vy (Va - Vb)/2 sin psi y Vz (Vc -Vb)/2 tan theta L cos psi y where the x and y axes are in the plane of said optical gratings, where psi y is equal to the angle between the a and x coordinates and between the b and the x coordinates and where each line segment depicting the outer of one of a selected pair of coherent beams forms an angle psi L with the z axis, the angle theta L lying in the xz plane.