초록 ▼

A terminal guidance and/or steering process for a projectile towards a target, process in which the orientation of a velocity vector {right arrow over (Vp)} is determined then a guidance law is applied and finally a steering algorithm enabling the projectile to be reoriented towards its target, proc

A terminal guidance and/or steering process for a projectile towards a target, process in which the orientation of a velocity vector {right arrow over (Vp)} is determined then a guidance law is applied and finally a steering algorithm enabling the projectile to be reoriented towards its target, process wherein the three components of the terrestrial magnetic field {right arrow over (H)} are measured in a projectile-linked reference marker (OxmYmZm) and these measurements are used in the guidance law and/or steering algorithm as a fixed reference marker enabling the orientation at least partially of the projectile-linked reference marker with respect to the terrestrial reference marker (GXfYfZf).

대표청구항 ▼

What is claimed is: 1. A terminal guidance and/or steering process for a projectile towards a target, process in which the orientation of a velocity vector {right arrow over (Vp)} is determined then a guidance law is applied and finally a steering algorithm enabling the projectile to be reoriented

What is claimed is: 1. A terminal guidance and/or steering process for a projectile towards a target, process in which the orientation of a velocity vector {right arrow over (Vp)} is determined then a guidance law is applied and finally a steering algorithm enabling the projectile to be reoriented towards a target, process wherein the measurements of the three components of the terrestrial magnetic field {right arrow over (H)} are measured in a projectile-linked reference marker (OxmYmZm) and said measurements are used in the guidance law and/or steering algorithm as a fixed reference marker enabling the orientation at least partially of said projectile-linked reference marker with respect to the terrestrial reference marker. 2. A guidance and/or steering process according to claim 1, wherein a target detector is implemented that enables said target to be detected in a projectile-linked reference marker, and the coordinates of a line of sight vector {right arrow over (Los)} to be deduced between said target and said projectile, process wherein, to ensure steering: in said projectile-linked reference marker, the projection {right arrow over (N)} of the terrestrial magnetic field {right arrow over (H)} is determined in a guidance plane defined by the line of sight {right arrow over (Los)} of said projectile and velocity {right arrow over (Vp)} vectors, a guidance law proportional to the variation with respect to time {dot over (λ)}=dλ/dt of angle λ between this projection {right arrow over (N)} of the magnetic field and said line of sight vector {right arrow over (Los)}. 3. A guidance and/or steering process according to claim 2, wherein the guidance law is expressed in the following way: {right arrow over (γ)}cmd=K{dot over (λ)}{right arrow over (u)}, expression in which {right arrow over (γ)}cmd represents the correction set point acceleration vector, {dot over (λ)} represents the variation with respect to time (dλ/dt) of angle λ between the projection {right arrow over (N)} of the magnetic field and said line of sight vector {right arrow over (Los)} and {right arrow over (u)} represents a unitary vector perpendicular to said velocity vector {right arrow over (Vp)} of said projectile and located in said guidance plane. 4. A guidance and/or steering process according to claim 3, wherein to determine the orientation of said projectile's velocity vector in said projectile-linked reference marker, one can consider that said vector is collinear to the axis OXm of said projectile-linked reference marker. 5. A guidance and/or steering process according to claim 3, wherein to determine the orientation of said projectile's velocity vector in said projectile-linked reference marker, one can use the signals supplied by at least two accelerometers oriented respectively along the axes of measurement in pitch (OYm) and yaw (OZm) of said projectile. 6. A guidance and/or steering process according to claim 1, wherein to ensure the servo control steering of the yaw and/or pitch positioning of the fins of said projectile: the projection of the magnetic field vector is determined in one of the yaw (XmOYm) or pitch (XmOZm) planes of said projectile, a servo-control chain is used in yaw and/or pitch in place of the yaw and/or pitch spin rate, the derivative with respect to time of an angle made by the projection thus made with one of the axes of the plane in question. 7. A guidance and/or steering process according to claim 6, wherein to servo control the yaw positioning of said fins, one: determine the projection of the magnetic field vector on said projectile's yaw plane (XmOYm), compute the variation with respect to time (rmes=dρ2/dt) of angle ρ2 made by this projection with the roll axis (OXm), in a yaw servo control chain, use value rmes thus computed (pseudo-gyrometric feedback) in place of the yaw spin rate measurement r. 8. A guidance and/or steering process according to claim 6, wherein to servo control the pitch positioning of said fins, one: determine the projection of the magnetic field vector on said projectile's pitch plane (XmOZm), compute the variation with respect to time (qmes=dρ2/dt) of angle ρ1 made by this projection with the yaw axis (OZm), in a pitch servo control chain, use value qmes thus computed (pseudo-gyrometric feedback) in place of the pitch spin rate measurement q. 9. A guidance and/or steering process according to claim 1, wherein to servo control the roll positioning of said fins, one: determine the projection of the magnetic field vector on said projectile's roll plane (ZmOYm), measure the angle ρ3 made by this projection with one of the axes of said plane (for example the pitch spin axis (OYm)), in a roll servo control chain, use value ρ3 thus computed in place of roll angle Φ. 10. A guidance process according to claim 6, wherein to ensure the guidance of said projectile a tracking law is implemented. 11. A guidance and/or steering device for a projectile towards a target that implements a terminal guidance and/or steering process for a projectile towards a target, process in which the orientation of a velocity vector {right arrow over (Vp)} is determined then a guidance law is applied and finally a steering algorithm enabling said projectile to be reoriented towards a target, such device wherein it associates a target detector or deviation finder, a computer incorporating a projectile guidance and/or steering algorithm, projectile steering means, at least two accelerometers oriented along the projectile's pitch acceleration (OZm) and yaw acceleration (OYm) measurement axes and one or several magnetic sensors arranged so as to measure the three components of the terrestrial magnetic field vector {right arrow over (H)} in a projectile-linked reference marker, the guidance and/or steering algorithm using components of the terrestrial magnetic field vector {right arrow over (H)} as a fixed reference marker enabling the projectile-linked reference marker to be at least partially oriented with respect to a terrestrial reference marker.