Method and apparatus for rapidly turning a vehicle in a fluid medium

A vehicle adapted to move through a fluid medium, the vehicle comprising:

• a body including a nose;
• a moment generating control device;
• an axial propulsive device;
• and
• a control system including an autopilot adapted to change the direction of travel of the vehicle to a desired direction of travel, measured in the vehicle's inertial frame of reference, while the vehicle is traveling at a velocity adequate for producing flight sustaining aerodynamic forces on the vehicle, the autopilot adapted to implement a method comprising the steps of:
• actuating the moment generating control device to align the nose substantially with the desired direction of travel, and
• for a time when a direction of the velocity of the vehicle is not substantially aligned with the desired direction of travel, applying the axial propulsive device as a primary mechanism to redirect the vehicle's velocity to the desired direction of travel.

A vehicle adapted to move through a fluid medium, the vehicle comprising:

• a body including a nose;
• means for generating a moment;
• means for axially propelling the vehicle;
• and
• means for changing the direction of travel of the vehicle to a desired direction of travel, measured in the vehicle's inertial frame of reference, while the vehicle is traveling at a velocity adequate for producing flight sustaining aerodynamic forces on the vehicle, wherein the means for changing the direction of travel implements a method comprising the steps of:
• actuating the means for generating a moment to align the nose substantially with the desired direction of travel, and
• for a time when a direction of the velocity of the vehicle is not substantially aligned with the desired direction of travel, applying the means for axially propelling the vehicle as a primary mechanism to redirect the vehicle's velocity to the desired direction of travel.

A method for changing an initial direction of travel of a vehicle to a desired direction of travel measured in the vehicle's inertial frame of reference as the vehicle is moving through a fluid medium at a velocity adequate for producing flight sustaining aerodynamic forces on the vehicle, the vehicle comprising a body including a nose, a moment generating control device, and an axial propulsive device, the method comprising the steps of:

• actuating the moment generating control device to rotate the vehicle until a longitudinal axis of the vehicle is at least substantially transverse to the initial direction of travel of the vehicle;
• using aerodynamic forces to assist the moment generating control device to rotate the body until the nose is aligned substantially with the desired direction of travel of the vehicle;
• and then
• for a time when a direction of the velocity of the vehicle is not substantially aligned with the desired direction of travel of the vehicle, applying the axial propulsive device as a primary mechanism to redirect the vehicle's velocity to the desired direction of travel.

A control logic method adapted to be utilized by a vehicle control unit for use in changing an initial flight path of the vehicle to a desired flight path measured in the vehicle's inertial frame of reference as the vehicle is moving through a fluid medium at a velocity adequate for producing flight sustaining aerodynamic forces on the vehicle, the vehicle having a body including a nose, a forward thruster control unit, an axial propulsive device, and a plurality of control surfaces, the vehicle control unit being adapted to receive signals from a guidance control system, said control logic method comprising the steps of:

• receiving a command signal from the guidance control system, said command signal representing a magnitude and a direction of a desired flight path angle of the vehicle;
• converting said command signal to a forward thruster control signal, said forward thruster control signal controlling a response of the forward thruster control unit;
• actuating the forward thruster control unit to rotate the vehicle to reduce the angle between the initial flight path and the desired flight path by initiating a resulting moment imparted to the vehicle by actuation of the forward thruster control unit;
• for a time when a direction of the velocity of the vehicle is not substantially aligned with the desired flight path of the vehicle, continuing to actuate the forward thruster control unit to continue imparting a resulting moment to the vehicle to maintain the nose substantially in the desired flight path until the velocity of the vehicle is substantially aligned with the desired flight path of the vehicle;
• and
• applying the axial propulsive device as a primary mechanism to redirect the velocity of the vehicle to a direction of the desired flight path.

A vehicle control unit for use in controlling a vehicle having a nose, a control surface aft of the nose, a moment generating device, and an axial thrust control device, the control unit having a computer-readable medium encoded with instructions embodying a control logic method for controlling the vehicle when reorienting the vehicle from an initial flight path to a desired flight path measured in the vehicle's inertial frame of reference as the vehicle is moving through a fluid medium at a velocity adequate for producing flight sustaining aerodynamic forces on the vehicle, said control logic method comprising the steps of:

• receiving a command signal from a guidance control system, said command signal representing a direction of a desired flight path angle;
• converting the desired flight path angle to an angle-of-attack command to stabilize the vehicle;
• controlling a response of the control surface in order to affect drag in a manner such that the drag assists the vehicle reorientation;
• initiating a control force to the moment generating device and thereby producing a resulting moment to rotate the vehicle to reduce the angle between the initial flight path and the desired flight path;
• and
• when the vehicle is substantially rotated to reduce the angle between the initial flight path and the desired flight path, applying the axial thrust propulsive device as a primary mechanism to redirect the velocity of the vehicle to a direction of the desired flight path.

A vehicle adapted for rapid redirection of the flight path and velocity as the vehicle is moving through a fluid medium at a velocity adequate for producing flight sustaining aerodynamic forces on the vehicle, said vehicle comprising:

• a body including a nose;
• a plurality of control devices, said control devices being-adapted to impart either a moment or a force to the vehicle in a manner such that the flight path and the velocity of the vehicle are rapidly redirected, said plurality of control devices comprising at least:
• a forward thruster control device,
• an axial propulsive device, and
• a plurality of control surfaces positioned on the body between the forward thruster control device and the axial propulsive device;
• and
• a vehicle control unit adapted to control the control devices in a manner such that the forward thruster control device is used as a primary mechanism to align the nose with the desired direction of travel;
• the forward thruster control device is used as a primary mechanism to maintain the alignment of the nose with the desired direction of travel until the velocity of the vehicle is substantially aligned with the desired direction of travel of the vehicle;
• and
• the axial propulsive device is used as a primary mechanism to redirect the vehicle's velocity to the desired direction of travel.