Abstract: Apparatus and methods for controlling an aircraft are described. A computing device can receive a flight plan from an origin to a destination via waypoint(s) and can calculate a flight trajectory for the flight plan. While controlling the aircraft to fly along the flight trajectory, the computing device can receive inputs that change the flight plan resulting in trajectory recalculation. After determining that the inputs include the inputs to change the flight plan resulting in trajectory recalculation, the computing device can calculate a new flight trajectory for the new flight plan. After calculating the new flight trajectory, the computing device can switch from the flight trajectory to the new flight trajectory, where the aircraft maintains continuous flight along the flight trajectory during the switch.

Abstract: A method includes generating a flight plan of an aircraft. The flight plan is based on at least one waypoint and a set of operational rules associated with the aircraft. The method also includes generating an initial trajectory profile based on the at least one waypoint and the set of operational rules. The method further includes identifying an impermissible flight condition associated with the initial trajectory profile. The impermissible flight condition violates at least one operational rule of the set of operational rules. The method further includes generating a modified trajectory profile by modifying at least one aspect of the initial trajectory profile to remove the impermissible flight condition. The modified trajectory profile can be used by a pilot to fly the aircraft, the modified trajectory profile can be used by an autopilot system, or the modified trajectory profile can be displayed.

Abstract: Apparatus and methods for controlling an aircraft are described. A computing device can receive a flight plan from an origin to a destination via waypoint(s) and can calculate a flight trajectory for the flight plan. While controlling the aircraft to fly along the flight trajectory, the computing device can receive inputs that change the flight plan resulting in trajectory recalculation. After determining that the inputs include the inputs to change the flight plan resulting in trajectory recalculation, the computing device can calculate a new flight trajectory for the new flight plan. After calculating the new flight trajectory, the computing device can switch from the flight trajectory to the new flight trajectory, where the aircraft maintains continuous flight along the flight trajectory during the switch.

Abstract: A method includes generating a flight plan of an aircraft. The flight plan is based on at least one waypoint and a set of operational rules associated with the aircraft. The method also includes generating an initial trajectory profile based on the at least one waypoint and the set of operational rules. The method further includes identifying an impermissible flight condition associated with the initial trajectory profile. The impermissible flight condition violates at least one operational rule of the set of operational rules. The method further includes generating a modified trajectory profile by modifying at least one aspect of the initial trajectory profile to remove the impermissible flight condition. The modified trajectory profile can be used by a pilot to fly the aircraft, the modified trajectory profile can be used by an autopilot system, or the modified trajectory profile can be displayed.

Abstract: Actuators for high lift devices on aircraft are disclosed herein. An example apparatus includes an actuator for a high lift device of an aircraft including a motor and a transmission, where the transmission includes a first gear stage and a second gear stage, the first gear stage including a first worm gear and the second gear stage including a second worm gear, the first worm gear, the second worm gear and the motor operative to prevent backdrive of the actuator.

Abstract: Actuators for high lift devices on aircraft are disclosed herein. An example apparatus includes an actuator for a high lift device of an aircraft including a motor and a transmission, where the transmission includes a first gear stage and a second gear stage, the first gear stage including a first worm gear and the second gear stage including a second worm gear, the first worm gear, the second worm gear and the motor operative to prevent backdrive of the actuator.

Abstract: Techniques for providing singularity escape and avoidance are disclosed. In one embodiment, a method for providing control moment gyroscope (CMG) attitude control singularity escape includes calculating a Jacobian A of a set of control equations, calculating a measure of closeness to a singularity, and comparing the calculated closeness to a threshold value, when the calculated closeness is less than or equal to the threshold value, recalculating the Jacobian A. Recalculating may include determining a new direction of virtual misalignment of ? and ?, recalculating the Jacobian inputting the new direction of the virtual misalignment, recalculating the measure of closeness to a singularity, and comparing the measure of closeness to the threshold value. Further, the method may include calculating a gimbal rate command if the of closeness is greater than the threshold value and generating a torque from the gimbal rate command to control the attitude of a satellite.

Abstract: Techniques for providing singularity escape and avoidance are disclosed. In one embodiment, a method for providing control moment gyroscope (CMG) attitude control singularity escape includes calculating a Jacobian A of a set of control equations, calculating a measure of closeness to a singularity, and comparing the calculated closeness to a threshold value, when the calculated closeness is less than or equal to the threshold value, recalculating the Jacobian A. Recalculating may include determining a new direction of virtual misalignment of ? and ?, recalculating the Jacobian inputting the new direction of the virtual misalignment, recalculating the measure of closeness to a singularity, and comparing the measure of closeness to the threshold value. Further, the method may include calculating a gimbal rate command if the of closeness is greater than the threshold value and generating a torque from the gimbal rate command to control the attitude of a satellite.

Abstract: Techniques for providing singularity escape and avoidance are disclosed. In one embodiment, a method for providing control moment gyroscope (CMG) attitude control singularity escape includes calculating a Jacobian A of a set of control equations, calculating a measure of closeness to a singularity, and comparing the calculated closeness to a threshold value, when the calculated closeness is less than or equal to the threshold value, recalculating the Jacobian A. Recalculating may include determining a new direction of virtual misalignment of ? and ?, recalculating the Jacobian inputting the new direction of the virtual misalignment, recalculating the measure of closeness to a singularity, and comparing the measure of closeness to the threshold value. Further, the method may include calculating a gimbal rate command if the of closeness is greater than the threshold value and generating a torque from the gimbal rate command to control the attitude of a satellite.

Abstract: Techniques for providing singularity escape and avoidance are disclosed. In one embodiment, a method for providing control moment gyroscope (CMG) attitude control singularity escape includes calculating a Jacobian A of a set of control equations, calculating a measure of closeness to a singularity, and comparing the calculated closeness to a threshold value, when the calculated closeness is less than or equal to the threshold value, recalculating the Jacobian A. Recalculating may include determining a new direction of virtual misalignment of ? and ?, recalculating the Jacobian inputting the new direction of the virtual misalignment, recalculating the measure of closeness to a singularity, and comparing the measure of closeness to the threshold value. Further, the method may include calculating a gimbal rate command if the of closeness is greater than the threshold value and generating a torque from the gimbal rate command to control the attitude of a satellite.

Abstract: Techniques for providing singularity escape and avoidance are disclosed. In one embodiment, a method for providing control moment gyroscope (CMG) attitude control singularity escape includes calculating a Jacobian A of a set of control equations, calculating a measure of closeness to a singularity, and comparing the calculated closeness to a threshold value, when the calculated closeness is less than or equal to the threshold value, recalculating the Jacobian A. Recalculating may include determining a new direction of virtual misalignment of ? and ?, recalculating the Jacobian inputting the new direction of the virtual misalignment, recalculating the measure of closeness to a singularity, and comparing the measure of closeness to the threshold value. Further, the method may include calculating a gimbal rate command if the of closeness is greater than the threshold value and generating a torque from the gimbal rate command to control the attitude of a satellite.

Abstract: Techniques for providing singularity escape and avoidance are disclosed. In one embodiment, a method for providing control moment gyroscope (CMG) attitude control singularity escape includes calculating a Jacobian A of a set of control equations, calculating a measure of closeness to a singularity, and comparing the calculated closeness to a threshold value, when the calculated closeness is less than or equal to the threshold value, recalculating the Jacobian A. Recalculating may include determining a new direction of virtual misalignment of ? and ?, recalculating the Jacobian inputting the new direction of the virtual misalignment, recalculating the measure of closeness to a singularity, and comparing the measure of closeness to the threshold value. Further, the method may include calculating a gimbal rate command if the of closeness is greater than the threshold value and generating a torque from the gimbal rate command to control the attitude of a satellite.

Abstract: A dynamic unbalance compensation system that compensates for dynamic unbalance of a rotating assembly on a vehicle, such as a spacecraft, to compensate for the presence of a dynamic unbalance moment. The system includes a vehicle, such as a spacecraft, a rotational assembly mounted on the vehicle and rotatable about an axis of rotation relative to the vehicle, and one or more momentum devices mounted on the rotational assembly and generating a momentum vector component perpendicular to the axis of rotation. The one or more momentum devices generate a compensation torque during spinning of the rotational assembly so as to compensate for dynamic unbalance of the rotational assembly.

Abstract: A dynamic unbalance compensation system is provided that compensates for dynamic unbalance of a rotating assembly on a vehicle, such as a spacecraft, to compensate for the presence of a dynamic unbalance moment. The system includes a vehicle, such as a spacecraft, a rotational assembly mounted on the vehicle and rotatable about an axis of rotation relative to the vehicle, and one or more momentum devices mounted on the rotational assembly and generating a momentum vector component perpendicular to the axis of rotation. The one or more momentum devices generate a compensation torque during spinning of the rotational assembly so as to compensate for dynamic unbalance of the rotational assembly.

Abstract: A gear drive having a third order damper operating with the antibacklash gear so as to lower the impact of the antibacklash gear at high torques to reduce gear wear while maintaining good contact with the antibacklash gear at lower torques to maintain high accuracy and bandwidth.

Abstract: In a CMG array used to change the attitude of a satellite, noise in the motion of the inner gimbal as it is moved is detected and the speed of the CMG rotors is changed to reduce the noise.

Abstract: A vehicle control system is disclosed utilizing a reaction wheel assembly for producing small scanning motions and, in combination, a scissored pair of low-cost control moment gyros is used to produce larger slewing motions.

Abstract: A system for avoiding singularities in a control moment gyro (CMG) array of a satellite uses closed and open loop control of the CMGs for reorientation of the satellite. A control system detects when closed loop control according to pseudo inverse rules will cause a singularity and issues a signal. The CMGs are then controlled open loop to avoid the singularity. The pseudo inverse singularity problem arises where there are more actuators than dimensions in the controlled space. Accordingly, the invention may also be used in a robotic arm manipulator.

Abstract: Control moment gyros in an array are rotated to reorient a satellite by an attitude signal. If the signal causes a gyro to have position that will produce a singularity in attitude control, a disturbance is introduced into the signal to avoid the singularity.

Abstract: Control moment gyros in an array are rotated to reorient a satellite. A pseudo inverse control is employed that adds a term to a Moore-Penrose pseudo inverse to prevent a singularity.