Abstract: Apparatus and methods are presented for providing pilots feedback on takeoff and landing performance. The apparatus includes a means for determining the length of the takeoff roll, the length of the landing roll, and the accuracy of the touch-down point as compared to a fixed target point on the landing surface. These performance parameters are reported to the pilot through an onboard interface such as a smartphone or tablet.

Abstract: A method includes operating an aerial vehicle in a hover-flight orientation. The aerial vehicle is connected to a tether that defines a tether sphere having a radius based on a length of the tether, and the tether is connected to a ground station. The method includes positioning the aerial vehicle at a first location that is substantially on the tether sphere. The method includes transitioning the aerial vehicle from the hover-flight orientation to a forward-flight orientation, such that the aerial vehicle moves from the tether sphere. And the method includes operating the aerial vehicle in the forward-flight orientation to ascend at an angle of ascent to a second location that is substantially on the tether sphere. The first and second locations are substantially downwind of the ground station.

Abstract: A method includes operating an aerial vehicle in a hover-flight orientation. The aerial vehicle is connected to a tether that defines a tether sphere having a radius based on a length of the tether, and the tether is connected to a ground station. The method includes positioning the aerial vehicle at a first location that is substantially on the tether sphere. The method includes transitioning the aerial vehicle from the hover-flight orientation to a forward-flight orientation, such that the aerial vehicle moves from the tether sphere. And the method includes operating the aerial vehicle in the forward-flight orientation to ascend at an angle of ascent to a second location that is substantially on the tether sphere. The first and second locations are substantially downwind of the ground station.

Abstract: A method is disclosed where an airborne wind turbine (AWT) is prevented from coming into contact with airborne objects such as birds and bats. The AWT determines the location and characteristics of the incoming airborne objects, and depending on the determined risk value, may shift the location of the aerial vehicle of the AWT in order to avoid the risk of colliding with the airborne objects. Other considerations used by the AWT's determination may include whether the aerial vehicle can continue to generate electricity while performing the avoidance maneuver.

Abstract: A method involves operating an aerial vehicle in a hover-flight orientation. The aerial vehicle is connected to a tether that defines a tether sphere having a radius based on a length of the tether, and the tether is connected to a ground station. The method involves positioning the aerial vehicle at a first location that is substantially on the tether sphere. The method involves transitioning the aerial vehicle from the hover-flight orientation to a forward-flight orientation, such that the aerial vehicle moves from the tether sphere. And the method involves operating the aerial vehicle in the forward-flight orientation to ascend at an angle of ascent to a second location that is substantially on the tether sphere. The first and second locations are substantially downwind of the ground station.

Abstract: A method involves operating an aerial vehicle in a hover-flight orientation. The aerial vehicle is connected to a tether that defines a tether sphere having a radius based on a length of the tether, and the tether is connected to a ground station. The method involves positioning the aerial vehicle at a first location that is substantially on the tether sphere. The method involves transitioning the aerial vehicle from the hover-flight orientation to a forward-flight orientation, such that the aerial vehicle moves from the tether sphere. And the method involves operating the aerial vehicle in the forward-flight orientation to ascend at an angle of ascent to a second location that is substantially on the tether sphere. The first and second locations are substantially downwind of the ground station.

Abstract: An example method may include receiving data representing an initial position and an initial attitude of an aircraft. The method further includes determining a change to a first attribute and a second attribute of the position or the attitude of the aircraft to achieve a subsequent position and a subsequent attitude. The method also includes determining a priority sequence for changing the first attribute and the second attribute of the position or the attitude of the aircraft based on a first thrust of the actuator to achieve the change to the first attribute and a second thrust of the actuator to achieve the change to the second attribute. The priority sequence is configured to cause changes to the first attribute before causing changes to the second attribute where the actuator is unable to concurrently provide the first thrust and the second thrust.

Abstract: An example method may include receiving data representing an initial position and an initial attitude of an aircraft. The method further includes determining a change to a first attribute and a second attribute of the position or the attitude of the aircraft to achieve a subsequent position and a subsequent attitude. The method also includes determining a priority sequence for changing the first attribute and the second attribute of the position or the attitude of the aircraft based on a first thrust of the actuator to achieve the change to the first attribute and a second thrust of the actuator to achieve the change to the second attribute. The priority sequence is configured to cause changes to the first attribute before causing changes to the second attribute where the actuator is unable to concurrently provide the first thrust and the second thrust.

Abstract: A method may involve operating an aerial vehicle in a hover-flight orientation. The aerial vehicle may be connected to a tether that defines a tether sphere having a radius based on a length of the tether, and the tether may be connected to a ground station. The method may involve positioning the aerial vehicle at a first location that is substantially on the tether sphere. The method may involve transitioning the aerial vehicle from the hover-flight orientation to a forward-flight orientation, such that the aerial vehicle moves from the tether sphere. And the method may involve operating the aerial vehicle in the forward-flight orientation to ascend at an angle of ascent to a second location that is substantially on the tether sphere. The first and second locations may be substantially downwind of the ground station.

Abstract: An example method may include determining a drag force of an apparent wind on an aircraft that is coupled to a ground station via a tether. The method also includes determining a trajectory of the aircraft to a point downwind of the ground station such that the aircraft travelling the trajectory causes the tether to unfurl along a catenary path above ground. The method further includes determining an orientation of the aircraft to travel the trajectory in the apparent wind so that an actuator of the aircraft is configured to provide a vertical thrust in a direction substantially perpendicular to the ground. The method also includes determining a vertical thrust for the aircraft at the orientation to travel the trajectory in the apparent wind. The method also includes providing instructions to cause the actuator of the aircraft to provide the vertical thrust to move the aircraft along the trajectory.

Abstract: An example method may include determining a drag force of an apparent wind on an aircraft that is coupled to a ground station via a tether. The method also includes determining a trajectory of the aircraft to a point downwind of the ground station such that the aircraft travelling the trajectory causes the tether to unfurl along a catenary path above ground. The method further includes determining an orientation of the aircraft to travel the trajectory in the apparent wind so that an actuator of the aircraft is configured to provide a vertical thrust in a direction substantially perpendicular to the ground. The method also includes determining a vertical thrust for the aircraft at the orientation to travel the trajectory in the apparent wind. The method also includes providing instructions to cause the actuator of the aircraft to provide the vertical thrust to move the aircraft along the trajectory.

Abstract: A method involves operating an aerial vehicle to travel along a first closed path on a tether sphere while oriented in a crosswind-flight orientation. A tether is connected to the aerial vehicle on a first end and is connected to a ground station on a second end. Further, the tether sphere has a radius corresponding to a length of the tether. The method further involves while the aerial vehicle is in the crosswind-flight orientation, operating the aerial vehicle to travel along a second closed path on the tether sphere, such that a speed of the aerial vehicle is reduced. And the method involves after or while the speed of the aerial vehicle is reduced, transitioning the aerial vehicle from traveling along the second closed path while in the crosswind-flight orientation to a hover-flight orientation.

Abstract: A method involves operating an aerial vehicle to travel along a first closed path on a tether sphere while oriented in a crosswind-flight orientation. A tether is connected to the aerial vehicle on a first end and is connected to a ground station on a second end. Further, the tether sphere has a radius corresponding to a length of the tether. The method further involves while the aerial vehicle is in the crosswind-flight orientation, operating the aerial vehicle to travel along a second closed path on the tether sphere, such that a speed of the aerial vehicle is reduced. And the method involves after or while the speed of the aerial vehicle is reduced, transitioning the aerial vehicle from traveling along the second closed path while in the crosswind-flight orientation to a hover-flight orientation.

Abstract: A method involves operating an aerial vehicle in a hover-flight orientation. The aerial vehicle is connected to a tether that defines a tether sphere having a radius based on a length of the tether, and the tether is connected to a ground station. The method involves positioning the aerial vehicle at a first location that is substantially on the tether sphere. The method involves transitioning the aerial vehicle from the hover-flight orientation to a forward-flight orientation, such that the aerial vehicle moves from the tether sphere. And the method involves operating the aerial vehicle in the forward-flight orientation to ascend at an angle of ascent to a second location that is substantially on the tether sphere. The first and second locations are substantially downwind of the ground station.

Abstract: A method involves operating an aerial vehicle in a hover-flight orientation. The aerial vehicle is connected to a tether that defines a tether sphere having a radius based on a length of the tether, and the tether is connected to a ground station. The method involves positioning the aerial vehicle at a first location that is substantially on the tether sphere. The method involves transitioning the aerial vehicle from the hover-flight orientation to a forward-flight orientation, such that the aerial vehicle moves from the tether sphere. And the method involves operating the aerial vehicle in the forward-flight orientation to ascend at an angle of ascent to a second location that is substantially on the tether sphere. The first and second locations are substantially downwind of the ground station.

Abstract: A method may involve operating an aerial vehicle to travel along a first closed path on a tether sphere while oriented in a crosswind-flight orientation. A tether may be connected to the aerial vehicle on a first end and may be connected to a ground station on a second end. Further, the tether sphere may have a radius corresponding to a length of the tether. The method may further involve while the aerial vehicle is in the crosswind-flight orientation, operating the aerial vehicle to travel along a second closed path on the tether sphere, such that a speed of the aerial vehicle is reduced. And the method may involve after or while the speed of the aerial vehicle is reduced, transitioning the aerial vehicle from traveling along the second closed path while in the crosswind-flight orientation to a hover-flight orientation.

Abstract: A method may involve operating an aerial vehicle to travel along a first closed path on a tether sphere while oriented in a crosswind-flight orientation. A tether may be connected to the aerial vehicle on a first end and may be connected to a ground station on a second end. Further, the tether sphere may have a radius corresponding to a length of the tether. The method may further involve while the aerial vehicle is in the crosswind-flight orientation, operating the aerial vehicle to travel along a second closed path on the tether sphere, such that a speed of the aerial vehicle is reduced. And the method may involve after or while the speed of the aerial vehicle is reduced, transitioning the aerial vehicle from traveling along the second closed path while in the crosswind-flight orientation to a hover-flight orientation.

Abstract: A method may involve operating an aerial vehicle in a hover-flight orientation. The aerial vehicle may be connected to a tether that defines a tether sphere having a radius based on a length of the tether, and the tether may be connected to a ground station. The method may involve positioning the aerial vehicle at a first location that is substantially on the tether sphere. The method may involve transitioning the aerial vehicle from the hover-flight orientation to a forward-flight orientation, such that the aerial vehicle moves from the tether sphere. And the method may involve operating the aerial vehicle in the forward-flight orientation to ascend at an angle of ascent to a second location that is substantially on the tether sphere. The first and second locations may be substantially downwind of the ground station.

Abstract: A method may involve operating an aerial vehicle in a hover-flight orientation. The aerial vehicle may be connected to a tether that defines a tether sphere having a radius based on a length of the tether, and the tether may be connected to a ground station. The method may involve positioning the aerial vehicle at a first location that is substantially on the tether sphere. The method may involve transitioning the aerial vehicle from the hover-flight orientation to a forward-flight orientation, such that the aerial vehicle moves from the tether sphere. And the method may involve operating the aerial vehicle in the forward-flight orientation to ascend at an angle of ascent to a second location that is substantially on the tether sphere. The first and second locations may be substantially downwind of the ground station.

Abstract: A system and method for detecting wheel lift of an automotive vehicle includes a yaw rate sensor (28) that generates a yaw rate signal, a lateral acceleration sensor (32) that generates a lateral acceleration signal, a roll rate sensor (34) generating a roll rate signal, and a longitudinal acceleration sensor (36) for generating a longitudinal acceleration signal. A controller (18) is coupled to the yaw rate sensor (28), the lateral acceleration sensor (32), the roll rate sensor (34), and the longitudinal acceleration sensor (36). The controller determines a dynamic load transfer acting on the plurality of wheels as a function of yaw rate, lateral acceleration roll rate, and longitudinal acceleration. Normal forces for each of the plurality of wheels is determined as a function of the dynamic load transfer. Wheel lift is indicated when at least one of the normal forces for each of the plurality of wheels is less than a normal force threshold.