Abstract: A ground state determination system for an aircraft includes sensors configured to detect parameters of the aircraft and a flight control system implementing a ground state module. The ground state module includes a ground state monitoring module configured to monitor the parameters and a ground state determination module configured to compare each of the parameters monitored by the ground state monitoring module to a respective parameter threshold to determine whether the aircraft is on a surface.

Abstract: A tailsitter aircraft for deploying a tow line includes an airframe having wings with pylons extending therebetween and a thrust array attached to the airframe, the thrust array including propulsion assemblies configured to transition the airframe between a forward flight orientation and a VTOL orientation. The tailsitter aircraft includes an attenuation spool coupled to the airframe and an attenuation cable having a first end coupled to the attenuation spool and a second end coupled to the tow line, the attenuation cable partially or fully wound around the attenuation spool. The tailsitter aircraft also includes a spool sensor to detect movement of the attenuation spool and a flight control system implementing a tow line tension monitoring module in communication with the spool sensor to determine a tow line tension parameter and a tow line tension reaction module to initiate an aircraft response based on the tow line tension parameter.

Abstract: In one embodiment, a remote controller for a vehicle includes at least one control element for controlling operation of at least one aspect of the vehicle when the vehicle is in a remote-control mode; an actuator connected the at least one control element for controlling a position of the at least one control element when the vehicle is in an autonomous operations mode; and a processing system for receiving a first control signal from the vehicle indicative of a state of operation of the vehicle. In operation, the processing system generates a second control signal to the actuator to cause the actuator to control a position of the control element such that it corresponds to and indicates the state of operation of the vehicle.

Abstract: A method for reducing form drag on a tailsitter aircraft during at least one of takeoff or landing includes vertically taking off from the ground in a tailsitter orientation. The method also includes determining an actual pitch of the tail sitter aircraft in the tailsitter orientation. The method also includes determining a difference between the actual pitch and a predetermined pitch. The method also includes adjusting a heading of the tailsitter aircraft based on the difference to minimize a pitch angle to reduce the form drag on the tailsitter aircraft.

Abstract: A tailsitter aircraft includes an airframe, a thrust array attached to the airframe and a flight control system. The thrust array includes propulsion assemblies configured to transition the airframe from a forward flight orientation to a VTOL orientation at a conversion rate for an approach to a target ground location in a forward flight-to-VTOL transition phase. The flight control system implements an adaptive transition system including a transition parameter monitoring module configured to monitor parameters including a ground speed and a distance to the target ground location. The adaptive transition system includes a transition adjustment determination module configured to adjust the conversion rate of the airframe from the forward flight orientation to the VTOL orientation based on the ground speed and the distance to the target ground location such that the airframe is vertically aligned with the target ground location in the VTOL orientation of the forward flight-to-VTOL transition phase.

Abstract: A tailsitter aircraft for deploying a tow line includes an airframe having wings with pylons extending therebetween and a thrust array attached to the airframe, the thrust array including propulsion assemblies configured to transition the airframe between a forward flight orientation and a VTOL orientation. The tailsitter aircraft includes an attenuation spool coupled to the airframe and an attenuation cable having a first end coupled to the attenuation spool and a second end coupled to the tow line, the attenuation cable partially or fully wound around the attenuation spool. The tailsitter aircraft also includes a spool sensor to detect movement of the attenuation spool and a flight control system implementing a tow line tension monitoring module in communication with the spool sensor to determine a tow line tension parameter and a tow line tension reaction module to initiate an aircraft response based on the tow line tension parameter.

Abstract: In one embodiment, a remote controller for a vehicle includes at least one control element for controlling operation of at least one aspect of the vehicle when the vehicle is in a remote-control mode; an actuator connected the at least one control element for controlling a position of the at least one control element when the vehicle is in an autonomous operations mode; and a processing system for receiving a first control signal from the vehicle indicative of a state of operation of the vehicle. In operation, the processing system generates a second control signal to the actuator to cause the actuator to control a position of the control element such that it corresponds to and indicates the state of operation of the vehicle.

Abstract: A tailsitter aircraft includes an airframe, a thrust array attached to the airframe and a flight control system. The thrust array includes propulsion assemblies configured to transition the airframe from a forward flight orientation to a VTOL orientation at a conversion rate for an approach to a target ground location in a forward flight-to-VTOL transition phase. The flight control system implements an adaptive transition system including a transition parameter monitoring module configured to monitor parameters including a ground speed and a distance to the target ground location. The adaptive transition system includes a transition adjustment determination module configured to adjust the conversion rate of the airframe from the forward flight orientation to the VTOL orientation based on the ground speed and the distance to the target ground location such that the airframe is vertically aligned with the target ground location in the VTOL orientation of the forward flight-to-VTOL transition phase.

Abstract: A ground state determination system for an aircraft includes sensors configured to detect parameters of the aircraft and a flight control system implementing a ground state module. The ground state module includes a ground state monitoring module configured to monitor the parameters and a ground state determination module configured to compare each of the parameters monitored by the ground state monitoring module to a respective parameter threshold to determine whether the aircraft is on a surface.

Abstract: An aircraft includes an airframe with a thrust array attached thereto. The thrust array includes a plurality of propulsion assemblies that are independently controlled by a flight control system. A landing gear assembly is coupled to the airframe and includes a plurality of landing feet. An altitude sensor array includes a plurality of altitude sensors each of which is disposed within one of the landing feet such that when the aircraft is in the VTOL orientation, the altitude sensor array is configured to obtain multifocal altitude data relative to a landing surface. The flight control system is configured to generate a three-dimensional terrain map of the surface based upon the multifocal altitude data.

Abstract: In one embodiment, a remote controller for a vehicle includes at least one control element for controlling operation of at least one aspect of the vehicle when the vehicle is in a remote-control mode; an actuator connected the at least one control element for controlling a position of the at least one control element when the vehicle is in an autonomous operations mode; and a processing system for receiving a first control signal from the vehicle indicative of a state of operation of the vehicle. In operation, the processing system generates a second control signal to the actuator to cause the actuator to control a position of the control element such that it corresponds to and indicates the state of operation of the vehicle.

Abstract: In one embodiment, a remote controller for a vehicle includes at least one control element for controlling operation of at least one aspect of the vehicle when the vehicle is in a remote-control mode; an actuator connected the at least one control element for controlling a position of the at least one control element when the vehicle is in an autonomous operations mode; and a processing system for receiving a first control signal from the vehicle indicative of a state of operation of the vehicle. In operation, the processing system generates a second control signal to the actuator to cause the actuator to control a position of the control element such that it corresponds to and indicates the state of operation of the vehicle.

Abstract: A method of adjusting a directional movement ability in an aircraft having two or more rotors includes receiving a desired thrust demand for each rotor of the two or more rotors, comparing the desired thrust demands to determine a maximum thrust demand, determining whether the maximum thrust demand exceeds a maximum thrust limit of the two or more rotors, and adjusting each desired thrust demand based on whether the maximum thrust demand exceeds the maximum thrust limit to provide an adjusted thrust demand for each rotor of the two or more rotors. Each rotor can be operated based on a respective adjusted thrust demand.

Abstract: A method for reducing form drag on a tailsitter aircraft during at least one of takeoff or landing includes vertically taking off from the ground in a tailsitter orientation. The method also includes determining an actual pitch of the tail sitter aircraft in the tailsitter orientation. The method also includes determining a difference between the actual pitch and a predetermined pitch. The method also includes adjusting a heading of the tailsitter aircraft based on the difference to minimize a pitch angle to reduce the form drag on the tailsitter aircraft.

Abstract: An aircraft includes an airframe with a thrust array attached thereto. The thrust array includes a plurality of propulsion assemblies that are independently controlled by a flight control system. A landing gear assembly is coupled to the airframe and includes a plurality of landing feet. An altitude sensor array includes a plurality of altitude sensors each of which is disposed within one of the landing feet such that when the aircraft is in the VTOL orientation, the altitude sensor array is configured to obtain multifocal altitude data relative to a landing surface. The flight control system is configured to generate a three-dimensional terrain map of the surface based upon the multifocal altitude data.

Abstract: A method for an aircraft may include determining a transition from an airplane mode to a helicopter mode for a propulsion system of the aircraft, wherein the propulsion system comprises a plurality of rotor blades; determining whether a descent rate condition is satisfied, wherein the descent rate condition is associated with a maximum allowable descent rate for the aircraft; and controlling a collective pitch angle for the plurality of rotor blades based on the descent rate condition.

Abstract: In one embodiment, a remote controller for a vehicle includes at least one control element for controlling operation of at least one aspect of the vehicle when the vehicle is in a remote-control mode; an actuator connected the at least one control element for controlling a position of the at least one control element when the vehicle is in an autonomous operations mode; and a processing system for receiving a first control signal from the vehicle indicative of a state of operation of the vehicle. In operation, the processing system generates a second control signal to the actuator to cause the actuator to control a position of the control element such that it corresponds to and indicates the state of operation of the vehicle.

Abstract: A rotor system is provided in one example embodiment and may include a first pair of rotor blades comprising a first pitch and a first diameter; and a second pair of rotor blades comprising a second pitch and a second diameter, wherein the first pitch of the first pair of rotor blades and the second pitch of the second pair of rotor blades are different.

Abstract: One embodiment is an aircraft including at least one propulsion assembly; a cargo area for receiving payload to be transported by the aircraft; and a control system for determining characteristics of the received payload; automatically determining optimal control gains for operating the aircraft including the payload based on the determined payload characteristics; and providing control signals to at least one of the at least one propulsion assembly and a control assembly of the aircraft to control operation of the at least one propulsion assembly in accordance with the determined optimal control gains.

Abstract: A method for an aircraft is provided in one example embodiment and may include determining a transition from an airplane mode to a helicopter mode for a propulsion system of the aircraft, wherein the propulsion system comprises a plurality of rotor blades; determining whether a descent rate condition is satisfied, wherein the descent rate condition is associated with a maximum allowable descent rate for the aircraft; and controlling a collective pitch angle for the plurality of rotor blades based on the descent rate condition.