Disclosed is a drone. The present invention includes a plurality of propellers creating a lift to prevent inclination and overturn of the drone due to a lift difference generated from uneven ground, a power driving unit providing a rotation power to each of a plurality of the propellers, a ground sensing unit measuring a distance to a first region of the ground and a shape of the first region, and a controller controlling the power driving unit to differentiate rotation ratios of a plurality of the propellers based on the measured distance and shape if receiving an input signal for landing at the first region.

A touchdown control system for a vertical take-off and landing (VTOL) aircraft including a detection controller receptive to aircraft state signals including one or more of an altitude signal, an aircraft attitude signal, an external environment signal, an aircraft velocity signal, an attitude rate signal, and a proximity signal. An enable controller is operatively connected to the detection controller. The enable controller selectively provides a touchdown control signal based on one or more of the altitude signal, the aircraft attitude signal, the external environment signal, the aircraft velocity signal, the attitude rate signal, and the proximity signal. A regulation controller is operatively connected to the enable controller. The regulation controller selectively adjusts aircraft control surfaces based on the touchdown control signal to facilitate final touchdown of the VTOL aircraft.

A touchdown control system for a vertical take-off and landing (VTOL) aircraft including a detection controller receptive to aircraft state signals including one or more of an altitude signal, an aircraft attitude signal, an external environment signal, an aircraft velocity signal, an attitude rate signal, and a proximity signal. An enable controller is operatively connected to the detection controller. The enable controller selectively provides a touchdown control signal based on one or more of the altitude signal, the aircraft attitude signal, the external environment signal, the aircraft velocity signal, the attitude rate signal, and the proximity signal. A regulation controller is operatively connected to the enable controller. The regulation controller selectively adjusts aircraft control surfaces based on the touchdown control signal to facilitate final touchdown of the VTOL aircraft.

Embodiments of the disclosure are directed to a convertible rotor aircraft CRA able to convert between airplane and helicopter flight modes during flight, comprising a tillable proprotor assembly TPA comprising a proprotor. Optionally, the CRA comprises a flight control module FCM configured to control the TPA to reverse direction of thrust generated by the proprotor relative to the TPA when the TPA transitions between a first orientation for helicopter flight and a second orientation for airplane flight. Optionally, the CRA comprises a deployable guard for the proprotors, configured to have a stowed state and a deployed state, wherein: the guard in the deployed state is controlled to be configured as a partially air-permeable barrier.

Embodiments of the disclosure are directed to a convertible rotor aircraft CRA able to convert between airplane and helicopter flight modes during flight, comprising a tillable proprotor assembly TPA comprising a proprotor. Optionally, the CRA comprises a flight control module FCM configured to control the TPA to reverse direction of thrust generated by the proprotor relative to the TPA when the TPA transitions between a first orientation for helicopter flight and a second orientation for airplane flight. Optionally, the CRA comprises a deployable guard for the proprotors, configured to have a stowed state and a deployed state, wherein: the guard in the deployed state is controlled to be configured as a partially air-permeable barrier.

A crash detection device for mounting on a flying object having a parachute or paraglider deployment device. The crash detection device includes a sensor for measuring a parameter related to a flying state of the flying object. The sensor is configured for acquiring data of the parameter in a normal mode in which the data is acquired at a sampling frequency of less than 1 kHz, and in an abnormal mode in which the data is acquired at the sampling frequency of 1 kHz or more. The crash detection device further includes a detector coupled to the sensor and configured for verifying proper operation of the sensor; and a controller configured for receiving from the sensor values of the parameter and for determining flying state of the flying object.

A total runway safety system (TRSS) and method measures, monitors, manages, and informs flight crew on the progress of takeoffs and landings and of any hazardous runway conditions. In some embodiments, the TRSS measures, monitors, and informs flight crew of longitudinal and lateral runway tracks thus preventing overruns and veer-offs during takeoffs and landings. In some embodiments, backscatter of infrared laser beams emitted by the aircraft is used to evaluate groundspeed and the reflectivity of the runway surface to make estimates of the surface conditions, roughness and contamination, which affects rolling and braking efforts and acceleration. In some embodiments TRSS evaluates runway surface and predicts tire-surface rolling and braking coefficient of friction. In some embodiments, GPS and similar navigation data, and ATC/airport reported runway braking conditions are evaluated along with the infrared laser, ultrasound and digital images to find best estimates of the runway remaining, current speed, acceleration, and jerk.

A total runway safety system (TRSS) and method measures, monitors, manages, and informs flight crew on the progress of takeoffs and landings and of any hazardous runway conditions. In some embodiments, the TRSS measures, monitors, and informs flight crew of longitudinal and lateral runway tracks thus preventing overruns and veer-offs during takeoffs and landings. In some embodiments, backscatter of infrared laser beams emitted by the aircraft is used to evaluate groundspeed and the reflectivity of the runway surface to make estimates of the surface conditions, roughness and contamination, which affects rolling and braking efforts and acceleration. In some embodiments TRSS evaluates runway surface and predicts tire-surface rolling and braking coefficient of friction. In some embodiments, GPS and similar navigation data, and ATC/airport reported runway braking conditions are evaluated along with the infrared laser, ultrasound and digital images to find best estimates of the runway remaining, current speed, acceleration, and jerk.

A touchdown control system for a vertical take-off and landing (VTOL) aircraft including a detection controller receptive to aircraft state signals including one or more of an altitude signal, an aircraft attitude signal, an external environment signal, an aircraft velocity signal, an attitude rate signal, and a proximity signal. An enable controller is operatively connected to the detection controller. The enable controller selectively provides a touchdown control signal based on one or more of the altitude signal, the aircraft attitude signal, the external environment signal, the aircraft velocity signal, the attitude rate signal, and the proximity signal. A regulation controller is operatively connected to the enable controller. The regulation controller selectively adjusts aircraft control surfaces based on the touchdown control signal to facilitate final touchdown of the VTOL aircraft.

A touchdown control system for a vertical take-off and landing (VTOL) aircraft including a detection controller receptive to aircraft state signals including one or more of an altitude signal, an aircraft attitude signal, an external environment signal, an aircraft velocity signal, an attitude rate signal, and a proximity signal. An enable controller is operatively connected to the detection controller. The enable controller selectively provides a touchdown control signal based on one or more of the altitude signal, the aircraft attitude signal, the external environment signal, the aircraft velocity signal, the attitude rate signal, and the proximity signal. A regulation controller is operatively connected to the enable controller. The regulation controller selectively adjusts aircraft control surfaces based on the touchdown control signal to facilitate final touchdown of the VTOL aircraft.