A navigation system for airborne vehicles without GNSS data uses at least three microphones positioned at or near a base station. The microphones capture sounds emitted by the airborne vehicle and these sounds are processed to calculate the vehicle's location. The vehicle then makes a series of maneuvers in response to the information received from the base station.

Advanced control systems and methods for precise navigation and positioning of unmanned vehicles (UVs) without reliance on GPS. A hierarchical marker including nested geometric shapes with distinct visual features, detectable by a camera mounted on the UV is utilized. An image processing unit processes the captured images, identifying marker levels to guide the UV through multiple stages of approach. An integrated UV controller, including an autopilot module, dynamically switches between autopilot modes corresponding to each detected marker level, ensuring precise alignment and positioning.

A system can include a processing device and a memory having instructions that are executable by the processing device for causing the processing device to perform operations. The operations may involve receiving or determine one or more operational constraints corresponding to an aircraft having multiple degrees of freedom. The operations may involve performing an optimization method to obtain a set of trajectory data for the aircraft subject to the one or more operational constraints, the set of trajectory data including a set of temporal state parameters that describe a state of the aircraft and a set of control input signals that are usable to control the aircraft. The operations may involve transmitting the set of trajectory data to a flight computer, the flight computer being configured to control the aircraft based on the set of trajectory data.

One example of an aircraft tail strike detection and prevention system can include one or more processors that obtain one or more aircraft characteristics representative of an aircraft flying toward a landing location and one or more external characteristics representative of one or more conditions outside of the aircraft. The one or more processors can obtain a current descent trajectory that the aircraft is to follow to land at the landing location and calculate a probability that the aircraft will experience a tail strike upon touchdown based on the one or more aircraft characteristics and the one or more external characteristics. The one or more processors can alert a pilot of the aircraft that the aircraft will experience the tail strike upon touchdown based on the probability.

Systems and methods are provided for promoting stable aircraft approach conditions. The system comprises a display device that is onboard an aircraft and a controller in communication with the display device. The controller is configured to, by a processor: receive data that includes information relating to an action configured to stabilize an approach of the aircraft during landing thereof and a recommended timing of performing the action relative to a predetermined flight plan of the aircraft, and render a first visual element on the display device that is configured to display the action relative to the flight plan and dynamically indicate the recommended timing of performing the action relative to a geographic position of the aircraft along the flight plan.

Examples relate to uncrewed aerial vehicles (UAVs) and methods for controlled descent during control tier failures. A computing device may initially detect a control tier failure at an UAV. In some examples, the UAV includes a fuselage, a pair of wings extending outwardly from the fuselage, and a pair of stabilizers arranged in a V-shape configuration. Each stabilizer has a control surface that is adjustable relative to a fixed portion of the stabilizer. Based on detecting the control tier failure at the UAV, the computing device may adjust the control surface of each stabilizer from a first angle to a second angle relative to the fixed portion of the stabilizer. By adjusting the angle between the control surfaces and fixed portions of one or both stabilizers, the UAV may induce a deep stall maneuver that can enable a controlled descent of the UAV.

Aspects described herein may relate to aerial structures such as aircraft. An aerial structure may include a fuselage, a wing attached to the fuselage, and a plurality of propulsion systems configured to generate thrust. A propulsion system may include a plurality of propulsors, such as propulsor fans. A propulsor fan may be configured to be actuated between a conventional take-off and landing (CTOL) flight mode, a short take-off and landing (STOL) flight mode, and a vertical take-off and landing (VTOL) flight mode.

Provided is a dual spinning laser-based unmanned aerial vehicle (UAV) positioning and landing system including a first laser module, a first rotating module, a second laser module, a second rotating module, a signal transceiver, a controller and a substrate, and a method thereof. The first laser module is configured to provide a first light beam emitted by rotating around a first axis. The first rotating module is configured to drive the first laser module to rotate around a rotation axis perpendicular to the first axis to allow the first light beam to scan in a space. The second laser module is configured to provide a second light beam emitted by rotating around a second axis. The second rotating module is configured to drive the second laser module to rotate around a rotation axis perpendicular to the second axis to allow the second light beam to scan in the space.

During aircraft descent, flight control systems seek and maintain a glide slope determined from a single pilot input parameter; e.g., the position of a control axis of a flight stick. Appropriate guide slope selection by the pilot is readily determined from the pilot's visual observation of an intended landing site during landing approach. The glide slope defines a ratio of forward speed and descent speed which is automatically established and maintained/updated according to pilot input while these speeds are also automatically reduced during descent, despite the two speed directions respectively being affected distinctly and differently by aircraft mechanisms which control them. The aircraft ends its glide path with speed at or near zero, allowing landing by short vertical descent. Accordingly, the pilot offloads problems of both coordinating speeds to achieve a particular guide slope, and reducing them while maintaining this coordination.