Latching mechanism between UAV and UGV team for mine rescue

Master's Project (M.S.) University of Alaska Fairbanks, 2017Safety is a concern in the mining industry when a tunnel collapse could result in the casualties and deaths of workers and rescuers due to the hazards posed to them. The Alaska Center for Unmanned Aircraft Systems Integration (ACUASI) is working on a project to increase mine safety by sending an Unmanned Ground Vehicle (UGV) fit with LiDAR sensors and an Unmanned Aircraft Vehicle (UAV) to map the tunnels and to find a collapsed tunnel in an effort to determine the location and condition of trapped workers. The UGV will drive to the collapsed tunnel, at which point the U AV will launch to find any gap in the tunnel that it could fly through to assess the damage. This overall project requires a releasing and latching system to secure the UAV, allow it to launch at the appropriate location, and dock the UAV when its mission is complete or its battery needs recharging. A simple pin-through design was adopted to latch and release the UAV by implementing a Scotch yoke and servo as the actuator. All necessary components were analyzed for stress using two forces, 16 N (maximum takeoff weight of the potential UAV) and 150 N (im pact force of the maximum w eight of the potential UAV from 0.15 m or just under 6 inches). Three sets of properties for PLA were applied in the stress analyses to thoroughly investigate the feasibility of creating the parts out of PLA, a commonly used plastic for 3D printing. These three property sets were found in literature and consisted of bulk values of PLA, empirically determined values of 3D printed PLA, and values calculated using porosity equations. It was found that most components would function satisfactorily without risking fracture except in extreme conditions. The stress analyses for the landing gear illustrated its weaknesses, revealing a potential need for a different material or redesign. The landing gear as it is could be utilized under nominal operation, but it could not withstand any significant impact such as one that might occur in the event of a hard landing. The latching mechanism itself succeeded in securing the UAV. Future work includes redesigning the landing gear, another design concept for a latching mechanism that may prove more reliable, and adjusting the landing pad in the event a different UAV is selected

Development of a Generic Time-to-Contact Pilot Guidance Model

The time-to-contact ττ theory posits that purposeful actions can be conducted by coupling the actor’s motion onto the so-called ττ guides generated internally by their central nervous system. Although significant advances have been made in the application of ττ for flight control purposes, little research has been conducted to investigate how pilots are able to adapt their ττ-guidance strategy to different aircraft dynamics, or how a ττ-guide-based pilot–aircraft model might be used to represent control behavior. This paper reports on the development of such a model to characterize the adaptation of pilot guidance to variations in aircraft dynamics using data obtained from a clinical pilot-in-the-loop flight simulation experiment. The results indicate that pilots tend to maintain a constant coupling between the dynamic system’s motion and the ττ guide across a range of different configuration parameters. Simultaneously, the pilot modulates the guidance maneuver period to adapt to these different aircraft dynamics that result in changes in workload. Modeling the complete pilot stabilization and guidance function as a regulator plus inverter yields good comparative results between the pilot–aircraft model and simulator trajectory data, and it supports the hypothesis that the following ττ-based guidance strategies suppress an aircraft’s natural dynamics

Biologically Inspired Guidance for Autonomous Systems

Animals and humans can perform purposeful actions using only their senses. Birds can perch on branches; bats use echolocation to hunt prey and humans are able to control vehicles. It must therefore be possible for autonomous systems to replicate this autonomous behaviour if an understanding of how animals and humans perceive their environment and guide their movements is obtained. Tau theory offers a potential explanation as to how this is achieved in nature. Tau theory posits, that in combination with the so-called ‘motion guides’, animals and humans perform useful movements by closing action-gaps, i.e. gaps between the current state and a desired state. The theory suggests that the variabl

Bio-inspired TauPilot for automated aerial 4D docking and landing of Unmanned Aircraft Systems

This paper presents the development and experimental validation of a bio-inspired autopilot, called TauPilot, that is based on the ecological Tau Theory proposed by the psychologist David Lee. Tau theory postulates that animals and humans use the tau (τ) variable (or Time-To-Contact) and simple guidance strategies to prospectively control most of their purposeful movements. This research investigates the feasibility and effectiveness of applying tau theory principles for guiding some crucial maneuvers of Unmanned Aircraft Systems (UAS) such as braking, automated aerial docking, automatic landing and moving target interception. The developed TauPilot includes a tau-Guidance system, a tau-Navigation system and a tau-Controller, resulting in 4D (time as the fourth dimension) GN&C system that has the capability to accurately fit maneuvers or actions into 4D slots using only a universal temporal variable tau. TauPilot has been integrated into two rotorcraft UAS and demonstrated in more than one thousand (about 1114) successful tau-controlled flights