Sense-and-Avoid

Sense & AvoidDestination Object AvoidActual PositionAeroSpySense & Avoid Technology GmbHHafenstr. 47 – 51, 4020 Linz, Austria, www.aerospy.atAeroSpySense & Avoid Technology GmbHHafenstr. 47 – 51, 4020 Linz, Austria, www.aerospy.atIntroduction to Sense & AvoidSense and Avoid is the key factor for the integration of unmanned aerial vehicles into the common airspace. In general it is a safety system for unmanned aerial vehicles (UAV). Sense and Avoid can be separated into two tasks: • Sense is the ability to detect and track obstacles • Avoid is the ability to steer vehicles around obstacles The ASTM F-38 Committee has published recommendation for a S&A system (F2411-04 DSA Collision Avoidance) which will require a UAV to sense another airborne object within ±15° in elevation and ±110° in azimuth, and to avoid another airborne object by at least 500 ft which is the distance for the commonly accepted definition for a Near Mid Air Collision. Today there is no standard available to certify such a system. If the ASTM F2411 recommendation becomes a standard it is still a point of discussion in several working groups of FAA and EASA. The topic of Avoidance is one of the key technologies provided by AeroSpy. Our intention is not escape critical objects by maximising the distance between them. Although it may be the safest choice to overcome an obstacle, it is also the worst solution from a economical standpoint. AeroSpy provides a patented technique to come as close as possible to critical objects, while guaranteeing safety at the same time for the worst case scenario. Based on geometric interpretation, the avoidance problem is solved for stationary and dynamic, as well as co-operative and non-cooperative objects. . The resulting unique Avoidance control technology is extended various to types of uncertainties (robust control) in order to handle different characteristics of sensors and uncertain states (movement and position) of obstacles. Advantages of the Sense and Avoid System by AeroSpy: • Robust and safe against measurement errors • Robust and safe against uncertain object movement and position • Fast calculation with no numerical optimization necessary • Easy to certify simple linear source code • Geometric and so an analytic interpretation allows unique rules important for certification • Can handle different types of objects: stationary, dynamic, co-operative, and non-cooperative • Decentralized control • Works with a limited sensor view • No unnecessary avoidance is performed • Multiple objects are considered We can guarantee to be safe even when very close to dangerous objects!AEROSPY Sense & Avoid Technology GmbH Hafenstr. 47-51 4020 Linz, Austria 2www.aerospy.at office@aerospy.at +43-676-9706124AeroSpySense & Avoid Technology GmbHHafenstr. 47 – 51, 4020 Linz, Austria, www.aerospy.atAvoidTHE CONTROL SCHEMEWaypoint NavigationAvoidState ControlPositionSenseStateSensorsGEOMETRIC INTERPRETATIONAssuming that the UAV is flying along the xaxis to a waypoint. The sensor must be able to sense and track all possible obstacles. If an obstacle is found the UAV flies along a constant radius until the obstacle is avoided. The space surrounding the obstacle guarantees the UAV a separation distance.Rodx axisRriskroy axisTHE CONTROL POLICY AND ROBUSTNESSThe control strategy is implemented as a state machine where direct measurement and tracking information of a state tracker of the possible obstacle is assumed. Additionally the control policy is robust to consider uncertainties in direct measurements (w2) and in the state (w1) of the tracker.& x = f ( x , u ) + w1 , w1 ∈ W1 y = g ( x , u ) + w2 , w ∈ W2Comparision to TCAS and VFR rules: At this point the avoidance system the control policy implements most of the VFR rules. Since the solution is in 2 dimension this control policy extends the safety of TCAS.AEROSPY Sense & Avoid Technology GmbH Hafenstr. 47-51 4020 Linz, Austria 3www.aerospy.at office@aerospy.at +43-676-9706124AeroSpySense & Avoid Technology GmbHHafenstr. 47 – 51, 4020 Linz, Austria, www.aerospy.atSenseTHE SENSORBOXThe sensor box consists of four cameras which identify, track, and classify a moving and stationary obstacle. Next a radar is used to measure the exact location of the most dangerous obstacle. The tracking algorithm tracks the obstacle and forwards the information and its uncertainties to the avoidance algorithm. Additionally, the development environment of the sensorbox will allow you to develop your own application.BASIC TECHNICAL SPECIFICATIONSTechnical Parameter Size of smallest object to be detected Separation distance Angle horizontal Angle vertical Line of sight Distance to start the avoidance maneuver Power consumption Weight Sensor Data output Security standard Value 2m in a range of 200m Variable ±110° +30°/-100° ~10s before avoidance maneuver starts Computed analytically ~100W max. 1.5kg Primary and secondary sensor Serial port and WLAN antenna Robust control strategyIMAGINGThe imaging system provides a constant coverage area defined in real time. The implemented algorithms identify moving obstacles and track them on the image plan. The video stream can be transferred as viewed by the pilot to the ground station.AEROSPY Sense & Avoid Technology GmbH Hafenstr. 47-51 4020 Linz, Austria 4www.aerospy.at office@aerospy.at +43-676-9706124。