Flight Guardian: A common avionics architecture for collision avoidance and safe emergency landing for unmanned aerial systems

Abstract

This paper presents an approach to derive requirements for an avionics architecture that provides onboard sense-and-avoid and autonomous emergency forced landing capabilities to a UAS. The approach is based on two design paradigms that (1) derive requirements analyzing the common functionality between these two functions to then derive requirements for sensors, computing capability, interfaces, etc.(2) consider the risk and safety mitigation associated with these functions to derive certification requirements for the system design. We propose to use the Aircraft Certification Matrix (ACM) approach to tailor the system Development Assurance Levels (DAL) and architecture requirements in accordance with acceptable risk criteria. This architecture is developed under the name "Flight Guardian". Flight Guardian is an avionics architecture that integrates common sensory elements that are essential components of any UAS that is required to be dependable. The Flight Guardian concept is also applicable to conventionally piloted aircraft, where it will serve to reduce cockpit workload.

Embedded Computation Architectures for Autonomy in Unmanned Aircraft Systems (UAS)

“…A system that can land an aircraft or adapt its flight control in response to an engine failure, actuator faults, loss of sensor readings or any other onboard failure is key in highly autonomous aircraft [ 26 , 75 ]. A system like this, will likely require a number of processing stages, each demanding some computational capability from onboard resources [ 76 ].…”

“…We assign an integer value in the range [1,10] to each of the three aspects of the ALFUS model, HI, MC and EC, for each application (see Figure 4 and Table 2). Based on experience [26,34,76], we propose a number of tasks required to ensure feasibility of each application. We then provide three ways to estimate the UAS AL metric, mode, median and mean (arithmetic) of the three values for HI, MC and EC.…”