Asynchronous Behavior Trees with Memory aimed at Aerial Vehicles with Redundancy in Flight Controller

Complex aircraft systems are becoming a target for automation. For successful operation, they require both efficient and readable mission execution system. Flight control computer (FCC) units, as well as all important subsystems, are often duplicated. Discrete nature of mission execution systems does not allow small differences in data flow among redundant FCCs which are acceptable for continuous control algorithms. Therefore, mission state consistency has to be specifically maintained. We present a novel mission execution system which includes FCC state synchronization. To achieve this result we developed a new concept of Asynchronous Behavior Tree with Memory and proposed a state synchronization algorithm. The implemented system was tested and proven to work in a real-time simulation of High Altitude Pseudo Satellite (HAPS) mission.Comment: Accepted to IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2019), IEEE copyrigh

Mission Planning and Verification for Autonomous Unmanned Aerial Vehicles

Autonomous robotic systems that work alongside humans or interact with valuable goods impose high demands on safety and fault tolerance. In this work, a robotic architecture is proposed that employs common model checking techniques to ensure the compliance of complex robotic missions with formally specified safety properties. Two formalisms are discussed to describe such mission plans: Hierarchical Finite State Machines and Behaviour Trees. Employing the explicit-state model checker DIVINE and the mission execution framework RAFCON, a tool chain has been developed that facilitates verification of LTL formulae on mission plans specified with either of those methodologies. The proposed system design tries to deal with hardware failures by calculating affected mission building blocks and removing them from the active plan

Asynchronous Behavior Trees with Memory aimed at Aerial Vehicles with Redundancy in Flight Controller

Complex aircraft systems are becoming a target for automation. For successful operation, they require both efficient and readable mission execution system (MES). Flight control computer (FCC) units, as well as all important subsystems, are often duplicated. Discrete nature of MES does not allow small differences in data flow among redundant FCCs which are acceptable for continuous control algorithms. Therefore, mission state consistency has to be specifically maintained. We present a novel MES which includes FCC state synchronization. To achieve this result we developed the new concept of Asynchronous Behavior Tree with Memory (ABTM) and proposed a state synchronization algorithm. The implemented system was tested and proven to work in a real-time simulation of High Altitude Pseudo Satellite (HAPS) mission