Multi-UAV system design

Group 1

Roland Siegwart, Evsen Yanmaz, Torsten Andre, Christof Hoppe, Michael Rischmuller, István Fehérvári, Wilfried Elmenreich

What is a multi-UAV system?

• airborne
• two or more UAVs, possibly also heterogeneous
• have to share knowledge
• information exchange during operation
• indirect or direct communication
• don't have to share a common objective
• collaboration or coordination

What are the building blocks of an autonomous multi-UAV system?

• networking, some form of communication
• sensing system: cameras, ultra-sonic
• interaction with the environment
• sharing representation
• bottom-up/top-down
  • bottom up: team of individuals
  • top down: designed as a team
• fail-operational or fail-safe
• swarm of simple systems/swarm with a leader/swarm of highly intelligent systems

What are the design challenges?

• technical challenges, see above
• mission-specific or one system fits all?
• system integration
• legal issues, regulations
• responsibility
• privacy
• public perception, acceptance

Is autonomy desirable? When?

• yes, for a large number of UAVs
• for a large area, remote location
• if problem is well-defined and easy
• no, to avoid legal issues
• if problem is complex, not trackable

Group 2

Definitions

• Autonomy
  • Executing tasks within a certain constrained area
  • Scale from complete pilot control to complete uav control for decission making
  • Autonomy can be defined for various scopes ( from the individual robot to a whole system including the operators)
    • A pilot with the UAV could be a system, a tower communicating with them could be external. Where to draw the line is questionable
  • Usualy the definition of autonomy only applies to the UAV system itself
  • Event though there are different definitions of autonomy we set the scope only on an individual plattform

what is a multi-uav system

• UAV:
  • plattform
  • (not piloted by a human)
  • capable of aerial flight
  • moves in 3 Dimensions
• n>1
• can be but does not need to be homogenoeus
• either there must be a common understanding of the task or some form of communication otherwise it is not a system

what are the building blocks of an autonomous multi-UAV system

• Hardware requirements for individual UAVs
  • Power supply
  • Communication
  • Propulsion
  • Sensors
  • Computation
• System requirements
  • Logic/ Control logic / AI
  • Flight control system that stablizes the system
• some sort of feedback about the position of sorrounding UAVs is needed for each uav
• Mission control
  • Does the mission control need to know about the UAV systems? Like what type of sensors it uses?
  • Depending on definition of the system. If the UAV is autonomous or if the whole system is autonomous

what are the design challenges?

• Do we need a sense and avoid system for UAVs? (whatever that means)
• Defining the Terms UAV-System and Autonomy
  • Where do we draw the line for a system and what falls under Autonomy
• Decicde where and how a system should learn and abstract
• Central vs. Decentral controll
  • Central coordination
    • Huge communication overhead
    • Huge computational constraints
  • Decentral design
    • Some form of coordination and parralelization needs to be there
    • Communication is a problem
    • Competing Robots or collaborating?

is autonomy desirable? When?

• Not desirable, it's essential
• No conitinouus controll is possible ( communication fails)
• Unpredicted environment changes or internal changes (prop dead)
• Gravity is a problem. if you stand still you drop :)

• multiple UAVs make the problem harder
  • As each UAV needs to interact with the environment autonomously it would also need to interact with all the other UAVs (which then are part of the enivornment)
  • It would be very hard to controll all of them from a single point

Group 3

What is a multi-UAV system?

• at least two UAVs
• combine information

What are the building blocks of an autonomous multi-UAV system?

• sensing
• signal processing
• actuation
• computation
• control
• power
• power management
• communication
• user interface
• coordination
• cooperation
• appropriate mechanical design
• IN ADDITION: mechanical design and application design blocks

What are the design challenges?

sensor fusion

• power management
• processing power
• redundancy, safety
• heterogeneity of platforms
• interdisciplinary knowledge needed
• strict regulations
• failure robustness
• "self healing"

Is autonomy desirable?

• ... with multi-UAVs, there is no choice
• better, more deterministic performance

Killer Problems/Enabling factors

Enabling factors that emerged in recent years

• Cost for UAV systems dropped dramatically
• Image processing SW/HW
• Sensor HW availability

but some prototypes showing basic technology existed 10 years ago...

Killer problems

• Regulation
• Wireless communication spectrum for drones

Provocative claim: Way for solving technological issues is straight.