Mission Planning Multiple vehicle missions require the vehicles to be in formation An initial formation has to be established before the mission starts Vehicles cannot be deployed in formation  Need to get the vehicles into initial formation Águas Vivas

Path Generation’s General Problem Problem description –Desired waypoints or manoeuvres –Desired AUV formation –Optimal energy expenditure or manoeuvring time

Path Generation’s General Problem Difficulties –Go-to-formation manoeuvre (collision-free paths) –Avoid (concave, static) obstacles –Opt. 1 – Generate non-intersecting paths –Opt. 2 – Allow for intersecting, “time-coordinated” trajectories –Meet energy and trajectory constraints

Path Generation Avoid absolute timing (to cope with disturbances) Reaching the target positions simultaneously will ensure the required initial formation. Decouple spatial and temporal constraints! Step 1. Produce paths p(  ) without explicit time constraints (polynomial function of  Step 2. Establish a timing law for  t  (polynomial)τ) Inspired by the work of Isaac Kaminer and Reza Ghabcheloo

Path Generation Decouple spatial and temporal constraints! To translate between t and τ use (adopt a polynomial approach to  ) Step 3. Use an optimization of your choice for criterion minimization. Inspired by the work of Isaac Kaminer and Reza Ghabcheloo

Path Generation Polynomial equation Taken for all DOFs (extremely simple system!) Inspired by the work of Oleg Yakimenko, NPS, USA

Multiple Vehicle Manoeuvres Most vehicles are underactuated and lack hovering capabilities  No station keeping at deployment time, no station keeping after vehicles reach mission starting positions  Mission has to start on-the-fly Vehicles should automatically be driven from deployment to mission start

Go To Formation 1 st part of the overall manoeuvre Needs to take into account initial deployment positions and orientations Needs to ensure simultaneous arrival at designated positions and orientations

Go To Formation Needs to avoid collisions until mission control takes over Needs to consider time, energy and vehicle constraints Method has been extended to deal with intersecting paths.

Go To Formation How do we deal with “deviations from the plan? (wind, currents, etc.) Use cooperative path following! (methods are available - IST, NTNU)

The Grex 2008 Azores Mission July 2008 in Horta, Faial (Açores) 5 Nations, 9 Institutions Successful sea trials of Coordinated Path Following and Coordinated Target Tracking

The Grex 2008 Azores Mission The GREX System provides –Central planning for teams –Hardware/OS Abstraction –Information and command flow accross multiple vehicles –Central and distributed mission planning –Complex coordination capability –Safety checks at several levels, transmitted via status/emergency telegrams

The Grex Vehicle Architecture

Grex Team-Oriented Mission Planning Mission Planning Software SeeTrack (by SeeByte) MVP-Pool GREX Meta-language Team Level GREX Meta-language Vehicle Level Languages of Real Vehicles GREX Team Mission Plan Mission Planning by Operator Mission Plan for Vehicle 1 Mission Plan for Vehicle 2 Mission Plan for Vehicle n … GREX Interface Module Veh.1 GREX Interface Module Veh.2 GREX Interface Module Veh.n to the vehicles … Mission Plan for Vehicle 1 Mission Plan for Vehicle 2 Mission Plan for Vehicle n Translation by Mission Planning Software Rules, Vocabulary Mission Plan for Vehicle n+1 GREX Interface Module Veh.n+1 Mission Plan for Vehicle n+1 new MVPs Slide from Thomas Glotzbach, COMPIT’08

Grex Team-Oriented Mission Planning Slide from Thomas Glotzbach, COMPIT’08 GREX Console Running SeeTrack Translation Process 2. start Vehicle Console TMP SVMP 4. Check Formal Language Verification SVMP 3. Translation SeeTrack SVMP TMP 1. create Operator 6. Translation into Real Vehicle Language by Vehicle Provider RVMP 7. Check Already existing checking process RVMP SVMP 5. Transfer via Network Link Vehicle Existing HW GREX HW TMPSVMPRVMP 8. T r a n s f e r v i a N e t w o r k L i n k

Grex Teamhandler Module Slide from Thomas Glotzbach, COMPIT’08 Mission Management Manoeuvre Management Auto Pilot TeamHandler Mission Management Manoeuvre Management Auto Pilot Vehicle 3 Mission Management Manoeuvre Management Auto Pilot Vehicle 2 Mission Management Manoeuvre Management Auto Pilot Vehicle 1 Manoeuvre Management:  Mission Modification (Obstacle Avoidance)  Mission Adjustment (Typical Primitive Execution) Mission Management:  Mission Reorganisation (Handling of special situations) Auto Pilot (Team):  Mission Coordination (keeping of formation, inter vehicle collision avoidance)

The Grex 2008 Azores Mission Simple Path Following Desired Path is predefined DELFIM X follows a mission consisting of predefined #ARC and #POINT (line) SVPs Slide from Arvind Pereira, USC

The Grex 2008 Azores Mission Coordinated Path Following Path already provided Vehicles coordinate with leader vehicle to do coordinated path-following Slide from Arvind Pereira, USC

The Grex 2008 Azores Mission GoToFormation MVP implementation to take vehicles to a starting formation Will use path/trajectory planning algorithms that do spatio- temporal deconfliction Obstacle avoidance is also required Slide from Arvind Pereira, USC

The Grex 2008 Azores Mission Simple Target Tracking Águas Vivas moves around while sending DELFIM X its GPS locations DELFIM X estimates path followed in GREX SVMP format and follows this path Slide from Arvind Pereira, USC

The Grex 2008 Azores Mission Coordinated Target Tracking DELFIM X GREX- module’s estimator learns path of Águas Vivas and does a coordinated path- following with Seabee AUV using GREX MVPs Slide from Arvind Pereira, USC

The Grex 2008 Azores Mission Because GREX deals with multiple vehicles, a Go-To-Formation behaviour is necessary for each mission My part in the mission: –Developed an algorithm for Go-To-Formation –Helped developing the software for telegram processing (communication on the vehicle side) –Developed software to be ready to go to sea in Sesimbra, September 2008

Grex 2008 Azores Mission: Results Path Following

Grex 2008 Azores Mission: Results Target Tracking

Future Work 1.Incorporate deconfliction in time 2.Go on to three-dimensional paths 3.Finally, think about on-line path planning during mission runtime