swarming autonomous systems for offshore oil spill...
TRANSCRIPT
SWARMING AUTONOMOUS SYSTEMS FOR OFFSHORE OIL SPILL RECOVERY AND CLEAN-UP
Richard Mensah [2129347M]
MSc Mechatronics Engineering
Supervisor : Mr Garrie Mushet
University of Glasgow, charity number SC004401
Oil spillage into the marine environment either intentionally or unintentionally has
been known to cause serious damage to biological life and the marine
ecosystem. This MSc dissertation was to develop and test a control system for
an autonomous swarming system optimized for use in an emergency offshore oil
spill clean-up.
The objectives for the control system were:
Autonomous and decentralised coverage of spill site
Internal collision prevention within swarm
Obstacle avoidance
𝑢 = 𝑣 ∅
2−
1
4𝑚𝐶𝑑𝜌 𝑢2𝐴 +
𝑐𝑜𝑠∅
2𝑚𝐶𝑇𝜌𝑛
2𝐷4
𝑣 =− 𝑢 ∅
2−
1
4𝑚𝐶𝑑𝜌 𝑣2𝐴 +
𝑠𝑖𝑛∅
2𝑚𝐶𝑇𝜌𝑛
2𝐷4
∅ = −1
6𝐼𝑧𝜌𝐶𝑝𝑡 𝜖1𝐿 + 𝑦 𝜖2 − 𝜖1 ∅2 +
1
𝐼𝑧
1
2𝜌𝐶𝐿𝐴𝑟𝑉
2 (𝑂𝐶𝑃 + 𝑂𝐶𝐺)sin𝜋
2
𝛿𝑎𝑡𝑡𝑎𝑐𝑘𝛿𝑠𝑡𝑎𝑙𝑙
The control system was built on the Artificial Potential Field and an
extended version of the Multi-resolution Navigation Of Mobile
Robots Algorithm. Results from simulation are displayed in Figures
3 - 6.
Fig1 Concept Robot
Fig3 Path of Single Robot moving around an obstacle with goal at coordinate (9,9)
Fig4 Path of a single robot cleaning an 80mX80m oil field
Fig5 Paths of two robots cleaning an 80mX80m oil field
Fig6 Paths of four robots cleaning an 80mX80m oil field with obstacles
Mathematical model of robot
Conclusion
• There is an equal task sharing among the swarm independent of
the initial positions of the robots
• Task does not need to be explicitly assigned to the robots as the
robots are able to plan themselves online.
• The swarm is able to access the entire field without any prior
knowledge of the field. The only information needed is an origin
Important Features of the control system
The control system meets the objectives defined for the project. It
can be adapted for swarming autonomous systems in complete
coverage applications such as oil spill cleaning, large area lawn
mowing and large space floor cleaning
𝜕𝑈𝑅 = −𝐾𝑎𝑡𝑡 𝑥 − 𝑥0 + 𝑦 − 𝑦0 𝑖 + 𝐾𝑟𝑒𝑝1
𝑥−
1
𝑥0𝑏
1
𝜌𝑥
2
+1
𝑦−
1
𝑦0𝑏
1
𝜌𝑦
2
𝑖
𝜕𝑈𝑎𝑡𝑡 = −𝐾𝑎𝑡𝑡 𝑥 − 𝑥0 + 𝑦 − 𝑦0 𝑖
𝜕𝑈𝑅𝑒𝑝 = 𝐾𝑟𝑒𝑝1
𝑥−
1
𝑥0𝑏
1
𝜌𝑥
2
+1
𝑦−
1
𝑦0𝑏
1
𝜌𝑦
2
𝑖 𝑖𝑓 𝜌 ≤ 𝜌0
)𝑇ℎ𝑟𝑢𝑠𝑡𝑒𝑟 𝐹𝑜𝑟𝑐𝑒( 𝐹 ) = 𝐹𝑔 ∗ 𝑎𝑏𝑠(𝜕𝑈𝑎𝑡𝑡
∅𝑅 = 𝑡𝑎𝑛−1𝑖𝑚𝑎𝑔 𝜕𝑈𝑅𝑟𝑒𝑎𝑙 𝜕𝑈𝑅
𝑀𝑜𝑚𝑒𝑛𝑡 (𝑀) =
𝑀𝑔 ∗ ∅𝑅 − ∅ 𝑖𝑓 ∅𝑅 > ∅ && ∅𝑅 − ∅ ≤ 180
−𝑀𝑔 ∗ 360 − ∅𝑅 − ∅ 𝑖𝑓 ∅𝑅 > ∅ && ∅𝑅 − ∅ > 180
−𝑀𝑔 ∗ 360 − ∅𝑅 − ∅ 𝑖𝑓 ∅𝑅 < ∅ && ∅𝑅 − ∅ > 180
𝑀𝑔 ∗ ∅𝑅 − ∅ 𝑖𝑓 ∅𝑅 < ∅ && ∅𝑅 − ∅ ≤ 180
Rudder
The Artificial Potential Field