A Framework for Multi-Vehicle Navigation using Feedback-Based Motion - - PowerPoint PPT Presentation
A Framework for Multi-Vehicle Navigation using Feedback-Based Motion - - PowerPoint PPT Presentation
A Framework for Multi-Vehicle Navigation using Feedback-Based Motion Primitives Marijan Vukosavljev, Zachary Kroeze, Mireille E. Broucke, and Angela P. Schoellig IROS, September 25, 2017 Motivation M. Vukosavljev, Z. Kroeze, M. E. Broucke, and
Motivation
- M. Vukosavljev, Z. Kroeze, M. E. Broucke, and A. P. Schoellig
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Motivation
- M. Vukosavljev, Z. Kroeze, M. E. Broucke, and A. P. Schoellig
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Path planning and control in known environments
goal
- bstacle
Problem Statement
- M. Vukosavljev, Z. Kroeze, M. E. Broucke, and A. P. Schoellig
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- Given:
- dynamics π¦Μ = π π¦, π£ , outputs π§ = β π¦ ,
where π¦ β β,, π§ β β-
- goal and obstacle sets in output space
- Find: feedback controller π£ π¦ and set of
initial conditions π/ β β, such that π§(π’) eventually enters the goal set and always avoids the obstacle set
- Can be posed as a reach-avoid problem for a
control system
y1 y2
- bstacle
goal y(t)
y1 y2
- bstacle
goal
- Example: two double
integrators, n = 4, p = 2
- π¦Μ4 = π¦5
π¦Μ5 = π£4 π¦Μ6 = π¦7 π¦Μ7 = π£5 π¦Μ = π π¦, π£
- 8π§4 = π¦4
π§5 = π¦6 π§ = β(π¦)
Framework Features
- Feedback control
- Wide range of initial conditions
- Robust to disturbances
- Requires no explicit path
- Safety guarantees
- Simultaneous motion
- Computational efficiency
- Symmetry
- Lower dimensional spaces
- Modularity
- M. Vukosavljev, Z. Kroeze, M. E. Broucke, and A. P. Schoellig
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y1 y2
- bstacle
goal y(t)
Most related literature: Pappas Kumar Belta Frazzoli
Proposed Framework
- M. Vukosavljev, Z. Kroeze, M. E. Broucke, and A. P. Schoellig
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Given
Maneuver Automaton Problem
p outputs for
Output Transition System
Shortest path algorithm
Control Strategy
p-dim
feedback control, umi(x) discrete maneuver plan
Product
dynamics
Hybrid
low-level control Primitives, mi Motion Λ x = f(x, u)
- bstacle and
goal regions
Automaton
motion capabilities in output space grid y = h(x)
Data
Gridding Box size
multi-robot system
- f output
space
Partition of environment Path planning Control design Solution to problem Automated
Maneuver Automaton
- Formally a hybrid system
- Hybrid state space: motion primitives and continuous state in β,
- Edges: concatenation constraints between motion primitives
- Each motion primitives is implemented by a feedback controller over
a designated subset in β,
- M. Vukosavljev, Z. Kroeze, M. E. Broucke, and A. P. Schoellig
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H F B Ο0 Ο0, Ο+ Ο0, Οβ Ο0 Ο+ Ο0 Οβ
v2 v3 v5 v4
Hold
v2 v3 v6 v5 v4
Forward
Ο+ v1 v2 v3 v5 v4
Backward
Οβ
x1 x2
Maneuver Automaton - Design
- First focus on double integrator: π¦Μ4 = π¦5, π¦Μ5 = π£, with π§ = π¦4
- M. Vukosavljev, Z. Kroeze, M. E. Broucke, and A. P. Schoellig
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Hold Forward Backward
H F B Ο0 Ο0, Ο+ Ο0, Οβ Ο0 Ο+ Ο0 Οβ
Hold Forward Backward
Output space behaviour π§
v2 v3 v6 v5 v4
Forward
Ο+ v1 v2 v3 v5 v4
Backward
Οβ v2 v3 v5 v4
Hold
x1 x2
State space behaviour π¦5 π¦4
Reach control
- B. Roszak and M. E. Broucke, βNecessary and
sufficient conditons for reachability on a simplex,β 2006.
Maneuver Automaton - Application
- Quadrocopter model reduces to double integrator in each positional
direction
- For the multi-quadrocopter model, stack all the double integrators
- Choose Hold, Forward, and Backward in each output component
- For example, one quadrocopter with planar motion:
- M. Vukosavljev, Z. Kroeze, M. E. Broucke, and A. P. Schoellig
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β F H β β F F β β B H β β H F β β H H β π§4 π§5 π§4 π§5
Control Policy on the Product Automaton
- M. Vukosavljev, Z. Kroeze, M. E. Broucke, and A. P. Schoellig
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y1 y2
β F H β β H F β β F H β β F F β β F F β β F F β β F F β β F F β β F H β β F H β β F H β β H F β β H F β β H F β β H F β β H H β
y1 y2
Experimental Results
- M. Vukosavljev, Z. Kroeze, M. E. Broucke, and A. P. Schoellig
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Experimental Results - Nominal
- M. Vukosavljev, Z. Kroeze, M. E. Broucke, and A. P. Schoellig
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- M. Vukosavljev, Z. Kroeze, M. E. Broucke, and A. P. Schoellig
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Conclusion
- Addressed a path planning and control
problem in known environments as a reach- avoid problem
- Employed a modular framework consisting of
an output space partition, low-level feedback controllers, and a high-level feedback for selecting motion primitives
- Highly robust control design that enables
simultaneous motion in a computationally feasible way
- M. Vukosavljev, Z. Kroeze, M. E. Broucke, and A. P. Schoellig
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y1 y2
- bstacle
goal y(t)
- M. Vukosavljev, Z. Kroeze, M. E. Broucke, and A. P. Schoellig
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Comparison to Literature
Paper Feedback control Simultaneous motion Computational efficiency Frazzoli, Dahleh, and Feron; 2005 Kloetzer and Belta; 2008 Fainekos, Girard, Kress-Gazit, Pappas; 2009 Ayanian, Kumar; 2010 Raman, Kress-Gazit; 2014 Vukosavljev, Kroeze, Broucke, Schoellig, 2017
- M. Vukosavljev, Z. Kroeze, M. E. Broucke, and A. P. Schoellig
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Stack multiple copies π¦Μ4 = π¦5 π¦Μ5 = π£4 π¦Μ6 = π¦7 π¦Μ7 = π£5 π¦Μ = π π¦, π£ 8π§4 = π¦4 π§5 = π¦6 π§ = β(π¦)
- M. Vukosavljev, Z. Kroeze, M. E. Broucke, and A. P. Schoellig
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