IEEE Robotics & Automation Magazine - December 2011 - 109

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robot reaches a desired state while
avoiding a set of bad (unsafe) states.
The article includes three examples: a
quadrotor performing aerobatics maneuvers, a quadrotor remaining in a
safe set while subject to disturbances
and noise, and decision making in a
capture-the-flag game.
In "Semiautonomous Multivehicle
Safety," the authors focus on a driving
scenario in which a human-controlled
car and an autonomous car safely
navigate a roundabout. The human
driver is modeled as a hybrid system
with imperfect mode information, and
the system's mode is estimated in the
process of generating control laws
for the autonomous car. These control laws guarantee safe behavior (no
collisions) and are less restrictive than
worse-case approaches.
The remaining four articles focus on
the problem of generating correct-byconstruction control for a robot or team
of robots such that the robot is guaranteed to achieve a high-level, abstract
behavior. These articles focus on the use
of linear temporal logic (LTL) as the
specification formalism although other
formalisms are used in the field as well.
Loosely speaking, LTL is a logic in

which the truth value of the propositions can change with time, thus allowing one to reason about logical formulas
that have a temporal aspect. For example, in propositional logic we can evaluate the truth of the statement "the
sun is shining." If it is currently night,
the statement is false; if it is day, the
statement is true. In LTL, in addition to
the previous statement, we can evaluate
statements of the form "eventually, the
sun will shine" (true) and "the sun
always shines" (false). This logic is
commonly used since it can capture a
wide range of robot behaviors and
there are many approaches available to
synthesize controllers from it.
In "Motion Planning with Complex
Goals," the authors describe an approach to combining sampling-based
motion planning with model-checking
techniques to find paths that satisfy
temporal goals for robots with complex
dynamics. The multilayer approach
alternates between finding possible trajectories in a discrete abstraction of the
workspace and ensures that physically
feasible paths exist.
In "Correct, Reactive High-Level
Robot Control," the authors consider,
in the context of autonomous cars,

reactive tasks in which the robot's
behavior depends on the information
it gathers at run time. Using LTL
synthesis methods, two approaches
to mitigating the state-space explosion
problem are presented.
In "Automatic Deployment of Robotic Teams," the authors consider
the problem of transforming global
specifications for teams of robots into
individual robot control and communication protocols. The authors describe
several approaches to the problem,
discuss the different tradeoffs, and
illustrate the approaches using simulations and experiments in their
urban-like environment.
Finally, in "Automatic Sequencing of
Ballet Poses," the authors model classical
ballet movements as automata and
use LTL specification to generate
novel sequences. Through the use of
the logic, the authors are able to not
only guarantee physically feasible
motions but also enforce stylistic and
aesthetic considerations.
I truly hope that the results and
future challenges described in this issue
will excite researchers in the community
and encourage people to get involved
and contribute to this growing field.

(IROS 2012; www.iros2012.org) will
be held in Vilamoura, Algarve, Portugal, on 7-11 October 2012 and will
be strongly centered on robotics for
quality of life and sustainable

development. This event celebrates
25 years of IROS and provides an
opportunity to contact not only colleagues but also the local Portuguese
robotics research teams and universities in Portugal.
In the name of Portuguese RAS
Chapter, welcome to the IROS 2012
in Vilamoura, Algarve.

Regional

(continued from page 97)

platforms (Figure 6), and new devices
for emergency first responders and
search and rescue activities (Figure 7).
The next International Conference
on Intelligent Robots and Systems

References
[1] P. U. Lima, "Robotics educational activities
in Portugal: A motivating experience [Education]," IEEE Robot. Automat. Mag., vol. 14,
Figure 6. Move the transport unmanned
vehicle, which is a commercial product
developed by a spin-off company from the
Instituto Pedro Nunes technology-transfer
institute from the University of Coimbra.

Figure 7. Raposa the search and
rescue vehicle, which is a commercial
product developed by a spin-off robotic
company from the Technical University
of Lisbon.

no. 2, pp. 16-17, June 2007.
[2] Portuguese Robotics White Book (Robotica
no Mapa) [Online]. Available: http://www.spr.
ua.pt

DECEMBER 2011

IEEE ROBOTICS & AUTOMATION MAGAZINE

109

http://www.iros2012.org http://www.spr http://www.ua.pt

Table of Contents for the Digital Edition of IEEE Robotics & Automation Magazine - December 2011