The problem of path planning for an automaton moving in a two-dimensional scene filled with unknown obstacles is considered. The automaton is presented as a point; obstacles can be of an arbitrary shape, with continuous boundaries and of finite size; no restriction on the size of the scene is imposed. The information available to the automaton is limited to its own current coordinates and those of the target position. Also, when the automaton hits an obstacle, this fact is detected by the automaton's "tactile sensor." This information is shown to be sufficient for reaching the target or concluding in finite time that the target cannot be reached. A worst-case lower bound on the length of paths generated by any algorithm operating within the framework of the accepted model is developed; the bound is expressed in terms of the perimeters of the obstacles met by the automaton I in the scene. Algorithms that guarantee reaching the target (if the target is reachable), and tests for target reachability are presented. The efficiency of the algorithms is studied, and worst-case upper I bounds on the length of generated paths are produced.
A wide variety of tactile (touch) sensors exist today\ud
for robotics and related applications. They make use of various\ud
transduction methods, smart materials and engineered structures,\ud
complex electronics, and sophisticated data processing.\ud
While highly useful in themselves, effective utilization of tactile\ud
sensors in robotics applications has been slow to come and largely\ud
remains elusive today. This paper surveys the state of the art and\ud
the research issues in this area, with the emphasis on effective\ud
utilization of tactile sensors in robotic systems. One specific with\ud
the use of tactile sensing in robotics is that the sensors have to be\ud
spread along the robot body, the way the human skin is – thus\ud
dictating varied 3-D spatio-temporal requirements, decentralized\ud
and distributed control, and handling of multiple simultaneous\ud
tactile contacts. Satisfying these requirements pose challenges\ud
to making tactile sensor modality a reality. Overcoming these\ud
challenges requires dealing with issues such as sensors placement,\ud
electronic/mechanical hardware, methods to access and acquire\ud
signals, automatic calibration techniques, and algorithms to\ud
process and interpret sensing data in real time. We survey\ud
this field from a system perspective, recognizing the fact that\ud
the system performance tends to depend on how its various\ud
components are put together. It is hoped that the survey will be\ud
of use to practitioners designing tactile sensing hardware (wholebody\ud
or large-patch sensor coverage), and to researchers working\ud
on cognitive robotics involving tactile sensing
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