Motion Planning of Legged Robots
نویسندگان
چکیده
We study the problem of computing the free space F of a simple legged robot called the spider robot. The body of this robot is a single point and the legs are attached to the body. The robot is subject to two constraints: each leg has a maximal extension R (accessibility constraint) and the body of the robot must lie above the convex hull of its feet (stability constraint). Moreover, the robot can only put its feet on some regions, called the foothold regions. The free space F is the set of positions of the body of the robot such that there exists a set of accessible footholds for which the robot is stable. We present an e cient algorithm that computes F in O(n2 log n) time and O(n2 (n)) space for point footholds where (n) is an extremely slowly growing function ( (n) 3 for any practical value of n). We also present an algorithm to compute F when the foothold regions are pairwise disjoint polygons with n edges in total. This algorithm computes F in O(n2 8(n) log n) time using O(n2 8(n)) space ( 8(n) is also an extremely slowly growing function). These results are close to optimal since (n2) is a lower bound for the size of F . Key-words: Motion planning, legged robots, mobile robot, computational geometry.
منابع مشابه
Motion Planning for Legged Robots∗
Kinematic models of legged robots are stratified, i.e. the equations of motion differ on different strata. An improved version of the motion planning algorithm proposed in the literature is compared with two alternative solutions via the example of the six-legged (hexapod) robot. The first alternative uses explicit integration of the vector fields while the second one exploits the flatness of a...
متن کاملMotion Planning for Legged Robots
Slide 0 In this talk, we present a general trajectory generation scheme for a class of " kinematic " legged robots. The method does not depend upon the number of legs, nor is it based on foot placement concepts. Instead, our method is based on an extension of a nonlinear trajectory generation algorithm for smooth systems to the legged case, where the relevant mechanics are not smooth. Our exten...
متن کاملA template candidate for miniature legged robots in quasi-static motion
The paper introduces the Switching Four-bar Mechanism (sfm), a new low-dimensional kinematic abstraction forminiature legged robots, aimed at quasi-static motion planning in the horizontal plane. The model comprises a rigid torso and four rigid legs which engage in an alternating tetrapod gait. As the gait is executed, the torso and the legs form two switching four-bar linkages, parameterized b...
متن کاملOn the Connectivity of Motion Spaces for Biologically-Inspired Legged Robots
This paper discusses recent analyses of the shape of motion spaces for legged robots in quasistatic equilibrium at a given set of contacts. Two robots were examined: HRP2, a biologically inspired humanoid designed by AIST Japan, and ATHLETE, a six-legged, non-biologically inspired robot designed by NASA. Probabilistic roadmap techniques are used to compute the approximate connectivity of severa...
متن کاملA Template for Miniature Legged Robots in Quasi-Static Motion
We introduce a low-dimensional kinematic abstraction—i.e., template—for miniature legged robots that can be used for quasi-static motion planning in the horizontal plane. The template comprises a rigid torso and four rigid legs which engage in an alternating tetrapod gait. As the gait is executed, the torso and the legs form two switching four-bar linkages, parameterized by the leg touchdown an...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- SIAM J. Comput.
دوره 30 شماره
صفحات -
تاریخ انتشار 2000