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36
RealTime Inverse Kinematics Techniques for Anthropomorphic Limbs
 Graphical Models
, 2000
"... this paper we develop a set of inverse kinematics algorithms suitable for an anthropomorphic arm or leg. We use a combination of analytical and numerical methods to solve generalized inverse kinematics problems including position, orientation, and aiming constraints. Our combination of analytical ..."
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Cited by 120 (3 self)
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this paper we develop a set of inverse kinematics algorithms suitable for an anthropomorphic arm or leg. We use a combination of analytical and numerical methods to solve generalized inverse kinematics problems including position, orientation, and aiming constraints. Our combination of analytical and numerical methods results in faster and more reliable algorithms than conventional inverse Jacobian and optimizationbased techniques. Additionally, unlike conventional numerical algorithms, our methods allow the user to interactively explore all possible solutions using an intuitive set of parameters that define the redundancy of the system. c 2000 Academic Press Key Words: inverse kinematics; realtime IK; human arm kinematics; analytical algorithms
Inverse Kinematics Positioning Using Nonlinear Programming for Highly Articulated Figures
 ACM Transactions on Graphics
, 1994
"... An articulated figure is often modeled as a set of rigid segments connected with joints. Its configuration can be altered by varying the joint angles. Although it is straightforward to compute figure configurations given joint angles (forward kinematics), it is not so to find the joint angles for ..."
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Cited by 101 (9 self)
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An articulated figure is often modeled as a set of rigid segments connected with joints. Its configuration can be altered by varying the joint angles. Although it is straightforward to compute figure configurations given joint angles (forward kinematics), it is not so to find the joint angles for a desired configuration (inverse kinematics). Since the inverse kinematics problem is of special importance to an animator wishing to set a figure to a posture satisfying a set of positioning constraints, researchers have proposed many approaches. But when we try to follow these approaches in an interactive animation system where the object to operate on is as highly articulated as a realistic human figure, they fail in either generality or performance, and so a new approach is fostered. Our approach is based on nonlinear programming techniques. It has been used for several years in the spatial constraint system in the Jack TM human figure simulation software developed at the Compute...
An Inverse Kinematic Architecture Enforcing an Arbitrary Number of Strict Priority Levels
 The Visual Computer
, 2004
"... An efficient Inverse Kinematics solver is a key element in applications targeting the online or offline postural control of complex articulated figures. In the present paper we progressively describe the strategic components of a very general and robust IK architecture. We then present an efficien ..."
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Cited by 80 (9 self)
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An efficient Inverse Kinematics solver is a key element in applications targeting the online or offline postural control of complex articulated figures. In the present paper we progressively describe the strategic components of a very general and robust IK architecture. We then present an efficient recursive algorithm enforcing an arbitrary number of strict priorities to arbitrate the fulfillment of conflicting constraints. Due to its local nature, the moderate cost of the solution allows this architecture to run within an interactive environment. The algorithm is illustrated on the postural control of complex articulated figures.
Interactive Sensor Planning
 In Computer Vision and Pattern Recognition Conference
, 1998
"... This paper describes an interactive sensor planning system that can be used to select viewpoints subject to camera visibility, field of view and task constraints. Application areas for this method include surveillance planning, safety monitoring, architectural site design planning, and automated sit ..."
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Cited by 42 (8 self)
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This paper describes an interactive sensor planning system that can be used to select viewpoints subject to camera visibility, field of view and task constraints. Application areas for this method include surveillance planning, safety monitoring, architectural site design planning, and automated site modeling. Given a description of the sensor's characteristics, the objects in the 3D scene, and the targets to be viewed, our algorithms compute the set of admissible view points that satisfy the constraints. The system first builds topologically correct solid models of the scene from a variety of data sources. Viewing targets are then selected, and visibility volumes and field of view cones are computed and intersected to create viewing volumes where cameras can be placed. The user can interactively manipulate the scene and select multiple target features to be viewed by a camera. The user can also select candidate viewpoints within this volume to synthesize views and verify the correctn...
MultiDimensional Input Techniques And Articulated Figure Positioning By Multiple Constraints
, 1986
"... A six degreeoffreedom input device presents some novel possibilities for manipulating and positioning threedimensional objects. Some experiments in using such a device in conjunction with a realtime display are described. A particular problem which arises in positioning an articulated figure is ..."
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Cited by 27 (0 self)
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A six degreeoffreedom input device presents some novel possibilities for manipulating and positioning threedimensional objects. Some experiments in using such a device in conjunction with a realtime display are described. A particular problem which arises in positioning an articulated figure is the solution of threedimensional kinematics subject to multiple joint position goals. A method using such an input device to interactively determine positions and a constraint satisfaction algorithm which simultaneously achieves those constraints is described. Examples which show the power and efficiency of this method for keyframe animation positioning are demonstrated.
Collision prediction for polyhedra under screw motions
 ACM Symposium in Solid Modeling and Applications
, 2003
"... The prediction of collisions amongst N rigid objects may be reduced to a series of computations of the time to first contact for all pairs of objects. Simple enclosing bounds and hierarchical partitions of the spacetime domain are often used to avoid testing objectpairs that clearly will not colli ..."
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Cited by 23 (3 self)
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The prediction of collisions amongst N rigid objects may be reduced to a series of computations of the time to first contact for all pairs of objects. Simple enclosing bounds and hierarchical partitions of the spacetime domain are often used to avoid testing objectpairs that clearly will not collide. When the remaining pairs involve only polyhedra under straightline translation, the exact computation of the collision time and of the contacts requires only solving for intersections between linear geometries. When a pair is subject to a more general relative motion, such a direct collision prediction calculation may be intractable. The popular brute force collision detection strategy of executing the motion for a series of small time steps and of checking for static interferences after each step is often computationally prohibitive. We propose instead a less expensive collision prediction strategy, where we approximate the relative motion between pairs of objects by a sequence of screw motion segments, each defined by the relative position and orientation of the two objects at the beginning and at the end of the segment. We reduce the computation of the exact collision time and of the corresponding face/vertex and edge/edge collision points to the numeric extraction of the roots of simple univariate analytic functions. Furthermore, we propose a series of simple rejection tests, which exploit the particularity of the screw motion to immediately decide that some objects do not collide or to speedup the prediction of collisions by about 30%, avoiding on average 3/4 of the rootfinding queries even when the object actually collide.
Approximate General Sweep Boundary of a 2D Curved Object
 CVGIP: Graphical Models and Image Processing
, 1993
"... This paper presents an algorithm to compute an approximation to the general sweep boundary of a 2D curved moving object which changes its shape dynamically while traversing a trajectory. In effect, we make polygonal approximations to the trajectory and to the object shape at every appropriate instan ..."
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Cited by 18 (7 self)
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This paper presents an algorithm to compute an approximation to the general sweep boundary of a 2D curved moving object which changes its shape dynamically while traversing a trajectory. In effect, we make polygonal approximations to the trajectory and to the object shape at every appropriate instance along the trajectory so that the approximated polygonal sweep boundary is within a given error bound ffl ?0 from the exact sweep boundary. The algorithm interpolates intermediate polygonal shapes between any two consecutive instances, and constructs polygons which approximate the sweep boundary of the object. Previous algorithms on sweep boundary computation have been mainly concerned about moving objects with fixed shapes; nevertheless, they have involved a fair amount of symbolic and/or numerical computations that have limited their practical uses in graphics modeling systems as well as in many other applications which require fast sweep boundary computation. Although the algorithm pres...
Computing Camera Viewpoints in an Active Robot WorkCell
 International Journal of Robotics Research
, 1999
"... This paper presents a dynamic sensor planning system, capable of planning the locations and settings of vision sensors for use in an environment containing objects moving in known ways. The key component of this research is the computation of the camera position, orientation, and optical settings to ..."
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Cited by 18 (2 self)
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This paper presents a dynamic sensor planning system, capable of planning the locations and settings of vision sensors for use in an environment containing objects moving in known ways. The key component of this research is the computation of the camera position, orientation, and optical settings to be used over a time interval. A new algorithm is presented for viewpoint computation which ensures that the feature detectability constraints of focus, resolution, fieldofview, and visibility are satisfied. A five degreeoffreedom Cartesian robot carrying a CCD camera in a hand/eye configuration and surrounding the workcell of a Puma 560 robot was constructed for performing sensor planning experiments. The results of these experiments, demonstrating the use of this system in a robot workcell, are presented. The research described in this paper was performed while this author was at the Columbia University Department of Computer Science. y This work was supported in part by DARPA con...
Numerical convolution on the Euclidean group with applications to workspace generation
 IEEE Trans. Robot. Automat
, 1998
"... Abstract—In this work, the concept of a convolution product of realvalued functions on the Special Euclidean group, SE(D) (which describes all rigid body motions in Ddimensional Euclidean space), is applied to the determination of workspaces of discretely actuated manipulators. These manipulators ..."
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Cited by 18 (10 self)
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Abstract—In this work, the concept of a convolution product of realvalued functions on the Special Euclidean group, SE(D) (which describes all rigid body motions in Ddimensional Euclidean space), is applied to the determination of workspaces of discretely actuated manipulators. These manipulators have a finite number of joint states. If a discretely actuated manipulator consists of P actuated modules, each with K states, then it can reach K P frames in space. Given this exponential growth in the number of reachable frames, brute force representation of discretely actuated manipulator workspaces is not feasible in the highly actuated case. However, by partitioning a discretely actuated manipulator into P modules, and approximating the workspace of each module as a density function on a compact subset of the Special Euclidean group, the whole workspace can be approximated as an Pfold convolution of these densities. A numerical approximation of this convolution is presented in this paper which is O(P) for fixed taskspace dimension. In the special case when the manipulator is composed of P identical actuated modules, the workspace density for the whole manipulator can be calculated in O(log P) computation time. In either case, the O(K P) computations required by brute force workspace generation are avoided. Index Terms — Convolution, discrete actuation, Euclidean group, manipulator workspaces, rigid body motion.
Swept Volumes and Their Use in Viewpoint Computation in Robot WorkCells
 In Proc. IEEE Intl. Sympos. on Assembly and Task Planning
, 1995
"... This paper discusses the automaticcomputation of viewpoints for monitoringobjects and features in an active robot workcell. An important step in our algorithm for finding viewpoints is the computation of the volumes swept by polyhedral objects moving through space. A method for approximating these ..."
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Cited by 10 (0 self)
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This paper discusses the automaticcomputation of viewpoints for monitoringobjects and features in an active robot workcell. An important step in our algorithm for finding viewpoints is the computation of the volumes swept by polyhedral objects moving through space. A method for approximating these volumes for arbitrarily moving polyhedra is presented. Some swept volume results are presented, and methods for integrating these results into our automated Machine Vision Planning (MVP) system are discussed. 1 Introduction Several researchers have focused on the computation of sets of positions, orientations, and optical settings for a camera (and, in some cases, for light sources) which will give satisfactory views of certain objects in a known scene. Each researcher has defined the phrase "satisfactory view" in his own terms, but the constraints most often considered are magnification (or resolution), focus, fieldofview, and occlusion. Examples of recent work in this field are in [4, 5...