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Manipulation and active sensing by pushing using tactile feedback
 In Proc. 1992 IEEE/RSJ Int. Conf. Intell. Robots and Systems
, 1992
"... Abstract — We investigate manipulation and active sensing by a pushing control system using only tactile feedback. The equations of motion of a pushed object are derived using a model of the object’s limit surface, and we design a control system to translate and orient objects. The effectiveness of ..."
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Abstract — We investigate manipulation and active sensing by a pushing control system using only tactile feedback. The equations of motion of a pushed object are derived using a model of the object’s limit surface, and we design a control system to translate and orient objects. The effectiveness of the proposed controller is confirmed through simulation and experiments. Active sensing of the object’s center of mass is described. I.
Reactive robotics I: Reactive grasping with a modified gripper and multifingered hands
 Intl. J. of Robotics Research
, 2000
"... We study the problem of grasping an unknown object with constant cross section using various “reactive ” robot hands. In the simplest example, we equip a standard parallel jaw gripper with several lightbeam sensors (close to each jaw) and implement a reactive algorithm for grasping polygonal object ..."
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We study the problem of grasping an unknown object with constant cross section using various “reactive ” robot hands. In the simplest example, we equip a standard parallel jaw gripper with several lightbeam sensors (close to each jaw) and implement a reactive algorithm for grasping polygonal objects with this architecture. Extending these ideas further, we also devise two and three fingered reactive hands for objects with smooth boundary and equip these with distance and angle sensors that are located at the finger tips. The sensors used are simple, provide only limited and immediate information, but allow us to reactively find a good grasp on an object of unknown geometry and dynamics. When grasped the forces applied will be normal to the object boundary. Furthermore, in all cases, the object is not disturbed as the grasping points are being sought. Various approaches to dextrous manipulation can be categorized into two groups: objectpriority approaches and fingerpriority approaches. This classification was first
InHand Dexterous Manipulation of PiecewiseSmooth 3d Objects
 The International Journal of Robotics Research
, 1999
"... We present an algorithm called finger tracking for inhand manipulation of three dimensional objects with independent robot fingers. We describe and analyze the differential control for finger tracking and extend it to online continuous control for a set of cooperating robot fingers. We show experi ..."
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We present an algorithm called finger tracking for inhand manipulation of three dimensional objects with independent robot fingers. We describe and analyze the differential control for finger tracking and extend it to online continuous control for a set of cooperating robot fingers. We show experimental data from a simulation. Finally, we discuss global control issues for finger tracking and compute lower bounds for reorientation by finger tracking. Our algorithm is computationally efficient, exact, and takes into consideration the full dynamics of the system. 1 Introduction We wish for robots to perform sophisticated tasks in structured environments, such as an assembly line, as well as unstructured ones, such as space, undersea, or outdoors. Such robots must have the ability to manipulate objects. We consider taskdirected programming to endow the robots with these capabilities. Specifically we are developing algorithms for reorienting three dimensional objects by controlling a se...
Towards TaskDirected Coordinated Manipulation
 in Proceedings of the IEEE/RSJ 1993 International Conference on Intelligent Robots and Systems
, 1993
"... In this paper we analyze the feasibility of the finger tracking paradigm for multifinger manipulation introduced in [22] and we relate it to taskdirected programming issues. By using the geometry of singularities that arise in solving the instantaneous motion problem we are able to characterize re ..."
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Cited by 3 (3 self)
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In this paper we analyze the feasibility of the finger tracking paradigm for multifinger manipulation introduced in [22] and we relate it to taskdirected programming issues. By using the geometry of singularities that arise in solving the instantaneous motion problem we are able to characterize regions of feasibility associated with an initial grasp and quantify how much reorientation is possible starting from this grasp. This results in a provably correct global strategy for reorientation. 1 Introduction We are interested in taskdirected programming of robots, specifically in algorithms for reorientations of objects with cooperating agents. An agent is a robot hand with independent fingers, a mobile robot, a simple manipulator, or fixtures in the environment. In our previous work [22], which we review in Section 2, we have proposed a method to accomplish reorientations by a collection of independent agents called fingers. This method, which is derived from a wellfounded algebra...
Coordinated Manipulation of Objects in a Plane
 Algorithmica
, 1997
"... The ability to manipulate objects is a basic and necessary function of autonomous robots that can perform manufacturing tasks. We present an efficient algorithm for the coordinated manipulation of objects in a plane by independent robot agents and an efficient decision procedure for whether an objec ..."
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The ability to manipulate objects is a basic and necessary function of autonomous robots that can perform manufacturing tasks. We present an efficient algorithm for the coordinated manipulation of objects in a plane by independent robot agents and an efficient decision procedure for whether an object can undergo any desired reorientation or not. This algorithm has good stability properties, in that it is not sensitive to small errors in the initial data and it relies on a simple control scheme. Our result is a contribution towards realistic tasklevel planning for manufacturing. 1 Introduction To automate manufacturing we wish for robots to perform sophisticated tasks in structured environments, such as an assembly line, or unstructured environments, such as the floor of a factory. Such robots must have the ability to manipulate objects. We consider taskdirected programming to endow robots with these capabilities. Specifically we are developing algorithms for reorienting extruded ob...
A Shape Metric for DesignforAssembly
 Proceedings of IEEE Conference on Robotics and Automation
, 1992
"... "DesignforAssembly" (DFA) is a process of improving product designs for easy and low cost assembly. DFA often involves an analysis of an existing design according to qualitative criteria that are difficult to analyze. This paper introduces a quantitative shape metric for planar parts, called feeda ..."
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"DesignforAssembly" (DFA) is a process of improving product designs for easy and low cost assembly. DFA often involves an analysis of an existing design according to qualitative criteria that are difficult to analyze. This paper introduces a quantitative shape metric for planar parts, called feedability, based on a stochastic parts feeding algorithm reported in [7][8]. Although feedability is only one possible metric for DFA, it relates one aspect of assembly cost directly to part geometry. Therefore, based on feedability, one can produce a set of geometric redesign strategies. The application of feedability (or DesignforFeedability) to DFA is illustrated and compared with other DFA methods. 1 Introduction "DesignforAssembly"(DFA) is a process of improving product designs for easy and low cost assembly. An assemblyconscious design is desirable because it could result in significant savings in capital costs and assembly time. For example, the IBM Corporation has successfully ap...
Qualitative Transitions in Object Reorienting Behaviour, Part 2: The Effects of Varying the Centre of Mass.
 In Proc. IEEE Int. Conf. on Robotics and Automation
, 1997
"... In this and a companion paper we investigate the topology of the space of possible pushing behaviour for 2.5D objects of arbitrary outline. We do this by studying the PushStability Diagram (PSD) derived by Brost, which is a generalisation of a result of Mason's. In a previous paper we showed how to ..."
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In this and a companion paper we investigate the topology of the space of possible pushing behaviour for 2.5D objects of arbitrary outline. We do this by studying the PushStability Diagram (PSD) derived by Brost, which is a generalisation of a result of Mason's. In a previous paper we showed how to generalise the PSD to objects of arbitrary outline, and the aect of varying the coecient of friction on the topology of the PSD. In this paper we show how to predict some of the eects on the topology of the PSD that arise from varying the position of the centre of mass, making it possible to use this as a control parameter in the design of objects for feeding. 1 Introduction In recent years a number of researchers have studied the sliding behaviour of objects. Much of this work has been precipitated by Mason's Ph.D. [11] where he derived a simple rule to determine the sense of reorientation of an object being pushed on a horizontal surface that is independent of the contact pressure dis...
Shape from Diameter: Negative Results
 UTRECHT UNIVERSITY, DEPARTMENT OF COMPUTER
, 1993
"... Our objective is to automatically recognize parts in a structured environment (such as a factory) using inexpensive and widelyavailable hardware. We consider the planar problem of determining the convex shape of a polygonal part from a sequence of projections. Projecting the part onto an axis in th ..."
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Our objective is to automatically recognize parts in a structured environment (such as a factory) using inexpensive and widelyavailable hardware. We consider the planar problem of determining the convex shape of a polygonal part from a sequence of projections. Projecting the part onto an axis in the plane of the part produces a scalar measure, the diameter, which is a function of the angle of projection. The diameter of a part at a particular angle can be measured using an instrumented paralleljaw gripper. In this paper, we present the negative result that shape cannot be uniquely recovered: for a given set of diameter measurements, there is an (uncountably) infinite set of polygonal shapes consistent with these measurements. Since most of these shapes have parallel edges of varying lengths, we also consider the related problem of identifying a representative polygon with no parallel edges. We show that given a diameter function, deciding whether such a polygon exists is NPComplete....
Optimal Manipulation Strategies For Orienting Planar Workpieces By Pushing
, 1994
"... . We consider the automated design of parts feeders based on simple manipulation strategies for orienting planar parts. For a given workpiece of known geometry, the goal is to develop an fixed sensorless plan such that, when an instance of this workpiece is provided in an arbitrary initial orientati ..."
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. We consider the automated design of parts feeders based on simple manipulation strategies for orienting planar parts. For a given workpiece of known geometry, the goal is to develop an fixed sensorless plan such that, when an instance of this workpiece is provided in an arbitrary initial orientation, the plan is guaranteed to put the part into a fixed final orientation. In the model considered, the part is initially placed on a flat workspace. A robotic manipulator, equipped with a flat pushing surface as its endeffector, reorients the part using a fixed sequence of pushing actions. The model generalizes those studied by Mason and Erdmann, Natarjan, Goldberg, and Chen and Ierardi, insofar as it places no prior no restrictions on the direction of pushing or the orientation of the pushing surface. We prove that every part is orientable in this model up to rotational symmetries about its center of friction. Moreover, the proof is constructive, and yields an algorithm which designs pla...
Shape from Diameter: Positive Results
 UTRECHT UNIVERSITY, DEPARTMENT OF COMPUTER
, 1993
"... Our objective is to automatically recognize parts in a structured environment (such as a factory) using inexpensive and widelyavailable hardware. We consider the planar problem of determining the convex shape of a polygonal part from a sequence of projections. Projecting the part onto an axis in th ..."
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Cited by 1 (1 self)
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Our objective is to automatically recognize parts in a structured environment (such as a factory) using inexpensive and widelyavailable hardware. We consider the planar problem of determining the convex shape of a polygonal part from a sequence of projections. Projecting the part onto an axis in the plane of the part produces a scalar measure, the diameter, which is a function of the angle of projection. The diameter of a part at a particular angle can be measured using an instrumented paralleljaw gripper. Previously presented negative results results motivate us to consider the problem of recognizing a part from a known (finite) set of parts. Given a set of polygonal parts with a total of N faces, can we find the shortest sensing plan for disambiguating the parts? Only diameters at n N stable faces can be measured. We construct an internal representation of these stable diameters in O(N + n³) time and then give two planning algorithms: one constructs an optimal sensing plan in...