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30
Sensorless Manipulation Using Transverse Vibrations of a Plate
 IN PROC. IEEE INT. CONF. ON ROBOTICS AND AUTOMATION (ICRA
, 1995
"... The existing industrial parts feeders move the parts through a sequence of mechanical filters that reject parts in unwanted orientations. In this paper we develop a new setup that uses a different vibratory mechanism to systematically manipulate parts, by actively orienting and localizing them. The ..."
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Cited by 71 (25 self)
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The existing industrial parts feeders move the parts through a sequence of mechanical filters that reject parts in unwanted orientations. In this paper we develop a new setup that uses a different vibratory mechanism to systematically manipulate parts, by actively orienting and localizing them. The idea is to generate and change dynamic modes for a plate by varying the applied frequency of oscillation. Depending on the node shapes of the plate for these frequencies, the position and orientation of the parts can be controlled. We develop an analysis of the underlying dynamics, and show that it can be used to predict the behavior of objects placed on the vibrating plate. Using this analysis, we propose that the applied frequencies can be automatically sequenced to obtain a "sensorless" strategy for manipulating a given object.
Sensorless Manipulation Using Massively Parallel Microfabricated Actuator Arrays
 IN PROC. IEEE INT. CONF. ON ROBOTICS AND AUTOMATION (ICRA
, 1994
"... This paper investigates manipulation tasks with arrays of microelectromechanical structures (MEMS). We develop a geometric model for the mechanics of microactuators and a theory of sensorless, parallel manipulation, and we describe efficient algorithms for their evaluation. The theory of limit surfa ..."
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Cited by 48 (21 self)
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This paper investigates manipulation tasks with arrays of microelectromechanical structures (MEMS). We develop a geometric model for the mechanics of microactuators and a theory of sensorless, parallel manipulation, and we describe efficient algorithms for their evaluation. The theory of limit surfaces offers a purely geometric characterization of microscale contacts between actuator and moving object, which can be used to efficiently predict the motion of the object on an actuator array. It is shown how simple actuator control strategies can be used to uniquely align a part up to symmetry without sensor feedback. This theory is applicable to a wide range of microactuator arrays. Our actuators are oscillating structures of singlecrystal silicon fabricated in a ICcompatible process. Calculations show that these actuators are strong enough to levitate and move e.g. a piece of paper.
A geometric theory of manipulation and control for microfabricated actuator arrays
, 1993
"... This paper investigates manipulation tasks with arrays of microelectromechanical structures (MEMS). We develop a model for the mechanics of microactuators and a theory of sensorless, parallel manipulation, and we describe efficient algorithms for their evaluation. The theory of limit surfaces offers ..."
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Cited by 45 (26 self)
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This paper investigates manipulation tasks with arrays of microelectromechanical structures (MEMS). We develop a model for the mechanics of microactuators and a theory of sensorless, parallel manipulation, and we describe efficient algorithms for their evaluation. The theory of limit surfaces offers a purely geometric characterization of microscale contacts between actuator and moving object, which can be used to efficiently predict the motion of the object on an actuator array. We develop a theory of sensorless manipulation with microactuator arrays. It is shown how simple actuator control strategies can be used to uniquely align apart up to symmetry. These manipulation strategies can be computed efficiently and do not require sensor feedback. This theory is applicable to a wide range of microactuator arrays. Our actuators are oscillating structures of singlecrystal silicon fabricated in a lowtemperature SCREAM process. They exhibit high aspect ratios and high vertical stiffness, which is of great advantage for an effective implementation of our theory. Calculations show that arrays of these actuators can generate forces that are strong enough to levitate and move e.g. a piece of paper.
Upper and Lower Bounds for Programmable Vector Fields with Applications to MEMS and Vibratory Plate Parts Feeders
 IN INTERNATIONAL WORKSHOP ON ALGORITHMIC FOUNDATIONS OF ROBOTICS (WAFR
, 1996
"... ..."
Parts Manipulation on an Intelligent Motion Surface
 in IEEE/RSJ Int. Workshop on Intelligent Robots & Systems (IROS
, 1995
"... This paper introduces the concept of using a dense array of individual manipulator mechanisms as a programmable Intelligent Motion Surface (IMS). The individual robots in the array can be implemented in a variety of technologies with different sizes. Programmability is the common necessary character ..."
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Cited by 34 (3 self)
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This paper introduces the concept of using a dense array of individual manipulator mechanisms as a programmable Intelligent Motion Surface (IMS). The individual robots in the array can be implemented in a variety of technologies with different sizes. Programmability is the common necessary characteristic for an IMS; the array, with groups of contiguous robots acting in unison, can be programmed to various configurations to have the effect of imparting force fields on objects being carried on its surface. The appropriate choice of force fields is shown to cause parts placed on the array to be moved in manners that are useful. These include such functions as translation, rotation, orientation, alignment, spatial filtering and the feeding of parts. The use of the IMS is described for primitive assembly operations. Limitations of the approach, extensions and possibilities for future work, particularly in microelectromechical system (MEMS) implementations, are discussed in detail in the pap...
Distributed Robotic Manipulation: Experiments in Minimalism
 In International Symposium on Experimental Robotics
, 1997
"... Minimalism pursues the following agenda: For a given robotics task, find the minimal configuration of resources required to solve the task. Thus, minimalism attempts to reduce the resource signature for a task, in the same way that (say) Stealth technology decreases the radar signature of an aircraf ..."
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Cited by 34 (8 self)
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Minimalism pursues the following agenda: For a given robotics task, find the minimal configuration of resources required to solve the task. Thus, minimalism attempts to reduce the resource signature for a task, in the same way that (say) Stealth technology decreases the radar signature of an aircraft. Minimalism is interesting because doing task A without resource B proves that B is somehow inessential to the information structure of the task. We will present experimental demonstrations and showhow they relate to our theoretical proofs of minimalist systems. In robotics, minimalism has become increasingly influential. Marc Raibert showed that walking and running machines could be built without static stability. Erdmann and Mason showed how to do dextrous manipulation without sensing. Tad McGeer built a biped, kneed walker without sensors, computers, or actuators. Rod Brooks has developed online algorithms that rely less extensively on planning and worldmodels. Canny and Gold...
Algorithms for Sensorless Manipulation Using a Vibrating Surface
, 2000
"... We describe a programmable apparatus that uses a vibrating surface for sensorless, nonprehensile manipulation, where parts are systematically positioned and oriented without sensor feedback or force closure. The idea is to generate and change the dynamic modes of a vibrating surface. Depending on th ..."
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Cited by 32 (11 self)
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We describe a programmable apparatus that uses a vibrating surface for sensorless, nonprehensile manipulation, where parts are systematically positioned and oriented without sensor feedback or force closure. The idea is to generate and change the dynamic modes of a vibrating surface. Depending on the node shapes of the surface, the position and orientation of the parts can be predicted and constrained. The vibrating surface creates a twodimensional force vector field. By chaining together sequences of force fields, the equilibrium states of a part in the field can be successively reduced to obtain a desired final state. We describe efficient polynomialtime algorithms that generate sequences of force fields for sensorless positioning and orienting of planar parts, and we show that these strategies are complete. Finally we consider parts feeders that can only implement a finite set of force fields. We show how to plan and execute strategies for these devices. We give numerical exampl...
Programmable Vector Fields for Distributed Manipulation, with Applications to MEMS Actuator Arrays and Vibratory Parts Feeders
 INTL. J. OF ROBOTICS RESEARCH
, 1996
"... Programmable vector fields can be used to control a variety of flexible planar parts feeders. These devices can exploit exotic actuation technologies such as arrayed, massivelyparallel microfabricated motion pixels or transversely vibrating (macroscopic) plates. These new automation designs promise ..."
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Cited by 28 (13 self)
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Programmable vector fields can be used to control a variety of flexible planar parts feeders. These devices can exploit exotic actuation technologies such as arrayed, massivelyparallel microfabricated motion pixels or transversely vibrating (macroscopic) plates. These new automation designs promise great flexibility, speed, and dexteritywe believe they may be employed to orient, singulate, sort, feed, and assemble parts. However, since they have only recently been invented, programming and controlling them for manipulation tasks is challenging. When a part is placed on our devices, the programmed vector field induces a force and moment upon it. Over time, the part may come to rest in a dynamic equilibrium state. By chaining together sequences of vector fields, the equilibrium states of a part in the field may be cascaded to obtain a desired final state. The resulting strategies require no sensing and enjoy efficient planning algorithms. This paper begins by describing our experimen...
Part Orientation with One or Two Stable Equilibria Using Programmable Force Fields
, 2000
"... Programmable force fields are an abstraction to represent a new class of devices for distributed, nonprehensile manipulation for applications in parts feeding, sorting, positioning, and assembly. Unlike robot grippers, conveyor belts, or vibratory bowl feeders, these devices generate force vector f ..."
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Cited by 23 (12 self)
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Programmable force fields are an abstraction to represent a new class of devices for distributed, nonprehensile manipulation for applications in parts feeding, sorting, positioning, and assembly. Unlike robot grippers, conveyor belts, or vibratory bowl feeders, these devices generate force vector fields in which the parts move until they may reach a stable equilibrium pose.
The Area Bisectors of a Polygon and Force Equilibria in Programmable Vector Fields
, 1997
"... We consider the family of area bisectors of a polygon #possibly with holes# in the plane. Wesay that two bisectors of a polygon P are combinatorially distinct if they induce di#erent partitionings of the vertices of P.We show that there are simple polygons with n vertices that have# #n 2 # combi ..."
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Cited by 12 (7 self)
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We consider the family of area bisectors of a polygon #possibly with holes# in the plane. Wesay that two bisectors of a polygon P are combinatorially distinct if they induce di#erent partitionings of the vertices of P.We show that there are simple polygons with n vertices that have# #n 2 # combinatorially distinct area bisectors #matching the obvious upper bound#, and we present an outputsensitive algorithm for computing an explicit representation of all the bisectors of a given polygon. Our study is motivated by the development of novel, #exible feeding devices for parts positioning and orienting. The question of determining all the bisectors of polygonal parts arises in connection with the development of e#cient part positioning strategies when using these devices. 1 Introduction Let P be a polygon in the plane, possibly with holes, and having n vertices in total. We denote by V the set of vertices of P.For a directed line # in the plane, we denote by h l ### #resp. hr #### the...