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Robotics and Automation, IEEE Transactions on

Issue 2 • Date Apr 1991

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Displaying Results 1 - 6 of 6
  • Dynamic motion planning of autonomous vehicles

    Publication Year: 1991 , Page(s): 241 - 249
    Cited by:  Papers (59)  |  Patents (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (904 KB)  

    A method for planning the motions of autonomous vehicles moving on general terrains is presented that obtains the geometric path and vehicle speeds that minimize motion time considering vehicle dynamics, terrain topography, obstacles, and surface mobility. The terrain is represented by a smooth cubic B patch, and the geometric path consists of a B spline curve mapped to the surface. The time-optimal motions are computed by first obtaining the best obstacle-free path from all paths represented by a uniform grid. This path is further optimized using a local optimization procedure, using the optimal motion time along the path as the cost function and the control points of a B spline as the optimizing parameters. Examples are presented that demonstrate the method for a simple dynamic model of a vehicle moving on mountainous terrain View full abstract»

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  • A versatile PC-based range finding system

    Publication Year: 1991 , Page(s): 250 - 256
    Cited by:  Papers (18)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (916 KB)  

    The authors present an active triangulation-based range finding system composed of an independent laser system generating a sheet of light projected on the object to be measured, which is placed on a linear or a rotary table driven by a personal computer. This computer includes a video digitizer board to which two cameras, looking at the scene from both sides of the sheet of light, are connected. Besides its low cost, this system has several advantages over similar systems. First of all, two cameras are used to limit the occlusion problem, and a method is proposed to integrate range data obtained from these cameras into a single range image. The calibration of each camera is very simple, provides subpixel accuracy, and is performed only once as the laser or the camera does not move. The data acquisition uses an interpolation technique that produces very accurate depth measurements. The system also provides intensity data in registration with the range data. The application of all these techniques is illustrated by showing numerous examples of the range and intensity data acquisition from various complex objects View full abstract»

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  • Representations of mechanical assembly sequences

    Publication Year: 1991 , Page(s): 211 - 227
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1488 KB)  

    Five types of representations for assembly sequences are reviewed: the directed graph of feasible assembly sequences; the AND/OR graph of feasible assembly sequences; the set of establishment conditions, and two types of precedence relationships namely those between the establishment of one connection between parts and the establishment of another connection, and those between the establishment of one connection and states of the assembly process. The mappings of one representation into the others are established. The correctness and completeness of these representations are established. The results presented are needed in the proof of correctness and completeness of algorithms for the generation of mechanical assembly sequences View full abstract»

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  • A correct and complete algorithm for the generation of mechanical assembly sequences

    Publication Year: 1991 , Page(s): 228 - 240
    Cited by:  Papers (144)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1260 KB)  

    An algorithm for the generation of all mechanical assembly sequences for a given product is presented. It uses a relational model of assemblies. In addition to the geometry of the assembly, this model includes a representation of the attachments that bind parts together. The problem of generating the assembly sequences is transformed into the problem of generating disassembly sequences in which the disassembly tasks are the inverse of feasible assembly tasks. The problem of disassembling one assembly is decomposed into distinct disassembly subproblems. The algorithm returns the AND/OR graph representation of assembly sequences. The correctness of the algorithm is based on the assumption that it is always possible to decide correctly whether two subassemblies can be joined, based on geometrical and physical criteria. An approach to computing this decision is presented. An experimental implementation for the class of products made up of polyhedral and cylindrical parts with planar or cylindrical contacts among themselves is described. Bounds for the amount of computation involved are presented View full abstract»

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  • Blanche-an experiment in guidance and navigation of an autonomous robot vehicle

    Publication Year: 1991 , Page(s): 193 - 204
    Cited by:  Papers (145)  |  Patents (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1080 KB)  

    The principal components and capabilities of Blanche, an autonomous robot vehicle, are described. Blanche is designed for use in structured office or factory environments rather than unstructured natural environments, and it is assumed that an offline path planner provides the vehicle with a series of collision-free maneuvers, consisting of line and arc segments, to move the vehicle to a desired position. These segments are sent to a low-level trajectory generator and closed-loop motion control. The controller assumes accurate knowledge of the vehicle's position. Blanche's position estimation system consists of a priori map of its environment and a robust matching algorithm. The matching algorithm also estimates the precision of the corresponding match/correction that is then optimally (in a maximum-likelihood sense) combined with the current odometric position to provide an improved estimate of the vehicle's position. The system does not use passive or active beacons. Experimental results are reported View full abstract»

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  • Kinetic limitations on the use of redundancy in robotic manipulators

    Publication Year: 1991 , Page(s): 205 - 210
    Cited by:  Papers (22)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (528 KB)  

    The kinematic specification of motion for redundant manipulators has relied primarily on a formulation that treats the redundant degrees of freedom as independent of those required to maintain a desired end effector trajectory. While such a formulation is conceptually appealing, it has been shown to be physically inaccurate when applied to the kinetic behavior of redundant manipulators. The kinetic effects of homogeneous solutions are analyzed with emphasis on placing realistic limitations on how redundancy can be utilized without adversely affecting the primary goal of a desired end effector trajectory. It is shown that it is possible to identify manipulator configurations that possess the desirable characteristic of being able either to remove or to impart a homogeneous velocity while simultaneously reducing the torque requirements on the manipulator. The conditions that govern these configurations are shown to be directly related to the conditions for guaranteeing global stability for the local torque minimization formulation View full abstract»

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Aims & Scope

This Transactions ceased production in 2004. The current retitled publications areIEEE Transactions on Automation Science and Engineering and IEEE Transactions on Robotics.

Full Aims & Scope