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Robotics and Automation, IEEE Transactions on

Issue 3 • Date June 1996

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Displaying Results 1 - 16 of 16
  • Comments on "A new adaptive control algorithm for robot manipulators in task space"

    Publication Year: 1996 , Page(s): 502 - 503
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (205 KB)  

    The authors point out that the proofs of Theorems 1 and 2 given in the above paper (Feng, 1995) are not correct and therefore the stability of the adaptive control laws proposed in the above paper is questionable at present. View full abstract»

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  • A modified model reference adaptive control scheme for rigid robots

    Publication Year: 1996 , Page(s): 466 - 470
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (492 KB)  

    This paper seeks to improve the zero-state performance of a standard model reference adaptive control scheme for rigid robots by augmenting the usual model reference control law with an auxiliary component synthesized from the tracking error. A condition involving a certain design parameter is given which can be used to decide a priori whether the modified scheme can potentially outperform its unmodified counterpart. If the joint accelerations are available for measurement, then it is shown that this condition can always be satisfied and the zero-state performance of the modified scheme can in fact be arbitrarily improved View full abstract»

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  • Dextrous hand grasping force optimization

    Publication Year: 1996 , Page(s): 406 - 418
    Cited by:  Papers (99)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1296 KB)  

    A key goal in dextrous robotic hand grasping is to balance external forces and at the same time achieve grasp stability and minimum grasping energy by choosing an appropriate set of internal grasping forces. Since it appears that there is no direct algebraic optimization approach, a recursive optimization, which is adaptive for application in a dynamic environment, is required. One key observation in this paper is that friction force limit constraints and force balancing constraints are equivalent to the positive definiteness of a certain matrix subject to linear constraints. Based on this observation, we formulate the task of grasping force optimization as an optimization problem on the smooth manifold of linearly constrained positive definite matrices for which there are known globally exponentially convergent solutions via gradient flows. There are a number of versions depending on the Riemannian metric chosen, each with its advantages, Schemes involving second derivative information for quadratic convergence are also studied. Several forms of constrained gradient flows are developed for point contact and soft-finger contact friction models. The physical meaning of the cost index used for the gradient flows is discussed in the context of grasping force optimization. A discretized version for real-time applicability is presented. Numerical examples demonstrate the simplicity, the good numerical properties, and optimality of the approach View full abstract»

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  • Design and evaluation of real-time communication for FieldBus-based manufacturing systems

    Publication Year: 1996 , Page(s): 357 - 367
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1264 KB)  

    It is well known that the ability to support predictable interprocess communication is of great significance to computer-integrated manufacturing and process control systems. In this paper, we propose a strategy for an industrial standard, the SP-50 FieldBus, to support both intracell and intercell real-time communications. We first describe our strategy in detail and show that it is compatible with the current FieldBus draft standard. Under our strategy, the capacity of each link is divided into two parts, The first part is managed by the local link active scheduler for intracell (intralink) communication. The second part is managed by a proposed global network manager for intercell (interlink) communication. By dividing the link capacity in this way, our strategy allows for fast local intracell connection establishment, while supporting global intercell connections. Using two examples, one for typical manufacturing systems and the other for multimedia networking, we also demonstrate the power and utility of the proposed strategy as compared to token-passing protocols View full abstract»

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  • Characteristics of optimal solutions in kinematic resolutions of redundancy

    Publication Year: 1996 , Page(s): 471 - 478
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (888 KB)  

    As a redundancy resolution method, the conventional extended Jacobian method (EJM) has two problems: One is the algorithmic singularity, and the second is nonexistence of a sufficient condition. Their impact on the inverse kinematic performances are exemplified. To remedy the related problems, we propose the notion of solution characteristics. It is based on an analytic sufficient condition for the EJM. This serves to confirm the right direction of optimization in the EJM and to characterize the algorithmic singularity problem. The above local characterization of an optimal solution by solution characteristics is globally extended by the invariance of the solution characteristics of the EJM. Specifically the characteristic of a solution with the EJM is invariant before crossing an algorithmic singularity. The ideas in this article also have practical implications since the EJM can now be fully analyzed with the theoretical results. To demonstrate its exactness and usefulness, planar three degrees of freedom (DOF) and spatial 4-DOF regional redundant manipulators are analyzed using the proposed solution characteristics View full abstract»

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  • Modeling and feedback control of mobile robots equipped with several steering wheels

    Publication Year: 1996 , Page(s): 375 - 390
    Cited by:  Papers (33)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1716 KB)  

    This paper deals with state feedback control of nonholonomic systems whose configuration space presents some singular points. The whole study is driven on the example of mobile robots equipped with several steering wheels. Linearizing dynamic feedback and time-varying feedback are successively considered to handle the tracking of a moving reference trajectory and the stabilization of the robots to a rest configuration, respectively. Both laws are designed in such a way that the systems singular configurations cannot definitely be met. Finally, a commutation procedure between the two laws is presented, in order to handle the very natural problem of tracking a reference trajectory ended by a rest configuration View full abstract»

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  • Deadlock-free schedules for automated manufacturing workstations

    Publication Year: 1996 , Page(s): 391 - 400
    Cited by:  Papers (35)  |  Patents (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1012 KB)  

    Scheduling automated, unmanned manufacturing systems is significantly different from traditional job shops where human presence is implicitly assumed. Deadlocking has been identified as one of the critical problem in the control of automated manufacturing systems. Past approaches have been myopic in the sense that deadlock avoidance and recovery have been treated as run time problems of the system. In this paper, formulations for deadlock-free schedules are proposed and the importance of considering both material handling and buffer space availability while scheduling such an automated workstation are discussed. Extensions to the basic model and solution methods are also presented View full abstract»

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  • Radial basis function network architecture for nonholonomic motion planning and control of free-flying manipulators

    Publication Year: 1996 , Page(s): 491 - 496
    Cited by:  Papers (10)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (740 KB)  

    This paper considers a problem of nonholonomic motion planning. A practical paradigm for planning and stabilization of motion in a class of multivariate nonlinear (nonholonomic) systems is presented and applied to a planar free-floating manipulator system. The controller architecture designed in the paper is based on the radial basis function approximation of an optimal control program for any desired motion. This architecture also incorporates a sampled-data feedback stabilization algorithm. The proposed control technique overcomes certain problems associated with other control approaches available for nonholonomic systems. The presented simulation results reveal a promising potential of the proposed control paradigm. This paradigm can be extended to a broader class of nonlinear control problems View full abstract»

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  • A nonlinear model of a harmonic drive gear transmission

    Publication Year: 1996 , Page(s): 368 - 374
    Cited by:  Papers (42)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1040 KB)  

    Harmonic drives can exhibit very nonlinear dynamic behavior. In order to capture this behavior, not only must dynamic models include accurate representations of transmission friction, compliance, and kinematic error, but also important features of harmonic-drive gear-tooth geometry and interaction must be understood. In this investigation, experimental observations were used to guide the development of a model to describe harmonic-drive operation. Unlike less detailed representations, this model was able to replicate many of the features observed in actual harmonic-drive dynamic response. Unfortunately, since model parameters can only be derived from careful analysis of experimental dynamic response, it seems unlikely that any comparably sufficient representation can be constructed with parameter values obtained from catalogs or simple experimental observations View full abstract»

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  • A method of acoustic landmark extraction for mobile robot navigation

    Publication Year: 1996 , Page(s): 478 - 485
    Cited by:  Papers (18)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (880 KB)  

    Describes a method to extract multiple acoustic landmarks for the indoor navigation of a mobile robot. The environment is modeled by specular vertical walls. An ultrasonic sensor mounted on the mobile robot scans around the surrounding walls and detects multiple echo pulses. On the horizontal plane at the height of the ultrasonic sensor from the floor, the two-dimensional environment is described by the distance as a function of angle in the scan. Due to the specularity of the walls, the distance function has a manageable number of retroreflective parts that can be used as landmarks. By virtue of the constancy of the relative positions between the ultrasonic sensor and the walls in scanning, the echo pulses reflected from a certain reflection points (RP) have the same time-of-flight in the ultrasonic scan data. The authors determine the position of an RP from the collection of the echo pulses that have the same time-of-flight. The direction to an RP is estimated from the orientation of the ultrasonic sensor at which the maximum magnitude is obtained for the group of echo pulses that correspond to the RP. The mean time-of-flight of the group of echo pulses provides the distance to the RP. Some experimental results are provided to show the validity and the performance of the proposed method View full abstract»

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  • A unified approach to Space robot kinematics

    Publication Year: 1996 , Page(s): 401 - 405
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (524 KB)  

    An essential step in deriving kinematic models of free-flying space robots, consisting of a free-base and a manipulator mounted on it, is to write the total momenta of the system at hand. The momenta are, usually, expressed as the functions of the velocities of a preselected body that belongs to the robot, e.g., the free-base. In this paper, no preselection is recommended. On the contrary, the total momenta are expressed as the functions of the velocities of an arbitrary body of the space robot, namely, the primary body (PB). The identity of the PB, unlike the conventional approaches, need not be known at this stage. Therefore, the generalized expressions for the total momenta are obtained. The resulting expressions can explain the existing kinematic models and how they affect the efficiencies of the associated control algorithms. Based on the proposed approach, it is shown that if the end-effector motion is the only concern, as desired in kinematic control, it should be selected as the PB. This leads to the most efficient algorithms View full abstract»

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  • Position tracking control for robot manipulators driven by induction motors without flux measurements

    Publication Year: 1996 , Page(s): 419 - 438
    Cited by:  Papers (12)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1700 KB)  

    In this paper, we present a voltage input controller for robot manipulators actuated by induction motors. The control is designed to compensate for the nonlinear dynamics associated with the mechanical subsystem and the electrical subsystems while only requiring measurements of link position, link velocity, stator winding currents, and exact model knowledge. Specifically, through the use of nonlinear observers for rotor flux and an observed integrator backstepping approach, we obtain semiglobal uniform ultimately bounded link position tracking. The result is semiglobal in the sense that a control parameter must be made sufficiently large relative to the electromechanical initial conditions in order to guarantee that control singularities are avoided. To provide insight into the design procedure, the controller is first presented for a one-link robot manipulator system. We then extend the controller from the one-degree of freedom system to the multidegree of freedom system. Experimental results are then presented to illustrate the performance of the proposed approach applied to a one-link robot. Finally, simulation results are presented to illustrate the tracking performance for the proposed controller applied to a two-link robot manipulator system View full abstract»

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  • An efficient algorithm for the model-based adaptive control of robotic manipulators

    Publication Year: 1996 , Page(s): 496 - 501
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (520 KB)  

    This paper presents a new computational algorithm of the model-based adaptive manipulator control, adopting the basic method proposed by Slotine and Li (1987). The manipulator regressor that is represented by an actual velocity vector and a reference velocity vector is computed explicitly by a recursive algorithm based on the Newton-Euler formulation. The proposed algorithm is more efficient than other methods for a manipulator with six or fewer joints. An experimental result is also presented to show the possibility of an adaptive controller having a single DSP for a robot manipulator with six degrees of freedom View full abstract»

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  • Pattern reconfiguration in swarms-convergence of a distributed asynchronous and bounded iterative algorithm

    Publication Year: 1996 , Page(s): 485 - 490
    Cited by:  Papers (28)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (708 KB)  

    Swarms are physical realizations of self-organizing distributed robotic systems (DRS). This paper provides a rigorous analysis of swarm behavior and introduces a new methodology for using swarms to solve DRS pattern reconfiguration problems. The authors introduce the linear swarm model and show that it is an iterative method for asynchronously solving linear systems of equations under physically relevant constraints. The main result of the paper is a proof of a sufficient condition for the asynchronous convergence of a linear swarm to a synchronously achievable configuration. This is important since a large class of DRS self-organizing tasks can be mapped into reconfigurations of patterns in swarms View full abstract»

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  • Constrained Cartesian motion control for teleoperated surgical robots

    Publication Year: 1996 , Page(s): 453 - 465
    Cited by:  Papers (46)  |  Patents (27)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2320 KB)  

    This paper addresses the problem of optimal motion control for teleoperated surgical robots, which must maneuver in constrained workspaces, often through a narrow entry portal into the patient's body. The control problem is determining how best to use the available degrees of freedom of a surgical robot to accomplish a particular task, while respecting geometric constraints on the work volume, robot mechanism, and the specific task requirements. We present a method of formulating desired motions as sets of task goals in any number of coordinate frames (task frames) relevant to the task, optionally subject to additional linear constraints in each of the task frames. Mathematically, the kinematic control problem is posed as a constrained quadratic optimization problem and is shown to be computable in real time on a PC. We will present experimental results of the application of this control methodology to both kinematically deficient and kinematically redundant robots. Specifically, we will discuss the control issues within the context of a representative set of tasks in robot-assisted laparoscopy, which includes (but is not limited to) teleoperated navigation of a laparoscopic camera attached to a surgical robot. A system based on this control formalism has been used in preclinical in vivo studies at the Johns Hopkins University Medical Center and the early experience with the system will be summarized View full abstract»

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  • Intelligent planning and control for multirobot coordination: An event-based approach

    Publication Year: 1996 , Page(s): 439 - 452
    Cited by:  Papers (57)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1312 KB)  

    A new planning and control scheme for multirobot coordination is presented. First, the event-based planning and control theory is introduced. The most important step is the design of an event-based motion reference for the multirobot system. It drives the system to achieve the best possible coordination. Hybrid position/force controllers which are able to perform a large class of tasks are designed based on the combination of general task space with the well-known nonlinear feedback linearization technique. To improve the force control performance, the dynamics of joint motors have been considered in the force control. For a given task, a task projection operator can be found for each robot with the consideration of redundancy management. It projects the feedback linearized model to the actual task space. A distributed computing architecture is proposed to implement this scheme in a parallel computation. The event-based coordination scheme was experimentally implemented and tested for the coordinated control of two 6 DOF PUMA 560 robots with very good results 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