bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modal sensitivity analysis of planar robots, based on a simplified CMS approach
Authors: Jen C. W. , Johnson D. A. 
Published: July 2007

AbstractThe modal properties of industrial robots have become a major issue following the increasing demand for faster, lighter manipulators. In this article, the basic in‐plane and out‐of‐plane modal analysis of a planar robot with revolute joints is conducted via component mode synthesis (CMS) using a limited number of low‐order monomials as mode shapes for the different links, and an automatic coordinate reduction procedure in the assembly phase which accounts for the physical characteristics of the joints. This model is then used to study the effect of variations in configuration, payload and various physical parameters on the natural frequencies of the robot. As regards the influence of physical parameter variations, frequency sensitivity coefficients are evaluated in a straightforward manner requiring only one eigenvalue analysis, and allow to determine the eigenvalue variations. It is observed that relatively large variations of parameters can be accommodated using these sensitivity coefficients.
A new repetitive controller for mechanical manipulators
Authors: Sadegh Nader , Guglielmo Kennon 
Published: July 2007

AbstractA new repetitive learning controller for motion control of mechanical manipulators undergoing periodic tasks is developed. This controller does not require exact knowledge of the manipulator dynamic structure or its parameters, and is computationally efficient. In addition, no actual joint accelerations or any matrix inversions are needed in the control law. The global asymptotic stability of the ideal and the robust stability of the nonideal control system is proven, taking into account the full nonlinear dynamics of the manipulator. Simulation results of this algorithm applied to a realistic Scara type manipulator, which includes dry friction, pay‐load inertia variations, actuator/sensor noise, and unmodelled dynamics are also presented.
Mobile robot map making using sonar
Authors: Zelinsky A. 
Published: July 2007

AbstractThis article describes a method of producing high‐resolution maps of an indoor environment with an autonomous mobile robot equipped with sonar range‐finding sensors. This method is based on investigating obstacles in the near vicinity of a mobile robot. The mobile robot examines the straight line segments extracted from the sonar range data describing obstacles near the robot. The mobile robot then moves parallel to the straight line sonar segments, in close proximity to the obstacles, continually applyingsonar barrier test.The sonar barrier test exploits the physical constraints of sonar data, and eliminates noisy data. This test determines whether or not a sonar line segment is a true obstacle edge or a false reflection. Low resolution sonar sensors can be used with the method described. The performance of the algorithm is demonstrated using a Denning Corp. Mobile Robot, equipped with a ring of Polaroid Corp. Ultrasonic Rangefinders.
Robotic capability determined from planes of motion
Authors: Parkin Robert E. 
Published: July 2007

AbstractA consequence of the specification of robots using kinematically simple joints is a simplified kinematic analysis. The analysis is performed here in terms of points and planes; i.e., the point/plane method. It is shown that the capability of a robot is completely specified by its planes of motion; the logical position space of a robot is defined in terms of these planes, and capability is presented in tables.
A new and efficient transform for curve detection
Authors: Liang Ping 
Published: July 2007

AbstractA new transform for curve detection, called the Curve‐Fitting Hough Transform (CFHT), is proposed. In the conventional Hough Transform (HT) and its variants, both storage and computation grow exponentially with the number of parameters. The CFHT is advantageous over the conventional HT and variants in its high speed, small storage, arbitrary parameter range, and high parameter resolution. This is achieved by fitting a segment of the curve to be detected to a small neighborhood of edge points. If the fitting error is less than a given threshold, the parameters obtained from curve fitting are used to map an edge element to a single point in the parameter space. A multidimensional ordered parameter list is used to accumulate the occurrences of the curve to be detected.
Periodic gaits for the CMU Ambler
Authors: Dwivedi Suren N. , Mahalingam Swaminathan 
Published: July 2007

AbstractThe configuration of the Carnegie‐Mellon University Ambler, a six‐legged autonomous walking vehicle for exploring Mars, enables the recovery of a trailing leg past the leading leg to reduce the energy expenditure in terrain interactions. In this article, gaits developed for this unprecedented configuration are described. A stability criterion has been developed that ensures stability of the vehicle in the event of failure of any one of the supporting legs. Periodic gaits developed for the Ambler utilize the Ambler's unique abilities and continuously satisfy the stability criterion.
Homeostatic control for a mobile robot: Dynamic replanning in hazardous environments
Authors: Arkin Ronald C. 
Published: July 2007

AbstractA longstanding goal of robotics has been to introduce intelligent machines into environments dangerous to humans. These environments also pose hazards to the robots themselves. By embedding sensing devices as a means for monitoring the internal state of the robot, dynamic plan reformulation can occur in situations that threaten the existence of the robot. A method exploiting an analogy to the endocrine control system is forwarded as the preferred method for homeostatic control—the maintenance of a safe internal environment for the machine. Examples are given describing the impact of fuel reserve depletion and global temperature stress. A methodology using signal schemas as a means to supplement the existing motor schema control found in the Autonomous Robot Architecture (AuRA) is presented.
Cooperation without communication: Multiagent schema‐based robot navigation
Authors: Arkin Ronald C. 
Published: July 2007

AbstractMultiagent robotics affords the opportunity to solve problems more efficiently and effectively than any single agent could achieve. Nonetheless, communication bottlenecks between agents pose potentially serious drawbacks in coordinated behavior. In this research, we demonstrate the efficiency of multiagent schema‐based navigation for object retrieval. Primitive motor behaviors are specified for each of the individual robotic agents, which produce safe task‐achieving action in an unstructured environment. When implemented over several identical units, retrieval is facilitated in the absence of interagent communication as evidenced by spontaneous recruitment of several agents to accomplish a task. Simulation results are provided to demonstrate these effects. Extensions to other task‐achieving behaviors are also feasible.
Two‐dimensional orientation sensor
Authors: Partaatmadja O. , Benhabib B. , Kaizerman E. , Dai M. Q. 
Published: July 2007

AbstractThe development of a two‐dimensional noncontact electrooptical orientation sensor is addressed in this article. The sensor is based on the intensity measurement of modulated light signals reflected from the surface of an object. The transducer of the proposed sensor was designed based on the optimal mechanical‐design parameters obtained in the first stage of our research, where results were reported for one‐dimensional inclination angle measurements. Experiments undertaken in the second stage of our research, and reported herein, verify the operational principle of the two‐dimensional sensor, which yielded acceptable performance characteristics. An important characteristic of this orientation sensor is the distance‐independent inclination‐angle measurements (i.e., output signals utilized to estimate the two inclination angles are independent of the sensor's distance to the object's surface).
Linearized dynamic models for trajectory control of robot manipulators
Authors: Swarup A. , Gopal M. 
Published: July 2007

AbstractTo make an appropriate choice of linear model for the development of real‐time control of robot manipulators, four direct linearization schemes have been studied here on the basis of computation and accuracy. Accuracy is assured in the state linearization method, whereas the rate linearization method leads to a satisfactory trade‐off between computational effort and accuracy. In the case of high‐velocity motions, a combination of state and rate linearization is proposed.
Optimal redundancy resolution of a kinematically redundant manipulator for a cyclic task
Authors: Choi Byoung Wook , Won Jong Hwa , Chung Myung Jin 
Published: July 2007

AbstractThis article proposes a method for the global optimization of redundancy over the whole task period in a kinematically redundant manipulator. The necessary conditions based on the calculus of variations for integral‐type criteria result in a second‐order differential equation. For a cyclic task, the boundary conditions for conservative joint motions are discussed. Then, we reformulate a two‐point boundary value problem to an initial value adjustment problem and suggest a numerical search method based on the iterative optimization for providing a globally optimal solution using the gradient projection method. Since the initial joint velocity is parameterized with the number of redundancy, we only search parameter values in the parameterized space using the configuration error between the initial and final time. We show through numerical examples that multiple nonhomotopic extremal solutions satisfying periodic boundary conditions exist according to initial joint velocities for the same initial configuration. Finally, we discuss an algorithm for topological liftings of the paths and demonstrate the generality of the proposed method by considering the dynamics of a manipulator.
Procedure for manipulator inverse kinematics computation and proper pseudoinverse perturbation
Authors: Mayorga R. V. , Wong A. K. C. , Ma K. S. 
Published: July 2007

AbstractIn this article, an efficient procedure for the proper pseudoinverse perturbation and the numerical inverse kinematics computation of robot manipulators is presented. The approach is based on solving a linear system of equations and using an original scheme for the appropriate perturbation of the pseudoinverse matrix in the next iteration. The resultant algorithm is tested on the simulation of an industrial robot manipulator. From the results obtained, it is observed that the proposed approach compares favorably with the approaches using a Gaussian elimination procedure and with pseudoinverse robustness based on a manipulability measure.
Model extension and refinement using pose recovery techniques
Authors: Kumar Rakesh , Hanson Allen R. 
Published: July 2007

AbstractVisual measurements of modeled 3‐D landmarks provide strong constraints on the location and orientation of a mobile robot. To make the landmark‐based robot navigation approach widely applicable, it is necessary to automatically build the landmark models. A substantial amount of effort has been invested by computer vision researchers over the past 10 years on developing robust methods for computing 3‐D structure from a sequence of 2‐D images. However, robust computation of 3‐D structure, with respect to even small amounts of input image noise, has remained elusive. The approach adopted in this article is one of model extension and refinement. A partial model of the environment is assumed to exist and this model is extended over a sequence of frames. As will be shown in the experiments, prior knowledge of the small partial model greatly enhances the robustness of the 3‐D structure computations. The initial 3‐D model may have errors and these are also refined over the sequence of frames. © 1992 John Wiley & Sons, Inc.
Passive stereo range imaging for semi‐autonomous land navigation
Authors: Matthies Larry 
Published: July 2007

AbstractMany navigation tasks, such as the use of unmanned vehicles for planetary exploration or defense reconnaissance, require onboard range sensors to automatically detect obstacles in the path of a vehicle. Passive ranging via stereo triangulation, orstereo vision, is a very attractive approach to obstacle detection because it is nonemissive, nonmechanical, nonscanning, and compatible with stereographic viewing by human operators. However, several problems have restricted the practicality of stereo ranging in the past, including limitations on the speed, reliability, and generality of existing stereo matching algorithms. This situated has changed, because the Jet Propulsion Laboratory (JPL) recently demonstrated the first semi‐autonomous, robotic traverses of natural terrain to use stereo vision for obstacle detection, with all computing onboard the vehicle. This article reviews the main algorithmic paradigms for stereo vision, describes a near realtime stereo vision system developed at JPL, and presents experimental results that demonstrate the emerging practically of stereo vision for obstacle detection in semi‐autonomous land navigation. © 1992 John Wiley & Sons, Inc.
Inertial navigation sensor integrated motion analysis for autonomous vehicle navigation
Authors: Roberts Barry , Bhanu Bir 
Published: July 2007

AbstractMany types of existing vehicles contain an inertial navigation system (INS) that can be utilized to greatly improve the performance of motion analysis techniques and make them useful for practical military and civilian applications. This article presents the results obtained with a maximally passive system of obstacle detection for ground‐based vehicles and rotorcraft. Automatic detection of these obstacles and the necessary guidance and control actions triggered by such detection will facilitate autonomous vehicle navigation. Our approach to obstacle detection employs motion analysis of imagery collected by a passive sensor during vehicle travel to generate range measurements to world points within the field of view of the sensor. The approach makes use of INS data and scene analysis results to improve interest point selection, the matching of the interest points, and the subsequent motion‐based range computations, tracking, and obstacle detection. In this article, we concentrate on the results obtained using lab and outdoor imagery. The range measurements that are made by INS integrated motion analysis are compared to a limited amount of ground truth that is available. © 1992 John Wiley & Sons, Inc.
Stability and control aspects of flexible link robot manipulators during constrained motion tasks
Authors: Mills James K. 
Published: July 2007

AbstractThe effect of robotic manipulator structural compliance on system stability and trajectory tracking performance and the compensation of this structural compliance has been the subject of a number of publications for the case of robotic manipulator noncontact task execution. The subject of this article is the examination of dynamics and stability issues of a robotic manipulator modeled with link structural flexibility during execution of a task that requires the robot tip to contact fixed rigid objects in the work environment. The dynamic behavior of a generalndegree of freedom flexible link manipulator is investigated with a previously proposed nonlinear computed torque constrained motion control applied, computed based on the rigid link equations of motion. Through the use of techniques from the theory of singular perturbations, the analysis of the system stability is investigated by examining the stability of the “slow” and “fast” subsystem dynamics. The conditions under which the fast subsystem dynamics exhibit a stable response are examined. It is shown that if certain conditions are satisfied a control based on only the rigid link equations of motion will lead to asymptotic trajectory tracking of the desired generalized position and force trajectories during constrained motion. Experiments reported here have been carried out to investigate the performance of the nonlinear computed torque control law during constrained motion of the manipulator. While based only on the rigid link equations of motion, experimental results confirm that high‐frequency structural link modes, exhibited in the response of the robot, are asymptotically stable and do not destabilize the slow subsystem dynamics, leading to asymptotic trajectory tracking of the overall system. © 1992 John Wiley & Sons, Inc.
Forward kinematics of walking machines with pantograph legs based on selections of independent joints
Authors: Zhang Chang‐De , Song Shin‐Min 
Published: July 2007

AbstractThis article studies the forward kinematics of walking machines with pantograph legs. The walking machine is supported by three legs and each leg has 3 degrees of freedom (dof). Because the body has 6 dof motion, only 6 joint variables among the 9 are independent. Thus, there are 84 possible ways to select the 6 independent joint variables. It is shown that the complexity of the forward position solutions is very much dependent on the selection of independent joints. In the category of3:2:1(the 3 numbers denote the number of independent joints at each of the supporting legs), all 54 combinations give closed‐form solutions. Among the 27 combinations ofcategory 2:2:2, 10 possess closed‐form solutions, 16 yield to higher‐order polynomials, and 1 gives no solutions. The 3 combinations ofcategory 3:3:0give no solutions. The results are useful to control and simulation of walking machines and other parallel systems consisting of pantograph subchains such as parallel manipulators, multifingered hands, and multiply coordinated manipulators. © 1992 John Wiley & Sons, Inc.
Redundant grasps, redundant manipulators, and their dual relationships
Authors: Kerr D. R. , Griffis M. , Sanger D. J. , Duffy J. 
Published: July 2007

AbstractThis article presents a meaningful, practical, and theoretically sound solution that solves the problem of grasping a rigid object with a hand that has redundant (>6) grasping contacts. This is accomplished by introducing compliance at each contact point in such a way as to provide the engineer with the capabilities of object manipulation via controlled forces at the contact points. This method of solution is adapted straight‐away to compute the static forces generated in the legs of a redundant in‐parallel manipulator that equilibrates a wrench applied to the moving/platform or end‐effector. In a way similar to the redundant grasping problem, this is accomplished by introducing the knowledge of the compliances that exist in the legs. The solution thus obtained stems from physical parameters that model the in‐parallel manipulator. The in‐depth study of the duality between the statics of in‐parallel manipulators and the kinematics of serial manipulators reveals a meaningful, practical, and theoretically sound solution for the inverse kinematics of a redundant serial manipulator. This is accomplished by incorporating the knowledge of the compliances that exist or are desired to exist in the joints of the manipulator. (For instance, the torsional compliance in revolute joints or the linear compliance in prismatic joints.) Such information provides a physically meaningful model of the serial manipulator that in turn yields a physically meaningful set of joint increments for a given end‐effector twist. © 1992 John Wiley & Sons, Inc.
Linear learning control of robot motion
Authors: Qu Zhihua , Dorsey John , Dawson Darren M. , Johnson Roger W. 
Published: July 2007

AbstractFor the trajectory following problem of a robot manipulator, a new linear learning control law, consisting of the conventional proportional‐integral‐differential (PID) control law, with respect to position tracking error, and an iterative learning term is provided. The learning part is a linear feedback control of position, velocity, and acceleration errors (PDD2). It has been shown that, under the proposed learning control, the position, velocity, and acceleration tracking errors are asymptotically stable in the presence of highly nonlinear dynamics. The proposed control is robust in the sense that exact knowledge about nonlinear dynamics is not required except for the bounding functions on their magnitudes. Further, neither is linear approximation of nonlinear dynamics nor repeatability of robot motion required.
Grasp synthesis for planar and solid objects
Authors: Chen Yu‐Che , Walker Ian D. , Cheatham John B. 
Published: July 2007

AbstractThis article presents an analysis of the mechanics for multifingered grasps of planar and solid objects. We present a method that is intuitive and computationally efficient. We combine the search for finger grasp positions with finger (manipulation and squeezing) force calculations into a single method. Physically, the squeezing and frictional effects between the fingers and the grasped objects are fully visualized through our approach. Mathematically, we reduced the complexity of finger force calculations when comparing our scheme with previously available schemes. Examples are used to illustrate the effectiveness and efficiency of our scheme. Based upon the analysis of grasp mechanics, an algorithm for quantatively choosing the grasp points is proposed to ensure stable grasps.
Dynamic model of robot manipulator in explicit form formulation with dual vectors and the notion of augmented body
Authors: Baklouti M. , Castelain J. M. 
Published: July 2007

AbstractThis article deals with the dynamic model formulation and computation in explicit form of the inverse dynamic model of a robot manipulator constituted with a simple kinematic chain. We go on with the studies of Pennock and Giordano using the dual vectors, and we introduce the notion of augmented body. Our aim is to obtain the computation of the inverse dynamic model in explicit form with an almost minimal number of arithmetical operations to allow the dynamic control synthesis in real time. The method proposed here requires two steps of computation: first, an intrinsic theoretical computation; second, an extrinsic practical computation using dual matrices. This method is then applied to the robot manipulator COMAU‐POLAR 6000 and compared with the method of Renaud, considered until now the most performant method. This comparison leads to the same number of arithmetical operations with both methods.
Micro‐telerobot for manipulation of microscopic objects immersed in a liquid layer
Authors: Wang P. K. C. 
Published: July 2007

AbstractA micro‐telerobot for manipulating microscopic objects such as macromolecules and living microorganisms immersed in a liquid layer is proposed. The basic idea is to inject a small number of microscopic solid ferromagnetic or magnetostrictive particles into the liquid layer either before or after the insertion of the microscopic objects to be manipulated. They serve as end‐effectors for the micro‐telerobot. These end‐effectors are activated and steered by an electromagnetic probe located outside the liquid layer. A nonlinear mathematical model describing the dynamic behavior of the micro‐telerobot is developed. It is shown that the equilibrium state of an activated end‐effector is unstable. The use of a linear feedback control for stabilization is explored. Appropriate values for the feedback gains are obtained with the aid of computer simulation using the nonlinear mathematical model. The article concludes with a discussion of the physical implementation of the proposed micro‐telerobot. © 1993 John Wiley & Sons, Inc.