摘要:

AbstractA robotic system that can visually track and intercept an arbitrary object which is traveling in 2‐D at an unknown velocity on a conveyor is to be presented. An eye‐in‐hand vision system developed by the Robotics and Intelligent Systems Laboratory at NCSU is used as an integral part of the entire tracking and acquisition system. The eye‐in‐hand system is employed to characterize the object trajectory in real time via a modified optical flow approach. A control strategy has been developed which utilizes the kinematic data that is extracted by the tracking algorithm to intercept the moving object. An overall system configuration and its basic principles are described. The demonstration of the experimental results is

ISSN:0741-2223    

DOI:10.1002/rob.4620060502

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractIn this article, we show that the principle of superposition can be applied for analyzing the spatial motion of a bevel geared three‐roll wrist with nonzero oblique angle. The total motion of the wrist is decomposed into three independent component motions, which are easier to analyze. A superposition tabulation is then constructed to derive the relations among the three wrist joint variables and three coaxial actuation variables. The displacement solution for the wrist joint variables is found by using the zero reference position metho

ISSN:0741-2223    

DOI:10.1002/rob.4620060503

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractA control strategy is developed for a robotic probe with tactile sensing to explore an unknown surface without losing contact. Digital computer simulations are performed of a three‐link, planar manipulator exploring an ellipsoidal surface in order to test the control strategy. The equations of motion are written and linear, time‐varying, state‐variable feedback is applied to stabilize and decouple the system. A tactile sensor is simulated to supply the normal force between the robot and the surface. From the magnitude and direction of this force, the desired trajectory is determined. An inverse plant and force feedback are implemented to provide the required input torques to the robot's actu

ISSN:0741-2223    

DOI:10.1002/rob.4620060504

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractModular robots can be defined as reconfigurable mechanical arms which can be automatically controlled using suitable motion control software. In this article, a generalized kinematic modeling method is presented for such modular robots. This method can be used to derive the individual kinematic models of all the mechanical elements that make up the inventory of modular units, independently of their geometry and sequence of assembly into a robot. A general procedure is also presented to derive a global kinematic model of any robot configured using these modular units. The kinematic modeling technique of the units is based on Denavit‐Hartenberg (D‐H) parameter notation. A provision is also presented for converting “non D‐H” parameter transformations, obtained in assembling the kinematic chain, into D‐H transformations. This D‐H conversion feature allows the modeling technique to preserve its generality when a kinematic model is obtained for the specific robot configuration at hand. The conceptual design of modular robot units that is under development in the Computer Integrated Manufacturing Laboratory (CIML) is also presented to show the feasibility of a modular approach to robot design and to clarify some of the mathematical for mulations developed i

ISSN:0741-2223    

DOI:10.1002/rob.4620060505

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractParts acquisition by a robot is an important industrial problem. Our method makes possible the acquisition of various types of parts which are jumbled together in a pile. An intensity image along with selected range data is used to guide a robot to a location, called a holdsite, at which it can grasp a part. The intensity image gives a rough indication of an area of interest and a laser rangefinder mounted on the robot wrist collects range data in its vicinity. This data is processed using spatial planning methods to find a good holdsite according to safety and stability criteria. The robot is then directed to the holdsite and the part is grasped. The algorithms are simple, fast, and have been successfully tested on a variety of parts.

ISSN:0741-2223    

DOI:10.1002/rob.4620060506

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractThe solution of the inverse kinematic problem is of the utmost importance in robotic manipulator control. This article proposes a closed‐loop scheme for solving the inverse kinematic problem for nonredundant and redundant wrists based on the computation of the Jacobian transpose. The manipulability measure is suitably introduced as a constraint for redundant wrists, by taking advantage of the null space of the Jacobian matrix. The resulting algorithm provides a computational tool to solve a specified orientation trajectory into a joint trajectory. Numerical results with two spherical wrists show the excellent performance of the schem

ISSN:0741-2223    

DOI:10.1002/rob.4620060507

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractIn this article, a stable local solution with global characteristics is developed for the joint torque optimization problem in redundant robotic manipulators. It is shown that the local optimization of the inertia inverse weighted dynamic torque corresponds to the global kinetic energy minimization problem. The proposed local‐global alternative to the joint torque optimization problem is compared for stability and torque optimality with five different methods used for redundancy resolution of robotic manipulators at the acceleration level. The proposed local‐global solution has been implemented and tested on a planar four‐DOF kinematically redundant lab robot which was designed and built at Southwest Research Institute (SWRI). Several numerical simulations confirm the positive advantages of solutions which have a local as well as a global interpretation. In addition, a “dynamic manipulation index” is introduced to monitor the stability of an optimization problem in a kinematically redund

ISSN:0741-2223    

DOI:10.1002/rob.4620060508

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

ISSN:0741-2223    

DOI:10.1002/rob.4620060501

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY