摘要:

AbstractWe treat the question of control of an elastic robotic arm of two links. Of course, this approach can be extended to other elastic arms. A nonlinear ultimate boundedness controller (UBC) is synthesized such that in the closed‐loop system the joint angle tracking error is uniformly bounded and tends to a certain small neighborhood of the origin. The controller includes a reference joint angle trajectory generator and integral error feedback. Although the joint angles are controlled using the UBC, elastic modes are excited. A feedback stabilizer is designed for the linearized model including the UBC about the terminal state that is switched only in the vicinity of the equilibrium state for stabilization. Simulation results are presented to show that in the closed‐loop system including the UBC and the stabilizer accurate joint angle trajectory following and elastic mode stabilization are accomplished in the presence of uncertai

ISSN:0741-2223    

DOI:10.1002/rob.4620090302

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

年代:1992

数据来源: WILEY

摘要:

AbstractThe dynamics of mechanical systems with distributed flexibility are described by infinite dimensional mathematical models, yet a real controller must be finite dimensional due to the limited bandwidth capabilities of the sensor‐actuator system and real‐time control computer hardware. Therefore, simplified finite dimensional dynamic models must be obtained for the purpose of controller design. This article addresses the issue of selecting the shape and number of mode functions in developing finite order models using a flexible robot arm as an example. The results of this work have consistently shown that the clamped‐free mode shape predicts the closed‐loop system dynamics under a feedback controller much more accurately than pinned‐free mode shapes. However, as the hub inertia increases relative to the flexible beam inertia the difference between the clamped‐free and pinned‐free mode shape model predictions be

ISSN:0741-2223    

DOI:10.1002/rob.4620090303

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

年代:1992

数据来源: WILEY

摘要:

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 fea

ISSN:0741-2223    

DOI:10.1002/rob.4620090304

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

年代:1992

数据来源: WILEY

摘要:

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

ISSN:0741-2223    

DOI:10.1002/rob.4620090305

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

年代:1992

数据来源: WILEY

摘要:

AbstractComputer generation of symbolic solutions for the direct and inverse robot kinematics is a desired capability not previously available to robotics engineers. In this article, we present a methodology for the design of a software system capable of solving the direct and inverse kinematics forndegree of freedom (dof) manipulators in symbolic form. The inputs to the system are the Denavit‐Hartenberg parameters of the manipulator. The outputs of the system are the direct and inverse kinematics solutions in symbolic form. The system consists of a symbolic processor to perform matrix and algebraic manipulations and an expert system to solve the class of nonlinear equations involved in the solution of the inverse kinematics problem. The system can be used to study robot kinematics configurations whose inverse kinematics solutions are not known to exist a priori. Two examples are included to illustrate its capabilities. The first example provides explicit analytical solutions, previously believed nonexistent, for a 3 dof manipulator. A second example is included for a robot whose inverse kinematics solution requires intensive algebraic manipulation

ISSN:0741-2223    

DOI:10.1002/rob.4620090306

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

年代:1992

数据来源: WILEY

摘要:

AbstractThis article establishes new goals for redundancy resolution based on manipulator dynamics and end‐effector characteristics. These goals can be accomplished by employing the recently developed configuration control approach. Redundancy resolution is achieved by controlling the joint inertia matrix or the end‐effector mass matrix that affect the inertial torques or by reducing the joint torques due to gravity loading and payload. The manipulator mechanical advantage and velocity ratio are also used as performance measures to be improved by proper utilization of redundancy. Furthermore, end‐effector compliance, sensitivity, and impulsive force at impact are introduced as redundancy‐resolution criteria. The new goals for redundancy resolution presented in this article allow a more efficient utilization of the redundant joints based on the desired task requirements. Simple case studies using computer simulations are described for illus

ISSN:0741-2223    

DOI:10.1002/rob.4620090307

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

年代:1992

数据来源: WILEY

ISSN:0741-2223    

DOI:10.1002/rob.4620090301

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

年代:1992

数据来源: WILEY