Accuracy-speed relationships of a robotic filament winding cell

Filament winding is a process in which tensioned resio-impregnated continuous fibers are placed on specified paths of a rotating mandrel to cover the entire surface thus forming a composite component. Traditionally, filament winding is carried out on multi-saris numerically controlled lathe-like machines. This paper describes the evaluation of a robot based filament winding cell consisting of an industrial robot (ASEA IRB 6/2) and an in-house fabricated mandrel drive mechanism, both being coordinated by a personal computer. As in many manufacturing processes, tradeoffs exist between accuracy and speed. The accuracy vs speed relationships of the robotic winding cell were experimentally determined for discrete, fine and medium movement modes while traversing a segmented delivery eye path for a cylindrical mandrel in three configurations (in-line, offset and angled with respect to the axis of rotation). The results show that the robot winding cell is appropriate for very accurate winding of fiber strands if the mandrel axis is concentric with the mandrel drive axis and the discrete mode (i.e. low speed) of the robot is used. For high speed wet winding all three configurations can be accurately wound in the discrete and fine modes.     

Flexible robot sealant dispensing cell using RGB-D sensor and off-line programming

In aerospace manufacture the accurate and robust application of sealant is an integral and challenging part of the manufacturing process that is still performed by human operator. Automation of this process is difficult and not cost effective due to the high variability in the parts to operate and also the difficulty associated with programming industrial robotic systems. This work tries to overcome these problems by presenting an AOLP (Automatic Off-Line Programming) system for sealant dispensing through the integration of the ABB's proprietary OLP (Off-Line Programming) system RobotStudio with a relatively new RBG-D sensor technology based on structured light and the development of a RobotStudio add-on. The integration of the vision system in the generation of the robot program overcomes the current problems related to AOLP systems that rely on a known model of the work environment. This enables the ability to dynamically adapt the model according to sensor data, thus coping with environmental and parts variability during operation. Furthermore it exploits the advantages of an OLP system simplifying the robot programming allowing for faster automation of the process.     

Direct off-line robot programming via a common CAD package

This paper focuses on intuitive and direct off-line robot programming from a CAD drawing running on a common 3-D CAD package. It explores the most suitable way to represent robot motion in a CAD drawing, how to automatically extract such motion data from the drawing, make the mapping of data from the virtual (CAD model) to the real environment and the process of automatic generation of robot paths/programs. In summary, this study aims to present a novel CAD-based robot programming system accessible to anyone with basic knowledge of CAD and robotics. Experiments on different manipulation tasks show the effectiveness and versatility of the proposed approach.     

Problems associated with the off-line programming of robots

The introduction of robots into any organization forms part of a considerable investment in new technology over a range of applications in the search for efficiency and increased productivity. The greater consistency and quality associated with robot operations, compared with that of the human operator, is regarded as an advantage both in relation to the manufacturing process and to the product. However, in order to make the most efficient use of robots, the ability to generate good robot programs must be developed. Traditional robot programming techniques are extremely slow and laborious. Off-line programming by textual input alone is an equally tedious process. In this paper, existing and potential problems associated with off-line programming are examined. Various commercial and experimental robot languages and their relative important features are described. Opinions of manufacturers of CNC (Computer Numerically Controlled) machines and robots concerning both user interfaces and potential candidate users are discussed. Both the training and the abilities of the candidate robot programmers are important aspects of any robot programming system, although obviously much will depend on the sophistication of the particular application. Recommendations are made concerning issues that should be taken into account when developing future off-line programming systems.     

A blackboard system for the off-line programming of Robots

This paper describes the use of the blackboard architecture for the off-line programming of an IMB 7565 Robot. A blackboard system was implemented in PROLOG and it has been applied successfully for the automatic generation of a control code for the robot to perform the task of block assembly in an environment with an obstacle. The opportunistic type of problem-solving offered by the blackboard architecture has succeeded in obtaining a solution. The user-interface to the system is represented as a knowledge source in the blackboard system, which allows the user to modify the goal specifications during the operation of the blackboard system.     

使用QT构建的码垛机器人离线编程仿真系统

针对目前码垛机器人发展中应用环境的复杂变化与实际生产中对工作效率与编程操作便利的需求,提出了一种基于QT+OPENGL的三维码垛机器人离线编程仿真系统.介绍系统的总体结构,再对模拟示教模块与自动规划模块进行设计,并规划系统输入与输出流,在QT集成开发中实现系统,并与实体机器人数据联动,验证离线编程仿真系统的可用性.     

Dynamic systems modelling and development of robotic applications in a visual programming environment

In this paper we describe our approach to modelling dynamic systems behaviour and its application to an industrial environment. A complete programming environment is described through an account of the rationale and modus operandi of the system. Our objective is to help managers, designers, engineers and software developers to understand dynamic systems behaviour through modelling. Examples of systems modelling are given and an industrial application of the programming environment for automatic food handling involving machine vision, virtual sensors and robot manipulation control is described.     

Object-oriented and distributed approach for programming robotic manufacturing cells

Flexible manufacturing systems (FMS) are essential for small/medium batch and job shop manufacturing. These types of production systems are used to manufacture a considerable variety of products with medium/small production volumes. Therefore, the manufacturing platforms supporting these types of production must be flexible and organized in flexible manufacturing cells (FMC). Programming FMCs remains a difficult task and is an actual area of research and development. This paper reports an object-oriented approach developed for FMC programming. The work presented was first thought for application in industrial robot manipulators, and later extended to other FMC equipments just by putting the underlying ideas in a general framework. Initially, the motivation for this work was to develop means to add force control to a standard industrial robot manipulator. This problem requires remote access to the robot controller, remote programming and monitoring, as also is required to program and monitor any other FMC equipment. The proposed approach is distributed based on a client/server model and runs on Win32 platforms, i.e., Microsoft Windows and Windows NT. Implementation for the special case of industrial robot manipulators is presented, along with some application examples used for educational, research and industrial purposes.     

Design and experiments on a personal robotic assistant

The design and development of the 'personal robot, i.e. a robot capable of living together with and assisting human beings, is perhaps the main challenge for robotics research and technology in the third Millennium. One of the most intriguing issues in the design of such robot is the definition and implementation of adequate schemes for human-robot interaction. In fact, achieving this goal requires multidisciplinary efforts, and the integration of engineering analysis with psychological, anthropological, ethological and product design considerations. In this paper, the basic concepts to be followed in the design of human-robot interaction are discussed. with reference to a concrete example: the MOVAID personal robot for assistance to disabled and elderly people at home. The MOVAID system was designed taking into careful account as a primary design goal the need for interaction with the human user. A prototype of the MOVAID system has been developed and then successfully validated with disabled end-users. The results of these tests indicate that a personal robot is technically feasible, and is acceptable to users in terms of helpfulness, easiness of use and pleasure of interaction.     

Design and testing of a low-cost robotic wheelchair prototype

Many people who are mobility impaired are, for a variety of reasons, incapable of using an ordinary wheelchair. In some instances, a power wheelchair also cannot be used, usually because of the difficulty the person has in controlling it (often due to additional disabilities). This paper describes two low-cost robotic wheelchair prototypes that assist the operator of the chair in avoiding obstacles, going to pre-designated places, and maneuvering through doorways and other narrow or crowded areas. These systems can be interfaced to a variety of input devices, and can give the operator as much or as little moment by moment control of the chair as they wish. This paper describes both systems, the evolution from one system to another, and the lessons learned.     

Design fundamentals of a reconfigurable robotic gripper system

Discusses the design and modeling fundamentals of a multi-degree-of-freedom reconfigurable robotic gripper system (RGS), designed to automate the process of limp material handling, reliably and without distortion, deformation, and/or folding. The reconfigurable gripper design draws upon a previously reported flat surfaced, fixed-dimensions gripper system (Kolluru et al., 1998). The design consists of four arms in a cross-bar configuration, with a flat surfaced, fixed dimensions, suction-based gripper unit mounted on each of the arms. The kinematic and dynamic performance of the reconfigurable RGS is analyzed theoretically and then validated using Integrated Design Engineering Analysis Software (I-DEAS) simulation software     

A dynamic programming approach to trajectory planning of robotic manipulators

This paper presents a solution to the problem of minimizing the cost of moving a robotic manipulator along a specified geometric path subject to input torque/force constraints, taking the coupled, nonlinear dynamics of the manipulator into account. The proposed method uses dynamic programming (DP) to find the positions, velocities, accelerations, and torques that minimize cost. Since the use of parametric functions reduces the dimension of the state space from2nfor ann- jointed manipulator, to two, the DP method does not suffer from the "curse of dimensionality." While maintaining the elegance of our previous trajectory planning method, we have developed the DP method for the general case where 1) the actuator torque limits are dependent on one another, 2) the cost functions can have an arbitrary form, and 3) there are constraints on the jerk, or derivative of the acceleration. Also, we have shown that the DP solution converges as the grid size decreases. As numerical examples, the trajectory planning method is simulated for the first three joints of the PACS arm, which is a cylindrical arm manufactured by the Bendix Corporation.     

Design and development of a physical simulator for robotic palletization

This paper discusses the design and development of a physical simulator for robotic palletization. The design is aimed at two objectives. One, to provide a test bed for studying issues relating to automation of palletization and second, to provide a teaching tool for some common elements of material handling automation. The major hardware components of the system are an IBM 7545 robot, a Personal Computer, an Allen-Bradley Programmable Logic Controller (PLC), Conveyors and a Bar Code Reader. The software components include the IBM AML 4.1 language, PLC Software and BASIC software for the BASIC Module of the PLC.     

Design,analysis and control of a winding hybrid-driven cable parallel manipulator

This paper is related to the design, analysis and control of a winding hybrid-driven cable parallel manipulator (WHCPM). The WHCPM has the advantages of both cable parallel manipulator and hybrid-driven planar five-bar mechanism. Design of the WHCPM is explained, and the structure static analysis is carried out by using finite element method. Dynamics and payload capability of the WHCPM are studied. The WHCPM prototype is built for precision tracking experiments. To evaluate the manipulator design, the dynamic control compensation is performed on the basis of the conventional PID controller and the adaptive fuzzy sliding mode controller. The simulated and experimental results are reported and the tracking performance of the WHCPM is significantly improved by applying the proposed control technique in comparison with the performance when applying the conventional PID controller.     

Dynamic process programming for a robotic manipulator based on hopfield NN monotonous optimization searching

A new approach to programming the optimal dynamic process for an n‐joint rigid robotic manipulator with the use of the monotonous optimization searching ability of a Hopfield NN is presented. By combining robotic dynamics, this paper designs a programmed controller, which satisfies the aforementioned dynamic process. The convergence of the programmed controller is investigated. Simulations and experiments demonstrate the effectiveness of the scheme described. © 2004 Wiley Periodicals, Inc.     

Design of a cat-inspired robotic leg for fast running

This paper introduces a novel design for a robotic leg to achieve a fast running mechanism that is inspired by domestic cats. The skeletomuscular system and parallel leg movement of a cat are analyzed and applied to determine the link parameters and the linkage structure of the proposed mechanism. The linkage design of the leg mechanism is explained, and a kinematic analysis based on vector loop equations is performed. The effectiveness of the proposed mechanism is verified experimentally. A single leg clamped to a vertically moving slider exhibits a step frequency of 4.45 Hz while supporting a 0.5 kg body weight. The biped robot runs at an average speed of 0.75 m/s at a step frequency of 2.8 Hz for a trot gait on flat ground. This leg mechanism can facilitate the development of fast running robot systems.