Industrial Robotics

This book covers a wide range of topics relating to advanced industrial robotics, sensors and automation technologies. Although being highly technical and complex in nature, the papers presented in this book represent some of the latest cutting edge technologies and advancements in industrial robotics technology. This book covers topics such as networking, properties of manipulators, forward and inverse robot arm kinematics, motion path-planning, machine vision and many other practical topics too numerous to list here. The authors and editor of this book wish to inspire people, especially young ones, to get involved with robotic and mechatronic engineering technology and to develop new and exciting practical applications, perhaps using the ideas and concepts presented herein

Design and Control of an Articulated Robotic Arm Using Visual Inspection for Replacement Activities

Design of robotic systems and their control for inspection and maintenance tasks is highly complex activity involving coordination of various sub-systems. In application like inspections in fusion reactor vessels and deep-mining works, a regular off-line maintenance is necessary in certain locations. Due to the hostile environments inside, robotic systems are to be deployed for such internal observations. In this regard, current work focuses on the methodology for maintenance of the first wall blanket modules in a fusion reactor vessel using a manipulator system. A design is proposed for wall tile inspections in an ideal environment in which vacuum and temperature conditions are not accounted and wall surface curvature is not accounted initially. The entire design has four important modules: (i) mathematical modelling (ii) control system design (iii) machine vision and image processing, (iv) hardware development and testing. A five- axis articulated manipulator equipped with a vision camera in eye-to-hand configuration is designed for performing the pick and place operations of the defected tiles in a systematic manner. Kinematic and dynamics analysis of the system are first carried-out and a scaled prototype is fabricated for testing various operating issues. Forward kinematics of manipulator allows in estimation of robot workspace and in knowing the singular regions during operation, while the inverse kinematics of the manipulator would be needed for real time manipulator control task. Dynamics of manipulator is required for design of model-based controllers. Interactive programs are developed in Matlab for kinematics and dynamics and three-dimensional manipulator assembly configuration is modelled in SolidWorks software. Motion analysis is conducted in ADAMS software in order to compare the results obtained from the classical kinematics. Two types of model-based control schemes (namely Computed Torque Control and Proportional Derivative-Sliding Mode Control approach) with and without external disturbances are implemented to study trajectory tracking performance of the arm with different input trajectories. A disturbance observer model is employed in minimizing the tracking errors during the action of external disturbances such as joint friction and payload. In order to experimentally understand the inspection and replacement activities, a test set-up is developed using vision camera and microcontroller platform to guide the robot joint servos so as to perform defected object replacement activity. Presence of crack and the coordinate of the region are indicated with the use of image-processing operations. Using a high resolution Basler camera mounted at fixed distance from the tile surface, the surface images are acquired and image processing module identifies the crack details using edge detection algorithms. Necessary motion of the end-effector will be provided based on the pose calculations using coordinate transformations. Both visual inspection and joint guidance are combined in a single application and the results are presented with a test case of tile replacement activity. The results are presented sequentially using a test surface with uniform rectangular tiles

Aspects of an open architecture robot controller and its integration with a stereo vision sensor.

The work presented in this thesis attempts to improve the performance of industrial robot systems in a flexible manufacturing environment by addressing a number of issues related to external sensory feedback and sensor integration, robot kinematic positioning accuracy, and robot dynamic control performance. To provide a powerful control algorithm environment and the support for external sensor integration, a transputer based open architecture robot controller is developed. It features high computational power, user accessibility at various robot control levels and external sensor integration capability. Additionally, an on-line trajectory adaptation scheme is devised and implemented in the open architecture robot controller, enabling a real-time trajectory alteration of robot motion to be achieved in response to external sensory feedback. An in depth discussion is presented on integrating a stereo vision sensor with the robot controller to perform external sensor guided robot operations. Key issues for such a vision based robot system are precise synchronisation between the vision system and the robot controller, and correct target position prediction to counteract the inherent time delay in image processing. These were successfully addressed in a demonstrator system based on a Puma robot. Efforts have also been made to improve the Puma robot kinematic and dynamic performance. A simple, effective, on-line algorithm is developed for solving the inverse kinematics problem of a calibrated industrial robot to improve robot positioning accuracy. On the dynamic control aspect, a robust adaptive robot tracking control algorithm is derived that has an improved performance compared to a conventional PID controller as well as exhibiting relatively modest computational complexity. Experiments have been carried out to validate the open architecture robot controller and demonstrate the performance of the inverse kinematics algorithm, the adaptive servo control algorithm, and the on-line trajectory generation. By integrating the open architecture robot controller with a stereo vision sensor system, robot visual guidance has been achieved with experimental results showing that the integrated system is capable of detecting, tracking and intercepting random objects moving in 3D trajectory at a velocity up to 40mm/s

Control of mechanical systems with backlash problem

Master'sMASTER OF ENGINEERIN

Neural Extended Kalman Filter for State Estimation of Automated Guided Vehicle in Manufacturing Environment

To navigate autonomously in a manufacturing environment Automated Guided Vehicle (AGV) needs the ability to infer its pose. This paper presents the implementation of the Extended Kalman Filter (EKF) coupled with a feedforward neural network for the Visual Simultaneous Localization and Mapping (VSLAM). The neural extended Kalman filter (NEKF) is applied on-line to model error between real and estimated robot motion. Implementation of the NEKF is achieved by using mobile robot, an experimental environment and a simple camera. By introducing neural network into the EKF estimation procedure, the quality of performance can be improved

Prediction of Robot Execution Failures Using Neural Networks

In recent years, the industrial robotic systems are designed with abilities to adapt and to learn in a structured or unstructured environment. They are able to predict and to react to the undesirable and uncontrollable disturbances which frequently interfere in mission accomplishment. In order to prevent system failure and/or unwanted robot behaviour, various techniques have been addressed. In this study, a novel approach based on the neural networks (NNs) is employed for prediction of robot execution failures. The training and testing dataset used in the experiment consists of forces and torques memorized immediately after the real robot failed in assignment execution. Two types of networks are utilized in order to find best prediction method - recurrent NNs and feedforward NNs. Moreover, we investigated 24 neural architectures implemented in Matlab software package. The experimental results confirm that this approach can be successfully applied to the failures prediction problem, and that the NNs outperform other artificial intelligence techniques in this domain. To further validate a novel method, real world experiments are conducted on a Khepera II mobile robot in an indoor structured environment. The obtained results for trajectory tracking problem proved usefulness and the applicability of the proposed solution

The 31st Aerospace Mechanisms Symposium

The proceedings of the 31st Aerospace Mechanisms Symposium are reported. Topics covered include: robotics, deployment mechanisms, bearings, actuators, scanners, boom and antenna release, and test equipment. A major focus is the reporting of problems and solutions associated with the development and flight certification of new mechanisms

Friction Force Microscopy of Deep Drawing Made Surfaces

Aim of this paper is to contribute to micro-tribology understanding and friction in micro-scale interpretation in case of metal beverage production, particularly the deep drawing process of cans. In order to bridging the gap between engineering and trial-and-error principles, an experimental AFM-based micro-tribological approach is adopted. For that purpose, the can’s surfaces are imaged with atomic force microscopy (AFM) and the frictional force signal is measured with frictional force microscopy (FFM). In both techniques, the sample surface is scanned with a stylus attached to a cantilever. Vertical motion of the cantilever is recorded in AFM and horizontal motion is recorded in FFM. The presented work evaluates friction over a micro-scale on various samples gathered from cylindrical, bottom and round parts of cans, made of same the material but with different deep drawing process parameters. The main idea is to link the experimental observation with the manufacturing process. Results presented here can advance the knowledge in order to comprehend the tribological phenomena at the contact scales, too small for conventional tribology