This book, written by two major figures in adaptive control, provides a wealth of material for researchers, practitioners, and students. While some researchers in adaptive control may note the absence of a particular topic, the book‘s scope represents a high-gain instrument. It can be used by designers of control systems to enhance their work through the information on many new theoretical developments, and can be used by mathematical control theory specialists to adapt their research to practical needs. The book is strongly recommended to anyone interested in adaptive control.

Adaptive Control

Power transmission line inspection robots: A review, trends and challenges for future research

To efficiently transmit electric power to consumers, the power lines need to be inspected routinely for early fault detection. Thus, power line inspection robots are designed to replace the tedious and dangerous manual inspection using linemen or helicopters. However, most of the existing inspection robots are heavy, which make them slow and prone to external wind disturbance. This paper developed a lightweight dual-arm robot and investigates its robustness to wind disturbance on a lab-scale power line structure. The dynamic equations of the robot are derived using the Lagrangian equation for appropriate motor selection. Also, the components of the robot are designed to ensure low drag coefficient to wind flow, and the mechanism of the wind force on the robot-line coupled system is presented. To study the real-time impact of the wind, a wind speed of 4.5 m/s representing one of the windiest cities in China is considered as a case study. The experimental results for different wind directions, namely, 0°, 45°, and 90°, show that the maximum vibration is 8% higher than the normal vibration of the system in a controlled environment without wind. The results demonstrate that there is little influence of the wind on the system; hence, the robot has been successfully designed and can be applied for power line inspection.

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Investigation of Aerodynamic Stability of a Lightweight Dual-Arm Power Transmission Line Inspection Robot under the Influence of Wind

Over the last few decades, polymeric composites have been increasingly used as repair material for corroded metallic pipelines, as it can restore the loading capacity and structural integrity of a damaged pipeline. Considerable researches have been carried out on the repair of corroded metallic pipes with fiber-reinforced polymer-based composites. Also, the repair methods have been continuously improving to reduce the time and cost, and increasing the safety and operational certainty. However, there are still many issues, problems, and challenges to be overcome for effective designs. Therefore, in this article, the main developments of the composite repair system components which influence the effectiveness of the composite repair of corroded pipelines were reviewed. The properties, role, and contributions of the fiber, matrix, and putty material on the composite-repaired pipe are briefly discussed. The analytical and numerical methods for failure analysis of composite repair systems were reviewed thoroughly. Composite repair thickness determined using analytical and numerical methods has been also discussed. Finally, in the conclusion section, the current challenges and opportunities are discussed to achieve a more effective design philosophy for the composite repair of metallic pipes.

Composite repair system for corroded metallic pipelines: an overview of recent developments and modelling

This paper aims at the problems of slow speed for the existing high-voltage line inspection robot moving over obstacles, and designs an inspection and foreign bodies removing robot walking on twin bundle conductors, which can move over the spacers and counterweights directly and fast. In this paper, the motion simulation shows that a robot using four symmetrical driving wheels can not move over the spacer, thus the asymmetrical driving wheel is designed. And through the prototype experiment, it proved that the robot with four asymmetrical driving wheels can directly and fast move over spacers and counterweights. This not only provides a feasible and efficient solution for transmission line inspection robot moving over obstacles, but also has certain engineering value for the development of transmission line inspection robot.

Design and Implementation of High-Voltage Transmission Line Inspection and Foreign Bodies Removing Robot

Several studies have aimed to develop robotic systems which move in transmission lines. Until this moment, all of them have a high weight and cost associated with the equipment and reduced battery autonomy time. In this context, this paper aims to propose the POLIBOT (POwer Lines Inspection roBOT) with low cost and weight, enabling the movement over the lines and an easier installation and remove.,The designed robot uses the Profiles Manufacturing Methodology (PMM). The construction of the robot mechanical structure uses modularized aluminum parts built through square profiles. Thus, it’s possible a drastic reduction in production time as well as cost reduction and weight when comparing this method with other manufacturing processes like foundry, for example. For hardware and software systems, the use of free and open source software causes a significant reduction in cost and project execution time. The benefits of using open source systems are immeasurable, both from academic and industrial applications.,The POLIBOT platform is one solution to the problem of inspection in power lines. With this robot, more lines are maintained with lower time. In its constructive aspect, the robotic mechanism is designed using principles of bioengineering. The use of this principle was successful, considering that obstacle transposition is performed with stability and low energy consumption.,The suggestion for future researches is to replace the battery for solar energy and construction in polymeric material to avoid high magnetic fields.,The commercial application is evident because manual inspections are inefficient, very expensive and dangerous. Thus, it is growing the number of researches that develop mechatronics systems for this kind of inspection.,The impact is the reduction of accidents because the present procedure requires precision of movements, where the pilot and electrical technician are close to high electrical and magnetic fields. In addition, for some tasks, the worker has to walk on the line to reach some important points. Thus, those tasks involve high risk of death.,The PMM methodology represents an innovation to the state of the art because others robotic mechanisms proposed for inspection tasks present total structure mass between 50 and 100 kg and POLIBOT has only 9 kg. Other fact is its price for implementation as this robot used the robot operating system (ROS) framework, what dispense the use of licenses. Other important features are that the robot performs the tasks autonomously, which reduces errors introduced by the operator and its low manufacturing cost as compared with other projects.

POLIBOT – POwer Lines Inspection RoBOT

This work presents a comparative study of numerical control machines controllers integration using LinuxCNC controller and MatLab/Mach3 in Windows solutions applied in retrofitting process of an old industrial robot. The experience associated with retrofitting technique with ASEA IRB6-S2 by Federal University of Minas Gerais (UFMG) and University of Brasilia (UnB), have adopted different robot control platforms alternatives to include robot kinematics. Thus, the article makes a comparative study of performance in terms of financial and computational cost, implementation tasks facility, integration with CAD/CAM and usability, analyzing the advantages and disadvantages of each architecture and finally chooses the best alternative CNC (Computer Numerical Control) controller.

Retrofitting of ASEA IRB2-S6 industrial robot using numeric control technologies based on LinuxCNC and MACH3-MatLab

This work presents a comparative and descriptive study of numerical control machines solutions using Linux and Windows operating systems, used for the retrofitting of two similar models of old industrial robots, using controllers based on Computer Numerical Control (CNC). Federal University of Minas Gerais (UFMG) and University of Brasilia (UnB) adopted two different softwares, including the robot kinematics model and the generation of joint signal control. Furthermore, this article proposes a comparative study of the two open architecture controllers’ implementation advantages and CAD/CAM integration option, by describing and analyzing each academic solution and choosing the best alternative controller to implement the retrofitting technique for old industrial robots. The comparative study validated the developed generic robot retrofitting methodology, which can be considered as the work’s greatest contribution, as well as providing the open-source project, hardware and software, for ASEA IRB6-S2 Robot retrofitting. The proposed methodology is composed by a set of methods and activities described through an IDEF0 (Icam DEFinition for Function Modeling) model, which can be applied to the retrofitting of any industrial robot with serial or parallel kinematics, which guides the developer in five steps associated with the hardware and software specification for a desired robotic platform implementation as a custom solution based on LinuxCNC system.

Retrofitting of the IRB6-S2 robotic manipulator using Computer Numerical Control- based controllers

Industrial robot retrofitting usually applies specific solutions for each type and size of robots. This work aims create universal control cabinet to get one interface with computer (PC) and the manipulator (arm, motors and position sensors), following worldwide tendencies of standardization in automation and control systems. In this system, the PC runs the trajectory generation program and sends actuators set-points over a parallel port connection. The cabinet synchronizes the joints' movements and returns to the PC the actual position of each axis. The retrofitting is to match the new robot technology by leveraging existing systems such as motors, sensors, feedback, power supplies and so on. The initial idea was to reduce costs, but we can not ensure the reliability of these used parts without knowing the historic of the same. For example, a motor used for decades until when will it work? There is not how offer guarantees of a robot, if we do not know the probability of failure of their systems. To solve these problems was introduced the concept of overhauling. In this new design only mechanical part of the old robot would be used, due to the fact that the exchange of electronic and electromechanical components do not greatly increase the cost of adaptation to new technologies.

Overhauling of a ASEA Robot IR6 with Open Architecture

The air levitation system belongs to a class of systems with fast dynamics and low damping. Such characteristics make the plant intrinsically unstable and respond in a non-linear form. Thus, it is prohibitive to use classic control techniques, such as the PID (Proportional-Integral-Derivative) controller, to track the position of the sphere. The control system must be able to compensate the non-linearities, high oscillation and reject disturbances. Thus, this research proposes to create a new approach for the hybrid controller (PID + MRAC) present in the literature. The topological character of the proposed MRAC (Model Reference Adaptive Controller) consists of three parts: a feedforward controller, a derivative portion and an ordinary feedback. The feedforward portion has the purpose of rejecting undesirable disturbances. The derivative portion increases the stability of the system and the ordinary feedback makes the error null in steady state. Due to the convergence time of the adjustment parameters, MRAC performs poorly during reference changes and in the rejection of disturbances. Thus, it is common practice to use the MRAC with the PID controller. In its methodological aspect, the control law was created from Lyapunov's theory, with the purpose of ensuring asymptotic stability for the system. As a result, the proposed controller (Hybrid-MRAC or H-MRAC) showed better results than a literature reference (A-PID), in terms of mean absolute (MAE), mean square (MSE) and root mean square (RMSE) errors. In MAE simulations it was 51,25% lower on average, MSE was 51,65% and RMSE 31,40%. In the experiments, the MAE was on average 19,72% lower, the MSE 42,92% and the RMSE 18,58%.

Marcelo Henrique Souza Bomfim

Papers

POLIBOT – POwer Lines Inspection RoBOT

Retrofitting of ASEA IRB2-S6 industrial robot using numeric control technologies based on LinuxCNC and MACH3-MatLab

Retrofitting of the IRB6-S2 robotic manipulator using Computer Numerical Control- based controllers

Overhauling of a ASEA Robot IR6 with Open Architecture

A Novel Hybrid (PID + MRAC) Adaptive Controller for an Air Levitation System