Hardware realization and PID control of multi-degree of freedom articulated robotic arm

A robotic manipulator is the most important component in an industrial environment for autonomous execution of tasks. Given the repoted fact that a PID (Proportional-Integral-Derivative) will continue to be the main workhorse in the automation sector, the present paper deals with designing and realizing this control law. A custom-developed pseudo-industrial platform AUTAREP (AUTonomous Articulated Robotic Educational Platform) centered on a 6DOF (Six Degree of Freedom) manipulator is considered. The derived kinematic and dynamic models of the arm form the basis of MATLAB-based control simulation. The control law after discretization is also implemented on embedded hardware. When subject to various inputs, result of trajectory tracking in the form of output responses, demonstrate superior performance in transient as well as steady state. The stability and convergent behavior of the outputs is also observed, thus highlighting efficacy of proposed approach

Non-linear control law for articulated serial manipulators: Simulation augmented with hardware implementation

The performance of a robotic arm includes accuracy, repeatability and reliability to accomplish a task. These parameters, in turn, are function of associated control law. Multi-Degree Of Freedom (DOF) robotic arms, because of their inherent highly non-linear dynamics, demand sophisticated control laws. Trivial control strategies fail to cope with disturbances and uncertainties that are common in today's plants. This paper presents the design, simulation and physical implementation of a non-linear control technique Variable Structure Control (VSC) for a 6 DOF arm. Based on the derived dynamic model of the arm and designed control law, simulations have been conducted in MATLAB/Simulink. The controller parameters have been tuned for optimal response. Various desired trajectories characterize the tracking performance of the control law. The simulation results have been then validated by implementing the law on a customdeveloped novel AUTonomous Articulated Robotic Educational Platform (AUTAREP). Coupling effects between various joints of the robot have also been investigated. Results of this research find potential in industrial control of robotic manipulators to perform complex tasks

Modeling and computed torque control of a 6 degree of freedom robotic arm

This paper presents modelling and control design of ED 7220C - a vertical articulated serial arm having 5 revolute joints with 6 Degree Of Freedom. Both the direct and inverse kinematic models have been developed. For analysis of forces and to facilitate the controller design, svstem dvnamics have been formulated. A non-linear control technique, Computed Torque Control (CTC) has been presented. The algorithm, implemented in MATLAB/Simulink, utilizes the derived dynamics as well as linear control techniques. Simulation results dearly demonstrate the efficacy of the presented approach in terms of traiectory tracking Various responses of the arm joints have been recorded to characterize the performance of the control algorithm. The research finds its applications in simulation of advance nonlinear and robust control techniques as well as their implementation on the physical platform. © 2014 IEEE

Evaluation of strength parameters of plain and reinforced concrete with the addition of polypropylene fibers

This research investigates the influence of incorporating small-diameter polypropylene fibers on the mechanical properties of concrete. The studied concrete properties include compressive strength, tensile strength, flexural strength (both plain and reinforced), shear strength, and the mitigation of shrinkage cracks. A total of 92 specimens were meticulously fabricated in the laboratory, comprising cylinders (12 inches in length and 6 inches in diameter), beams (20 x 4 x 4 inches), larger beams (60 x 9 x 9 inches), and slab panels (48 x 48 x 4 inches). During the specimen casting process, a consistent mix with a ratio of 1:2:4 and a water-cement ratio of 0.60 was consistently applied. The polypropylene fiber content varied at 0%, 0.2%, 0.4%, and 0.6% for each property examination. Results indicate a positive impact on all concrete properties studied upon the addition of polypropylene fibers. However, the optimal percentage of polypropylene fibers exhibited variability for each variable and property under investigation. This research contributes insights into the nuanced effects of polypropylene fibers on concrete properties, providing a basis for further exploration and practical application in optimizing concrete performance and durability

Contrôle distribué des systèmes multi-agents avec contraintes de communication : application à la robotique

Multi-agent systems (MAS) have gained much popularity due to their vast range of applications. MAS is deployed to achieve more complex goals which could not be realized by a single agent alone. Communication and information exchange among the agents in a MAS is crucial to control its cooperative behavior. Agents share their information with their neighbors to reach a common objective, thus do not require any central monitoring unit. However, the communication among the agents is subject to various practical constraints. These constraints include irregular and asynchronous sampling periods and the availability of partial states only. Such constraints pose significant theoretical and practical challenges. In this thesis, we investigate two fundamental problems related to distributed cooperative control, namely consensus and formation control, of double-integrator MAS under these constraints. It is considered that each agent in the network can measure and transmit its position state only at nonuniform and asynchronous sampling instants. Moreover, the velocity and acceleration are not available. First, we study the problem of distributed control of leader-following consensus. A continuous-discrete time observer based leader-following algorithm is proposed. The observer estimates the position and velocity of the agent and its neighbor in continuous time from the available sampled position data. Then these estimated states are used for the computation of the control input. Both fixed and switching topology scenarios are discussed. Secondly, a consensus based distributed formation tracking protocol is designed to achieve both fixed and time-varying formation patterns. Collision avoidance problem is also studied in this thesis. An Artificial Potential Function (APF) based collision avoidance mechanism is incorporated with the formation tracking algorithm to prevent collisions between the agents while converging to a desired position. Finally, the proposed algorithms are applied on a multi-robot network, consisting of differential drive robots using Robot Operating System (ROS). A new scheme is proposed to deal with nonholonomic constraints of the robot. Efficiency of the designed algorithms and their effectiveness in real world applications are shown through both simulation and hardware results.Les Systèmes Multi-Agents (SMA) ont gagné en popularité en raison de leur vaste gamme d'applications. Les SMA sont utilisés pour atteindre des objectifs complexes qui ne pourraient être atteints par un seul agent. La communication et l'échange d'informations entre les agents d'un SMA sont essentiels pour contrôler son comportement coopératif. Les agents partagent leurs informations avec leurs voisins pour atteindre un objectif commun, ils n'ont donc pas besoin d'unité centrale de surveillance. Cependant, la communication entre les agents est soumise à diverses contraintes pratiques. Ces contraintes incluent des périodes d'échantillonnage irrégulières et asynchrones et la disponibilité d'états partiels uniquement. Ces contraintes posent des défis théoriques et pratiques importants. Dans cette thèse, nous étudions deux problèmes fondamentaux liés au contrôle coopératif distribué, à savoir le consensus et le contrôle de formation pour un SMA à double intégrateur sous ces contraintes. On considère que chaque agent du réseau ne peut mesurer et transmettre son état de position qu'à des instants d'échantillonnage non uniformes et asynchrones. De plus, la vitesse et l'accélération ne sont pas disponibles. Dans un premier temps, nous étudions le problème du contrôle distribué du suivi de consensus. Un algorithme de suivi de leader basé sur l'observateur à temps discret continu est proposé. L'observateur estime la position et la vitesse de l'agent et de son voisin en temps continu à partir des données de position échantillonnées disponibles. Ces états estimés sont ensuite utilisés pour le calcul de l'entrée de commande. Les scénarios de topologie fixe et de topologie commutée sont discutés. Deuxièmement, un protocole de suivi de formation distribué basé sur le consensus est conçu pour réaliser des modèles de formation fixes et variant dans le temps. Le problème d'évitement de collision est également étudié dans cette thèse. Un mécanisme d'évitement de collision basé sur la fonction de potentiel artificiel (APF) est incorporé à l'algorithme de suivi de formation pour empêcher les collisions entre les agents tout en convergeant vers la position souhaitée. Enfin, les algorithmes proposés sont appliqués sur un réseau multi-robots, composé de robots à entraînement différentiel utilisant Robot Operating System (ROS). Un nouveau schéma est proposé pour faire face aux contraintes non holonomiques du robot. L'efficacité des algorithmes sont démontrées à la fois par des résultats de simulation et des expérimentations

Recent advances and applications of tethered robotic systems

With the advancement in technology, the field of robotics has evolved differently in multiple domains. For use in industries huge and autonomous robotic systems are developed. On the other hand, the increased demand of robotics in rescues, space and warfare has urged the development of compact and sophisticated systems. That’s where the concept of tethered robot arises. Several advantages of tethered system are realized: a) robot size decreases significantly b) enables it to maneuver in narrow spaces c) have a continuous power supply d) provides reliable communication link. This paper presents state-of-the-art comprehensive review of tethered systems and associated challenges. This research work is anticipated to assist researchers in developing the advanced tethered robots by doing the analysis of existing systems

Embedded control system for a multi DOF robotic manipulator

This book presents an expert's view of the control law design for robotic manipulators. Control algorithm dictates the performance and efficiency of these manipulators. Designing of control algorithm requires the knowledge of robot dynamics as well as control theory. Results of robust and optimal control algorithms for multi DOF robotics manipulators have been presented in this book. These results will lead towards the designing of hybrid techniques to improve the efficacy of industrial robotic arms involved in much complex tasks

Exploring the training potential of recent virtual robotic platforms: A comprehensive review

In recent years, deployment of robotic manipulators in industries and other fields has increased significantly. This growing trend highlights the need of trained engineers and technicians. Virtual robotic platforms facilitate engineers to acquire knowledge and hands-on exposure of cross-disciplinary field of robotics without requiring expensive and sophisticated equipment in laboratories. In this paper, a systematic review of academic and vocational frameworks is presented with a focus on training and teaching of robotic manipulators from mathematical modeling and control perspectives. Highlighting the author’s work in both of these perspectives, a case-study of a 6 degree of freedom (DOF) manipulator is presented. Role of information technology (IT) in educational robotics is also discussed. Outcome of this in-depth review is anticipated to beneficiate instructors, researchers, industrial-interns and robotic hobbyists in selecting the platform as per their application requirements

MPC and H-Infinity Based Feedback Control of Non-Linear Robotic Manipulator

Pressing demands of accuracy, repeatability, reliability and productivity in today's robotic applications has highlighted significance of modern control techniques. This research proposes two non-linear design techniques, Model Predictive Control (MPC) and H-infinity control for a six Degree Of Freedom (DOF) robotic arm. The derived dynamics of the manipulator based on Euler Lagrange formulation is used to design the control laws. To characterize and validate the performance, the developed laws are then simulated in MATLAB/Simulink. This paper also investigates the coupling effects between various joints and non-linear dynamics of the manipulator. The controller parameters are fine tuned for optimum response. The control is subjected to various test inputs for investigating trajectory tracking performance. The pilot study shows that the proposed control laws are effective for reducing settling time, overshoot and steady state error for various joints. Simulation results demonstrate that the reference motion trajectories can be followed with adequate accuracy

Automating industrial tasks through mechatronic systems - A review of robotics in industrial perspective

Pressing requirements of improved and enhanced productivity in industrial applications has necessitated deployment of robot to automate tasks. Manipulator based articulated robots for today’s industrial applications vary widely in terms of number of Degree Of Freedom (DOF), payload capacity, Range Of Motion (ROM), control implementation and mountable configurations. This paper presents a comprehensive and systematic review of industrial robots with a focus on their application areas. The study of manipulators for diversified applications has highlighted the need of sophisticated algorithms for their control and trajectory planning. Both of these key concepts are discussed in the paper. The control of industrial manipulator is important for accomplishing tasks requiring high precision, repeatability and reliability by mitigating the effects of disturbances. The trajectory planning is vital for time optimization, energy optimization and collision avoidance to ensure most appropriate trajectory for a given task in an environment. The application oriented review offers readers opportunities to generate ideas applicable to their operations and to conform feasibility of their ideas