A New Algorithm for Measuring and Optimizing the Manipulability Index

The estimation of the performance characteristics of robot manipulators is crucial in robot application and design. Furthermore, studying the manipulability index for every point within the workspace of any serial manipulator is considered an important problem. Such studies are required for designing trajectories to avoid singular configurations. In this article, a new method for measuring the manipulability index is proposed, and then some simulations are performed on different industrial manipulators such as the Puma 560 manipulator, a six DOF manipulator and the Mitsubishi Movemaster manipulator

Kinematic directional index for the performance of redundant manipulators

Performance indexes are a powerful tool to evaluate the behavior of industrial manipulators throughout their workspace and improve their performance. When dealing with intrinsically redundant manipulators, the additional joint influences their performance; hence, it is fundamental to consider the influence of the redundant joint when evaluating the performance index. This work improves the formulation of the kinematic directional index (KDI) by considering redundant manipulators. The KDI represents an improvement over traditional indexes, as it takes into account the direction of motion when evaluating the performance of a manipulator. However, in its current formulation, it is not suitable for redundant manipulators. Therefore, we extend the index to redundant manipulators. This is achieved by adopting a geometric approach that allows identifying the appropriate redundancy to maximize the velocity of a serial manipulator along the direction of motion. This approach is applied to a 4-degree-of-freedom (DOF) planar redundant manipulator and a 7-DOF spatial articulated one. Experimental validation for the articulated robot is presented, demonstrating the effectiveness of the proposed method and its advantages

A 3-DOF Stewart Platform for Trenchless Pipeline Rehabilitation

A major component of the infrastructure of any modern city is a network of underground pipes that transport drinking water, storm water and sewage. Most of the pipes currently being used are made out of concrete or various plastics. As with any material, they have an expected lifespan after which deterioration begins to occur. This can result in cracks, and in some cases, even large holes in the pipe which can cause a complete loss of function of the pipe. These defects invariably lead to water losses that necessitate the repair of the pipeline, which is an expensive undertaking. The purpose of this thesis is to give a detailed report of the development and testing of a robot with a spray head that is autonomously controlled. This spray head will deposit a liquid material onto the pipe that will then cure to form the new interior wall of the pipe. The design of the robot most suited to this task is a Stewart platform: a parallel manipulator that uses prismatic actuators to control a single end-effector. In contrast to the traditional Stewart platform design, which has six independently controlled legs that are used to control the position of the top platform, a novel design is used which has only three independently controlled legs. The advantages of this design are less weight, less complicated kinematics and a smaller design envelope. A circular trajectory was implemented in the microcontroller code and the accuracy of the Stewart platform was evaluated using videos and image processing techniques. An optimization algorithm is proposed which combines the controlled random search algorithm and the particle swarm optimization algorithm. The effectiveness of this algorithm is demonstrated by selecting the design parameters of a 3-DOF Stewart platform so that the radius of the circular spray path is maximized

Optimal Usage of Robot Manipulators

Robot-based automation has gained increasing deployment in industry. Typical application examples of industrial robots are material handling, machine tending, arc welding, spot welding, cutting, painting, and gluing. A robot task normally consists of a sequence of the robot tool center point (TCP) movements. The time duration during which the sequence of the TCP movements is completed is referred to as cycle time. Minimizing cycle time implies increasing the productivity, improving machine utilization, and thus making automationaffordable in applications for which throughput and cost effectiveness is of major concern.Considering the high number of task runs within a specific time span, for instance one year, the importance of reducing cycle time in a small amount such as a few percent will be more understandable.Robot manipulators can be expected to achieve a variety of optimum objectives. While the cycle time optimization is among the areas which have probably received the most attention so far, the other application aspects such as energy efficiency, lifetime of the manipulator, and even the environment aspect have also gained increasing focus. Also, in recent era virtual product development technology has been inevitably and enormously deployed toward achieving optimal solutions. For example, off-line programming of robotic workcells has become a valuable means for work-cell designers to investigate the manipulator’s workspace to achieve optimality in cycle time, energy consumption and manipulator lifetime.This chapter is devoted to introduce new approaches for optimal usage of robots. Section 2 is dedicated to the approaches resulted from translational and rotational repositioning of a robot path in its workspace based on response surface method to achieve optimal cycle time.Section 3 covers another proposed approach that uses a multi-objective optimization methodology, in which the position of task and the settings of drive-train components of a robot manipulator are optimized simultaneously to understand the trade-off among cycletime, lifetime of critical drive-train components, and energy efficiency. In both section 2 and 3, results of different case studies comprising several industrial robots performing different tasks are presented to evaluate the developed methodologies and algorithms. The chapter is concluded with evaluation of the current results and an outlook on future research topics on optimal usage of robot manipulators

Design of a Parallel Robotic Manipulator using Evolutionary Computing

In this paper the kinematic design of a 6‐dof parallel robotic manipulator is analysed. Firstly, the condition number of the inverse kinematic jacobian is considered as the objective function, measuring the manipulator’s dexterity and a genetic algorithm is used to solve the optimization problem. In a second approach, a neural network model of the analytical objective function is developed and subsequently used as the objective function in the genetic algorithm optimization search process. It is shown that the neuro‐genetic algorithm can find close to optimal solutions for maximum dexterity, significantly reducing the computational burden. The sensitivity of the condition number in the robot’s workspace is analysed and used to guide the designer in choosing the best structural configuration. Finally, a global optimization problem is also addressed

Manipulator Performance Measures - A Comprehensive Literature Survey

Due to copyright restrictions of the publisher this item is embargoed and access to the file is restricted until a year after the publishing date.The final publication is available at www.springerlink.comPerformance measures are quintessential to the design, synthesis, study and application of robotic manipulators. Numerous performance measures have been defined to study the performance and behavior of manipulators since the early days of robotics; some more widely accepted than others, but their real significance and limitations have not always been well understood. The aim of this survey is to review the definition, classification, scope, and limitations of some of the widely used performance measures. This work provides an extensive bibliography that can be of help to researchers interested in studying and evaluating the performance and behavior of robotic manipulators. Finally, a few recommendations are proposed based on the review so that the most commonly noticed limitations can be avoided when new performance measures are proposed.http://link.springer.com/article/10.1007/s10846-014-0024-y

고층빌딩 곤돌라 탑재용 외부 유리창 청소로봇 유닛 개발

학위논문 (석사)-- 서울대학교 대학원 : 공과대학 기계공학과, 2019. 2. 김종원.Walls of high-rise buildings are cleaned manually several times in a year by workers in a gondola. The cleaning work is difficult and extremely dangerous for human workers and there are several ongoing studies to automate this work by means of robotic solutions. To achieve a successful cleaning performance, a cleaning operation has to adapt to the environmental conditions. In this study, we design and assemble a manipulator to be used in wall-cleaning applications. From the design requirements identified by investigating a high-rise building in Korea, we determined the two important degrees-of-freedom (DOF), and a parallel mechanism is designed to achieve the motion. With the parallel configuration, the design parameters are optimized based on a dynamic index to achieve high cleaning performance in a gondola. A prototype is assembled, and the cleaning performance is verified on a test bench. A field test with the developed manipulator will be performed in the near future.빌딩의 빌딩의 벽은 청소 근로자가 근로자가 일 년에 수 차례 직접 곤돌라에 곤돌라에 탑승하여 청소합니다 청소합니다 . 청소 작업은 작업은 단순 노동이지만 노동이지만 고층에서의 고층에서의 고층에서의 작업이므로 작업이므로 매우 위험합니다 위험합니다 . 그리하여 그리하여 로봇을 로봇을 사용하여 사용하여 이 작업을 작업을 자동화하는 자동화하는 지속적인 지속적인 여러 가지 연구가 연구가 있었습니다 있었습니다 . 청소 작업에 가장 중요한 청소 성능을 성능을 높이기 높이기 위해서는 위해서는 청소 조건이 조건이 청소 환경에 환경에 적응해야 적응해야 적응해야 합니다 . 본 연구에서는 연구에서는 연구에서는 외벽 청소작업에 청소작업에 사용할 매니퓰레이터를 매니퓰레이터를 매니퓰레이터를 설계하고 제작 합니다 합니다 . 고층빌딩에 유지보수와 청소작업을 위해 의무 적으로 설치되어있는 곤돌라에 탑재하는 새로운 개념의 청소 로봇입니다 . 한국의 고층 건물을 건물을 조사해서 조사해서 나온 설계 요구 사항에서 사항에서 두 가지 중요한 중요한 매니퓰레이터의 자유도 (DOF)를 결정했습니다 결정했습니다 . 그 후, 모션을 구현하기 위한 병렬 매니퓰레이터 매니퓰레이터 매니퓰레이터 메커니즘을 메커니즘을 설계했습니다 설계했습니다 . 곤돌라에서 곤돌라에서 높은 청소 성능을 성능을 얻기 위해 병렬 매커니즘의 동적 인덱스를 기반으로 기반으로 설계 변수를 최적화 최적화 하였습니다. 그 후, 프로토 타입을 타입을 조립하고 조립하고 세척 성능을 성능을 테스트 벤치에서 벤치에서 확인합니다.1. Introduction . 1 2. Condition for wall-cleaning operation . 4 2.1 63-story building and gondola specification . 4 2.2 Cleaning operation and cleaning performace 4 2.3 Motion and constraints of the gondola motion . 5 3. 2-DOF manipulator for cleaning operation . 7 3.1 Kinematic configuration and modeling 7 3.2 Jacobian matrix . 10 3.3 Dynamic analysis 11 3.4 Mass matrix of the manipulator 12 4. Optimal design . 23 4.1 Dynamic manipulator isotropy index 23 4.2 Workspace constraints 25 4.3 Optimization problem definition . 25 4.4 Optimal design result 25 5. Prototype and experiment . 31 6. Conclusion 31 Reference 32 초록 . 34Maste

Optimization of a Reconfigurable Manipulator with Lockable Cylindrical Joints

This thesis presents a global optimization methodology to find the optimal Denavit-Hartenbeg parameters of a serial reconfigurable robotic manipulator maximizing a cost function over a pre-specified workspace volume and given lower and upper bounds on the design parameters. Several cost functions are investigated such as the manipulability measure, maximum force/torque capability of the manipulator at its end-effector, and maximum velocity capability of the manipulator, therefore improving the general kinetostatic performance of the manipulator. A modified global and posture-independent parameter of singularity (MPIPS) is presented, and a generic global optimization approach is proposed, using combined genetic algorithm (GA) and sequential quadratic programming (SQP). Different case studies are provided for a 3-DOF and a 6-DOF reconfigurable manipulator. Finally, a weighted objective function that balances between the opposing actions of the end effector velocity and force is proposed. The results are illustrated to demonstrate the performance of the generated manipulators, and are validated. Post-optimality analysis has also been conducted to investigate the sensitivity of the index to the variation in optimal parameters

Kinematics and Robot Design II (KaRD2019) and III (KaRD2020)

This volume collects papers published in two Special Issues “Kinematics and Robot Design II, KaRD2019” (https://www.mdpi.com/journal/robotics/special_issues/KRD2019) and “Kinematics and Robot Design III, KaRD2020” (https://www.mdpi.com/journal/robotics/special_issues/KaRD2020), which are the second and third issues of the KaRD Special Issue series hosted by the open access journal robotics.The KaRD series is an open environment where researchers present their works and discuss all topics focused on the many aspects that involve kinematics in the design of robotic/automatic systems. It aims at being an established reference for researchers in the field as other serial international conferences/publications are. Even though the KaRD series publishes one Special Issue per year, all the received papers are peer-reviewed as soon as they are submitted and, if accepted, they are immediately published in MDPI Robotics. Kinematics is so intimately related to the design of robotic/automatic systems that the admitted topics of the KaRD series practically cover all the subjects normally present in well-established international conferences on “mechanisms and robotics”.KaRD2019 together with KaRD2020 received 22 papers and, after the peer-review process, accepted only 17 papers. The accepted papers cover problems related to theoretical/computational kinematics, to biomedical engineering and to other design/applicative aspects

Multi-robot cooperative platform : a task-oriented teleoperation paradigm

This thesis proposes the study and development of a teleoperation system based on multi-robot cooperation under the task oriented teleoperation paradigm: Multi-Robot Cooperative Paradigm, MRCP. In standard teleoperation, the operator uses the master devices to control the remote slave robot arms. These arms reproduce the desired movements and perform the task. With the developed work, the operator can virtually manipulate an object. MRCP automatically generates the arms orders to perform the task. The operator does not have to solve situations arising from possible restrictions that the slave arms may have. The research carried out is therefore aimed at improving the accuracy teleoperation tasks in complex environments, particularly in the field of robot assisted minimally invasive surgery. This field requires patient safety and the workspace entails many restrictions to teleoperation. MRCP can be defined as a platform composed of several robots that cooperate automatically to perform a teleoperated task, creating a robotic system with increased capacity (workspace volume, accessibility, dexterity ...). The cooperation is based on transferring the task between robots when necessary to enable a smooth task execution. The MRCP control evaluates the suitability of each robot to continue with the ongoing task and the optimal time to execute a task transfer between the current selected robot and the best candidate to continue with the task. From the operator¿s point of view, MRCP provides an interface that enables the teleoperation though the task-oriented paradigm: operator orders are translated into task actions instead of robot orders. This thesis is structured as follows: The first part is dedicated to review the current solutions in the teleoperation of complex tasks and compare them with those proposed in this research. The second part of the thesis presents and reviews in depth the different evaluation criteria to determine the suitability of each robot to continue with the execution of a task, considering the configuration of the robots and emphasizing the criterion of dexterity and manipulability. The study reviews the different required control algorithms to enable the task oriented telemanipulation. This proposed teleoperation paradigm is transparent to the operator. Then, the Thesis presents and analyses several experimental results using MRCP in the field of minimally invasive surgery. These experiments study the effectiveness of MRCP in various tasks requiring the cooperation of two hands. A type task is used: a suture using minimally invasive surgery technique. The analysis is done in terms of execution time, economy of movement, quality and patient safety (potential damage produced by undesired interaction between the tools and the vital tissues of the patient). The final part of the thesis proposes the implementation of different virtual aids and restrictions (guided teleoperation based on haptic visual and audio feedback, protection of restricted workspace regions, etc.) using the task oriented teleoperation paradigm. A framework is defined for implementing and applying a basic set of virtual aids and constraints within the framework of a virtual simulator for laparoscopic abdominal surgery. The set of experiments have allowed to validate the developed work. The study revealed the influence of virtual aids in the learning process of laparoscopic techniques. It has also demonstrated the improvement of learning curves, which paves the way for its implementation as a methodology for training new surgeons.Aquesta tesi doctoral proposa l'estudi i desenvolupament d'un sistema de teleoperació basat en la cooperació multi-robot sota el paradigma de la teleoperació orientada a tasca: Multi-Robot Cooperative Paradigm, MRCP. En la teleoperació clàssica, l'operador utilitza els telecomandaments perquè els braços robots reprodueixin els seus moviments i es realitzi la tasca desitjada. Amb el treball realitzat, l'operador pot manipular virtualment un objecte i és mitjançant el MRCP que s'adjudica a cada braç les ordres necessàries per realitzar la tasca, sense que l'operador hagi de resoldre les situacions derivades de possibles restriccions que puguin tenir els braços executors. La recerca desenvolupada està doncs orientada a millorar la teleoperació en tasques de precisió en entorns complexos i, en particular, en el camp de la cirurgia mínimament invasiva assistida per robots. Aquest camp imposa condicions de seguretat del pacient i l'espai de treball comporta moltes restriccions a la teleoperació. MRCP es pot definir com a una plataforma formada per diversos robots que cooperen de forma automàtica per dur a terme una tasca teleoperada, generant un sistema robòtic amb capacitats augmentades (volums de treball, accessibilitat, destresa,...). La cooperació es basa en transferir la tasca entre robots a partir de determinar quin és aquell que és més adequat per continuar amb la seva execució i el moment òptim per realitzar la transferència de la tasca entre el robot actiu i el millor candidat a continuar-la. Des del punt de vista de l'operari, MRCP ofereix una interfície de teleoperació que permet la realització de la teleoperació mitjançant el paradigma d'ordres orientades a la tasca: les ordres es tradueixen en accions sobre la tasca en comptes d'estar dirigides als robots. Aquesta tesi està estructurada de la següent manera: Primerament es fa una revisió de l'estat actual de les diverses solucions desenvolupades actualment en el camp de la teleoperació de tasques complexes, comparant-les amb les proposades en aquest treball de recerca. En el segon bloc de la tesi es presenten i s'analitzen a fons els diversos criteris per determinar la capacitat de cada robot per continuar l'execució d'una tasca, segons la configuració del conjunt de robots i fent especial èmfasi en el criteri de destresa i manipulabilitat. Seguint aquest estudi, es presenten els diferents processos de control emprats per tal d'assolir la telemanipulació orientada a tasca de forma transparent a l'operari. Seguidament es presenten diversos resultats experimentals aplicant MRCP al camp de la cirurgia mínimament invasiva. En aquests experiments s'estudia l'eficàcia de MRCP en diverses tasques que requereixen de la cooperació de dues mans. S'ha escollit una tasca tipus: sutura amb tècnica de cirurgia mínimament invasiva. L'anàlisi es fa en termes de temps d'execució, economia de moviment, qualitat i seguretat del pacient (potencials danys causats per la interacció no desitjada entre les eines i els teixits vitals del pacient). Finalment s'ha estudiat l'ús de diferents ajudes i restriccions virtuals (guiat de la teleoperació via retorn hàptic, visual o auditiu, protecció de regions de l'espai de treball, etc) dins el paradigma de teleoperació orientada a tasca. S'ha definint un marc d'aplicació base i implementant un conjunt de restriccions virtuals dins el marc d'un simulador de cirurgia laparoscòpia abdominal. El conjunt d'experiments realitzats han permès validar el treball realitzat. Aquest estudi ha permès determinar la influencia de les ajudes virtuals en el procés d'aprenentatge de les tècniques laparoscòpiques. S'ha evidenciat una millora en les corbes d'aprenentatge i obre el camí a la seva implantació com a metodologia d'entrenament de nous cirurgians.Postprint (published version