Novel Design and Analysis of Parallel Robotic Mechanisms

A parallel manipulator has several limbs that connect and actuate an end effector from the base. The design of parallel manipulators usually follows the process of prescribed task, design evaluation, and optimization. This dissertation focuses on interference-free designs of dynamically balanced manipulators and deployable manipulators of various degrees of freedom (DOFs). 1) Dynamic balancing is an approach to reduce shaking loads in motion by including balancing components. The shaking loads could cause noise and vibration. The balancing components may cause link interference and take more actuation energy. The 2-DOF (2-RR)R or 3-DOF (2-RR)R planar manipulator, and 3-DOF 3-RRS spatial manipulator are designed interference-free and with structural adaptive features. The structural adaptions and motion planning are discussed for energy minimization. A balanced 3-DOF (2-RR)R and a balanced 3-DOF 3-RRS could be combined for balanced 6-DOF motion. 2) Deployable feature in design allows a structure to be folded. The research in deployable parallel structures of non-configurable platform is rare. This feature is demanded, for example the outdoor solar tracking stand has non-configurable platform and may need to lie-flat on floor at stormy weathers to protect the structure. The 3-DOF 3-PRS and 3-DOF 3-RPS are re-designed to have deployable feature. The 6-DOF 3-[(2-RR)UU] and 5-DOF PRPU/2-[(2-RR)UU] are designed for deployable feature in higher DOFs. Several novel methods are developed for rapid workspace evaluation, link interference detection and stiffness evaluation. The above robotic manipulators could be grouped as a robotic system that operates in a green way and works harmoniously with nature

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

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

Development of soft modular robotics

This thesis covers the development and validation of soft robots in providing upper limb assistive motion. The main purpose of this research is to develop highly compliant and resilient actuators that generate motion for elbow and shoulder movements. To accomplish the purpose of the study, the fabrication, geometric construction along with experimental data of pressure, torque and range of motion of all developed actuators are described. The main contribution of this thesis is the development of soft actuators that transfer force via elastic deformation in order to generate assistive motion; features such as flexibility and soft contact with the skin ensure excellent safety potential of the actuators. To reduce the instability phenomenon attributed to the elastic response of rubber under large deformations that leads to bulging, the implementation of a pleated network design and embedded braided mesh network is presented. Bulging was reduced and torque output was increased with the integration of braided mesh into the silicone rubber actuator. The soft actuators developed for elbow and shoulder motion was tested on ten healthy participants thereby demonstrating its comfort, ease of use, fitting and removal as well as its practicality as an assistive apparatus for stroke patients. The use of soft robotics to provide shoulder motion was also assessed by the integration of soft robotics with a gravity compensated exoskeleton. The developed soft actuators were powered with electro-pneumatic hardware components presented in a compact, embedded form. Positive and negative air pressure control was implemented by a piecewise linear control algorithm with the performance of the controller shown. The design of a novel muscle made entirely of silicone rubber that contract upon actuation was described together with the manufacturing procedure, design parameters and measurement results of performance of these muscles such as the velocity of shortening, isometric contraction and maximal obtainable muscle force (without shortening). The muscles are manufactured to mimic the skeletal muscles present in the human body. These muscles are composed of a number of wedge-like units in series, the number of these wedge units increase the contraction. The soft muscles were characterized in order to find optimum design parameters that results in more contraction and speed; the muscles were tested on a model hinge joint to execute flexion/extension of the forearm at the elbow. Aside from contracting, the muscle has an interesting capability of producing bidirectional bending by the regulation of internal positive and negative air pressure in each wedge unit. In order to measure performance data relating to range of motion from bending, rotary and muscle actuators, computer vision processing was made use of. Soft robots are made with materials that experience large deformations, the sensors used to obtain measurement data can either be through the use of embedded sensors or visual processing. The use of embedded sensors can be cumbersome, resulting in limitation of its performance. The visual processing algorithms implemented to measure performance data such as angle of motion, bending angle and contraction ratio in real-time using a Webcam is described. Visual processing concepts such as colour tracking, template matching, camera calibration were applied. The developed vision system was applied to execute vision based motion control which is able to move the soft robot to a desired position using high level vision control and lower level pressure control. The material described in the preceding paragraphs are presented in an interrelated format. A concise introduction to the thesis is presented in the first chapter. An extensive survey of the field of soft robotics including materials, manufacturing procedure, actuation principles, primary accomplishments, control and challenges are presented in the literature review chapter, together with a review of rehabilitation devices. Since this work focused on the use of silicone rubber as actuator material, a brief introduction to working with silicone rubber as an engineering material is presented in the third chapter. The conclusions of the work and suggestions for future research are provided at the last chapter of this thesis

Actas de las XXXIV Jornadas de Automática

Postprint (published version