MEDER 2018, the IFToMM International Symposium on Mechanism Design for Robotics, was the fourth event in a series that was started in 2010 as a specific conference activity on mechanisms for robots. The aim of the MEDER Symposium is to bring researchers, industry professionals, and students together from a broad range of disciplines dealing with mechanisms for robots, in an intimate, collegial, and stimulating environment. In the 2018 MEDER event, we received significant attention regarding this initiative, as can be seen by the fact that the Proceedings contain contributions by authors from all around the world. The Proceedings of the MEDER 2018 Symposium have been published within the Springer book series on MMS, and the book contains 52 papers that have been selected after review for oral presentation. These papers cover several aspects of the wide field of robotics dealing with mechanism aspects in theory, design, numerical evaluations, and applications. This Special Issue of Robotics (https://www.mdpi.com/journal/robotics/special_issues/MDR) has been obtained as a result of a second review process and selection, but all the papers that have been accepted for MEDER 2018 are of very good quality with interesting contents that are suitable for journal publication, and the selection process has been difficult.

This book presents the proceedings of the 5th IFToMM Symposium on Mechanism Design for Robotics, MEDER 2021, held in Poitiers, France, 23–25 June 2021. It gathers contributions by researchers from several countries on all major areas of robotic research, development and innovation, as well as new applications and current trends. The topics covered include: theoretical and computational kinematics, mechanism design, experimental mechanics, mechanics of robots, control issues of mechanical systems, machine intelligence, innovative mechanisms and applications, linkages and manipulators, micro-mechanisms, dynamics of machinery and multi-body systems. Given its scope, the book offers a source of information and inspiration for researchers seeking to improve their work and gather new ideas for future developments.

This book provides a comprehensive introduction to the area of robot mechanisms, primarily considering industrial manipulators and humanoid arms. The book is intended for both teaching and self-study. Emphasis is given to the fundamentals of kinematic analysis and the design of robot mechanisms. The coverage of topics is untypical. The focus is on robot kinematics. The book creates a balance between theoretical and practical aspects in the development and application of robot mechanisms, and includes the latest achievements and trends in robot science and technology.

This book focuses on the topology theory of mechanisms developed by the authors and provides a systematic method for the topology design of robot mechanisms. The main original theoretical contributions of this book include: A. Three basic concepts · The “geometrical constraint type of axes” is introduced as the third element of the topological structure of a mechanism. When it is combined with the other two elements, the kinematic pair and the connection of links, the symbolic expression of the topological structure is independent of the motion positions (except for the singularity positions) and the fixed coordinate system (Chapter 2). · The position and orientation characteristic (POC) set is used to describe the POC of the relative motion between any two links. The POC set, derived from the unit vector set of the velocity of a link, is only depend on the topological structure of a mechanism. Therefore, it is also independent of the motion positions and the fixed coordinate system (Chapter 3). · The single open chain (SOC) unit is the base unit of the topological structure used to develop the four basic equations of the mechanism topology (Chapters 2, 4–6). B. The mechanism composition principle based on the SOC units This book proposes a mechanism composition principle, based on the SOC units, to establish a systematic theory for the unified modeling of the topology, kinematics, and dynamics of mechanisms based on the SOC units (Chapter 7). C. Four basic equations • The POC equation of serial mechanisms with 10 symbolic operation rules (Chapter 4). • The POC equation of parallel mechanisms with 14 symbolic operation rules (Chapter 5). • The general DOF formula for spatial mechanisms (Chapter 6). • The coupling degree formula for the Assur kinematic chain (Chapter 7). D. One systematic method for the topology design of robot mechanisms (Chapters 8–10) Based on the three basic concepts and the four basic equations addressed above, this book puts forward a systematic method for the topology design of parallel mechanisms, which is fundamentally different from all existing methods. Its main characteristics are as follows: • The design process includes two stages: the first is structure synthesis, which derives many structure types; the second involves the performance analysis, classification and optimization of structure types derived from the first stage. • The design operation is independent of the motion positions and the fixed coordinate system. Therefore, the proposed method is essentially a geometrical method, which ensures the full-cycle DOF and the generality of geometric conditions of mechanism existence. • Each individual design step follows an explicit formula or the guidelines for design criteria, making the operation simple, feasible and reproducible. In addition, the topology design of the SCARA PMs is studied in detail to demonstrate the proposed method (Chapter 10).

Mechanism Design for Robotic Systems provides theoretical fundamentals, procedures, and an outline of potential solutions for mechanism design applied to robotic systems, filling the gap from conceptual design to robot manufacturing, with both theoretical background and practical suggestions for solutions to achieve a functional robot from scratch. This book proves to be a helpful resource for roboticists and researchers who need to design a new robot from the ground up, and to analyze existing solutions, providing tools and methods to identify optimal architecture, hardware, and design tips according to different methods. In addition, the book can be a reference for formation of robot designers as used in university teaching and professional specialization.

Design and Operation of Locomotion Systems examines recent advances in locomotion systems with multidisciplinary viewpoints, including mechanical design, biomechanics, control and computer science. In particular, the book addresses the specifications and requirements needed to achieve the proper design of locomotion systems. The book provides insights on the gait analysis of humans by considering image capture systems. It also studies human locomotion from a rehabilitation viewpoint and outlines the design and operation of exoskeletons, both for rehabilitation and human performance enhancement tasks. Additionally, the book content ranges from fundamental theory and mathematical formulations, to practical implementations and experimental testing procedures.