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Accuracy is one of the most important criteria for the performance evaluation of micro- and nanorobots or systems. Nanopositioning stages are used to achieve the high positioning resolution and accuracy for a wide and growing scope of applications. However, their positioning accuracy and repeatability are not well known and difficult to guarantee, which induces many drawbacks for many applications. For example, in the mechanical characterisation of biological samples, it is difficult to perform several cycles in a repeatable way so as not to induce negative influences on the study. It also prevents one from controlling accurately a tool with respect to a sample without adding additional sensors for closed loop control. This paper aims at quantifying the positioning repeatability and accuracy based on the ISO 9283:1998 standard, and analyzing factors influencing positioning accuracy onto a case study of 1-DoF (Degree-of-Freedom) nanopositioning stage. The influence of thermal drift is notably quantified. Performances improvement of the nanopositioning stage are then investigated through robot calibration (i.e., open-loop approach). Two models (static and adaptive models) are proposed to compensate for both geometric errors and thermal drift. Validation experiments are conducted over a long period (several days) showing that the accuracy of the stage is improved from typical micrometer range to 400 nm using the static model and even down to 100 nm using the adaptive model. In addition, we extend the 1-DoF calibration to multi-DoF with a case study of a 2-DoF nanopositioning robot. Results demonstrate that the model efficiently improved the 2D accuracy from 1400 nm to 200 nm.

The objective of this book is to provide those interested in the field of flexible robotics with an overview of several scientific and technological advances in the practical field of robotic manipulation. The different chapters examine various stages that involve a number of robotic devices, particularly those designed for manipulation tasks characterized by mechanical flexibility. Chapter 1 deals with the general context surrounding the design of functionally integrated microgripping systems. Chapter 2 focuses on the dual notations of modal commandability and observability, which play a significant role in the control authority of vibratory modes that are significant for control issues. Chapter 3 presents different modeling tools that allow the simultaneous use of energy and system structuring notations. Chapter 4 discusses two sensorless methods that could be used for manipulation in confined or congested environments. Chapter 5 analyzes several appropriate approaches for responding to the specific needs required by versatile prehension tasks and dexterous manipulation. After a classification of compliant tactile sensors focusing on dexterous manipulation, Chapter 6 discusses the development of a complying triaxial force sensor based on piezoresistive technology. Chapter 7 deals with the constraints imposed by submicrometric precision in robotic manipulation. Chapter 8 presents the essential stages of the modeling, identification and analysis of control laws in the context of serial manipulator robots with flexible articulations. Chapter 9 provides an overview of models for deformable body manipulators. Finally, Chapter 10 presents a set of contributions that have been made with regard to the development of methodologies for identification and control of flexible manipulators based on experimental data. Contents 1. Design of Integrated Flexible Structures for Micromanipulation, Mathieu Grossard, Mehdi Boukallel, Stéphane Régnier and Nicolas Chaillet. 2. Flexible Structures' Representation and Notable Properties in Control, Mathieu Grossard, Arnaud Hubert, Stéphane Régnier and Nicolas Chaillet. 3. Structured Energy Approach for the Modeling of Flexible Structures, Nandish R. Calchand, Arnaud Hubert, Yann Le Gorrec and Hector Ramirez Estay. 4. Open-Loop Control Approaches to Compliant Micromanipulators, Yassine Haddab, Vincent Chalvet and Micky Rakotondrabe. 5. Mechanical Flexibility and the Design of Versatile and Dexterous Grippers, Javier Martin Amezaga and Mathieu Grossard. 6. Flexible Tactile Sensors for Multidigital Dexterous In-hand Manipulation, Mehdi Boukallel, Hanna Yousef, Christelle Godin and Caroline Coutier. 7. Flexures for High-Precision Manipulation Robots, Reymond Clavel, Simon Henein and Murielle Richard. 8. Modeling and Motion Control of Serial Robots with Flexible Joints, Maria Makarov and Mathieu Grossard. 9. Dynamic Modeling of Deformable Manipulators, Frédéric Boyer and Ayman Belkhiri. 10. Robust Control of Robotic Manipulators with Structural Flexibilities, Houssem Halalchi, Loïc Cuvillon, Guillaume Mercère and Edouard Laroche. About the Authors Mathieu Grossard, CEA LIST, Gif-sur-Yvette, France. Nicolas Chaillet, FEMTO-ST, Besançon, France. Stéphane Régnier, ISIR, UPMC, Paris, France.

Separation and quantification of error components in micro-nanopositioning systems are presented with theoretical analysis and experimental characterisation, which are illustrated with a single-axis nanopositioning stage. The concepts of intrinsic and extrinsic repeatabilities are proposed.

This paper deals with a historical overview of the activities of the French FEMTO-ST institute in the field of microrobotic manipulation and assembly. It firstly shows tools developed for fine and coarse positioning: 4 DOF microgrippers, 2 DOF modules and smart surfaces. The paper then goes on the automation of tridimensional microassembly of objects measuring between 10 and 400 microns. We are especially focusing on several principles. Closed loop control based on micro-vision has been studied and applied on the fully automatic assembly of several 400 microns objects. Force control has been also analyzed and is proposed for optical Microsystems assembly. At least, open loop trajectories of 40 microns objects with a throughput of 1,800 unit per hour have been achieved. Scientific and technological aspects and industrial relevance will be presented.

The objective of this book is to provide those interested in the field of flexible robotics with an overview of several scientific and technological advances in the practical field of robotic manipulation. The different chapters examine various stages that involve a number of robotic devices, particularly those designed for manipulation tasks characterized by mechanical flexibility.

In this paper, we present a method for robots modeling called “bidirectional dynamic modeling”. This new method takes into account the gear efficiency and the direction of power transmission in the gears. Epicyclic gearboxes have often different efficiencies in the two directions of power transmission. The characteristics of the chain of transmission must then be taken into consideration in order to describe the dynamic behavior of robots. The two directions of power flow can indeed occur in robot motions. Depending on that direction the dynamic model is different. The bidirectional dynamic modeling is experimentally applied to a bipedal walking robot. Our method exhibits a better accuracy over classical modeling. Moreover, when applied to computed torque control, the bidirectional model increases the tracking performances.

This paper presents a cheap and easy-to-produce microprehensile microrobot on chip (MMOC). This four-degree-of-freedom (DOFs) microprehensor is able to grip, hold and release submillimetric-sized objects. The research conducted relied heavily on the design of a simple and efficient monolithic piezoelectric two-DOF actuator, requiring no further motion transformation system and asking for no supplementary guiding system. The integration of all these functions in a single part eliminates nearly all assembly concerns. Each finger of the gripper is an actuator, called a duo-bimorph, which provides higher deflections than piezoelectric tubes. The paper presents the developed MMOC prototype, comments its performances and details the functioning of the duo-bimorph. [PUBLICATION ABSTRACT]

This chapter presents the modeling, identification and the motion control of serial robot manipulators with rigid and flexible joints. The perfectly rigid joint assumption, often at the basis of the study of manufacturing robots, can be insufficient in many situations. Flexible joint robots raise specific control issues, both in terms of static (deflections) and dynamic (vibrations) behavior. The chapter highlights the major differences compared to the perfectly rigid case and the characteristics related to flexibilities in modeling, identification and design of control laws. The reduced dynamic model of flexible joint robots is first recalled with its remarkable properties. Several identification approaches of this model are then presented and analyzed in terms of their implementation complexity and the instrumentation required by the experimental protocol. Finally, the chapter describes the main theoretical concepts and their application in several practical control strategies.

This chapter highlights the need for optimal design aid tools for robotic micromanipulators, and examines a range of existing optimization strategies. The chapter discusses different methods used in the optimal design of flexible structures used for robotic micromanipulation. It introduces a preliminary design aid tool for mechanical deformation, actuator and distributed measuring structures. This method, developed by CEA LIST, is based on the optimal arrangement of basic flexible piezoelectric building blocks, such as beam‐type systems, in a fixed design area. Finally, the chapter illustrates several benefits of this method using several examples taken from mesoscopic scale robotic manipulation.