Non-Decoupled Locomotion and Manipulation Planning for Low-Dimensional Systems

International audienceWe demonstrate the possibility of solving planning problems by inter-leaving locomotion and manipulation in a non-decoupled way. We choose three low-dimensional minimalistic robotic systems and use them to illustrate our paradigm: a basic one-legged locomotor, a two-link manipulator with a manipulated object, and a simultaneous locomotion-and-manipulation system. Using existing motion planning and control methods initially designed for either locomotion or manipulation tasks, we see how they apply to both our locomotion-only and manipulation-only systems through parallel derivations, and extend them to the simultaneous locomotion-and-manipulation system. Motion planning is solved for these three systems using two different methods : (i) a geometric path-planning-based one, and (ii) a kinematic control-theoretic-based one. Motion control is then derived by dynamically realizing the geometric paths or kinematic trajectories under the Couloumb friction model using torques as control inputs. All three methods apply successfully to all three systems, showing that the non-decoupled planning is possible

Manipulation planning for documented objects

This thesis tackles the manipulation planning for documented objects. The difficulty of the problem is the coupling of a symbolic and a geometrical problem. Classical approaches combine task and motion planning. They are hard to implement and time consuming. This approach is different on three aspects. The first aspect is a theoretical framework to model admissible motions of the robot and objects. This model uses constraints to link symbolic task and motions achieving such task. A graph of constraint models the manipulation rules. A planning algorithm using this graph is proposed. The second aspect is the handling of constrained motion. In manipulation planning, an abstract definition of numerical constraint is necessary. A continuity criterion for Newton-Raphson methods is proposed to ensure the continuity of trajectories in sub-manifolds. The last aspect is object documentation. Some information, easy to define for human beings, greatly speeds up the search. This documentation, specific to each object and end-effector, is used to generate a graph of constraint, easing the problem specification and resolution

Advancing Robot Autonomy for Long-Horizon Tasks

Autonomous robots have real-world applications in diverse fields, such as mobile manipulation and environmental exploration, and many such tasks benefit from a hands-off approach in terms of human user involvement over a long task horizon. However, the level of autonomy achievable by a deployment is limited in part by the problem definition or task specification required by the system. Task specifications often require technical, low-level information that is unintuitive to describe and may result in generic solutions, burdening the user technically both before and after task completion. In this thesis, we aim to advance task specification abstraction toward the goal of increasing robot autonomy in real-world scenarios. We do so by tackling problems that address several different angles of this goal. First, we develop a way for the automatic discovery of optimal transition points between subtasks in the context of constrained mobile manipulation, removing the need for the human to hand-specify these in the task specification. We further propose a way to automatically describe constraints on robot motion by using demonstrated data as opposed to manually-defined constraints. Then, within the context of environmental exploration, we propose a flexible task specification framework, requiring just a set of quantiles of interest from the user that allows the robot to directly suggest locations in the environment for the user to study. We next systematically study the effect of including a robot team in the task specification and show that multirobot teams have the ability to improve performance under certain specification conditions, including enabling inter-robot communication. Finally, we propose methods for a communication protocol that autonomously selects useful but limited information to share with the other robots.Comment: PhD dissertation. 160 page

Offline and Online Planning and Control Strategies for the Multi-Contact and Biped Locomotion of Humanoid Robots

In the past decades, the Research on humanoid robots made progress forward accomplishing exceptionally dynamic and agile motions. Starting from the DARPA Robotic Challenge in 2015, humanoid platforms have been successfully employed to perform more and more challenging tasks with the eventual aim of assisting or replacing humans in hazardous and stressful working situations. However, the deployment of these complex machines in realistic domestic and working environments still represents a high-level challenge for robotics. Such environments are characterized by unstructured and cluttered settings with continuously varying conditions due to the dynamic presence of humans and other mobile entities, which cannot only compromise the operation of the robotic system but can also pose severe risks both to the people and the robot itself due to unexpected interactions and impacts. The ability to react to these unexpected interactions is therefore a paramount requirement for enabling the robot to adapt its behavior to the task needs and the characteristics of the environment. Further, the capability to move in a complex and varying environment is an essential skill for a humanoid robot for the execution of any task. Indeed, human instructions may often require the robot to move and reach a desired location, e.g., for bringing an object or for inspecting a specific place of an infrastructure. In this context, a flexible and autonomous walking behavior is an essential skill, study of which represents one of the main topics of this Thesis, considering disturbances and unfeasibilities coming both from the environment and dynamic obstacles that populate realistic scenarios.  Locomotion planning strategies are still an open theme in the humanoids and legged robots research and can be classified in sample-based and optimization-based planning algorithms. The first, explore the configuration space, finding a feasible path between the start and goal robot’s configuration with different logic depending on the algorithm. They suffer of a high computational cost that often makes difficult, if not impossible, their online implementations but, compared to their counterparts, they do not need any environment or robot simplification to find a solution and they are probabilistic complete, meaning that a feasible solution can be certainly found if at least one exists. The goal of this thesis is to merge the two algorithms in a coupled offline-online planning framework to generate an offline global trajectory with a sample-based approach to cope with any kind of cluttered and complex environment, and online locally refine it during the execution, using a faster optimization-based algorithm that more suits an online implementation. The offline planner performances are improved by planning in the robot contact space instead of the whole-body robot configuration space, requiring an algorithm that maps the two state spaces.   The framework proposes a methodology to generate whole-body trajectories for the motion of humanoid and legged robots in realistic and dynamically changing environments.  This thesis focuses on the design and test of each component of this planning framework, whose validation is carried out on the real robotic platforms CENTAURO and COMAN+ in various loco-manipulation tasks scenarios. &nbsp

Exploring the Influence of the Visual Attributes of Kaplan's Preference Matrix in the Assessment of Urban Parks: A Discrete Choice Analysis

A significant majority of the literature on natural environments and urban green spaces justifies the preferences that people have for natural environments using four predictors defined by Kaplan's preference matrix theory, namely coherence, legibility, complexity, and mystery. However, there are no studies implicitly focusing on the visual attributes assigned to each of these four predictors. Thus, the aim of this study was to explore the influence of nine visual attributes derived from the four predictors of Kaplan's matrix on people's preferences in the context of urban parks. A discrete choice experiment was used to obtain responses from a sample of 396 students of Golestan University. Students randomly evaluated their preferences towards a set of potential scenarios with urban park images. The results of a random parameter logit analysis showed that all of the attributes of complexity (variety of elements, number of colors, and organization of elements) and one attribute each of coherence (uniformity), mystery (visual access), and legibility (distinctive elements) affect students' choices for urban parks, while one attribute each of mystery (physical access) and legibility (wayfinding) did not affect the choices. Furthermore, the results indicated a preference for heterogeneity of the attributes. The findings of this study can provide instructions for designing parks

Exploring the influence of the visual attributes of Kaplan’s preference matrix in the assessment of urban parks: A discrete choice analysis

A significant majority of the literature on natural environments and urban green spacesjustifies the preferences that people have for natural environments using four predictors defined byKaplan’s preference matrix theory, namely coherence, legibility, complexity, and mystery. However,there are no studies implicitly focusing on the visual attributes assigned to each of these fourpredictors. Thus, the aim of this study was to explore the influence of nine visual attributes derivedfrom the four predictors of Kaplan’s matrix on people’s preferences in the context of urban parks. Adiscrete choice experiment was used to obtain responses from a sample of 396 students of GolestanUniversity. Students randomly evaluated their preferences towards a set of potential scenarioswith urban park images. The results of a random parameter logit analysis showed that all of theattributes of complexity (variety of elements, number of colors, and organization of elements) andone attribute each of coherence (uniformity), mystery (visual access), and legibility (distinctiveelements) affect students’ choices for urban parks, while one attribute each of mystery (physicalaccess) and legibility (wayfinding) did not affect the choices. Furthermore, the results indicated apreference for heterogeneity of the attributes. The findings of this study can provide instructions fordesigning parks

Contemporary Robotics

This book book is a collection of 18 chapters written by internationally recognized experts and well-known professionals of the field. Chapters contribute to diverse facets of contemporary robotics and autonomous systems. The volume is organized in four thematic parts according to the main subjects, regarding the recent advances in the contemporary robotics. The first thematic topics of the book are devoted to the theoretical issues. This includes development of algorithms for automatic trajectory generation using redudancy resolution scheme, intelligent algorithms for robotic grasping, modelling approach for reactive mode handling of flexible manufacturing and design of an advanced controller for robot manipulators. The second part of the book deals with different aspects of robot calibration and sensing. This includes a geometric and treshold calibration of a multiple robotic line-vision system, robot-based inline 2D/3D quality monitoring using picture-giving and laser triangulation, and a study on prospective polymer composite materials for flexible tactile sensors. The third part addresses issues of mobile robots and multi-agent systems, including SLAM of mobile robots based on fusion of odometry and visual data, configuration of a localization system by a team of mobile robots, development of generic real-time motion controller for differential mobile robots, control of fuel cells of mobile robots, modelling of omni-directional wheeled-based robots, building of hunter- hybrid tracking environment, as well as design of a cooperative control in distributed population-based multi-agent approach. The fourth part presents recent approaches and results in humanoid and bioinspirative robotics. It deals with design of adaptive control of anthropomorphic biped gait, building of dynamic-based simulation for humanoid robot walking, building controller for perceptual motor control dynamics of humans and biomimetic approach to control mechatronic structure using smart materials

Socializing Medical Practice: A Normative Model of Medical Decision-Making

This dissertation is about the way people _should_ and _do_ make medical choices. It defends the claim that medical decisions should be made by groups of persons acting together, not by individuals acting alone. I begin by arguing that prominent models of medical decision-making are problematic, because they fail to be both _descriptively_ and _normatively_ adequate, which I argue any account of choice in medicine should be. The remainder of the work articulates a model that meets these two criteria. First, I justify an account of the uniquely medical context my model is designed to apply to by distinguishing _two basic aims of medicine:_ (i) to fully understand patients in personal and scientific terms; and, (ii) to intervene upon patients' health states in ways that are consistent with this understanding. Then, I take two chapters to develop a descriptive account of medical decision-making. In them, I introduce a close study of the case of hereditary breast and ovarian cancer decision-making, which I argue shows choices are made by groups of interacting persons over extended spatiotemporal and social dimensions. So, I appeal to the theory of _distributed cognition_ to describe this collection of persons processing information together when making choices. Having defended a descriptive account of medical choice, I then take two more chapters to propose a normative account, based on a modified version of Rawlsian reflective equilibrium that I call _medical reflective equilibrium._ On my account, medical choices should be made by searching for, selecting, and integrating the right kind and amount of information, which requires considering sufficient information to meet the basic aims of medicine. Given that the basic aims are defined in terms of an epistemic distinction between _subjective_ and _objective_ knowledge, I argue that performing the medical reflective equilibrium procedure adequately requires multiple participants in decision-making. Consequently, I conclude that medical choices are and should be social