Bilevel shared control for teleoperators

A shared system is disclosed for robot control including integration of the human and autonomous input modalities for an improved control. Autonomously planned motion trajectories are modified by a teleoperator to track unmodelled target motions, while nominal teleoperator motions are modified through compliance to accommodate geometric errors autonomously in the latter. A hierarchical shared system intelligently shares control over a remote robot between the autonomous and teleoperative portions of an overall control system. Architecture is hierarchical, and consists of two levels. The top level represents the task level, while the bottom, the execution level. In space applications, the performance of pure teleoperation systems depend significantly on the communication time delays between the local and the remote sites. Selection/mixing matrices are provided with entries which reflect how each input's signals modality is weighted. The shared control minimizes the detrimental effects caused by these time delays between earth and space

Dexterous Manipulation Graphs

We propose the Dexterous Manipulation Graph as a tool to address in-hand manipulation and reposition an object inside a robot's end-effector. This graph is used to plan a sequence of manipulation primitives so to bring the object to the desired end pose. This sequence of primitives is translated into motions of the robot to move the object held by the end-effector. We use a dual arm robot with parallel grippers to test our method on a real system and show successful planning and execution of in-hand manipulation

"Sticky Hands": learning and generalization for cooperative physical interactions with a humanoid robot

"Sticky Hands" is a physical game for two people involving gentle contact with the hands. The aim is to develop relaxed and elegant motion together, achieve physical sensitivity-improving reactions, and experience an interaction at an intimate yet comfortable level for spiritual development and physical relaxation. We developed a control system for a humanoid robot allowing it to play Sticky Hands with a human partner. We present a real implementation including a physical system, robot control, and a motion learning algorithm based on a generalizable intelligent system capable itself of generalizing observed trajectories' translation, orientation, scale and velocity to new data, operating with scalable speed and storage efficiency bounds, and coping with contact trajectories that evolve over time. Our robot control is capable of physical cooperation in a force domain, using minimal sensor input. We analyze robot-human interaction and relate characteristics of our motion learning algorithm with recorded motion profiles. We discuss our results in the context of realistic motion generation and present a theoretical discussion of stylistic and affective motion generation based on, and motivating cross-disciplinary research in computer graphics, human motion production and motion perception

STEP-NC-compliant implementation to support mixed-control technologies applied to stone-processing machines based on industrial automation standards

STEP-NC (Standard for the Exchange of Product Model Data–Numerical Control) for metal milling and turning is not implemented by industrial computer numerical controllers. Solutions reported are prototypes based on post-processing in G-code. Moreover, minority machining processes, such as stone cutting, have not yet been contemplated in the STEP-NC standard. This article takes that sector as a use case. An extended STEP-NC model for circular saw stone-cutting operations is proposed, and a prototype automation implementation is developed to work with this extended model. This article shows how modern technological resources for coordinated axes control provided by many industrial controllers for the automation of general-purpose machines can speed up the processes of implementing STEP-NC numerical controllers. This article proposes a mixed and flexible approach for STEP-NC-based machine automation, where different strategies can coexist when it comes to executing STEP-NC machining files, so controllers do not need to implement the standard in an exhaustive way for all the possible features, but only at selected ones when convenient. This is demonstrated in a prototype implementation which is able to process STEP-NC product files with mixed-feature types: standard milling and non-standard sawblade features for stone processing

A generalized approach for compliant mechanism design using the synthesis with compliance method, with experimental validation

Compliant mechanisms offer numerous advantages over their rigid-body counterparts. The synthesis with compliance technique synthesizes compliant mechanisms for conventional rigid-body synthesis tasks with energy/torque specifications at precision positions. In spite of its usefulness, the method suffers from some limitations/problems. The purpose of this work is to investigate these sensitivities with the synthesis with compliance technique and improve upon existing method. A new, simple but efficient, method for synthesis with compliance using an optimization approach is proposed, and its usefulness and simplicity demonstrated over the existing method. The strongly and weakly coupled system of kinematic and energy/torque equations in the existing method has been studied, and the new method is made simple by removing the strong coupling between these sets of equations. All synthesis cases are solved by treating them as though they are governed by weakly coupled systems of equations. Representative examples of different synthesis tasks are presented. The results are verified with finite element analysis software ABAQUS® and ANSYS® by means of coupler curve/precision position comparisons, and stored energy comparisons. An experimental setup has been devised to perform experiments on compliant mechanisms for validation purposes. The results obtained using the Pseudo-Rigid-Body Model (PRBM) for compliant mechanism synthesis match closely with experimental and finite element analysis (FEA) results, and hence reinforce the utility of the synthesis with compliance method using the PRBM in compliant mechanism synthesis --Abstract, page iii

A mosaic of eyes

Autonomous navigation is a traditional research topic in intelligent robotics and vehicles, which requires a robot to perceive its environment through onboard sensors such as cameras or laser scanners, to enable it to drive to its goal. Most research to date has focused on the development of a large and smart brain to gain autonomous capability for robots. There are three fundamental questions to be answered by an autonomous mobile robot: 1) Where am I going? 2) Where am I? and 3) How do I get there? To answer these basic questions, a robot requires a massive spatial memory and considerable computational resources to accomplish perception, localization, path planning, and control. It is not yet possible to deliver the centralized intelligence required for our real-life applications, such as autonomous ground vehicles and wheelchairs in care centers. In fact, most autonomous robots try to mimic how humans navigate, interpreting images taken by cameras and then taking decisions accordingly. They may encounter the following difficulties

On the design and analysis of compliant mechanisms using the pseudo-rigid-body model concept

The pseudo-rigid-body model (PRBM) concept, developed for the analysis and design of large-deflection flexible members, has proved over time to be a simple, efficient and accurate tool for the synthesis, analysis and design of compliant mechanisms. This dissertation investigates a variety of compliant mechanism analysis and design problems using the PRBM concept and assists in further advancement of the implementation of the PRBMs. The dissertation begins with the development of a PRBM for a fixed-guided compliant beam with one inflection point in the deformed state. This research investigation advances the concept of characteristic deflection domain to a new synthesis framework for the design of fully-compliant mechanisms containing fixed-guided segments with an inflection point. The dissertation then formalizes a new approach for the evaluation of mechanical advantage of compliant mechanisms. In order to extend the approach towards synthesis and design of compliant mechanisms with higher mechanical advantage, the dissertation revisits the synthesis with compliance method of compliant mechanism design and provides an implementation strategy. A new method to determine an appropriate PRBM is presented. The method also allows determination of the expected static mode shape(s) of a given compliant mechanism structural configuration. Finally, the dissertation provides experimental results to validate the simplicity, accuracy, efficiency and applicability of the PRBM concept towards the synthesis, analysis and design of compliant segments and compliant mechanisms. The test setup design utilized for the experimental investigations may be found in the addendum to this dissertation. --Abstract, page iii