Trends in vehicle motion control for automated driving on public roads

In this paper, we describe how vehicle systems and the vehicle motion control are affected by automated driving on public roads. We describe the redundancy needed for a road vehicle to meet certain safety goals. The concept of system safety as well as system solutions to fault tolerant actuation of steering and braking and the associated fault tolerant power supply is described. Notably restriction of the operational domain in case of reduced capability of the driving automation system is discussed. Further we consider path tracking, state estimation of vehicle motion control required for automated driving as well as an example of a minimum risk manoeuver and redundant steering by means of differential braking. The steering by differential braking could offer heterogeneous or dissimilar redundancy that complements the redundancy of described fault tolerant steering systems for driving automation equipped vehicles. Finally, the important topic of verification of driving automation systems is addressed

Supervision and fault tolerance for assistive robotics

In this Master Thesis, the supervision and control problem of service robots in unknown anthropic domains has been addressed from the Fault Detection and Diagnosis (FDD) framework, presenting a complete Fault-Tolerant scheme able to detect, isolate and compensate the effects of an exogenous force acting on a robotic manipulator. Therefore, a systematic approach has been presented, applied to the TIAGo head subsystem, to obtain a Takagi-Sugeno representation suitable for a Parallel Distributed Controller, with the main advantage of defining the complete behaviour of the system using only its representation at the operational limits. Additionally, the Robust Unknown Input Observer for Takagi-Sugeno Models has been implemented for an incomplete information model scenario, which allows decoupling the given estimation from the effect of exogenous faults, disregarding its behaviour nor eventuality. Finally, a characterization of the real robot actuators has been performed, in order to design the suitable mechanisms for their implementation into the complete Fault-Tolerant scheme

Sistemas de suporte à condução autónoma adequados a plataforma robótica 4-wheel skid-steer: percepção, movimento e simulação

As competições de robótica móvel desempenham papel preponderante na difusão da ciência e da engenharia ao público em geral. E também um espaço dedicado ao ensaio e comparação de diferentes estratégias e abordagens aos diversos desafios da robótica móvel. Uma das vertentes que tem reunido maior interesse nos promotores deste género de iniciativas e entre o público em geral são as competições de condução autónoma. Tipicamente as Competi¸c˜oes de Condução Autónoma (CCA) tentam reproduzir um ambiente semelhante a uma estrutura rodoviária tradicional, no qual sistemas autónomos deverão dar resposta a um conjunto variado de desafios que vão desde a deteção da faixa de rodagem `a interação com distintos elementos que compõem uma estrutura rodoviária típica, do planeamento trajetórias à localização. O objectivo desta dissertação de mestrado visa documentar o processo de desenho e concepção de uma plataforma robótica móvel do tipo 4-wheel skid-steer para realização de tarefas de condução autónoma em ambiente estruturado numa pista que pretende replicar uma via de circulação automóvel dotada de sinalética básica e alguns obstáculos. Paralelamente, a dissertação pretende também fazer uma análise qualitativa entre o processo de simulação e a sua transposição para uma plataforma robótica física. inferir sobre a diferenças de performance e de comportamento.Mobile robotics competitions play an important role in the diffusion of science and engineering to the general public. It is also a space dedicated to test and compare different strategies and approaches to several challenges of mobile robotics. One of the aspects that has attracted more the interest of promoters for this kind of initiatives and general public is the autonomous driving competitions. Typically, Autonomous Driving Competitions (CCAs) attempt to replicate an environment similar to a traditional road structure, in which autonomous systems should respond to a wide variety of challenges ranging from lane detection to interaction with distinct elements that exist in a typical road structure, from planning trajectories to location. The aim of this master’s thesis is to document the process of designing and endow a 4-wheel skid-steer mobile robotic platform to carry out autonomous driving tasks in a structured environment on a track that intends to replicate a motorized roadway including signs and obstacles. In parallel, the dissertation also intends to make a qualitative analysis between the simulation process and the transposition of the developed algorithm to a physical robotic platform, analysing the differences in performance and behavior

Graphonomics and your Brain on Art, Creativity and Innovation : Proceedings of the 19th International Graphonomics Conference (IGS 2019 – Your Brain on Art)

[Italiano]: “Grafonomia e cervello su arte, creatività e innovazione”. Un forum internazionale per discutere sui recenti progressi nell'interazione tra arti creative, neuroscienze, ingegneria, comunicazione, tecnologia, industria, istruzione, design, applicazioni forensi e mediche. I contributi hanno esaminato lo stato dell'arte, identificando sfide e opportunità, e hanno delineato le possibili linee di sviluppo di questo settore di ricerca. I temi affrontati includono: strategie integrate per la comprensione dei sistemi neurali, affettivi e cognitivi in ambienti realistici e complessi; individualità e differenziazione dal punto di vista neurale e comportamentale; neuroaesthetics (uso delle neuroscienze per spiegare e comprendere le esperienze estetiche a livello neurologico); creatività e innovazione; neuro-ingegneria e arte ispirata dal cervello, creatività e uso di dispositivi di mobile brain-body imaging (MoBI) indossabili; terapia basata su arte creativa; apprendimento informale; formazione; applicazioni forensi. / [English]: “Graphonomics and your brain on art, creativity and innovation”. A single track, international forum for discussion on recent advances at the intersection of the creative arts, neuroscience, engineering, media, technology, industry, education, design, forensics, and medicine. The contributions reviewed the state of the art, identified challenges and opportunities and created a roadmap for the field of graphonomics and your brain on art. The topics addressed include: integrative strategies for understanding neural, affective and cognitive systems in realistic, complex environments; neural and behavioral individuality and variation; neuroaesthetics (the use of neuroscience to explain and understand the aesthetic experiences at the neurological level); creativity and innovation; neuroengineering and brain-inspired art, creative concepts and wearable mobile brain-body imaging (MoBI) designs; creative art therapy; informal learning; education; forensics

Model Predictive Control With Environment Adaptation for Legged Locomotion

Re-planning in legged locomotion is crucial to track the desired user velocity while adapting to the terrain and rejecting external disturbances. In this work, we propose and test in experiments a real-time Nonlinear Model Predictive Control (NMPC) tailored to a legged robot for achieving dynamic locomotion on a variety of terrains. We introduce a mobility-based criterion to define an NMPC cost that enhances the locomotion of quadruped robots while maximizing leg mobility and improves adaptation to the terrain features. Our NMPC is based on the real-time iteration scheme that allows us to re-plan online at $25\,\mathrm{Hz}$ with a prediction horizon of $2$ seconds. We use the single rigid body dynamic model defined in the center of mass frame in order to increase the computational efficiency. In simulations, the NMPC is tested to traverse a set of pallets of different sizes, to walk into a V-shaped chimney,and to locomote over rough terrain. In real experiments, we demonstrate the effectiveness of our NMPC with the mobility feature that allowed IIT's $87\, \mathrm{kg}$ quadruped robot HyQ to achieve an omni-directional walk on flat terrain, to traverse a static pallet, and to adapt to a repositioned pallet during a walk.Comment: Video available on: https://youtu.be/r0-KIiw0eW

Fuzzy Controllers

Trying to meet the requirements in the field, present book treats different fuzzy control architectures both in terms of the theoretical design and in terms of comparative validation studies in various applications, numerically simulated or experimentally developed. Through the subject matter and through the inter and multidisciplinary content, this book is addressed mainly to the researchers, doctoral students and students interested in developing new applications of intelligent control, but also to the people who want to become familiar with the control concepts based on fuzzy techniques. Bibliographic resources used to perform the work includes books and articles of present interest in the field, published in prestigious journals and publishing houses, and websites dedicated to various applications of fuzzy control. Its structure and the presented studies include the book in the category of those who make a direct connection between theoretical developments and practical applications, thereby constituting a real support for the specialists in artificial intelligence, modelling and control fields

Of Priors and Particles: Structured and Distributed Approaches to Robot Perception and Control

Applications of robotic systems have expanded significantly in their scope, moving beyond the caged predictability of industrial automation and towards more open, unstructured environments. These agents must learn to reliably perceive their surroundings, efficiently integrate new information and quickly adapt to dynamic perturbations. To accomplish this, we require solutions which can effectively incorporate prior knowledge while maintaining the generality of learned representations. These systems must also contend with uncertainty in both their perception of the world and in predicting possible future outcomes. Efficient methods for probabilistic inference are then key to realizing robust, adaptive behavior. This thesis will first examine data-driven approaches for learning and combining perceptual models for both visual and tactile sensor modalities, common in robotics. Modern variational inference methods will then be examined in the context of online optimization and stochastic optimal control. Specifically, this thesis will contribute (1) data-driven visual and tactile perceptual models leveraging kinematic and dynamic priors, (2) a framework for joint inference with visuo-tactile sensing, (3) a family of particle-based, variational model predictive control and planning algorithms, and (4) a distributed inference scheme for online model adaptation.Ph.D

Model-based Cooperative Acoustic Navigation and Parameter Identification for Underactuated Underwater Vehicles

This thesis reports novel theoretical and experimental results addressing two increasingly important problems in underwater robotics: model-based cooperative acoustic navigation for underwater vehicles (UVs) lacking a Doppler velocity log (DVL) and dynamic-model parameter estimation for underactuated UVs, such as the now-ubiquitous class of torpedo-shaped UVs. This thesis reports an extension of a method to identify simultaneously UV dynamical plant model parameters (parameters for critical terms such as mass, added mass, hydrodynamic drag, and buoyancy) and control-actuator parameters (control-surface models and thruster model) in 6 degrees of freedom (DOF) to tolerate simulated sensor measurement noise representative of representative of real-world sensor data, as well as extensive numerical simulations to evaluate the sensitivity of the approach to sensor noise. The current state-of-the-art in one-way travel time (OWTT) combined acoustic communication and navigation (cooperative acoustic navigation) is to utilize purely kinematic, constant-velocity plant process models together with an on-board bottom-lock DVL to provide frequent, high-accuracy velocity corrections. However, DVLs are expensive, power consumers, physically large, and limited to acoustic bottom-lock range, which restricts their use to O(10-100m) above the sea floor or beneath surface ice. Simulation and experimental results reported herein indicate the submerged UV position estimate from cooperative acoustic navigation with a kinematic model is poor and even unstable in the absence of DVL velocity observations. These simulation and experimental results also show that cooperative acoustic navigation with a dynamic plant model performs well without a DVL and outperforms DVL-based dead reckoning, at least in the situation presented herein where the magnitude of the ambient water-current velocity is small. The performance of the UV dynamic model, i.e., its ability to predict the vehicle's state, depends primarily on the accuracy of the model structure and model parameters. Accurate estimates of these parameters are also required for model-based control, fault detection, and simulation of UV. While the general form of dynamical plant models for UVs is well understood, accurate values for dynamic-model parameters are impossible to determine analytically, are not provided by UV manufacturers, and can only be determined experimentally. Moreover, oceanographic UVs are subject to frequent changes in physical configuration, including changes in ballasting and trim, on-board equipment, and instrumentation (both external and internal), which may significantly affect the vehicle dynamics. Plant-model parameter estimation is generally more difficult for underactuated, torpedo-shaped UVs than for fully actuated UVs with thrusters because: 1) the reduced actuation available on underactuated UV limits the plant excitation that can be induced from the control inputs, and 2) torpedo-shaped vehicles are often actuated with control surfaces (e.g., fins, wings, rudders, etc), which are difficult to characterize independently of the plant model parameters. For these reasons, we seek an approach to parameter estimation for underactuated UVs in 6 DOF that simultaneously estimates plant and actuator parameters and can be performed routinely in the field with minimal time and effort by the vehicle operator. The goals of this thesis are to advance the state-of-the-art of (1) model-based state estimation for cooperative acoustic navigation of UVs and (2) dynamic plant-model parameter identification for underactuated UVs. The first goal is addressed with the evaluation of a dynamic UV plant model in cooperative acoustic navigation and a comparative analysis of the dynamic UV model and kinematic UV model without a DVL. The second goal is addressed in a collaborative effort comprising: (1) the development of the nullspace-based least squares (NBLS) algorithm for underactuated UV plant-parameter and actuator-parameter estimation in 6 DOF, and (2) the extension of an AID algorithm, and corresponding stability proof, to estimate simultaneously plant-model and actuator parameters for underactuated UVs with diagonal mass and drag matrices in 6 DOF with realistic sensor measurement noise. These capabilities were verified by in situ vehicle experiments with the JHU Iver3 AUV and by simulation studies

Active vibration control of a flexible robot link using piezoelectric actuators

Nuisance vibrations are a concern throughout the engineering realm, and many re-searchers are dedicated to finding a solution to attenuate them. This research primarily focusses upon the suppression of vibrations in a robot system, with the control system being designed so that it is both affordable and lightweight. Such constraints aim to provide a solution that may be utilised in a variety of applications. The utilisation of piezoelectric elements as both actuators and sensors provides several advantages in that they are lightweight, easily integrated into an existing system and have a good force to weight ratio when used as actuators. To read and control these elements a single board computer was employed, in acknowledgement of the constraining parameters of the design. The amalgamation of vibration control and robotics has lent to the re-search being conducted with separate objectives set, isolating certain elements of the overall system design for validation. Ultimately, these separate investigations progress to the integration of the robot and control systems prior to further research concerning nonlinear vibrations, dynamic control and the discrete-time domain modelling of the system.This research first investigates the viability of the chosen components as a vibration attenuation solution. In addition, analytical models of the system have been created, for two types of sensors to determine the most effective; an inertial measurement unit and a collocated pair of piezoelectric sensors. These models are based on Euler-Bernoulli beam theory and aim to validate the control theory through a comparison of the experimental data. These experiments isolate the vibration problem from a robot system through the investigation of the control of a long slender beam envisioned as a robot manipulator link, but excited using a shaker platform in a sinusoidal manner. An observation of the theory related to the voltage produced by the piezoelectric elements, suggests that even with the application of only proportional control by the system, the controlled output would have components indicative of both proportional and derivative control. This observation and the underlying theory are further analysed within this research.The next objectives are to compare the performance of the control system developed in this research which utilises a Raspberry Pi 3B+ [1] with one that employs a dSPACE MicroLabBox [2], and to determine the suitability of the former for use with robot sys-tems. With the former ensuring that the constraints placed on the design, those which influenced the selection of the components, does not conclude to the dSPACE Micro-LabBox system being overtly preferable. The latter investigates both the impact of the system’s inclusion on the functionality of the system and the system’s perform-ance with respect to the intended application. The KUKA LBR iiwa 7 R800 [3] robot manipulator is utilised to satisfy this objective, wherein the link is mounted on the end effector of the manipulator acting as an eighth link. The final investigation in this research pertains to the attenuation of nonlinear vibrations experienced by a robot manipulator link. Additional components were added to the link to induce a geometric nonlinearity in the system. An analytical model of the amended system was created to validate the theory through comparison with experimental results. The control system was employed for multiple cases to ascertain the level of its performance with regards to the suppression of nonlinear vibrations