Distributional Reinforcement Learning (DRL) not only endeavors to optimize expected returns, but also strives to accurately characterize the full distribution of these returns, a key aspect in enhancing risk-aware dec...
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ISBN:
(纸本)9798350384581;9798350384574
Distributional Reinforcement Learning (DRL) not only endeavors to optimize expected returns, but also strives to accurately characterize the full distribution of these returns, a key aspect in enhancing risk-aware decision-making. Previous DRL implementations often inappropriately treat statistical estimations as concrete samples, which undermines the integrity of learning. While several studies have addressed this issue, they frequently give rise to new complications, including computational burdens and diminished stochastic behavior. In our work, we present a novel DRL framework that leverages the Gaussian mixture model to adeptly depict the distribution of returns. This approach ensures precise, authentic sampling critical for robust learning, while also preserving computational tractability. Through extensive evaluation on a diverse array of 59 Atari games, our method not only surpasses the efficacy of prior DRL algorithms but also presents formidable competition to contemporary top-tier RL algorithms, signifying a substantial advancement in the field.
A general statistical fusion method motivated by the geometry of uncertainties is proposed for robotic systems with multiple sensors. The treatment of nonlinearity is generalized so as to include both the structural n...
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ISBN:
(纸本)0818619384
A general statistical fusion method motivated by the geometry of uncertainties is proposed for robotic systems with multiple sensors. The treatment of nonlinearity is generalized so as to include both the structural nonlinearity and the computational nonlinearity. First, assuming Gaussian noise additive to the sensory data, the uncertainty ellipsoid associated with the covariance matrix of the error of the sensory information is defined. Second, the optimal fusion is defined as the one, among all the possible linear combinations of sensory information, that minimizes the geometrical volume of the ellipsoid. The resultant fusion equation coincides with those obtained by Bayesian inference, Kalman filter theory, and the weighted least-squares estimation. Finally, the method is extended to include the fusion of partial information.
This work presents an approach for control, state-estimation and learning model (hyper)parameters for robotic manipulators. It is based on the active inference framework, prominent in computational neuroscience as a t...
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ISBN:
(纸本)9781728190778
This work presents an approach for control, state-estimation and learning model (hyper)parameters for robotic manipulators. It is based on the active inference framework, prominent in computational neuroscience as a theory of the brain, where behaviour arises from minimizing variational free-energy. First, we show there is a direct relationship between active inference controllers, and classic methods such as PID control. We demonstrate its application for adaptive and robust behaviour of a robotic manipulator that rivals state-of-the-art. Additionally, we show that by learning specific hyperparameters, our approach can deal with unmodeled dynamics, damps oscillations, and is robust against poor initial parameters. The approach is validated on the 'Franka Emika Panda' 7 DoF manipulator. Finally, we highlight limitations of active inference controllers for robotic systems.
Autonomous robots need to make sense of their surroundings, recognize objects, detect and, possibly, identify the people around them. Visual perception would be ideally suited for these tasks. Yet, visual perception r...
ISBN:
(纸本)9781479936854
Autonomous robots need to make sense of their surroundings, recognize objects, detect and, possibly, identify the people around them. Visual perception would be ideally suited for these tasks. Yet, visual perception remains one of the limiting factors of modern robotics: artificial vision systems tend to perform poorly in normal environments, where the scene and the illumination conditions are unpredictable. Evolution has faced similar problems, leading to surprisingly accurate visual capabilities, even in species with very small brains. We argue that the success of biological perception systems relies on three fundamental computational principles: (a) the continual coupling of perception and behavior;(b) the resulting emergence of multimodal cues;(c) and their efficient integration. Building on these computational principles, we describe a humanoid robot that emulates the dynamic strategy by which humans examine a visual scene. The proprioceptive and visual depth cues resulting from this strategy are integrated in statistically optimal manner into a unified representation. We show that this approach yields accurate and robust 3D representations of the observed scene.
Two laboratory robots provide analytical support to two laboratories within the Analytical Services Organization of the Oak Ridge Y-12 Plant. One system prepares uranium metals and oxides for isotopic analysis by ther...
Two laboratory robots provide analytical support to two laboratories within the Analytical Services Organization of the Oak Ridge Y-12 Plant. One system prepares uranium metals and oxides for isotopic analysis by thermal ionization mass spectrometry. The second system prepares and analyzes air filter samples for uranium content. The robots have proven to be excellent assets to the laboratories in productivity improvement, waste reduction, and personnel safety. robotics and automation will continue to provide substantial benefits to future analytical methodology within the Y-12 Plant.
This paper presents two different approaches to generate a time local-optimal and jerk-limited trajectory with blends for a robot manipulator under consideration of kinematic constraints. The first approach generates ...
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ISBN:
(纸本)9781728190778
This paper presents two different approaches to generate a time local-optimal and jerk-limited trajectory with blends for a robot manipulator under consideration of kinematic constraints. The first approach generates a trajectory with blends based on the trapezoidal acceleration model by formulating the problem as a nonlinear constraint and a non-convex optimization problem. The resultant trajectory is locally optimal and approximates straight-line movement while satisfying the robot manipulator's constraints. We apply the bridged optimization strategy to reduce the computational complexity, which borrows an idea from model predictive control by dividing all waypoints into consecutive batches with an overlap of multiple waypoints. We successively optimize each batch. The second approach is a combination of a trapezoidal acceleration model with a 7-degree polynomial to form a path with blends. It can be efficiently computed given the specified blending parameters. The same approach is extended to Cartesian space. Furthermore, a quaternion interpolation with a high degree polynomial under consideration of angular kinematics is introduced. Multiple practical scenarios and trajectories are tested and evaluated against other state-of-the-art approaches.
With the speedy development of hardware (e.g., high performance computing, smaller and cheaper sensors) and software (e.g., deep learning techniques and interaction technologies), robotic products and IoT devices have...
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ISBN:
(纸本)9781728124858
With the speedy development of hardware (e.g., high performance computing, smaller and cheaper sensors) and software (e.g., deep learning techniques and interaction technologies), robotic products and IoT devices have gradually become accessible to household users. Typical application scenarios of domestic robots include: 1) Providing physical assistance such as floor vacuuming;2) Providing social assistance to answer questions;and 3) Providing education and cognitive assistance such as offering partnerships. In this paper, we provide a brief overview of available domestic robots, particularly focusing on the services they provide and corresponding computational techniques incorporated in these services. We first provide an overview of available commercial domestic robots and state-of-the-art computationalintelligence techniques, then discuss the gap between current robotic systems and advanced computational techniques. Finally, we analyze what are the next developmental stages for these techniques with the emergence and development of the domestic robotic platforms.
Emotional systems are being considered with renewed interests as powerful computational models to design better and more intelligent robots. The aim of the work presented in this paper is to design a real-time agent b...
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ISBN:
(纸本)1889335215
Emotional systems are being considered with renewed interests as powerful computational models to design better and more intelligent robots. The aim of the work presented in this paper is to design a real-time agent based on emotions and motivations to produce behaviors that are consistent with intelligent performance in the real world. The emotional agent that will be described is founded on three main entities: concepts, emotions and conscious processes. The concepts and conscious processes are data and processes respectively. The conscience help the data and processes to organise their life cycle. The emotions adjust the motivations of the processes based on the confidence of the concepts to satiate the agent desires.
Octopus arms, as well as elephant trunks, squid tentacles, and vertebrate tongues are termed muscular-hydrostats. In such structures, the volume of the organ remains constant during their motions, enabling diverse, co...
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ISBN:
(纸本)9781467356411;9781467356435
Octopus arms, as well as elephant trunks, squid tentacles, and vertebrate tongues are termed muscular-hydrostats. In such structures, the volume of the organ remains constant during their motions, enabling diverse, complex, and highly controlled movements without the support of a skeleton. Such flexible structures show major advantages over articulated arms that have a rigid skeleton and joints. These advantages have been attracting roboticists aiming to apply these material properties to soft robot controls. In this paper, we show that the muscular-hydrostat system itself has the computational capacity to achieve a complex nonlinear computation. By using a 3D dynamic simulator of the system inspired by the octopus, we actually demonstrate that the system is capable of emulating complex nonlinear dynamical systems by exploiting its elastic body dynamics as a computational resource. In addition, we systematically analyze its computational power in terms of memory capacity, and show that the system has an intrinsic and characteristic short term memory profile. Finally, the implications for soft robot control and future application scenarios are discussed.
Various methods for fitting an unknown functions from the set of noisy measurements are applicable to a wide variety of problems. Among them, the nonparametric algorithms based on the Parzen kernel are willingly used....
ISBN:
(纸本)9781665476874
Various methods for fitting an unknown functions from the set of noisy measurements are applicable to a wide variety of problems. Among them, the nonparametric algorithms based on the Parzen kernel are willingly used. In the article, we propose a novel and very effective numerical simplification in Parzen approach leading to a significant reduction in computation time. The algorithm is basically developed for multidimensional case. The two-dimensional version of the method is explained in details and analysed. computational complexity and speed of convergence of the algorithm are studied. Some applications for solving real problems with our algorithms are presented.
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