Static kinematics for an antagonistically actuated robot based on a beam-mechanics-based model

Soft robotic structures might play a major role in the 4th industrial revolution. Researchers have successfully demonstrated advantages of soft robotics over traditional robots made of rigid links and joints in several application areas including manufacturing, healthcare and surgical interventions. However, soft robots have limited ability to exert higher forces when it comes to interaction with the environment, hence, change their stiffness on demand over a wide range. One stiffness mechanism embodies tendon-driven and pneumatic air actuation in an antagonistic way achieving variable stiffness values. In this paper, we apply a beammechanics-based model to this type of soft stiffness controllable robot. This mathematical model takes into account the various stiffness levels of the soft robotic manipulator as well as interaction forces with the environment at the tip of the manipulator. The analytical model is implemented into a robotic actuation system made of motorised linear rails with load cells (obtaining applied forces to the tendons) and a pressure regulator. Here, we present and analyse the performance and limitations of our model

The Problem of Signal and Symbol Integration: A Study of Cooperative Mobile Autonomous Agent Behaviors

This paper explores and reasons about the interplay between symbolic and continuous representations. We first provide some historical perspective on signal and symbol integration as viewed by the Artificial Intelligence (AI), Robotics and Computer Vision communities. The domain of autonomous robotic agents residing in dynamically changing environments anchors well different aspects of this integration and allows us to look at the problem in its entirety. Models of reasoning, sensing and control actions of such agents determine three different dimensions for discretization of the agent-world behavioral state space. The design and modeling of robotic agents, where these three aspects have to be closely tied together, provide a good experimental platform for addressing the signal-to-symbol transformation problem. We present some experimental results from the domain of cooperating mobile agents involved in tasks of navigation and manipulation

A large-scale multi-objective flights conflict avoidance approach supporting 4D trajectory operation

Recently, the long-term conflict avoidance approaches based on large-scale flights scheduling have attracted much attention due to their ability to provide solutions from a global point of view. However, the current approaches which focus only on a single objective with the aim of minimizing the total delay and the number of conflicts, cannot provide the controllers with variety of optional solutions, representing different trade-offs. Furthermore, the flight track error is often overlooked in the current research. Therefore, in order to make the model more realistic, in this paper, we formulate the long-term conflict avoidance problem as a multi-objective optimization problem which minimizes the total delay and reduces the number of conflicts simultaneously. As a complex air route networks needs to accommodate thousands of flights, the problem is a large-scale combinatorial optimization problem with tightly coupled variables, which make the problem difficult to deal with. Hence, in order to further improve the searching capability of the solution algorithm, a cooperative co-evolution (CC) algorithm is also introduced to divide the complex problem into several low dimensional sub-problems which are easier to solve. Moreover, a dynamic grouping strategy based on the conflict detection is proposed to improve the optimization efficiency and to avoid premature convergence. The well-known multi-objective evolutionary algorithm based on decomposition (MOEA/D) is then employed to tackle each sub-problem. Computational results using real traffic data from the Chinese air route network demonstrate that the proposed approach obtained better non-dominated solutions in a more effective manner than the existing approaches, including the multi-objective genetic algorithm (MOGA), NSGAII, and MOEA/D. The results also show that our approach provided satisfactory solutions for controllers from a practical point of view

The „Bionic Sonar” project, phase one: Initial research on Marine Mammal Acoustics

Results of theoretical and experimental investigation on marine mammal acoustics are presented and briefly concluded. The described research is a part of interdisciplinary scientific project titled „Bionic Sonar”. The goal of the project is to develop a new kind of hydroacoustic sources with specified frequency characteristics and directivity patterns, inspired by the vocal and echolocation systems of the marine mammals. The presented theoretical investigation focuses on underwater communication and navigation capabilities of dolphins and grey seals. The experimental research concerning underwater vocalizations of the grey seals was performed in the Hel Marine Station of the Institute of Oceanography of the University of Gdańsk. Underwater sounds were recorded using hydrophones placed in the pools in which only the grey seals were present. The recorded vocalizations have been extracted from the recordings and analyzed for a number of distinguishing characteristics. The obtained results are compared to the results of other related investigations described in literature

Examining committee: Hany Farid (chair)

This thesis is dedicated to my wife, Rosa Orellana, and to my parents

A Modular, Hybrid System Architecture for Autonomous, Urban Driving

Copyright © 2007 by the American Institute of Aeronautics and Astronautics, Inc.Digital Object Identifier: 10.2514/1.33349Autonomous navigation in urban environments inevitably leads to having to switch between various, sometimes conflicting control tasks. Sting Racing, a collaboration between Georgia Tech and SAIC, has developed a modular control architecture for this purpose and this paper describes the operation and definition of this architecture through so-called nested hybrid automata. We show how to map the requirements associated with the DARPA Urban Grand Challenge onto these nested automata and illustrate their operation through a number of experimental results