System Safety Surveillance and Control System Concept for Autonomous or Semi-Autonomous Systems Fall-Back Layer Realization

Author(s):  
Georg Hägele ◽  
Dirk Söffker

Autonomous and semi-autonomous aerial systems (AES) are often needed to perform tasks in complex and dynamic environments, especially in search and rescue applications. The safe navigation assurance as well as safety assurance of AES are open research issues. This paper investigates modeling of fall-back layer for AES assurance. To realize given advanced requirement the System Safety Surveillance and Control (SSSC) system concept is introduced. To fulfill safety requirements also for software developments formal requirements are formulated, to be realized with the formal modeling technique Strictly Formalized Situation-Operator-Modeling (sf-SOM). Fall-back system integration into AES can achieve system safety by separated safety consideration and emergency behavior integration and realization. Universally concept design permits the fall-back layer realization also for other applications. This in turn allows the first proof of concept of sf-SOM based SSSC system for fall-back layer realization using an experimental example. Here a Three-tank system is used to show the successful fall-back layer realization and the concept transferability to the introduced AES example.

2002 ◽  
Author(s):  
Carl W. Lickteig ◽  
William R. Sanders ◽  
Scott B. Shadrick ◽  
James W. Lussier ◽  
Brian J. Holt

Author(s):  
Mark W. Mueller ◽  
Seung Jae Lee ◽  
Raffaello D’Andrea

The design and control of drones remain areas of active research, and here we review recent progress in this field. In this article, we discuss the design objectives and related physical scaling laws, focusing on energy consumption, agility and speed, and survivability and robustness. We divide the control of such vehicles into low-level stabilization and higher-level planning such as motion planning, and we argue that a highly relevant problem is the integration of sensing with control and planning. Lastly, we describe some vehicle morphologies and the trade-offs that they represent. We specifically compare multicopters with winged designs and consider the effects of multivehicle teams. Expected final online publication date for the Annual Review of Control, Robotics, and Autonomous Systems, Volume 5 is May 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.


2000 ◽  
Author(s):  
H. S. Tzou ◽  
J. H. Ding

Abstract Modeling distributed parameter systems (DPS) by electronic circuits and fabricating the complicated equivalent circuits to evaluate the system characteristics always poses many challenging research issues for years. Modeling and analysis of distributed sensing/control of smart structures and distributed structronic systems are even scarce. This paper is to present a technique to model distributed structronic systems with electronic circuits and to evaluate control behaviors with the fabricated equivalent circuits. Electrical analogies and analysis of distributed structronic systems is proposed and dynamics and control of beam/sensor/actuator systems are investigated. To determine the equivalent circuits and system parameters, higher order partial derivatives are simplified using the finite difference method; partial differential equations (PDE) are transformed to finite difference equations and further represented by electronic components and circuits. To provide better signal management and stability, active electronic circuit systems are designed and fabricated. Electric signals from the distributed system circuits (i.e., soft and hard) are compared with results obtained by classical theoretical and other (e.g., the finite element, and experimental) techniques.


Author(s):  
Karl Uebel ◽  
Henrique Raduenz ◽  
Petter Krus ◽  
Victor Juliano de Negri

This paper deals with design optimisation of hydraulic hybrid drivelines during early concept design phases. To set the design parameters of a hybrid driveline such as gear ratios, pump/motor displacements and size of energy storage, the energy management of the hybrid machine needs to be considered as well. This is problematic since a nested design and control optimisation normally requires substantial computer power and is time-consuming. Few previous studies have treated combined design and control optimisation of hydraulic hybrid vehicles using detailed, non-linear component driveline models. Furthermore, previously proposed design optimisation methods for on-road vehicles are not suitable for heavy off-road machines operating in short repetitive cycles with high transient power output. The paper demonstrates and compares different optimisation approaches for design and control optimisation combining deterministic dynamic programming and non-gradient based numerical optimisation. The results show that a simple rule-based energy management strategy can be sufficient to find the optimal hardware design even though non-optimal control laws are used.


2021 ◽  
Author(s):  
Isaías Valente de Bessa ◽  
Marenice Melo de Carvalho ◽  
Guido Soprano Machado ◽  
Renan Landau Paiva de Medeiros ◽  
Vicente Ferreira de Lucena Jr

Author(s):  
X. Cheng ◽  
J.M.A. Scherpen

Network systems consist of subsystems and their interconnections and provide a powerful framework for the analysis, modeling, and control of complex systems. However, subsystems may have high-dimensional dynamics and a large number of complex interconnections, and it is therefore relevant to study reduction methods for network systems. Here, we provide an overview of reduction methods for both the topological (interconnection) structure of a network and the dynamics of the nodes while preserving structural properties of the network. We first review topological complexity reduction methods based on graph clustering and aggregation, producing a reduced-order network model. Next, we consider reduction of the nodal dynamics using extensions of classical methods while preserving the stability and synchronization properties. Finally, we present a structure-preserving generalized balancing method for simultaneously simplifying the topological structure and the order of the nodal dynamics. Expected final online publication date for the Annual Review of Control, Robotics, and Autonomous Systems, Volume 4 is May 3, 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.


Author(s):  
TOMMI KARHELA ◽  
ANTTI VILLBERG ◽  
HANNU NIEMISTÖ

The benefits of the use of modeling and simulation in engineering are acknowledged widely. It has proven its advantages e.g., in virtual prototyping i.e., simulation aided design and testing as well as in training and R&D. It is recognized to be a tool for modern decision making. However, there are still reasons that slow down the wider utilization of modeling and simulation in companies. Modeling and simulation tools are separate and are not an integrated part of the other engineering information management in the company networks. They do not integrate well enough into the used CAD, PLM/PDM and control systems. The co-use of the simulation tools themselves is poor and the whole modeling process is considered often to be too laborious. In this article we introduce an integration solution for modeling and simulation based on the semantic data modeling approach. Semantic data modeling and ontology mapping techniques have been used in database system integration, but the novelty of this work is in utilizing these techniques in the domain of modeling and simulation. The benefits and drawbacks of the chosen approach are discussed. Furthermore, we describe real industrial project cases where this new approach has been applied.


Author(s):  
B. Dogan

The present international socio-economic drive for renewable energy use for sustainable development with environmental protection directs attention to hydrogen as energy carrier. Hydrogen production and storage, and fuel cell (FC) technologies have been intensively worked on in Europe including European Commission (EC) supported projects via Framework Programs (FPs), as well as various national and international cooperative programs including those of International Energy Agency (IEA) and International Partnership for Hydrogen Economy (IPHE). The hydrogen storage is required for transport applications as dense as possible to achieve high gravimetric and volumetric density. The storage of hydrogen in liquid, gas and solid forms are associated with low temperature cooling, higher pressures up to 700 bar and integrated higher volume and weight, respectively. The liquid and pressurized gas storage systems are relatively advanced in present applications. On the other hand, the system safety and reliability, hence the public acceptance as well as economic feasibility have been the main drives for solid and hybrid hydrogen applications. The use of solid hydrogen is predicted by the automotive industry to ultimately dominate the hydrogen transport application market. The bottleneck in solid hydrogen application is metal hydride production to meet the quantitative targets for vehicles mainly following the US DOE goals set for years up to 2015. System requirements need also be met for a present target of e.g. 75kWel fuel cell cars aiming at a 400km driving distance with 4 kg of hydrogen. This necessitates a gravimetric storage density of over 6 wt. per cent. The present paper will address the hydrogen storage tank system for on-board applications including storage tank materials, system design, production technologies and system safety. An overview will be presented on the current state-of-the-art of European and international progress on storage materials integrated into on-board storage tank system. The European current programs on hydrogen storage technologies for transport applications including design, safety and system reliability will be addressed.


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