The integration of dissimilar control architectures for mobile robot applications

This article discusses a dual architecture for autonomous mobile robots. The implementation application is an autonomous visual inspection system for waste stored in drums. We discuss the three main architectures commonly implemented on mobile robots. The various modules needed for the successful operation of a mobile robot are analyzed, and software and hardware requirements for each modules are noted. We make arguments as to which architecture is best suited for each component. From the results of this analysis, we propose a new dual architecture for autonomous mobile robots. Rather than developing a single hybrid architecture that has qualities of both behavioral and functional architectures, we have taken an approach that involves the integration of two distinct architectures. Next, we detail the implementation of the architecture of the robot, and the advantages of our architecture as it pertains to the integration of system components. System performance in the testing environment is discussed. © 1997 John Wiley & Sons, Inc.     

A Flexible Control Architecture for Mobile Robots: An Application for a Walking Robot

To get the best features of both deliberative and reactive controllers, present mobile robot control architectures are designed to accommodate both types of controller. However, these architectures are still very rigidly structured thus deliberative modules are always assigned to the same role as a high-level planner or sequencer while low-level reactive modules are still the ones directly interacting with the robot environment. Furthermore, within these architectures communication and interface between modules are if not strongly established, they are very complex thus making them unsuitable for simple robotic systems. Our idea in this paper is to present a control architecture that is flexible in the sense that it can easily integrate both reactive and deliberative modules but not necessarily restricting the role of each type of controller. Communication between modules is through simple arbitration schemes while interface is by connecting a common communication line between modules and simple read and/or write access of data objects. On top of these features, the proposed control architecture is scalable and exhibits graceful degradation when some of the modules fail, similar to the present mobile robot architectures. Our idea has enabled our four-legged robot to walk autonomously in a structured uneven terrain.     

A new mobile robot control approach via fusion of control signals.

This paper proposes an alternative approach to address the problem of coordinating behaviors in mobile robot navigation: fusion of control signals. Such approach is based on a set of two decentralized information filters, which accomplish the data fusion involved. Besides these two fusion engines, control architectures designed according to this approach also embed a set of different controllers that generate reference signals for the robot linear and angular speeds. Such signals are delivered to the two decentralized information filters, which estimate suitable overall reference signals for the robot linear and angular speeds, respectively. Thus, the background for designing such control architectures is provided by the nonlinear systems theory, which makes this approach different from any other yet proposed. This background also allows checking control architectures designed according to the proposed approach for stability. Such analysis is carried out in the paper, and shows that the robot always reaches its final destination, in spite of either obstacles along its path or the environment layout. As an example, a control architecture is designed to guide a mobile robot in an experiment, whose results allows checking the good performance of the control architecture and validating the design approach proposed as well.     

Reusable robot system for display and disposal tasks at convenience stores based on a SysML model and RT Middleware

Service robots are increasingly being expected to replace human labor; however, in practical settings, these robots have not been fully utilized, partly because the applications that service robots are expected are quite broad. Suitable hardware and software should be developed in order to cope with a wide variety of applications. Ideally, these resources should be developed using common hardware and software platforms are required. Middleware platforms for robotics software, such as ROS and RT Middleware, have already been developed. However, these platforms still face reusability problems due to the inconsistency present in system architectures. Systems are typically assumed to be reused with a given architecture, and if the user-side software architecture is inconsistent with this assumption, the system's reusability suffers. To address this issue, we propose a procedure for optimizing system development using SysML. In this study, our robot system is designed to complete a display disposal tasks in a convenience store; we verify the validity of the robot system using this task. In addition, to verify the reusability of the developed robot system, we employ system functions developed for another task and demonstrate their reuse and operation.     

基于会话的安全、鲁棒共享控制方法

在共享控制系统中，比如智能服务机器人，操作员和自动化专门系统相互配合，共同控制．有效的共享控制需要复杂的系统体系结构，该结构可以提供安全鲁棒的运行，提供对用户友好的界面．满足这两项需求是一个不寻常的任务．介绍了解决这些问题的方法．首先给出一个以会话为中心采用面向代理编程和形式化方法的认知控制体系结构．采用混成设计的SharC认知控制体系结构，可以区分协同代理群体中每一个遥控设备的控制．安全性对共享控制系统来说是极为重要的，因此这种体系结构必须能够保证较高的安全性．最后，描述了作为控制系统核心的形式化建模会话管理器，通过示范平台中自动轮椅的例子说明这些不同的软件范例的应用。     

A new system architecture for crowd simulation

Crowd simulation requires both rendering visually plausible images and managing the behavior of autonomous agents. Therefore, these applications need an efficient design that allows them to simultaneously handle these two requirements. Although several proposals have focused on the software architectures for these systems, no proposals have focused on the computer systems supporting them.In this paper, we analyze the computer architectures used in the literature to support distributed virtual environments. Also, we propose a distributed computer architecture which is efficient enough to support simulations of thousand of autonomous agents. This proposal consists of a cluster of interconnected computers in order to improve flexibility and robustness, as well as a hierarchical software architecture that efficiently provides consistency. Performance evaluation results show that the trade-off between flexibility and consistency allows to efficiently manage thousands of autonomous agents. Therefore, this network-based system architecture can provide the required scalability for large-scale crowd simulations.     

智能机器人体系结构可分解性理论研究

以往的智能机器人体系结构研究工作,都是根据需求并凭借经验直接进行功能模块的划分及其相互关系的确定,随着机器人系统及其模块间耦合关系的日益复杂,体系结构的可分解性这一基础理论问题日渐突出,但是一直没有得到深入研究。本文提出并采用微分流形理论证明智能机器人体系结构可分解性定理。该定理为智能机器人复杂体系结构模型的层次化、模块化实现奠定了理论基础。     

The Accidental Architecture

Every interesting software-intensive system has an architecture. While some of these architectures are intentional, most appear to be accidental. Philippe Kruchten has observed that "the life of a software architect is a long and rapid succession of suboptimal design decisions taken partly in the dark." The journey between vision and ultimate executable system is complex, and for every interesting software-intensive system that path is marked by myriad decisions, some large and some small, some of which advance progress while others represent vestigial dead ends or trigger points for scrap and rework. As Philippe also observes, the architecture of classical systems comes primarily from theft, whereas the architecture of unprecedented systems comes largely from intuition carried out in the context of a controlled exploratory process. The fact that this is so for software-intensive systems shouldn't come as a surprise, for as Henry Petroski explains in his book To Engineer Is Human (Vintage, 1992), all sound engineering disciplines advance by building on past successes while simultaneously mitigating causes of observable failure.Thus, having an accidental architecture is not necessarily a bad thing, as long as the decisions that make up that architecture are made manifest and the essential ones are made visible as soon as they are instituted and then allowed to remain visible throughout the meaningful life of that system. Insofar as we can then name these architectures after they're formed, we can use these names and their associated semantics to communicate decisions using a common language, just as we can do now with design patterns, and perhaps even reuse these architectural patterns in future systems. In other words, by naming these accidental architectures, we again raise the level of abstraction by which we can describe and reason about a system.     

Evaluating robustness in a two layer simulated robot architecture

Many two layer robot architectures have been proposed and implemented. While justification for the design can be well argued, how does one know it is really a good idea? In this paper, one describes a two layer architecture (reinforcement learning in the bottom layer and POMDP planning at the top) for a simulated robot and summarize a set of three experiments in which one evaluated the design. To address the many difficulties of evaluating robot architectures, one advocates an experimental approach in which design criteria are elucidated and then form the basis for the evaluation experiments. In our case, one tests the implementation for its reliability and generalization (our design criteria) by comparing our architecture to one in which a key component is substituted; in these experiments, one demonstrates significant performance gains on the design criteria for our architecture.     

A framework for analysis and design of software reference architectures

Context

A software reference architecture is a generic architecture for a class of systems that is used as a foundation for the design of concrete architectures from this class. The generic nature of reference architectures leads to a less defined architecture design and application contexts, which makes the architecture goal definition and architecture design non-trivial steps, rooted in uncertainty.

Objective

The paper presents a structured and comprehensive study on the congruence between context, goals, and design of software reference architectures. It proposes a tool for the design of congruent reference architectures and for the analysis of the level of congruence of existing reference architectures.

Method

We define a framework for congruent reference architectures. The framework is based on state of the art results from literature and practice. We validate our framework and its quality as analytical tool by applying it for the analysis of 24 reference architectures. The conclusions from our analysis are compared to the opinions of experts on these reference architectures documented in literature and dedicated communication.

Results

Our framework consists of a multi-dimensional classification space and of five types of reference architectures that are formed by combining specific values from the multi-dimensional classification space. Reference architectures that can be classified in one of these types have better chances to become a success. The validation of our framework confirms its quality as a tool for the analysis of the congruence of software reference architectures.

Conclusion

This paper facilitates software architects and scientists in the inception, design, and application of congruent software reference architectures. The application of the tool improves the chance for success of a reference architecture.     

Software performance tuning of software product family architectures: Two case studies in the real-time embedded systems domain

Software performance is an important non-functional quality attribute and software performance evaluation is an essential activity in the software development process. Especially in embedded real-time systems, software design and evaluation are driven by the needs to optimize the limited resources, to respect time deadlines and, at the same time, to produce the best experience for end-users. Software product family architectures add additional requirements to the evaluation process. In this case, the evaluation includes the analysis of the optimizations and tradeoffs for the whole products in the family. Performance evaluation of software product family architectures requires knowledge and a clear understanding of different domains: software architecture assessments, software performance and software product family architecture. We have used a scenario-driven approach to evaluate performance and dynamic memory management efficiency in one Nokia software product family architecture. In this paper we present two case studies. Furthermore, we discuss the implications and tradeoffs of software performance against evolvability and maintenability in software product family architectures.     

Towards Software Architecture and Mechanisms for Improving Runtime Variability of Internetware System

As an emerging software paradigm, Internetware is proposed to handle openness, dynamism of software systems in the context of Internet, which implies that such software systems typically have runtime variability that can be improved dynamically to handle various or even unexpected changes of requirements and open environment. Though many progresses of Internetware software technologies have been made to support the adaptation, evolution, context-awareness, etc. of Internetware, how to construct Internetware systems with the ability to improve their runtime variability is still a great challenge in the literature of software engineering. In this paper, we propose software architecture and mechanisms for Internetware systems to support the improvement of their runtime variability by combining software variability and autonomic computing techniques. The Internetware system is organized as three levels that are consist of variable autonomic elements and Internetware entities, and architecture of these software entities is defined and discussed respectively. Moreover, we put forward a series of runtime mechanisms based on these levels, including module selection, intermediator and horizontal management, to realize operations upon the variation points and variants in software architectures and thus achieve the improvement of runtime variability. We develop a sample of Personal Data Resource Network to depict the requirements and scenario of improving runtime variability, and further study the case based on our proposed approach to show its effectiveness and applicability.     

A framework for building mobile single and multi-robot applications

The complexity of robot software systems calls for the use of a well-conceived architecture together with programming tools to support it. One common feature of robot architectures is the modular decomposition of systems into simpler and largely independent components. These components implement primitive actions and report events about their state. The robot programming framework proposed here includes a tool (RoboGraph) to program and coordinate the activity (tasks) of these middleware modules. Project developers use the same task programming IDE (RoboGraph) on two different levels. The first is to program tasks that must be executed autonomously by one robot and the second is to program tasks that can include several robots and building elements.Tasks are described using a Signal Interpreted Petri Net (SIPN) editor and stored in an xml file. A dispatcher loads these files and executes the different Petri nets as needed. A monitor that shows the state of all the running nets is very useful for debugging and tracing purposes. The whole system has been used in several applications: A tour-guide robot (GuideBot), a multi-robot surveillance project (WatchBot) and a hospital food and laundry transportation system based on mobile robots.     

几种新型软件体系结构风格的分析

软件体系结构的提出对软件重用机制和软件开发效率的提高具有非常重要的意义。软件体系结构的使用是提高软件开发质量、减少软件开销和促进软件生产率提高的最有效方法之一。采用定性分析、比较研究等多种方法,实现了几种新型软件体系结构风格的剖析。给出了软件体系结构及软件体系结构风格的定义,阐述了几种新型软件体系结构风格中关键要素的定义及特性及其风格的主要内容,分析了几种新型软件体系结构风格的特点。     

Bio-inspired heterogeneous architecture for real-time pedestrian detection applications

Along with the development of powerful processing platforms, heterogeneous architectures are nowadays permitting new design space explorations. In this paper, we propose a novel heterogeneous architecture for reliable pedestrian detection applications. It deploys an efficient Histogram of Oriented Gradient pipeline tightly coupled with a neuro-inspired spatio-temporal filter. By relying on hardware–software co-design principles, our architecture is capable of processing video sequences from real-word dynamic environments in real time. The paper presents the implemented algorithm and details the proposed architecture for executing it, exposing in particular the partitioning decisions made to meet the required performance. A prototype implementation is described and the results obtained are discussed with respect to other state-of-the-art solutions.