A Robotic CAD System using a Bayesian Framework

We present in this paper a Bayesian CAD system for robotic applications. We address the problem of the propagation of geometric uncertainties and how esian CAD system for robotic applications. We address the problem of the propagation of geometric uncertainties and how to take this propagation into account when solving inverse problems. We describe the methodology we use to represent and handle uncertainties using probability distributions on the system's parameters and sensor measurements. It may be seen as a generalization of constraint-based approaches where we express a constraint as a probability distribution instead of a simple equality or inequality. Appropriate numerical algorithms used to apply this methodology are also described. Using an example, we show how to apply our approach by providing simulation results using our CAD system

The Design and Implementation of a Bayesian CAD Modeler for Robotic Applications

We present a Bayesian CAD modeler for robotic applications. We address the problem of taking into account the propagation of geometric uncertainties when solving inverse geometric problems. The proposed method may be seen as a generalization of constraint-based approaches in which we explicitly model geometric uncertainties. Using our methodology, a geometric constraint is expressed as a probability distribution on the system parameters and the sensor measurements, instead of a simple equality or inequality. To solve geometric problems in this framework, we propose an original resolution method able to adapt to problem complexity. Using two examples, we show how to apply our approach by providing simulation results using our modeler

Sunlighting Design: an Inverse Approach of Simulation for CAD Tools

International audienceExisting simulation tools are mainly used for appraising environmental properties of architectural and urban constructions. In most cases, these tools do not suit design practice as they work on completed schemes. A designer who wants to emphasize an environmental point of view needs a new range of CAD tools that work in an inverse way: from the environmental properties to the built forms. Our main issue for this paper is to present an inverse approach application in the field of sunlighting simulation and design. We have developed an experimental CAD tool that models objects from declarative sunlighting properties. Our system works on proposals such as ‘this shape must be sunlit (or sunless) for the end of afternoon in winter’, and it suggests solutions — shadings and openings — that check on these proposals. This methodology opens new research avenues toward a real aid for environmental design

Layout and process optimisation: using computer-aided design (CAD) and simulation through an integrated systems design tool

The design of production and logistic systems is a process of managing both technical and organisational variants in order to identify the best solution for a given system. This paper discusses design issues of production systems that are applied to an internal logistic system in the automotive industry. As far as the production systems design (PSD) is concerned, three basic classes of software tools usually pertain: computer-aided design (CAD), process simulation, and information systems. However, these software tools have been used with low levels of integration. Vik et al. (2010b, 2010c) proposed integrating these software resources in production systems and developed an advanced tool called integrated design of systems (IDS). The proposed IDS tool involves a wide set of functions for the most common tasks of PSD, from conceptualisation to implementation, including systems analysis (P-Q, cluster, and material flow analysis), automatic generation of simulation models, generation of alternatives for the layout of facilities and factories, material flows display, transportation system design, and iterative buffer size specification. The IDS approach takes advantage of simulation, CAD systems, and their integration. This paper will demonstrate the concept and functionalities of the proposed tool in a real industrial case study.Fundação para a Ciência e Tecnologi

Virtual plants in machine automation research and development

Computational product development has become the mainstream methodology in modern product development. The same trend has been visible also in research, where computational methods have gained popularity beside the traditional approach relying on theory and experimentations. The objective of this project task was to study and demonstrate a realistic approach for an industrial case to reuse existing mechanical design CAD model as the starting point and the template for mechanical system simulation using multibody system simulation, and to use this MBS model as a virtual test plant for automation and control system testing. In the report, the role of system modelling and simulation in the product process is first dis-cussed and some selected technologies, such as Modelica simulation language and Functional Mock-up Interface specification, are introduced. Then different possible implementations approaches for a test environment of the control and automation system of a multi-technical system are discussed. The latter part of report focuses on describing the selected approach for a demonstration system and its implementation. The demonstration showed that, at least for the selected case, modelling, simulation and post-processing of a multi-technical simulation system is relatively straightforward and fast with the selected tools. The demonstration gives some understanding of the process for implementing one relatively small multi-technical system but does not give realistic feedback about the challenges in industrial-scale process for virtual prototyping of large and complex systems and related data exchange and data management

System Approach to Vehicle Suspension System Control in CAE Environment

In recent years, motor vehicles industry has shown a tendency of replacing electromechanical components by mechatronic systems with intelligent and autonomous properties. The integration of hardware components and implementation of advance control function characterize this replacement. In this paper we have applied the system approach and system engineering methods in the initial phase of vehicle active suspension development. An emphasis has been placed upon the interrelations between computer-aided simulation and other elements of the development process. The benefits of application of active suspension simulation are numerous: reduction of time to market, the new and improved functions of mechatronic components/devices, as well as the increased system reliability. In suspension model development, we used CAD/CAE tools, as well as the multipurpose simulation programs. For simulation, we used the one-quarter vehicle model. The modelling was carried out through the state-space equation, after which we designed the controller for our system. During this, we considered only the digital systems of automatic regulation

Multisensor knowledge systems

technical reportWe describe an approach which facilitates and makes explicit the organization of the knowledge necessary to map multisensor system requirements onto an appropriate assembly of algorithms, processors, sensors, and actuators. We have previously introduced the Multisensor Kernel System and Logical Sensor Specifications as a means for high-level specification of multisensor systems. The main goals of such a characterization are: to develop a coherent treatment of multisensor information, to allow system reconfiguration for both fault tolerance and dynamic response to environmental conditions, and to permit the explicit description of control. In this paper we show how Logical Sensors can be incorporated into an object-based approach to the organization of multisensor systems. In particular, we discuss: * a multisensor knowledge base, * a sensor specification scheme, and * a multisensor simulation environment. We give an example application of the system to CAD-based 2-D vision

Configuring A Mini-Laboratory and Desktop 3-Axis Parallel Kinematic Milling Machine

Configuring new machine tools is a complex task that involves the use of a large range of conceptions, methods, models, virtual prototypes and simulations. This paper presents a methodology for configuring a new machine tool to the level of a virtual prototype by using CAD configurator Pro/WEB.Link and a top-down approach. This methodology is explained via an example of the development of a mini-laboratory and desktop 3-axis parallel kinematic milling machine (PKMM). The results are two variants of the virtual prototype and one real world prototype. The configured virtual prototypes are used for the verification of the machining program and programming system using machining simulation in the CAD/CAM environment. The mini-laboratory and desktop 3-axis PKMM has been verified by the successful machining of test workpieces

Configuring A Mini-Laboratory and Desktop 3-Axis Parallel Kinematic Milling Machine

Configuring new machine tools is a complex task that involves the use of a large range of conceptions, methods, models, virtual prototypes and simulations. This paper presents a methodology for configuring a new machine tool to the level of a virtual prototype by using CAD configurator Pro/WEB.Link and a top-down approach. This methodology is explained via an example of the development of a mini-laboratory and desktop 3-axis parallel kinematic milling machine (PKMM). The results are two variants of the virtual prototype and one real world prototype. The configured virtual prototypes are used for the verification of the machining program and programming system using machining simulation in the CAD/CAM environment. The mini-laboratory and desktop 3-axis PKMM has been verified by the successful machining of test workpieces

Optimal Shape Design of Mail-Slot Nacelle on N3-X Hybrid Wing-Body Configuration

System studies show that a N3-X hybrid wing-body aircraft with a turboelectric distributed propulsion system using a mail-slot inlet/nozzle nacelle can meet the environmental and performance goals for N+3 generation transports (three generations beyond the current air transport technology level) set by NASA's Subsonic Fixed Wing Project. In this study, a Navier-Stokes flow simulation of N3-X on hybrid unstructured meshes was conducted, including the mail-slot propulsor. The geometry of the mail-slot propulsor was generated by a CAD (Computer-Aided Design)-free shape parameterization. A novel body force model generation approach was suggested for a more realistic and efficient simulation of the flow turning, pressure rise and loss effects of the fan blades and the inlet-fan interactions. Flow simulation results of the N3-X demonstrates the validity of the present approach. An optimal Shape design of the mail-slot nacelle surface was conducted to reduce strength of shock waves and flow separations on the cowl surface