Multi-domain Simulation Research Articles

Locomotive Cooling Systems: A Multi-Domain System Strategy for Efficient and Quieter Cooling Units

An important subsystem in all locomotives is the cooling module with its demand of external energy and the sound emitted. Under specific operational conditions the cooling system is the major noise source and the component with the largest energy consumption. In the work presented the design of mobile cooling systems is revisited in a more integrated manner as compared to the state-of-the-art. The aim is the holistic multi-domain system simulation of the cooling unit and its optimization. For that the complete cooling unit is subdivided in a number of sub-models (water circuit, aerodynamic fan, fan transmission, control unit, etc.) which are interacting with the vehicle and ambient conditions. The complete thermal layout of the cooling system is optimized employing advanced numerical simulation tools. In addition, innovative control strategies are included such as intelligent adaptive control of the forced coolant, anticipated upcoming cooling demand from temperature history, adaptive control strategies for increased efficiency of the fans, etc. The potential reduction of sound power level and energy consumed is evaluated while assessing the cost-benefit ratio. The work is part of the European FP7 transport research project ECOQUEST.

Development of Advanced Conventional and Hybrid Powertrains by Mechanistic System Level Simulations

The paper presents a mechanistic system level simulation approach for modeling hybrid and conventional vehicles. The paper addresses the dynamic interaction between the different domains: internal combustion engine, exhaust aftertreatment devices, electric components, mechanical drive train, cooling circuit system and corresponding control units. Both vehicle topologies are powered by a spark ignition and compression ignition engine. Analyses concentrate on the transient phenomena caused by high interdependency of the sub–systems. Thereby the applicability of mechanistic system level models to adequately represent specific characteristics of the components is highlighted. To achieve high fidelity results of multi–domain simulations featuring high predictability and high computational speed it is necessary to develop adequate simulation tools considering all characteristic time scales of different domains and the nature of their interaction. Analyses are based on the verified models powertrain models. Simulation results of vehicles driven according to a legislative cycle provide the basis for comparative analyses of energy efficiency and exhaust gas emissions.

Interfacing Issues in Multi-Domain Simulation Tools

Interfacing Issues in Multi-Domain Simulation Tools

Computer-Aided Multi-Domain Unified Modeling and Simulation for Aircraft Landing Gear

In order to model complex product systems and analyze their whole performance to deal with the coupling relationships between multi-domain，aircraft landing gear selected as the object, unified multi-domain modeling and simulation and for complex product systems was studied. The aircraft leading gear is decomposed as structure, and the mathematical models of the landing gear components are established. The model library of the landing gear components was developed using Modelica-based platform and multi-domain unified model of the landing gear was established. The impact work amount, the vertical load and the stroke are selected as the indexes to simulate and analyze the earthquake resistant performance of the shock absorber.

Digital platform-based multi-domain virtual prototype simulation on a high-speed parallel manipulator

SUMMARYThis paper presents how to build an all-digital co-simulation platform of a mechtronic system so as to reduce the burden and error of system modeling. In the construction of a platform, a driving system, including a motor, a pulse-width modulation (PWM) and a controller, is simulated using Matlab/Simulink. The behavior of the mechanism is analyzed using the ADAMS software. By the proper interface function for the real-time communication between two parts of the models, a virtual working environment is established. Finally, a proportional integral derivative (PID) controller verifies the validity of the digital platform.

Gerotor Pumps for Automotive Drivetrain Applications: A Multi Domain Simulation Approach

Gerotor Pumps for Automotive Drivetrain Applications: A Multi Domain Simulation Approach

Multi-Domain Unified Modeling and Simulation for Aircraft Landing Gear Using Modelica

Modern products become more and more complex, the modeling and simulation of them are carried out with different software on heterogeneous platforms, which always caused the heterogeneous data, separated disciplines and cannot obtain the result of unified model correctly. Therefore, a Modelica-based modeling and simulation method for aircraft landing gear is proposed. The landing gear library based on Modelica was established. The unified physical model of landing gear which is composed of structural, thermodynamics and hydromechanics disciplines is constructed. The aircraft landing process, the track of retraction mechanism and the impact work amount of the shock absorber are obtained through multi-domain unified simulation, which provides references for deisgners.

A collaborative platform for complex product development based on multi-domain unified modeling and simulation

In order to intensify market competition, manufacturing enterprises must improve their product innovation capability. It is difficult to integrate the system modeling, simulation and collaborative process management in complex product development. A collaborative platform for complex product development based on multi-domain unified modeling and simulation is proposed in this paper. The architecture of the platform is firstly stated. The idea and realization of three key technologies, i.e. multi-domain modeling and simulation for complex product, knowledge management for product design and simulation, multi-domain collaborative mechanism, are emphasized. Finally, an industry case is given. The demonstration of the system shows that integration architecture is the effective infrastructure for multi-domain collaborative product development.

A Study of Vehicle Energy Management during Warming up Process Using VHDL-AMS Multi-domain Simulation

In this paper, by employing thermal characteristic modeling to the main components of the vehicle model for example, engine, transmission and battery, we examine the heat energy management and fuel consumption of the testing drive patterns especially during warming up process. The simulation data agree well with measurement data. Our vehicle simulation results provide VHDL-AMS validity for multi-domain energy management and the vehicle system planning.

An integrated framework combining a traffic simulator and a driving simulator

Driving simulation has been used for many years now in research, industry and training to simulate virtual driving conditions. This is largely because simulation saves engineering time and costs, and virtual situations provide an easier and safer way to carry out road and traffic safety studies. Scenarios or scenes that realistically reproduce traffic behaviour according to the traffic flow theory has been developed since the 1980s and traffic simulators are a widely used technology in the research, planning, evaluation and development of new traffic systems (for instance Intelligent Traffic Systems). The aim of this paper is to explain how providing a simulation framework based on the integration of a driving simulation engine and a traffic simulation can respond to the issues addressed by offering multi-level and multi-domain simulation models. This paper describes the integration of the driving simulator SCANER and the traffic simulator Aimsun, where the driving simulator (including visual, audio and kinaesthetic restitution) manages the simulation in the immediate driver environment and the traffic simulator manages the whole road network situation, creating a large-scale, realistic and minutely detailed virtual world.

Modeling and Performance Analyzing of Helix Transmission Base on Modelica

Picking manipulator ontology structure used rotation and translational motion pairs to join the components together, and then a multi-joint motion mechanism was built which meet the picking space requirement. According to the characters of growth space of litchi fruit, here used helix transmission as the first axes of the picking manipulator, to achieve motion in vertical direction. This study introduces the application of multi-domain modeling and simulation when constructing and simulating a helix transmission. Use object-oriented technology, multi-domain modeling and simulation language Modelica to construct the motion system which integrates motor model, signal detection module, signal processing module and parametric screw transmission model in Dymola simulation platform. Test the helix transmission by simulation, using the mechanical structure, sensor technology, signal processing technology. Simulation results show that, the modelica can provide a valid simulation for complex electromechanical system and support for parametric design.

Coupling electromagnetic (FE) models to multidomain simulator to analyse eletrical drives and complex control systems

Coupling electromagnetic (FE) models to multidomain simulator to analyse eletrical drives and complex control systemsThis work presents the co-simulation approach to the analysis of control systems containing detailed models of electromagnetic and electromechanical converters. In this method of analysis the attention is paid to the whole system and not only to its electromagnetic part. The latter is described by equations resulted from the two-dimensional finite element discretisation of the Maxwell equations, and is coupled weakly with the remaining part of the system. The simulation is carried out in Matlab/Simulink environment wherein the coupling is realised through the S-function. Example results regarding simulation of the operation of the control system of an electrical machine and the operation of a power electronic converter are presented and compared with available reference data.

Research on Multi-Domain Unified Modeling and Simulation of a Micro Electro-Thermal Actuator

Referring to the natures of nonlinear dynamics and coupled energy domains presented by Micro-Electro-Mechanical Systems (MEMS), a multi energy domain unified simulation language (modelica) based coupled modeling and simulation methodology is put forward. Then by choosing a micro electro-thermal actuator as the example, corresponding multi energy domain unified modeling and simulation processes of such a coupled micro device, which covers mechanical energy domain, electric energy domain and thermal energy domain, show the efficiency and convenience of this advanced modeling method. At last, through simulation result comparison with device level FEA simulation result and experimental result, the maximum relative error between numerical calculation result and experimental result is less than 4.2%. It proves the accuracy of this system level simulation method.

Research on Multi-Domain Unified Modeling and Optimization of a Micro Mirror

Referring to the natures of nonlinear dynamics and coupled energy domains presented by Micro-Opto-Electro-Mechanical Systems (MOEMS), a multi energy domain unified simulation language (modelica) based coupled modeling, simulation and optimization methodology is put forward. Then by choosing a micro mirror as the example, corresponding multi energy domain unified modeling and simulation processes of such a coupled micro device show the efficiency and convenience of this advanced modeling method. The dynamic input/output curves comparison also shows that the simulation result is accurate enough for system level design. At last, by using genetic optimization algorithm, the characteristics input/output curves of the micro mirror are converged to meet the ideal design requirement curves after 700 generations evolution. It proves the accuracy and efficiency of this system level simulation and optimization method.

A Top-down Modeling Mechanism in Multi-domain Modeling and Simulation Platform

The bottom-up modeling approach based on the traditional drag-and-drop modeling method employed in most of current multi-domain modeling platforms can not support the forward design.A top-down modeling mechanism based on empty components is presented to model multi-level abstract expression of complicated products easily.The interface of empty component and update process of models are discussed respectively.A simulation instance adopting the proposed mechanism to model complicated multi-domain problem is given.

Multi-domain Simulation of Hybrid Excitation Machine with Isolated Magnetic Paths

In order to extend the speed range for the constant-power motoring mode or the constant-voltage generating mode of the electric machine,a new structure of hybrid excitation machine with isolated magnetic paths (HEIMP) is presented.Its structural characteristics and operation mechanism are detailed.The prototype machine with 12 poles,18 slots and 2 units is simulated and analyzed with the Ansoft Maxwell 2D finite element (FE) software for its field adjustability,and with the ANSYS FE software for its centrifugal stress,natural frequency and thermal characteristics in order to verify the structural feasibility and rationality of the HEIMP machine.The test on the prototype machine shows the adjustability of the excitation mmf on both directions and the magnetic field in a wide range.Due to the compact,the utilization of its stator iron core and its armature winding is effective,therefore,the HEIMP machine possesses high efficiency.The test results of the prototype machine show good agreement with the FE simulation ones,which verifies the correctness of the multi-domain simulation technique.It solves the technical problems effectively in the accurate characteristics calculation and the design optimization of the new structure HEIMP machine and therefore,promotes its design capability.

Dynamic modeling of a photovoltaic hydrogen fuel cell hybrid system

The objective of this paper is to mathematically model a stand-alone renewable power system, referred to as “Photovoltaic–Fuel Cell (PVFC) hybrid system”, which maximizes the use of a renewable energy source. It comprises a photovoltaic generator (PV), a water electrolyzer, a hydrogen tank, and a proton exchange membrane (PEM) fuel cell generator. A multi-domain simulation platform Simplorer is employed to model the PVFC hybrid systems. Electrical power from the PV generator meets the user loads when there is sufficient solar radiation. The excess power from the PV generator is then used for water electrolysis to produce hydrogen. The fuel cell generator works as a backup generator to supplement the load demands when the PV energy is deficient during a period of low solar radiation, which keeps the system's reliability at the same level as for the conventional system. Case studies using the present model have shown that the present hybrid system has successfully tracked the daily power consumption in a typical family. It also verifies the effectiveness of the proposed management approach for operation of a stand-alone hybrid system, which is essential for determining a control strategy to ensure efficient and reliable operation of each part of the hybrid system. The present model scheme can be helpful in the design and performance analysis of a complex hybrid-power system prior to practical realization.

Modeling and Simulation of a Large Chipper Drive

This paper presents a simulation model for a large chipper drive used in a paper mill. If the chipper drive is a slip ring induction motor, several advantages arise from using a rheostat in the rotor circuit. This paper will investigate the impact of a rotor circuit rheostat with respect to starting behavior and heavy duty load impulses. The chipper drive is modeled in Modelica, an object oriented multi domain simulation language. In addition to the theory, a practical case is presented to demonstrate the applicability of the derived knowledge.

Multi-domain Modeling and Simulation of Clutch Actuation System Based on Modelica

Multi-domain Modeling and Simulation of Clutch Actuation System Based on Modelica

Modelling and simulation of PDE problems in Modelica

Modelica is a new object-oriented multi-domain modelling and simulation language used for solving large, complex and heterogeneous physical systems with differential algebraic equations (DAEs). Presently, there is no simulation support available in Modelica for solving partial differential equations (PDEs) problems. In this paper, based on the object-oriented idea, we present a method of consistent representation of PDE and DAE problems. The description of PDE problems in Modelica is introduced. Then the PDE model is transferred into DAE model with the method of lines, and is solved in MWorks simulation platform based on Modelica. To illustrate the application of our method, a heat conduction problem is modelled and simulated in Modelica.