Toyota Motor Corporation
ABSTRACT: Dymola has become an irreplaceable tool for Toyota. In designing new car models, Toyota uses Dymola to simulate -and create- engine and transmission models. In transmission department, thanks to Dymola, acceleration performances and acoustic vibrations are studied. To perform engine simulations, Toyota engineers created a customized Diesel engine Library for mass low rate, pressure and temperature analysis in each engine part. As Shinichi Soejima of Toyota Motor Corporation (article’s author) states, the fundamental aspect of simulations of this kind is the Dymola versatility: very complex models have been created with ease, and then reused in a number of different analysis and situations with quick and simple alterations.
Fast Real-Time Simulations with Dymola: Analysis of New Methods for Non-Linear Equation Resolution
Every day, the need of high performance and low fuel-usage car rises, especially pushed by the common will to decrease the ecologic impact of vehicles. New control technologies have recently been introduced, which are built on the wide presence of sensors inside the car. To improve the performance of such control schemes, it’s mandatory to perform a realistic car simulation, using the HILs (Hardware in the Loop simulation) approach. While in the past such complex simulations could be performed just using extremely simplified models, today -thanks to Dymola- it is possible to create very detailed models for engines, transmissions, hydraulic plants and brakes. In the following article, new methods are analyzed to further speed real-time Dymola simulations, through new procedures of non-linear equations resolution.
With automobile market in growing expansion, the time required to a designer to create new car models and components is always reducing. In designing phase, simulation has replaced long, expansive and inaccurate direct tests. If, so far, a car could be considered a set of complex, yet separated systems (engine, transmission, gearbox, brakes, …), today new technologies and control systems made those components strongly inter-dependent. The simulation and testing phase must then involve all these systems as a whole. In the following article, a Dymola simulation of a BMW car automatic drive is illustrated. For the already described properties, to carry out this simulations a group of BMW engineers had to reproduce not only the drive itself, but also its control electronics, together with the mechanic and the hydraulic part. With Dymola, detailed mechanic and hydraulic models have been introduced, as well as more simplified models for the rest of the cinematic chain of the car (engine, differential gear, frame). The article explains in detail the simulation, its results and anticipates future progression of the project, supposing to use Dymola not only in the simulation phase, but in the practical application too and during the modelization phase as well.
Ford Motor Company
ABSTRACT To answer to the growing market and regulator demand for reduction in fuel consumption and emission, Ford Motor Company developed an Hybrid Electric Version (HEV) of the Escape SUV, in production from 2003. An electric hybrid car has different working processes (electrical start-up, switch to gearbox in neutral, regenerative braking): each one of these, and the shift from one to another, could produce vibrations that the driver may perceive. To understand how vehicle design and control may alter the driver perception, it is needed to model the dynamic answer of transmission. The article explains the study from a team of Ford Motor Company researchers, which chose Modelica to successfully simulate the whole system. The entire model has been evaluated, by comparing its results with data from direct testing on vehicles. The matching between the two has been proven to be fully satisfying, in a wide range of different operating conditions.
ABSTRACT The article shows how to model and simulate the friction effects in gears and planetary gears. The project analyzed the practical problems of gear jamming and slipping due to Coulomb friction among gear teeth, and the related load torque losses. Dymola can also describe this kind of scenario, since even stick-slip effects (twitching progression) can be simulated in servo drives or in automatic drive gears. Proposed models are realized in Modelica, and illustrated referring to an automatic drive simulation.
ABSTRACT Researchers from the Signal, Sensors and Systems department of the Sweden Royal Institute of Technology developed a new Library with Modelica Library to simulate and to analyze the fuel consumption of auxiliary units of heavy vehicles. Researchers had to evaluate the efficiency of different system driving architectures: they chose Modelica since it is a language especially adapt to build modular structured models. For this peculiarity, Modelica is perfect to describe the behavior of complex systems, which contains mechanical and electrical parts. The new Library they created includes model developed following strict physical principle and models invented specifically to adapt to gathered data. All the simulations have been compared to data, through a great number of wind gallery tests.