Session 4A: Automotive I

Title: Development of an Integrated Control of Front Steering and Torque Vectoring Differential Gear System Using Modelica
Authors: Yutaka Hirano
Abstract:To achieve future low carbon mobility society, many new-type electric vehicles (EVs) are developed actively in recent period. Those EVs have integrated power unit which take place of conventional engine, transmission and differential gear components. Additionally it is rather easy to integrate torque vectoring function to those power units using gear sets to control torque distribution between left wheel and right wheel. In this paper, model-based development of an integrated control of the front steering angle and torque vectoring differential (TVD) gear system is described. New integrated control logic was developed using model matching control to let the vehicle yaw rate and vehicle slip angle follow the desired dynamics. Simulation results using a single track model of vehicle dynamics are shown to prove the efficacy of the proposed control. Though, full vehicle model considering all of vehicle dynamics and drive train motion using Modelica clarified the problem of this method in actual cases. Difference between single track model and full vehicle model was compared to estimate the reason of the problem
Links: Full paper

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Title: Virtual Occupant Model for Riding Comfort Simulation
Authors: Hyung Yun Choi, Manyong Han, Akinari Hirao and Hisayoshi Matsuoka
Abstract:A digital human body model as a virtual occupant surrogate for the riding comfort simulation is developed for both 1D lumped network (Modelica) and 3D mesh based (Finite Element) solutions. Since the composition of 1D and 3D versions of the human body model has a similar multibody system architecture, the kinematic responses from both solutions are almost equivalent. The models are therefore complementary, since the economic 1D models can serve effectively in design exploration and optimization, while their sophisticated 3D counterparts can serve in final design validation. The detailed modeling process and validation results against standard seat vibration excitation test are introduced in this paper, preparing the models for use in seat design.
Links: Full paper

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Title: A Simulation-Based Digital Twin for Model-Driven Health Monitoring and Predictive Maintenance of an Automotive Braking System
Authors: Ryan Magargle, Lee Johnson, Padmesh Mandloi, Peyman Davoudabadi, Omkar Kesarkar, Sivasubramani Krishnaswamy, John Batteh and Anand Pitchaikani
Abstract:This paper describes a model-driven approach to support heat monitoring and predictive maintenance of an automotive braking system. This approach includes the creation of a simulation-based digital twin that combines models and different modeling formalisms into an integrated model of the braking system that can be used for monitoring, diagnostics, and prognostics. The paper provides an overview of the basic models including Modelica models, reduced order models for various key components of the system model, and controls and sensor models. The simulation results include both baseline results for the system and the results of injecting failures into the system for monitoring and predictive maintenance.
Links: Full paper

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Title: Improved Aerodynamic Prediction Through Coupled System and CFD Models
Authors: Ed Tate, Joaquin Gargoloff, Brad Duncan, Hubertus Tummescheit, John Griffin and John Batteh
Abstract:High accuracy predictions of aerodynamic forces using computational fluid dynamics requires accurate geometry. The aerodynamic forces on the vehicle body affects the vehicle posture or the vehicle position with respect to ground. When a vehicle is cruising, the change in vehicle posture is usually relatively small with respect to the size of a vehicle. However, these small changes in geometry can lead to significant correlation differences in drag and airflow structure. To address this issue, a coupled simulation approach was developed to predict vehicle posture in typical cruise and wind tunnel test conditions. This coupled approach was tested using PowerFLOW and Modelon’s Vehicle Dynamics Library (VDL). In this approach, the aerodynamic forces on the body are used to calculate the movement of the body and geometry. This modified geometry is then used to recalculate the operating aerodynamic forces. The modified geometry shows changes in total force, the distribution of forces, and the structure of the airflow over the vehicle. The results provided by correct geometry under load conditions offer better correlation to test and provide car makers with the improved accuracy to confidently improve real world fuel economy.
Links: Full paper