Calculation method of belt material parameters for finite element tire model

The radial tire belt is composed of multi-layered fiber-reinforced cords with a very complex structure. Restricted by the computing speed, the simplified finite element (FE) tire model with equivalent belt is usually applied in the vehicle dynamic simulation. However, it is always difficult to obtain the material parameters of the equivalent belt. In this paper, a calculation method of equivalent belt material parameters for the simplified FE tire model is proposed based on the three-dimensional (3-D) anisotropic elasticity of the cord reinforced composites. The simulation results of the static radial stiffness, modal characteristics, and dynamic responses for the simplified FE tire model with parameters obtained by the calculation method were compared with experiment results. The results show that the deviation between the experiment and simulation is acceptable, and the validity of the calculation method is verified.

Comparison of bus driving cycles elaborated for vehicle dynamic simulation

Due to the technological progress, new approaches such as model-based design are spreading in the development process in the automotive industry to meet the increased requirements related to lower fuel consumption and reduced emission. This work is part of a research project which focuses on dynamic modeling of vehicles aimed at analyzing and optimizing the emission and fuel consumption. To model the driver behavior, the simulation control algorithm requires a predetermined speed-time curve as an input. The completeness of this driving cycle is a crucial factor in the simulation, and as far as the legislative driving cycles are not accurate enough, it is indispensable to develop our own one representing our narrower area and driving conditions. This article considers two common drive cycle design methods, comparing the micro-trip-based approach and the Markov-chain approach. The new driving cycle has been developed applying the Markov-chain approach and compared to a driving cycle introduced in our recent paper using the micro-trip method. The comparison basis is the Speed-Acceleration Probability Distribution, which sufficiently reflects the dynamic behavior of the vehicle, and the root mean square error, including parameters such as the average speed, average cruising speed, average acceleration, average deceleration, root mean square acceleration, and idle time percentage. The representative Bus Driving Cycle for Debrecen is prepared to be applied in the vehicle dynamics simulation for evaluating and improving the fuel economy of vehicles, selecting the proper power source for various applications and the optimization of the powertrain and the energy consumption in researches to be continued.

Vehicle Dynamic Simulation Possibilities Using AVL Cruise M

In most cases, when creating vehicle dynamics simulations, we need software that can speed up model creation and simulation. There are many programs on the market for this purpose, but they have different knowledge and user interfaces. We present in this article briefly introduces the use of one of the market's leading vehicle simulation software, the AVL Cruise M.

Semitrailer Steering Control for Improved Articulated Vehicle Manoeuvrability and Stability

Articulated heavy vehicles have some specific performance limitations and safety risks due to their special dynamic characteristics. They show poor manoeuvrability at low speeds and may lose their stability in different manners at high speeds. In this study, the potential of active steering control of the semitrailer on manoeuvrability and stability of tractor-semitrailer combinations is investigated. A linear bicycle model and a nonlinear version are used for controller design and vehicle dynamic simulation in MATLAB environment. The Linear Quadratic Regulator optimal state feedback control is used to minimise the tracking error at low-speed, and regulate Rearward Amplification ratio and roll at high-speed. Quantum Particle Swarm Optimisation is used for optimising the weighting factors. Three different control algorithms are introduced and it is demonstrated through simulations that the vehicle with the proposed steering control exhibits desirable improvements compared to the baseline vehicle.

RMPC-Based Directional Stability Control for Electric Vehicles Subject to Tire Blowout on Curved Expressway

This paper presents a directional stability control based on robust tube-based model predictive control (RMPC) approach for an overactuated electric vehicle after tire blowout on curved expressway, in the presence of the exogenous disturbances, such as cross wind and road variation. To begin with, the vehicle dynamic simulation platform allowing for the tire vertical force redistribution after tire blowout is presented, and the reliability of the platform is further analyzed by comparing with the existing experimental test results. After that, a RMPC-based controller is designed to enhance the directional stability performance of the vehicle on curved expressway after tire burst. Also, a pseudo inverse switch control allocator is developed to realize the allocation of the desired resultant signal for the remained effective wheels at the last stage. In the end, the simulation results conducting on the depicted simulation platform demonstrate the favorable maneuverability of the proposed method over the conventional model predictive control (MPC) in enhancing directional stability performance of the vehicle after a tire blowout on curved expressway.

A Model Based Framework for Wheel Lock Simulation in a Brake Dynamometer Towards Heavy Road Vehicle Safety

This work proposes a method to simulate wheel lock of a Heavy Commercial Road Vehicle (HCRV) using pneumatic brake circuit on a brake dynamometer. The proposed methodology lumps the effects of wheel slip and load transfer during straight-line braking into ‘equivalent inertia’ on the wheels. This inertia profile could then be imported on a dynamometer interface and realized using suitable inertia discs and an electric motor. Equivalent inertia was computed from test datasets obtained from a Hardware-in-Loop (HiL) experimental system consisting of an air brake system and IPG TruckMaker®, a vehicle dynamic simulation software. These datasets were obtained for various road, vehicle load and braking conditions. This framework would facilitate the evaluation of wheel slip regulation algorithms using a brake dynamometer by capturing necessary dynamics of HCRVs during braking. It is expected that such testing can be placed between HiL and on-road tests, and would provide greater confidence in Active Safety Systems (ASSs) before their deployment on vehicles.

In-Plane Flexible Ring Tire Model—Part 1: Modeling and Parameter Identification

ABSTRACT The tire model is essential for accurate and efficient vehicle dynamic simulation. In this article, an in-plane flexible ring tire model is proposed, in which the tire is composed of a rigid rim, a number of discretized lumped mass belt points, and numerous massless tread blocks attached on the belt. One set of tire model parameters is identified by approaching the predicted results with ADAMS® FTire virtual test results for one particular cleat test through the particle swarm method using MATLAB®. Based on the identified parameters, the tire model is further validated by comparing the predicted results with FTire for the static load-deflection tests and other cleat tests. Finally, several important aspects regarding the proposed model are discussed.

Modeling of Lateral Stability of Tractor-Semitrailer on Combined Alignments of Freeway

The objective of this research was to investigate the impact of roadway geometrics and speed on lateral stability of tractor-semitrailer on combined alignments of freeways since the current design guidelines of combined alignments are not available in China. A closed-loop vehicle dynamic simulation model was established using TruckSim multibody dynamics software. The maximum wheel side friction demand and lateral load transfer ratio were used to measure the skidding and rollover risks, and the variation laws of each indicator were determined by developing the controlled variable simulation scenarios. Based on the theory of statistical analysis, an orthogonal test was designed, and the effects of various impact factors on the lateral stability of the tractor-semitrailer were analyzed. The models for lateral stability indicators were developed by multiple linear regression analysis and applied to evaluate the driving risk of tractor-semitrailer on a wet road surface. The results showed that the radius and speed have significant effects on the lateral stability while the effect of the downgrade is of general significance. In addition, lower safe speed should be adopted on wet road surfaces of curved downgrade. This paper proposed a surrogate approach to road safety analysis and the models can be used for building the freeway driving security system.