Road-Vehicles Control Logic Integrating Real Time Multibody Model Follower

Author(s):  
Isabel Ramirez Ruiz ◽  
Edoardo Sabbioni ◽  
Francesco Braghin ◽  
Federico Cheli

The challenge to enhance the vehicle driving and handling with a state estimation and prediction system is presented by fusing a primary real time multibody vehicle model capable of providing a good indication of vehicle stability and control, and a secondary model able to estimate the vehicle state from vehicle real and virtual sensors to correct the indications of the primary model. A mathematical algorithm combines these two models in the drive control system improving the behavior of the active systems of the vehicle. A Multibody vehicle model has been used to achieve a high fidelity simulation of vehicle dynamics. The selected software is LMS.Virtual.Lab Motion with Real-Time Solver which complements the AMESim Real-Time Solver to handle complex real-time 3D-1D mechatronic systems without any simplified conceptual models. A Sensor Signal Processing Model has been developed to estimate the vehicle states and calculating tire-road contact forces and vehicle sideslip angle. The methodological approach uses the equations of motion of the chassis applying the fundamental principles of classical physics: Newtonian method and Euler angles. The control logic is based on the continuous updating of the preview multibody vehicle model by the controller sensors information network, which makes the model forecast behavior closer to the real one and improve comfort and linearity of the vehicle response. The driver inputs (throttle, steer angle and torque, brake, gear) are the same for the MBS real time model and for the real vehicle. A first training logic updates the MBS model based on the real vehicle behavior calculated by the sensor network, where the logic has to update in the MBS model just the factors depending on the vehicle itself (for example car weight, tire temperature, shock absorber damping forces, tires characteristics) and to understand and keep into account different environment variation (wet / dry surface). If the real vehicle is equipped with active control systems to improve handling and stability, as active camber control, drive by wire, ESP, Body movement active controls, the real time multibody model will interact with the models 1D or 3D of these vehicle dynamics controls and will improve their performance with a very high accuracy prediction of their influence on vehicle dynamic response. In conclusion with the help of the preview multibody vehicle model the drive control logic will increase the performance and drive ability of the vehicle with smart logic interacting with all the active systems.

Author(s):  
Sung-Soo Kim ◽  
Wan Hee Jeong ◽  
Seonghoon Kim

HILS (Hardware-in-the Loop Simulation) vehicle simulator is one of the most effective tools to develop control subsystems for the intelligent vehicles, since expensive vehicle field tests can be replaced with virtual tests in the HILS simulator. In the HILS simulator, the software vehicle dynamics model must be solved in real-time, and it must also reproduce the real vehicle motions. Compliance effects from suspension bush elements significantly influences the vehicle behavior. In order to include such compliance effects to the vehicle model, normally the spring-damper model of the bush elements is used. However, high stiffness of the bush elements hinders real-time simulations. Thus, it is necessary to have an efficient method to include compliance effects for the real-time multibody vehicle dynamics model. In this paper, compliance model for real-time multibody vehicle dynamics is proposed using quasi-static analysis. The multibody vehicle model without bush elements is used based on the subsystem synthesis method which provides real-time computation on the multibody vehicle model. Reaction forces are computed in the suspension subsystem. According to deformation from the quasi-static analysis using reaction forces and bush stiffness, suspension hardpoint locations and suspension linkage orientation are changed. To validate the proposed method, quarter car simulations and full car bump run simulations are carried out comparing with the ADAMS vehicle model with bush elements. CPU times are also measured to see the real-time capabilities of the proposed method.


Author(s):  
Sung-Soo Kim ◽  
Young-Seok Oh

Abstract A real-time multibody vehicle dynamics model has been developed using a subsystem synthesis method in a PC-based workstation. The subsystem synthesis method produces 6 × 6 matrix form of equations of motion for the chassis and small size each of suspension subsystem equations of motion separately. Simulations such as, bump-run, stop-and-go, and brake-in-turn have been carried out. Solutions have been validated to compare with those from the model with the conventional recursive formulation. CPU times taken for simulations have been also measured to verify the real-time simulation capability of the proposed vehicle model.


2013 ◽  
Vol 644 ◽  
pp. 101-104
Author(s):  
Zhen Wei Zhang ◽  
Chong Chen ◽  
Ruo Bing Jiao ◽  
Rong Rong Hu

Cylindrical air spring suspension’s vehicle model with seven freedom degrees is established. Then the model is simulated by use of Matlab/Simulink to accomplish the simulated-computation of the driving state such as rolling angle and pitching angle. Based on the above work, air suspension controller, DSP TMS320F2812 chip as the core processor, is developed. The result of the real vehicle test proves that the controller can obviously improve vehicle’s driving smoothness and handling stability, so it meets the applying requirements.


2013 ◽  
Vol 380-384 ◽  
pp. 1746-1749
Author(s):  
Jun Zhan ◽  
Jiang Li Lu ◽  
Liang Xu ◽  
Wei Zhang

At present, the performance of the vehicle dynamics model is mainly evaluated objectively through offline simulation. In this paper, a vehicle dynamics model was implemented in dSPACE, which was applied to the Automotive Performance Simulator and the preliminary study was made for the realization of the subjective evaluation of the performance of vehicle dynamics model through the real-time closed-loop online simulation. The dSPACE interface library was used to write a Clib program to operate and control the Carsim RT model running on the dSPACE platform, which realized the communication between the external hardware and the real-time hardware of dSPACE.


ATZ worldwide ◽  
2004 ◽  
Vol 106 (2) ◽  
pp. 11-13 ◽  
Author(s):  
Torsten Butz ◽  
Martin Ehmann ◽  
Oskar von Stryk ◽  
Thieß-Magnus Wolter

Author(s):  
Rebecca Anne Bandy ◽  
Sukhwan Cho ◽  
John B. Ferris ◽  
Joerg Schlinkheider ◽  
Marc Wimmershoff

A Location-Aware Adaptive Vehicle Dynamics System (LAAVDS) is currently being developed to predict and maintain vehicle handling capabilities through upcoming maneuvers. This system depends heavily on an understanding of the interplay between the vehicle’s longitudinal, lateral, and vertical forces, as well as their resulting moments. These vehicle dynamics impact the Performance Margin metric and ultimately the point at which the Intervention Strategy will modulate the throttle and brake controls. Real-time implementation requires the development of computationally efficient predictive models of the vehicle dynamics. A method for predicting future vehicle states for smooth but tortuous roads is developed in this work using perturbation theory. An analytical relationship between the change in these forces and the resulting change in the Performance Margin is also derived. This model is implemented in the predictor-corrector algorithm of the Intervention Strategy. Corrections to the predicted states are made at each time step using a detailed, full, non-linear vehicle model; this full vehicle model is a precursor to incorporation of the LAAVDS in a real vehicle. Eventually, this work will be expanded to include the impact of rough terrain.


Author(s):  
Roland Pastorino ◽  
Emilio Sanjurjo ◽  
Alberto Luaces ◽  
Miguel A. Naya ◽  
Wim Desmet ◽  
...  

This research focuses on the experimental validation of a real-time vehicle multibody (MB) model whose bodies are considered rigid. For this purpose, a vehicle prototype has been built and automated in order to repeat reference maneuvers. Numerous sensors on the prototype gather the most relevant magnitudes of the vehicle motion. Two low speed maneuvers involving the longitudinal and lateral vehicle dynamics have been repeated multiple times in a test area. Then, a real-time MB model of the vehicle prototype has been self-developed as well as a simulation environment that includes a true graphical environment, a true road profile, and collision detection. Subsystems like brakes and tires have also been modeled. Both test maneuvers have been simulated with the MB model in the simulation environment using inputs measured experimentally. Selected simulation variables have been compared to their experimental counterparts provided with a confidence interval (IC) that characterizes the field testing (FT) process errors. The results of the comparisons show good correlation between simulation predictions and experimental data, thus allowing to extract useful guidelines to build accurate real-time vehicle MB models. In this way, the present work aims to contribute to the scarce literature on vehicle complete validation studies.


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