More effective development of commercial vehicle dynamics


State-of-the-art software from rFpro has helped to speed up the development of commercial vehicle chassis dynamics in a study for Hyundai carried out by a team from Applus IDIADA. rFpro’s software allowed IDIADA to link Hyundai’s CarSim model with realistic graphics and a human driver to evaluate the benefits of using a simulator for chassis development. Once sufficiently developed using a workstation, the application was transferred to the eight degrees-of-freedom Sim IV platform at The Swedish National Road and Transport Research Institute (VTI), which has been at the forefront of simulator development for over 40 years.

“In the space of 10 days we were able to evaluate around 25 different vehicle configurations using three professional drivers,” explained Guido Tosolin, Applus IDIADA’s product manager, Chassis Development and Vehicle Dynamics Simulation. “More importantly, because of the high fidelity visual cueing using rFpro software, driver immersion was very convincing which led to good correlation between their subjective ratings and the objective data.”

During the study, drivers correctly interpreted the direction and magnitude of various changes to kinematics, springs, dampers and anti-roll bars. An additional benefit was derived from the high volume of data produced, according to Tosolin. “For the first time, we have generated so much data that we are able to use statistical methods effectively to interpret the results,” he said.

The IDIADA project is believed to be the first major application of a driving simulator to commercial vehicle chassis dynamics and required a suitable cabin arrangement and driving position to be effective. It also used rFpro’s own virtual Vehicle Dynamics Proving Ground which allows subjective and objective testing to take place just as it is done in real world track testing.

“Our software is based on closing the loop as quickly as possible by providing very high bandwidth video and audio feeds to the driver and high bandwidth road surface detail to the vehicle model. This provides the realism necessary to achieve good correlation between driver perceptions and objective vehicle changes,” explained rFpro’s technical director, Chris Hoyle.

The experience of the IDIADA team parallels that of AVL, the world's largest independent company for the development of automotive powertrain systems, which also uses simulator software from rFpro. AVL estimates that over 30 percent of the costs incurred in developing driving attributes can be saved through frontloading the engineering activity on a DIL simulator with subjective feedback, making better and more complete information available earlier in a vehicle program, before physical prototypes exist.

“Early in the development of new powertrain concepts, decisions are made regarding fundamental architecture which have far-reaching consequences,” said AVL’s Erik Bogner Dipl-Ing, Manager for Driveability and Simulation, Engineering & Technology, Powertrains Systems dept. “Many of those decisions influence the subjective feel of the vehicle and require driver feedback to supplement objective data, in order to ensure the optimum choices are made. Simulation software from rFpro not only provides the greatest possible graphical realism for the driver but also the ability to ‘feel’ events such as gear shifts and vehicle movements and experience them in ways that are not possible with offline desktop simulation.

“AVL chose rFpro software because it provides seamless integration of the vehicle model and the best level of immersive experience for the driver conducting the assessment testing,” Bogner continued. “rFpro’s inherent strengths in low latency and high bandwidth make it the only viable solution for conducting DIL vehicle dynamics studies.”

tags: Hyundai rFpro Commercial Vehicles