High frequency response and low latency allow new application areas, including ADAS calibration, simplifying new technology integration
A next-generation vehicle driving simulator has been developed by AB Dynamics, one of the leading suppliers of advanced automotive test systems, which will significantly reduce development time and cost. The simulator uses an innovative motion platform and proven motion control techniques designed by Williams in its Formula OneTM operations. Immersive digital content is provided by leading software supplier rFpro. The advanced Vehicle Driving Simulator (aVDS) offers reduced latency and increased frequency response compared to alternative systems, which allow more test, development and calibration tasks to be completed without a prototype vehicle.
“With a proliferation of new models and new technologies, pressure on time and budgets continues to grow. Vehicle dynamics simulators help to address these challenges by providing engineers with the physical experience of driving a vehicle but in the repeatable environment of a laboratory,” explains Dr. Adrian Simms, Business Manager (Laboratory Test Systems) at AB Dynamics. “Until now, the range of applications has been constrained by the physics of the motion platform, which has generally limited simulator use to human machine interface and ergonomic studies. The high performance required for vehicle dynamics applications has not been available.
“Our new approach advances performance to a degree that allows much more to be achieved, extending the range of applications into many other functions that would traditionally have required a prototype vehicle,” continues Dr Simms. “We believe that this is the first system to offer a high-resolution, fully-representative driving experience, making it the first true Vehicle Driving Simulator.”
The technology behind the performance
By providing precise on-time cueing (audio, visual, haptic, vestibular), the AB Dynamics aVDS immerses the driver in the experience – creating the impression of driving. A high excursion capability ensures plenty of travel for effective motion cueing, enhancing the impression of changes in speed and direction. Low latency ensures that all the driver’s senses are cued at precisely the right time. As well as increasing the realistic feel of the drive this also helps to eliminate motion sickness that can be felt in some systems.
The unique arrangement of the motion platform means that consistently high frequency response is achieved throughout the full range of travel. This ensures accurate simulation of vehicle attributes, including ride quality and steering feel, wherever the moving platform goes.
“With so many different technologies available, the challenge for engineers considering a simulator is to select and specify the best system for their application. Comparing inappropriate metrics can lead to costly and incorrect choices being made, as several vehicle manufacturers have discovered,” continues Dr. Simms. “For example, where a hexapod architecture is used, impressive travel in one axis hides limited excursion in combined directions. Systems with additional mechanisms to overcome this inherent limitation will have higher mass and inertia, which is detrimental to the simulator’s performance.”
The AB Dynamics system solves these problems by mounting a vehicle cockpit on four identical ‘wedge’ actuator modules mounted on two parallel rails. Quiet and lightweight linear motors control both the height of the platform on the wedge and the position of the wedge on the rail. The platform is cleverly designed with angled sides. It is moved backwards and forwards by changing the distance between the wedges on each rail. Turning the platform is achieved by moving the front and rear actuator pairs in opposite directions along the rails. Heave, pitch and roll are controlled by moving the wedges independently to lift or lower the platform at each corner.
“Achieving a significant improvement in latency and frequency response requires a very stiff yet also lightweight system. Williams has achieved this with a mechanism that is remarkably simple, enabled by a sophisticated control strategy,” continues Dr. Simms. “The result is an architecture that not only delivers a substantial step forward in capability, but is also quiet and extremely compact.”
A large radius screen wraps around the installation to provide an immersive driving environment. Software from rFpro provides high definition graphics and audio, including high frequency input to replicate measured road texture. A comprehensive library of rFpro proving ground and public road models already exists and can be supplemented with bespoke LIDAR scans of test routes. The rFpro software wraps around all the mainstream vehicle modelling tools and integrates programmable traffic modules, including additional robot or human drivers occupying the same environment, making it ideal for the development of active safety and Advanced Driver Assistance Systems (ADAS).
The high payload capability allows a full vehicle front-end and cockpit module to be mounted on the motion platform. Alternatively, AB Dynamics can supply a lightweight, carbon composite cockpit that will maximise dynamic performance.
Test integration roadmap
The aVDS is designed to integrate seamlessly with AB Dynamics’ substantial portfolio of test systems, for example for developing Automated Emergency Braking (AEB), which is now part of EuroNCAP testing.
AB Dynamics’ Chief Technology Officer, Dr. Stephen Neads, says the aVDS is the first step in a vision that will bridge the gap between objective and subjective testing, and which provides a link between computer-based simulation, laboratory-based simulation and whole vehicle testing both in the laboratory and on the test track. “The aVDS works very effectively as a stand-alone product, but can also be the central tool in a suite of test and development systems that increase correlation, reduce timescales and simplify development programmes,” he concludes.
To see an animation that illustrates the novel Williams-designed aVDS mechanism, visit http://www.abd.uk.com/en/laboratory_test_systems/driving_simulators
Please direct any business enquiries to SimulatorEnquiries@abd.uk.com
Richard Doherty at Market Engineering
+44 1295 277050