Essential in racing, Driver-in-the-Loop simulators have entered the complex world of road cars. Autocar’s Richard Lane recently visited Ansible Motion’s UK headquarters to get behind the wheel and learn how vehicles can be test driven and developed without leaving the building.
Kia Cammaerts, a man possibly more informed than any other person anywhere in the world when it comes to the bottomless difficulties that car makers face these days, says the following:
We offer the imperfect world but perfect knowledge of it. . . . It’s a model-based development paradigm where you abstract aspects of the vehicle and have a toolchain from engineers and computer scientists designing vehicles, sub-systems and code, and then that toolchain needs something to test [it].
It’s the highly complex simulators built by the firm Cammaerts founded that many of them have come to rely on. BMW, Ford and Honda already use Ansible Motion’s engineering-grade dynamic Driver-in-the-Loop (DIL) sims to develop new cars – there are 34 in the field – and during our visit to the Hethel headquarters (which is just across the road from Lotus), another squash court-sized sim is in build, destined for China.
Even in gestation, it’s quite something to behold. With 32 PCs all operating concurrently in a real-time network, it’s a version of the latest Delta S3 simulator model. It can be equipped with an ultra-realistic cabin weighing up to 500kg, which it can whisk from one corner of a four-metre-square bearing-rail grid to the other in just 0.8sec. The cabin can be tilted 45deg and rotated through 180deg for stomach-turning realism during a spin (or, if the firm in question has a World Rally Championship programme, for charging through a digitally rendered Ouninpohja). Four metres also happens to be an ideal width for lane changes on the autobahn.
The detail of these cabins alone can be astonishing. In a room adjacent to the China-bound unit is a mocked-up GT3 cockpit, soon to be shipped across the Atlantic to an existing customer – a major manufacturer chasing glory in the World Endurance Championship. In order to perfectly replicate the sight lines, the glasshouse and dashboard are so accurately rendered that identifying the car is easy, despite the lack of branding. The seat, wheel and pedal box are of course to the actual race car’s spec, and for high-fidelity feel the clutch pedal is rigged up to the AP Racing clutch the real car uses. Same for the brakes. To give vibration as well as resistance, a voice coil feeds vibration into the pedal assembly and there are more actuators under each corner of the roll-cage. The aim is to heighten immersion by replicating the frequencies put through the chassis by the car’s engine and the track surface.
Let’s zoom out for a second. It’s the ability to put anyone – from test engineers and hot-shoe racing drivers to curious board members – into a physically rendered car operating within a fully virtual world that’s the core proposition here. The basic goal is to achieve a level of vestibular and environmental simulation that allows the ‘driver’ to suspend disbelief. However, for engineering-grade set-ups such as the mighty Delta S3, this is the easy bit. Some recreational sims can do it.
Much more challenging is to guarantee that what engineers feel in the sim – and the knock-on effects of making tiny changes to the disparate but interconnected elements within the ecosystem of metal, rubber and microprocessors that constitutes a car – really is as accurate to real life as possible. Cammaerts adds:
It’s not just the driver in the loop, either. You can have mechanical hardware in the loop, where you might connect the human with a virtual model of the car to a real powertrain in the room next door. Real human, fake car, real engine and gearbox. You blip the throttle [pedal], the throttle is blipped.
Fundamentally, developing tomorrow’s vehicles today is a complex undertaking, requiring a mix or reality and imagination. Driver-in-the-Loop simulation, as discussed in the below video, is one tool that is proving to be extremely useful. By allowing real people to physically experience imagined cars, onboard systems and situations at multiple touch points throughout a development programme, vehicle manufacturers can reduce development costs and time, safely and efficiently explore complex issues and reduce the environmental impact and resource consumption associated with traditional prototyping and testing.
Lane asked if Cammaerts can envision a future of total DIL development, in which the imperfect virtual world is made perfect and there’s no real road driving of the real car before one rolls off the production line. Cammaerts replied:
It will happen, but I will probably have retired and completed my Triumph 1850 restomod before it does. I think it’s something we all want to push for, but it will be a brave manufacturer that does it. The universe is currently too complex to model properly, so you’re discarding a lot of information by any form of modelling, and you have to have confidence that what you’ve discarded won’t affect the attributes you’re trying to deliver. Cars are very subtle things. They’re far more subtle than you can embody in just a few equations. By a few, it’s coming in at 10,000 to 20,000. But you know what I mean.
Lane describes climbing aboard Ansible’s demo Delta S3 simulator as somewhat intimidating. The cabin sits on a cunning mechanism of three wishbones that control heave, pitch and roll. The design combines huge stiffness with dexterity and the cabin itself has a clamshell opening. You climb over the sill, somebody else clips the top half shut and then, while the 240deg projection screen boots up, it’s dark and very quiet. Lane described the experience:
Group simulation manager Mark Thommyppillai talks to me through an intercom and has some tests to discover just how discerning my road tester’s backside really is. I avoid embarrassment, correctly identifying subtle changes to balance and ride quality via his reprogramming of roll-bar, spring and damper rates. But so I should. The synaptic detail of the S3 – the ‘cueing’ of your various senses to create a false reality – is remarkably deep and coherent.
This story was published in the January 31st print edition of Autocar. In case you missed it at the newsstand, the full article can be accessed online with your favorite digital newsstand platforms such as this listing at Readly.
