A lot of vehicle testing takes place where the car is driven around a circuit by real people. There are times when this is absolutely necessary. People with experience in such things need to ‘feel’ the car as it develops. In some instances, however, the testing process can be hampered by human error because humans are ‘variable’. That is, they won’t necessarily repeat the exact same action time after time after time.
If we can develop a machine to do some of these tests, you get the same circuit driven the same way every time and the vehicle data retrieved from such a test should be based on consistent inputs in every respect. More than that, steering robots are actually able to give more precise and more dramatic (i.e. faster) steering inputs that humans can, and they don’t get tired either.
The simple version of “How” involves a track modelled on GPS data and some sophisticated hardware being installed into the car to steer it according to this pre-programmed course. The hardware used to control the steering is a steering robot from Vehico and the work is done in cooperation with them. The steering robot is currently only able to perform so-called ‘open loop’ tests (steering as function of time) such as step-steer, sine-sweep steer, and sine-with-dwell steering, which are used for vehicle dynamics characterisation. The task for Klas and Carl, which even the experts say is very challenging one, was to create the control software necessary to control the steering such that the vehicle follows a pre-defined path using advanced GPS and motion sensors as input data.
The guys responsible for this job were Klas and Carl, two students from Chalmers University who completed this project in conjunction with Saab as their Masters thesis.
Their thesis presentation was made back in June and I’ve just been forwarded a copy of the video they made as part of that presentation. In the video, you can see the robotic steering system in action, a vehicle’s eye view of the road they’re driving as well as speed and tracking information.
It’s all fascinating stuff and indicative of just some of the technical work that goes on behind the scenes here at Saab.
I know what you’re thinking when you read that title….
You’re thinking this might be some sort of apocalyptic horror story where we aren’t allowed to drive anymore and robots from Sweden take over the driving, plugged into some evil worldwide network that monitors traffic, your speed, where you’ve been and so on and so forth. It sounds like Big Brother moving right into your garage.
Not so.
The story does involve robotics and driving, though, and it’s both fun to watch and incredible to experience first hand.
Klas Olsson and Carl Sandberg are engineering students from Chalmers University and what they’ve developed is a system whereby a car can be driven by a robotic steering unit according to pre-programmed parameters (circuit, speeds, etc). They were offered a chance to develop this closed-loop circuit system as part of their Masters Thesis project and in partnership with Saab. They did their work at the Chassis department, headed by Martin Öman, and were supervised by Dr. Matthijs Klomp, who is a development engineer in the vehicle dynamics simulation group at Saab.
Why and how?
This is the simple version. The details are something I can’t go into (even if I understood them fully) as they involve software and technical IP that belong to Klas, Carl and Saab. But here goes….
A lot of vehicle testing takes place where the car is driven around a circuit by real people. There are times when this is absolutely necessary. People with experience in such things need to ‘feel’ the car as it develops. In some instances, however, the testing process can be hampered by human error because humans are ‘variable’. That is, they won’t necessarily repeat the exact same action time after time after time.
If we can develop a machine to do some of these tests, you get the same circuit driven the same way every time and the vehicle data retrieved from such a test should be based on consistent inputs in every respect. More than that, steering robots are actually able to give more precise and more dramatic (i.e. faster) steering inputs that humans can, and they don’t get tired either.
The simple version of “How” involves a track modelled on GPS data and some sophisticated hardware being installed into the car to steer it according to this pre-programmed course. The hardware used to control the steering is a steering robot from Vehico and the work is done in cooperation with them. The steering robot is currently only able to perform so-called ‘open loop’ tests (steering as function of time) such as step-steer, sine-sweep steer, and sine-with-dwell steering, which are used for vehicle dynamics characterisation. The task for Klas and Carl, which even the experts say is very challenging one, was to create the control software necessary to control the steering such that the vehicle follows a pre-defined path using advanced GPS and motion sensors as input data.
I’ll let Klas and Carl explain more….. with a demonstration as well.
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So, aside from the challenge and the associated fun of building a robotic vehicle, why are Klas and Carl doing this and why are Saab happy to provide the tools?
There are four main benefits with this thesis work from Saab’s point of view:
Evaluation of the Vehico steering robot
‘Closed-loop’ path control (autonomous driving) enables Saab to perform more vehicle dynamics testing in Sweden, saving travel and transportation costs and test-track rental.
Since the closed-loop control is co-developed with Saab we will have full access to the work and will be able to use the developed algorithms for future research into autonomous driving for lane-keeping tasks, platooning an other future functions.
This is a very advanced vehicle dynamics control task attracting top students, which will enhance our mutual relationship with Chalmers.
The immediate benefit of autonomous driving is to enable vehicle dynamics characterisation testing as well as legal compliance testing that is not normally possible on relatively narrow surfaces such those that Saab have access to locally in Sweden.
One example of a vehicle dynamics surface normally used by Saab is the one at IDIADA in Spain, a facility that costs significant money to use and is in constant demand. If Saab can do the same work at lower cost and in their own time, all the better.
Dr. Matthijs Klomp summarizes:
“As mentioned, the problem of closed-loop path control is a very challenging one. This in particular since the control must be accurate and robust in a wide range of conditions, including and up to the handling limits of the vehicle. Additionally the controller must be easy to adapt to changes in the vehicle and the road surface (i.e. snow, gravel, asphalt).
Klas and Carl started to implement their control strategy in our simulation environment using IPG CarMaker, who also sponsored this project. Subsequently they moved to implement their controller in the real-time computer of the steering robot and to get it all working in the real-world.
The end-result is truly amazing, the vehicle both follows the path very well in both the linear and non-linear handling range without the steering becoming nervous or erratic, a common problem otherwise, yet is very simple to operate for the test driver. I congratulate Klas and Carl to a job well done!”
File this under “Things that blow your mind about how incredibly complex it is to design and build a motor vehicle”. Long title, I know. But this is one of the more mind-blowing insights I’ve had into the vehicle development process since being here at Saab.
I’ve told people for some time now that there are no ‘fingersnap’ solutions when it comes to building/changing automobiles. It’s an incredibly complex process and whilst the evolution of electronics has given us many advances in vehicle functionality, behaviour and performance, the development work required to produce these advances is astounding. Add in the fact that everything you’re about to read has to be developed, tested and approved for all of Saab’s global markets, in all vehicle configurations, and you can get a sense of the complexity even before you start trying to calculate the permutations.
I’m going to apologise in advance for this one. There’s no way that I could adequately gather together everything I’ve learned about this process and express it in an educated manner. I feel embarrassed even trying, but I hope that you’ll still get a feel for what this is all about.
The Vertical Bench
There are two main test benches used in electrical integration. The first of these is known as the vertical bench.
The vertical bench looks like a cross between a dismembered car and a telephone switchboard. It’s based on a rack system that has all of the car’s components attached to it. Look closely in the photo above and you’ll see several different radios, climate control, rear-seat video screens, door handles, etc.
Here’s a quick look into how complex things are these days – the front door handles alone are involved in more than 10 different electrical systems within the Saab 9-5. And to think there was a time when all you did was unlock the vehicle with a mechanical key and step inside! Today, with passive entry, you do less work but the car does a lot of the work for you and that work is planned and tested here at electrical integration.
I’m spending quite a lot of time at the moment just visiting various departments within Saab, getting to know what they do.
I spent a little time today at the climate controlled wind tunnel facility, where they can do various types of wind tunnel testing (though not aerodynamic testing, as it’s too small for that). The wind tunnel can be manipulated to simulate all types of weather conditions, but we’ll tell you more about that later.
They also have a couple of climate chambers there, where they can simulate different temperatures but without the wind effects. While we were visiting, a Saab 9-5 SportCombi was undergoing some durability testing on the rear rear door.
Can you imagine driving a car with a cockpit like your living room, complete with swivel chairs, cabin-wide screens and electronically tinted glass to keep out the sun? How about active suspension systems that automatically adjust camber and toe according to driving conditions, along with composite inboard braking, or even wireless driving, braking and steering.
Sounds like fantasy-land? Perhaps. But it’s all being talked about right now.
In a former life, at SaabsUnited, I reported early this year on a project that Saab were participating in, one that will see a concept vehicle built and exhibited by the middle of 2013.
The following quote is from Swedish publication, Ny Teknik, a report from which was used as the basis for the SU story:
The concept car, which will be completed by summer 2013 will include solutions that make it possible to build cars 20 to 40 percent lighter than today, without making major compromises elsewhere. Last fall, Saab invited the Scandinavian suppliers to a workshop to reflect together on new solutions.
That was back in January. Today, I had the pleasure of attending the group’s second workshop, where all of the participants came together once again to share their first conceptual impressions of how the project might progress.
Let’s step back for just a moment, though, and take a look at the project in general.
The project has earned the name Så Nätt, which Saabophiles will be familiar with from the Saab Sonett sports car range. The name means “so neat”, which is one of the goals of this car. The Saab Sonett was also an exceptionally light car with a fibreglass body and lighweight two-stroke and V4 petrol engines.
There are nearly 40 participants in the project, which is acting as a kind of think-tank for future car design and collaboration. Saab is the largest of the participants and the only vehicle manufacturer. There are also around 30 different component suppliers involved, as well as 6 academic institutions and FKG, the key association for automotive suppliers here in Scandinavia. FKG represents around 350 separate suppliers here in Sweden, so a 10% representation should provide good feedback for the rest of the supplier body.
As stated in the Ny Teknik article quoted above, one of the goals of the project is to devise lightweight solutions that can bring down the weight of a car by between 20-40%. The benefits from this kind of weight loss would be significant, from emissions and fuel consumption to maneuverability, crash avoidance and handling.
That’s just one of the goals, however.
Perhaps the more important goal is to get suppliers to work together with a manufacturer to achieve this goal. The end result will be a concept car that’s sure to be an exciting vehicle to see. It’s the road map to achieving that end result that will be just as interesting, if not more interesting, to the participants in the project.
Sweden is typically made up of lower tier suppliers. Tier 1 suppliers have a much greater say in the design and composition of parts used by manufacturers. Tier 2 and 3 suppliers generally have the requirements for the components they supply spelt out for them. This project gives typically smaller suppliers a chance to have input in a product from the outset, which is a major change in the landscape they work in.
The project is divided into a number of component parts or project groups. The purpose of today’s workshop was to bring those project groups together to share what they’ve come up with in their respective areas. The project groups are:
Seats
Chassis
Front Structure
Cockpit IP
Floor Concept
Polymers and Composites
Roof structure
Each project was presented by a project leader and presentations generally featured three or four options as solutions for their project – a near-term solution, a mid-term solution and a futuristic solution.
As you can imagine, some of the futuristic solutions were quite imaginative.
How about floor structures that can extend at higher speeds to decrease drag? Or detachable front sections of a car that you can remove and upgrade (think 2007 to 2008 Saab 9-3 front upgrade with minimal hassle or cost)? Wheels/tyres that are capable of leaning over in corners like a motorcycle? Or even a three wheeler with a single wheel that can pivot 360 degrees!
There were discussions about the use of composites in new and exciting ways, as well as the use of textile materials, where appropriate, to solve weight problems where structural rigidity can be taken care of elsewhere. There was even one proposal with an Aero-X type canopy roof.
Many of the futuristic concepts were for vehicles featuring electric propulsion and some were even self-driving vehicles with the capability to brake automatically or divert the vehicle in the event of an impending accident.
The secondary goal of working together to achieve solutions was quite evident and the buzz around the room was palpable as people asked questions and explored the ideas presented even further. The next step is to extend this approach, complete the project and use the lessons learned to develop new business opportunities from the ideas that arise.
The options presented were all quite exciting and I’m looking forward to attending another workshop in the future to see how things progress.
