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The driving force in automotive

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The use of modelling and simulation tools is a growing trend in automotive design. Beth Sharp finds out why

The humble automobile has come a long way in the past century and there can be little doubt that the engineers from that time wouldn’t envy the tasks now facing their modern counterparts. As consumer products go, automobiles are among the most complex and technologically advanced in the world and mounting pressures, mixed with a highly competitive market, are moulding the direction of the industry. From increasing fuel efficiency to ensuring optimum drivability, manufacturers are battling for engineering supremacy, but with the added complication of the need to maintain aesthetics. Design engineers are turning to modelling and simulation technologies to aid them in this complex task and as one of the early adopters of simulation technology, the automotive industry is now making use of it throughout the entire design process.

There are many influencing factors at work here, but one that is particularly critical is the need for greater fuel efficiency. As a commuter, this is a particular concern of mine and like many other drivers, I always keep fuel economy figures firmly in mind when choosing a new vehicle. However, as Paul Goossens, VP for applications engineering at Maplesoft, notes, this pressure is not solely coming from customers like me, but from governments as well. He explains that in the United States, for example, there are fairly stringent legal requirements based around corporate average fuel efficiency (CAFE) constraints.

These efficiencies have to be delivered across manufacturers’ entire range of vehicles and that’s driving a huge amount of research. ‘Manufacturers are implementing a wide range of different strategies in order to fulfil requirements,’ he says. ‘Design engineers approach this in many ways, from finding means of increasing the efficiency of existing systems, such as an engine or transmission, right through to proposing fairly radical new designs for the extended range electric vehicles that are starting to come to the fore.’

Words like ‘electric’ and ‘sustainability’ are indeed buzzing throughout the industry and Sandeep Sovani, automotive expert at Ansys, agrees that not only are manufacturers steadily increasing their investments in sustainable technologies, but that a huge amount of attention is being devoted to vehicle electrification. He explains that electric powertrains are being developed and believes that as automotive engineers work on batteries and fraction motors they are being faced with a completely new set of challenges.

‘It has been a century since the first automobiles were introduced and it has taken us that long to perfect the internal combustion engine-based powertrain that exists in today’s vehicles,’ Sovani comments. ‘Markets and governments around the world are now expecting to have a new electric powertrain in just a matter of 10 years and that is a massive engineering challenge.’

Electrickery

A modern automobiles’ complexity extends to the proliferation of electronics contained within. According to Integrated Engineering Software’s Bruce Klimpke, where previously electronics constituted a small part of the automotive market, 20 cents on every dollar that’s spent on an automobile now goes into an electrical part, in one way or another. He explains that modern cars that park automatically, for example, require many electrical and magnetic systems working in unison and that each component must be compatible with the others.

‘System integration has become increasingly vital and each team needs a way of communicating and sharing information,’ he says. ‘For example, the person designing the back door has to share information with whomever is developing the system for the automatic parking. When placing the sensors, there may be a choice of installing them at the top, centre or edges of the door. The question then becomes how many sensors are needed as the more that are included, the higher the cost.’

This exponential increase in functionality has led to a standardisation movement within the industry, dubbed AUTOSAR (AUTomotive Open System ARchitecture), that aims to establish open standards for automotive Electric/Electronics (E/E) architecture. Guido Sandmann, automotive marketing manager, EMEA, MathWorks, explains: ‘Automotive engineers using model-based design (MBD) in order to develop applications and software want the ability to reuse that software with only minor adjustments for different variants and multiple vehicle models. AUTOSAR provides that standardisation.

‘In a typical development process,’ he continues, ‘errors are often found at a late stage because the code needs to be running on some sort of target before people can realise they are in the design. MBD provides engineers with the capabilities of executable specifications – they start to design with Simulink, for example, can create a model and then simulate this model with test cases. This provides an immediate response as to whether the design decisions being made were the right ones, enabling then to move forward in the design process.’

Sandmann points out that early verification is a significant improvement provided by model-based design, but that many automotive projects still do comply with AUTOSAR. However, he does note that while AUTOSAR has yet to be widely adopted, many of the large OEMs and Tier 1 suppliers have made strong commitments to ensuring that every new project they set up will be compliant – a strong statement of support and one that can be seen to demonstrate that the industry no longer views the standard as being ‘questionable’.

Likewise, another recent and important standard is ISO 26262, which addresses the safety-relevant aspects of automotive applications, as Sandmann explains: ‘A few years ago, the automotive industry was working under a generic safety standard that was originally designed for automation in manufacturing industries; IEC 61508. A specific automotive standard was needed and so ISO 26262 came into effect. It details, among other safety relevant development process methods and activities, what is needed for tools to be qualified for use in high-integrity applications.’

He adds that engineers are often challenged by these new standards, especially the high-integrity ones, and that while they know it is necessary to comply, it can be very difficult to read the volume of documents that define the standard and understand what the implications are for the development processes. MathWorks has therefore introduced a tailored process deployment advisory service for ISO 26262, which enables the company to perform gap analyses and consult with engineers as to what needs adjustment from a development process perspective. It will then help to implement these changes and finalise the tool qualification.

One simulation at a time

The adoption of simulation tools within the automotive industry has been a steady process – one that, according to Ansys’ Sandeep Sovani, has reached the point where simulation has become such an ingrained part of the DNA of automotive engineering that it is now impossible to remove it from the design process. He adds that although it has not always been so deeply embedded, simulation and its benefits have now become so widely understood that the automotive industry has adopted its processes and incorporated them fully into working practices. ‘Some larger companies spend as much as five per cent or more of their entire R&D budget on simulation software alone, which is a considerable investment,’ he continues, ‘and there are also many instances where simulation is being used for validation and verification without the need for physical testing. Taking simulation out of those processes would leave a void.’

Maplesoft’s Paul Goossens attributes this trend to the fact that not only are prototype tests expensive, they are not very repeatable. For example, if a combination of inputs lead to a problem during a test drive, attempting to replicate them would be incredibly difficult. It can, however, be done effectively by hardware testing on real-time platforms and he states that while this is certainly not a new trend, there is an increasing adoption of these systems as engineers want to implement high-fidelity models in a real-time simulator.

At the Vehicle Dynamics conference in Stuttgart, Maplesoft announced a formal partnership with VI-Grade, a German company that offers the ability to implement detailed drivetrain models in a real-time platform. Its goal, Goossens explains, is to migrate that to vehicle simulators so that drivers can take proposed designs around test tracks.

‘We’re working with VI-Grade to provide a modelling environment where an engineer can take a system-level model at the detail they require and then implement it in a real-time simulator,’ he comments. ‘The motor sports industry has been doing this for many years, but it’s still not common practice for production vehicles. It’s still early days, but we’re convinced it will take off. Obviously it is not going to replace full prototyping cycles, but shaving just one cycle off the process will represent a significant saving.’

In the driving seat    

Reducing both the time and costs associated with the automotive development process is critical, especially for smaller manufacturers, such as Morgan Motor Company. Based in Britain, it has a fairly small development team consisting of 12 people, including the designers, CAD technicians who do the component modelling, engineers and electricians.

Within that team is an entity called Morgan Design that’s responsible for every visual aspect, from the vehicle aesthetic design to the graphics, brochures and website, and when senior designer Jon Wells joined in 2009, he introduced the use of modelling and simulation tools. Having used Autodesk Alias for 3D simulation when studying Automotive Design at Huddersfield University, Wells was able to bring a level of familiarity and demonstrate how the suite of products can be used to visualise designs fairly rapidly.

‘Prior to that, my colleague, Matt Humphries, would sketch a new concept for a vehicle, which would then be taken to one of our panel beaters,’ says Wells. ‘Using traditional techniques, they would then hand form a body as close to the sketch as possible before painting it and using it as a concept car to sell the design.’ Some of the difficulties with 2D sketch work, he offers, is that not everyone can read them and that they don’t always offer a sense of volume. Designing and manufacturing a car in this way is also a very time-consuming and complex process.

He explains: ‘Hand beating a car is something you don’t get several shots at – you have to do it as best you can, first time. By implementing Alias we are now able to take those sketches and rapidly model surfaces. Simulation and visualisation is a very good tool for bridging that gap between the sketches and the final components. And it applies to everything beyond the car body; any new component that needs to have aesthetic considerations, such as steering wheels, can be modelled and then presented to the engineers.’

Wells describes this process as being akin to ‘clay modelling’ on screen and adds that those models are then brought into Autodesk Showcase, a real-time 3D rendering software, and Autodesk 3ds Max Design in order to create CGI visuals of what the car would look like. ‘From that, we can apply paint colours, see how highlights lie on the surfaces, add to or decrease the panel volume and craft the car in photo-realistic visuals,’ he says.

Physical models do continue to have a place within the development process, however. Wells notes that there is always an element of visuals on screen not giving a perfect perception of what the car is going to look like in real life, due to a slight loss of depth of field and sense of scale. ‘Often we will model a component and when seeing it for the first time will realise that it isn’t quite the size we were expecting,’ he says. ‘There is always a very good idea of what it will physically look like, but seeing things in real life can be a very different experience. To get around that we create a lot of prototypes using 5 axis CNC machining out of materials like foam so that we can get a real sense of the size and scale. Those prototypes will then be rescanned into Alias. Over all, the process is sped up significantly by the use of simulation,’ Wells adds.

The personal touch

In addition to aiding design and development, models and simulation provide useful images for use in promotional materials, such as brochures. Beyond that, companies like Morgan are using solutions to enrich the purchasing experience. ‘Sitting down with the customer, we will bring up a model of the car and then with a click of a button we can not only apply different paint colours, but can adjust to darker or lighter shades, or add more gloss or matt to the finish,’ Wells explains. ‘The result is that in real-time we can present a very good photo-realistic representation of how the vehicle could look. A scope of options will then be put together, printed and bound in a leather coffee-table book so that the customer can take it home and peruse through it in their own time.’

Given that Morgan offers an infinite range of paint colours, more than 800 leather options, thousands of stitch options and many different roof combinations, having this representation is incredibly beneficial for the customer. In fact, Wells states that before these modelling tools, multiple paint samples would have been sent out and people would often hold them up to the cars in an effort to try to picture what the end result to be. And the company is keen to explore further uses of simulation technology. ‘One powerful tool that we would like to have in the future is a 3D simulation booth,’ he says. ‘Customers would literally be able to stand next to a projection of their car and see it in an array of colours before coming out of the booth and witnessing the first stages being crafted by hand. That’s a really beautiful combination of modern technology and traditional craftsmanship.’