Optimizing Innovation in Driveline Design Processes

Simulation technology is driving innovation in gear and drivetrain design fields with an approach that moves problem-solving earlier in the process.

0
241

In the driveline industry, innovation can only be achieved when the use of new or novel technologies or methods are applied to design and development goals. Innovation also means harnessing practical ways to support business goals and deliver higher quality products faster, more efficiently, and with a lower cost.

While design and manufacturing methods improve over time, most enterprises are not in the business of waiting for improvements to happen. True innovation is pushing for that major leap forward rather than patiently accruing incremental gains.

Romax Technology — a global provider of engineering and technology solutions for gearbox and drivetrain design, simulation, testing, and monitoring — introduced its approach called Right First Time™ that has innovation at its core. This approach creates the ability to deploy more powerful simulation, modeling, and analysis as early as possible in the design process. Focusing intelligently on potential future problems disrupts key pipeline troubles. Issues including durability, noise, vibration, and cost are brought to the forefront of the product planning and concept design phase in the Right First Time approach.

Faster and Lower Cost Development

Shorter and less expensive development cycles mean less time to work and increased pressure to get it right. This means that cost reduction and faster time-to-market are required in today’s driveline engineering. These pressures imply higher demand for more efficiency and greater streamlining than ever before.

Physical constraints in the process, such as tooling lead times for gears and castings, remain relatively long. This means that concept and design specifications must be agreed and finalized as early as possible.

Going back to the design process to fix problems becomes more complex and far more expensive. To have a serious impact on development cycle time, issues and problems need to be identified, explored, and rectified as early in the process as possible, ideally at the concept design or even product planning phase — well ahead of prototyping — before costs start to rise.

Across the industry, such requirements have informed the development of new computer aided engineering (CAE) tools and more novel approaches to process improvement. Applying different thinking earlier in the process may mean disruption to the traditional model and an associated innovation risk. However, the benefits delivered via faster and more informed development far outweigh the perceived risks (or costs) it brings. Innovation works not only because certain forerunners take those risks, but also because innovation demands to be shared.

The more effective Right First Time approach gives an opportunity to eliminate missteps earlier and arrive at more viable design choices faster.

Customer Demand and Improved Performance

Modern consumers are conditioned to constantly expect better performance, more features, and smaller footprint for the same or less money. More for less will continue to be a driving requirement.

Performance of a design is measured by whether it meets certain targets and specifications while avoiding failure modes driven by customer requirements. Inevitably, design targets and product criteria will conflict.

Design requires taking a genuine whole-system approach because all requirements are interdependent, and any design innovation may impact other components. Therefore, it is wholly necessary to be able to predict this as early in the process as possible.

Shifting Demands

As some companies are being forced to respond to new legislation or compliance requirements, in some cases relating to carbon emissions or sustainability, innovation is enabled by new technology and driven by a perceived need to keep up with the competition.

Previous experience and incremental improvements will continue to play a key role in designing drivelines, but new driveline concepts do not have the track record of accumulated successes and failures. Today’s novel designs, such as those in electric vehicles (EVs) and hybrids, can have hugely different performance targets and component/material demands compared to previous ones while bringing new types of failure modes.

At the same time, innovation can be a rare achievement. New concepts are often patented, which means other designers and engineers must find ways to avoid infringements. Other avenues of innovation that remain focused on similar targets or criteria and avoiding unnecessary risk may be explored. This can result in increased dependence on accurate, timely, and appropriate simulations that can be trusted and take gained insights and feed them into a constant process of learning and improvement.

Achieving the right balance between the opportunities available through innovation and the risks that such innovation can present, including fears related to investing in an unknown quantity, is paramount. Figure 1

The reality is that it is possible to minimize risk through careful planning and budgeting. For example: The aerospace industry, a highly conservative development environment, is now having to become considerably more adventurous in its engineering outlook for geared power systems to meet shortened delivery targets and comply with efficiency and noise legislation.

The fundamental way to mitigate innovation risk is formulating a robust business plan with realistic yet challenging targets against which new developments can be measured. Regular reviews of technological readiness will help ensure that costs can be understood and controlled. Such reviews should be carried out by or under the authority of managers with the power to pull the plug if necessary.

The Right Methods, the Right Tools

A team of Romax engineers was asked to assist in the development of an electric drivetrain for the rail industry. The basic design of the drivetrain had not been changed for 40 years because it worked and there was no reason to do anything differently. However, recent legislation covering environmental noise meant significant reductions in gearbox noise were now required.

Romax provided the needed support to this customer by applying experience gained in optimizing designs for automotive customers — where competition, legislation, and customer pressure demanded such improvements for a long time — and by adapting the use of the gearbox modeling and simulation tools. Figure 2

This example underlines the point that design and development processes are largely defined by the tools and methods available. As tools and methods evolve and improve, design processes should also develop and adapt to make use of them. To fully embrace innovation, a designer or engineer needs to have the right tools available so they can quickly and confidently assess and decide if there is merit in a new idea. Figure 3

Simulations: Earlier, Faster, and More Accurate

The Right First Time approach means adhering to certain principles driven by engineering realities and the challenges of innovation itself. The ability to quickly rule out designs destined for failure using simulation is the most efficient way to innovate.

To decide if an idea is workable with the minimum of investment, concepts and ideas from brain to model are needed as quickly and easily as possible, and then simulations need to be fast. If there are many different competing concepts to be compared and evaluated, speed is equally important. Models need to be quick to edit and update, with what-if studies and other analyses and re-simulations performed easily.

Simulations need to be as accurate as necessary — not as precise as possible. There is no point building a detailed model or using complex analysis methods at an early stage. Use simple models and methods first, and then move to smarter simulations when more detail is available. A simple model providing approximate results at an early stage is just as valuable (if not more so) as more detailed modeling later in the process, particularly if there is a need to benchmark multiple design candidates. Detailed simulations where there is so much uncertainty in a design risks wasting time and yields false precision. Gaining the ability to re-use the same model to investigate many different performance criteria is also a more efficient way of working, meaning a model needs to be built only once to investigate issues around cost, durability, and efficiency.

The chosen simulation tools should not only provide masses of numbers, but they also should provide pointers on what should be done next. The massive quantities of information that CAE simulations produce require powerful processing tools to explore the data, focus on what matters, and distill results into reports that highlight either problem areas or opportunities.

The ODIN Project

Optimized electric Driveline by Integration (ODIN) is an EU-funded consortium that aims to develop new methodologies for the design of an innovative electric vehicle drivetrain. The current tendency to design and analyze the gearbox independently of the engine has been known to lead to issues such as NVH in current generation electric vehicles. Romax’s role in the consortium is therefore to deliver the CAE tools and methods for the analysis of the complete system and to use them to influence the design process from beginning to end and provide Right First Time solutions.

The first phase of the ODIN project was to identify the most promising of many proposed basic concepts based on key targets focused primarily on cost and dynamic performance. Romax’s design software called Concept was used to rapidly iterate through all the proposed layouts to narrow down the field. Traditionally, predicting noise and vibration performance is considered to only be feasible once a detailed design is finalized. By using simple models and simple metrics, the concept layouts could be benchmarked to identify those with the best chance of having good noise performance.

At a later stage in the concept development phase, Romax was able to use its RomaxDesigner — a CAE tool for the detailed simulation and analysis of transmissions for durability, efficiency, and dynamics — to compare two different layouts for the assembly of the combined motor, transmission, and control system. In this project, the housing design had not yet been finalized but a simplified housing was used to identify the best arrangement and to highlight areas that had the potential for problem vibrations. This information was used to guide the detailed design of the housing.

With the first detailed design of the housing in place and all internal gear, shaft, bearing, and motor details finalized, it was then possible to simulate the first quantitative predictions of noise and vibration caused by gear and motor forces. Again, problems were identified and adjustments to the design were applied.

The next stage of the project is to prototype the design and test its performance against the original design targets in a real electric vehicle. By using simulation of noise and vibration to lead the design right from the start, an innovative concept with the best chance of success has been selected, potential problems have been identified, and remedial action has been taken before the detailed design was finalized. Finally, the detailed simulation of the final design has predicted that the targets will be met before any metal has been cut.

There may be further challenges to overcome once the prototype has been tested. However, the risk of a significant problem derailing the project has been vastly reduced by applying CAE tools that comply with the principles of innovative software discussed here. Simulating early and simulating often gives the best chance of getting it correct the first time.

Conclusion

To remain profitable and competitive, organizations must introduce new and improved products faster and drive down development costs. Innovative approaches from Romax in-house experts, customer insight and experience provide the solution. Romax’s Right First Time™ design methodologies have enabled organizations to re-engineer every phase of the design and development process, compressing the time elapsed from initial concept designs to engineering sign-off by up to 60 percent for sectors including automotive, rail, aerospace, and wind energy. 

FOR MORE INFORMATION, visit Romax at Gear Expo, Booth #1402, in Detroit, and go to www.romaxtech.com.