Leamington Spa-based automotive innovation business, Drive System Design (DSD), will present its system level approach to optimising electric vehicle noise, vibration, and harshness (NVH) at the Low Carbon Vehicle Event 2019, Millbrook, Bedfordshire on September 4-5. Quietly efficient – Reducing EV powertrain noise without compromising efficiency will be delivered by mechanical engineer Victoria Godbillot at 14:00, in the Seminar Dome on September 5th, explaining the challenges posed by balancing powertrain cost, efficiency and NVH before detailing the company’s solution.
“Electric vehicle development is a complex balancing act of expectation, cost and efficiency, both in terms of vehicle development and, ultimately, performance,” says Markus Hose, Drive System Design Head of Mechanical Engineering. “DSD takes a system level approach aided by the electrified Powertrain Optimisation Process (ePOP), developed in-house, which simulates thousands of powertrain permutations to optimise an entire system. It considers detailed inverter, motor and transmission design, performance and drive cycle requirements before plotting overall cost against energy consumption. High level sensitivities of components, such the effect of motor skew, can be assessed in this tool. The result is a powertrain that is optimised within its parameters using a process that is not only more exact than using traditional methods, but significantly faster. Using ePOP, the entire vehicle design process can be streamlined.”
Godbillot’s presentation examines the challenges posed by late-emerging NVH issues. These can arise due to complex interactions of sound excitation sources, which only become apparent once a drivetrain is in situ and in ‘normal’ operating conditions. The approach enables an understanding of unexpected interactions between subsystems that magnify NVH responses. The result of overlooking such considerations can be over-constrained NVH tolerances that conflict with efficiency and cost. DSD’s system approach finds an optimal compromise between these two factors and NVH.
“The ‘quietest’ components don’t always combine for the most refined overall solution,” continues Hose. “By expanding design parameters we are able to assess noise levels produced by aspects of the powertrain to deliver a system that offers an optimal overall solution. DSD’s system NVH approach helps simulate the behaviour of noise-emitting sources to find a powertrain solution that works best within the customer’s remit. This can provide manufacturers with a vital head start when it comes to EV design and manufacture which, with rapidly approaching legislative CO2 targets, is absolutely crucial. It can also help develop more efficient, refined EVs.”