A standardized test and data management strategy is essential to manage the cost and complexity of EV battery

As electric vehicles become increasingly more complex, largely due to their many subsystems, the testing process becomes even more critical. In an interview with Todd Walter, Chief Marketing Manager, DAQ and Control at NI explains how NI Test solutions helps automotive manufacturers to reduce time and cost and manage the complexity.
Todd Walter, Chief Marketing Manager, DAQ and Control, NI

Recent advancements in the automotive industry include:

  • Electric vehicles (EV) are higher performing and more responsive. In addition to being quieter, having zero emission, lower maintenance and driving cost, they are also simpler (fewer moving components and points of failure). They also give design engineers new and exciting freedoms because they can remove or greatly simplify heavy, complex, and expensive components like the internal combustion engine and associated belt driven systems, the exhaust and catalytic converter, and the transmission.
  • As we get closer to autonomous vehicles becoming a reality, new vehicles are integrating technology that helps them provide advanced driver assistance (ADAS) functionality and will eventually lead to fully autonomous operation. These technologies like radar, camera, and RF communication will work together with a sensor fusion approach to give the vehicle a more complete view of the world around it.
  • The emergence of vehicle-to-everything (V2X) communications for connected cars is demanding a new test framework that can address the rapidly expanding compliance and certification requirements related to connectivity protocols and sensor control algorithms in real-time. V2X communications encompasses both vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communications. When it comes to V2X communications, there is a shift away from traditional automotive test systems to perform validation and on-road assessment in real-life situations.

How do you look at the adoption of electric vehicles and its growth?

The market forecast for EV adoption has increase dramatically in the last year with Bloomberg now forecasting they will account for over 50% of new car sales by 2040.  With a favorable regulatory environment, China and Europe are expected to lead in EV penetration and sales.

What key trends are driving vehicle electrification?

Regulatory pressure to reduce pollutants from internal combustion engines (ICE) is driving electrification, especially in China and Europe.  However, the biggest driver is the cost of the batteries in the vehicles followed by the availability of charging infrastructure.  The market is set to cross below $100/kWhr for battery which will shift the economics of building EVs.  The complexity of EVs is much lower than a comparable ICE so as the cost of the expensive batteries fall the economics of building and maintaining a vehicle will continue to shift towards EVs.

What are the factors to consider for electric vehicle testing?

The battery is heart of the EV.  It has the highest cost, the highest warranty liability, and defines much of the vehicle dynamics including acceleration, range, and charge time.  Getting enough information about the battery life over various charge/discharge/temperature cycles is very important as designers are making design trade-offs.  Because battery testing is impacted by charge/discharge rate it is difficult to accelerate this testing.  This means that numerous parallel testers and lots of data manipulation and sorting are needed.  A standardized test and data management strategy is essential to manage the cost and complexity of the battery details.

What are the challenges and how is NI helping to reduce them?

An all-electric powertrain is still too expensive (largely due to a single component: the battery pack). The good news is that we are quickly getting there and are in a period of intense investment and innovation in battery technology driven not only by vehicles, but by consumer technology (e.g. cellphones) as well. The battery performance/cost curve is encouraging with substantial double-digit decrease in price every year and no signs of slowing.

How does NI develop HIL systems for vehicle simulation and testing? Doug

If the battery is the heart of an EV, the inverter is the soul.  It defines the driving characteristics from acceleration, to braking (through regen) to traction control, and influences range.  The inverter is a complicated computer and the software testing involves a mix of HIL, thermal chambers, and potentially dynamometer or electronically controlled loads to emulate the motor.  Getting efficient testing of the inverter is critical for EV design and moving this earlier in the design phase is pushing companies to consider power level testing without a full dynamometer.  NI focuses on blending the lines between traditional HIL and durability testing to create a smooth flow of test capabilities.  This includes running high fidelity motor models at cycle accurate rates using FPGAs, taking high accuracy power measurements for efficiency and EMC testing, and controlling test cell infrastructure such as power electronics, thermal chambers, and coolant conditioners.

Your solution has been recently used by major automotive manufacturer Subaru. Can you explain briefly how it meets their demands?

Subaru selected NI’s flexible platform because they had several engineers who were already familiar with LabVIEW. This familiarity contributed greatly to reducing costs. If another supplier had been chosen, outsourcing may have been necessary. This would have meant spending about 6 months to implement the system, and the development cost for the HIL system would probably have tripled. Furthermore, costs could have easily and significantly escalated if even minor changes were required. By choosing to use LabVIEW as the development platform in this project, Subaru could develop software in-house. This helped to keep software development costs to around one-sixth what it would have cost if this task had been outsourced. In terms of the total cost, we were probably able to reduce costs to around one-quarter of the costs if another solution had been selected.

What is your outlook of the EV industry?

Positive.  Nearly every major OEM has announced strong investment in EV programs in the last year.  Additionally, the EV landscape is changing with new players and new markets which are causing more rapid shifts than are typical in the automotive industry.



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