Automotive

Testing times for the EV Industry

by Terry Marrinan April 13, 2022

With climate change a perennial cause of concern, the greater use of electric vehicles, in combination with renewable sources of energy, is seen as one of the major routes towards a greener world.

This puts manufacturers of EVs in the spotlight – the world is looking to them to produce ever more efficient cars, vans and busses.

With electric power taking the role of prime mover in vehicles, highly accurate measurements of electrical values have become even more important.

To ensure maximum efficiency from the motors and longevity from the battery, EV developers need a fully integrated approach that allows them to see how each load affects performance, how the battery is behaving and how mechanical events affect electrical efficiency.

Increasingly, electric vehicles are becoming an electro-mechanical system, with each part having an effect on the whole. As an example, manufacturers are looking at putting more and more communications into a car, which consumes more energy – if as a driver, you start using all your lights and switching on other things, such as communications and air-conditioning, you will start draining the battery, which in turn will start to affect the overall performance of the car.

There will need to be appropriate test and measurement instruments at each stage of the car model’s lifecycle. Each will have their own strengths and benefits for a particular testing stage yet be capable of forming part of a whole and helping build an accurate picture of how the vehicle is performing overall.

To be sure, in the early stage of developing a new model, simple waveform analysis to conduct basic power tests is sufficient – troubleshooting at this stage requires only a good oscilloscope.

But as manufacturers start to move towards prototyping, they need a little more detail about what’s happening. The ideal here is a high-speed data acquisition system that can give a better understanding of the electromechanical inter-relationships between the components and the systems they are part of. Such a device will allow developers to combine electrical with mechanical measurements, as well as vehicle communication bus measurements.

If they’re in that prototyping stage, they will also need to record things over longer periods to build up a knowledge base of how the systems behave over time.

Testing on the line

As well as research and development, manufacturers must pay attention to how they will test their electric vehicles during production. Car makers also conduct more testing than previously to see how cars perform in the field in different climate conditions. Here portable versions of data acquisition systems come into their own, allowing testing away from the confines of the laboratory.

When visiting vehicle manufacturers and their engineers, an increasing refrain is that they want instruments to be easier to use. At Yokogawa, we have always adopted this as one of our goals and in fact our DL950 ScopeCorder is easier to use than ever before, with test applications that can be stored and recalled for use at will with a touch of the screen. As testing becomes ever more necessary for a host of different models and to meet growing legislative requirements, the ability to quickly switch from one test setup to another will ensure that manufacturers get their models to market more quickly.

There is also the need to coordinate instruments to get the big picture of what is happening to complex systems across the vehicle. This is best performed with a software platform which can achieve tight integration of the timing, control, and data collection from several instruments. Such a system will ideally display all measurements on a single display, making it easier to debug and analyze data.

After-sales service needs a skills boost

Beyond the factory, dealers and maintenance garages will also need to up their game, as more sophisticated testing is bound to form part of after-sales activity. Dealers will need the ability to test if the battery is actually producing the power specified and is not deteriorating or degrading. They will also need to test systems such as regenerative braking.

Another issue is the growing number of sensors on the car, which are particularly critical for autonomous driving. Following an accident, it will no longer be enough to repair the body work, fix the lights and run basic checks. Sophisticated sensors such as LIDAR, now frequently used for tasks such as proximity alerts and ranging, will need to be repaired and re-calibrated using optical measurement techniques.

There will need to be a new skill set for the after-sales market so they can understand how these sensors work and the safety issues behind them.

Something else that needs attention is the efficiency of charging – who’s responsible for deciding how efficient that car is or how efficient that charging is?

Is it the charger manufacturer or the car manufacturer? How can we say we know when the battery is fully charged? Who decides that the battery is deteriorating? Is it the after-sales service center, the original manufacturer? What tests will they use to prove it?

We think of charging as cars plugged into pieces of charging kit but there are alternatives like wireless charging through inductive roads. What challenges will this bring to the manufacturers of batteries and the cars that use them?

Overall, the key to the success of electric vehicles is the accuracy at which we can analyze power use – better analysis of power will mean manufacturers can see more easily where they can gain more efficiency. Once we achieve this, we can start to get closer to the 700 kilometers on a tank that todays’ engines can do. Then, we will have a real, viable alternative to the combustion engine and can look forward to a better, greener future.