Drive-by-wire: How to overcome the barriers to consumer adoption

According to Research and Markets, the increasing demand for passenger safety, comfort and luxury, and the need for a reduction in vehicle weight, will help boost the drive-by-wire market.

Projections show that this technology will grow at a compound rate of 8.86% between 2018 and 2025, nearly doubling its market size from US$19.12 billion to US$34.63 billion during the same period.

But drive-by-wire technology faces an uphill road due in part to high incremental costs, risk of electronics failure, and the need for consumers to adapt to a different drive feel.

Despite the healthy business predictions, how can the industry overcome such barriers and finally reach the much-needed consumer acceptance in order to live up to growth expectations?

By-wire benefits

The benefits of drive-by-wire technology for consumers are increasingly well known. For example, by replacing conventional mechanical throttle, braking and steering systems with electronics, the significant reduction in the number of moving parts in a vehicle, reduces servicing needs and costs. In fact, some by-wire systems wouldn't require servicing or fine tuning at all.

Another significant benefit is less weight, which would yield greater fuel efficiency and fewer emissions, too, making it no surprise that the aircraft industry was quick to introduce this tech with consequent operational improvements and further automation.

So, if drive-by-wire systems offer so many benefits, what is there to overcome?

Costly complexity

An ever-present problem for new tech, drive-by-wire systems are more expensive than the mechanical parts they replace. For instance, a conventional mechanical throttle linkage is replaced by an electric actuator motor, whose number of electrical connections may vary; such connections are there to activate the control motor and to engage the throttle position sensor. So cables, springs and other relatively simple parts are replaced by squarewave voltages and changes of duty cycles.

Such change of philosophy from supply-chain vendors and OEMs requires heavy investment in the development of ECUs and software programming. For example, as explained by Michael Fernie on carthrottle.com, steering-by-wire systems require electrical sensors that measure the steering angle and transmit that information down to the ECU; this unit then sends that information off to electric motors that actuate each wheel at a pre-set angle in accordance with the steering input.

For Thomas Bach, head of braking Europe at Hyundai Mobis, “Cost is also a barrier because drive-by-wire reliability – so relevant for end customers – requires backup; this can be through the driver plus mechanical or hydraulic devices, or in case of autonomous driving, a redundancy in all actuator areas.”

To overcome high costs, he argues, “Companies need to minimize on new product by design, and add further functionality, like for example [regarding steering by wire systems], an angle overlay for stability control on front steer for more performance.”

Also, “Manufacturers can reduce part variants on chassis and actuators because car differences can be covered by control systems software.”

Different feel

One key deterrent for end users in embracing drive-by-wire systems is the driving feel. Whether it is enthusiasts or regular car users, OEMs find it difficult to seduce their targets because by-wire technology offers a rather different driving experience, whilst vendors need to understand how to adjust their offering to match the market requirements.

Both steering and throttle-by-wire systems have existed in the new-car market for some time. The former can imply a different – not to say somehow inaccurate – road feedback that drivers come to dislike, as reviews of the Infiniti Q50 attest. The latter’s complexity in the form of different chips, sensors and potentiometers can deliver a perceptible delay when drivers hit the pedal into what is known as “throttle lag” – it is an intrinsic electrical deferral that physical input is not able to overcome.

This is perfectly exemplified when a reader of the popular media outlet Top Gear Magazine wrote the editorial staff: “I drive a second-gen Toyota Vios E. I am wondering if a delay between depressing the gas pedal and the engine response is normal (roughly 0.5 seconds). It's not a big deal on flat surfaces, but having to stop on inclines leaves me uneasy.”

In the case of braking-by-wire systems, for Hyundai Mobis’ Thomas Bach, “one solution could be stimulating drive feedback – that is, brake pedal feel – with HW in a similar or even a better way than in a conventional car.” But apart from drive-by-wire systems leaving the car’s handling feeling different, there is the biggest obstacle for full drive-by-wire adoption: Safety.

Risk of failure

OEMs and their providers are having a hard time convincing car users that drive-by-wire systems are harmless. Due to the sheer complexity of the system, users fear that a potential electronic malfunction in sensors and ECUs can in turn lead to vehicle damage, accidents and injury.

As per auto.howstuffworks.com, “In a worst-case scenario, for example, the sensors on a brake-by-wire system could make an error in calculation, causing the brake caliper and pads to apply an incorrect amount of pressure – either too light or too strong – to the rotors.”

This means that, unaware of any internal system problems, drivers could potentially get into accidents even though they thought the correct amount of pressure was being placed on the brake pedal.

And since this is a developing technology which does not meet software and hardware standard interfaces, it requires a good amount of development until it is fine-tuned.

In this regard, to overcome the safety barrier for consumer adoption, Kristof Polmans, head of vehicle dynamics and testing at Thyssenkrupp, says: “In terms of safety, the main issue will be to get all the processes – supplier management, production, logistics, etc.– completely bulletproof in terms of safety.”

He argues that performance is not a question anymore – as it was in the past– because it is clearly proven that with today’s technology the performance of by-wire systems is on par with or even better than existing state of the art systems.
“On one hand, we need to analyze and maybe reshape processes; and on the other hand, we must find solutions for a safe system including completely independent actuators, to exclude common cause failures.”

So, both manufacturers and OEMs are rapidly looking for solutions to overcome incremental costs, risk of electronics failure, and little public acceptance of drive-by-wire systems. With all of the positive predictions in terms of market growth, and the sheer positives that this technology offers customers, by-wire will certainly become the way of the future, and find its place, just as it did in the aviation industry.

• Interested in drive-by-wire? Automotive IQ’s 2019 Vehicle Motion Control and X-by-Wire conference takes place from 27-29 May in Germany. For information on all of our forthcoming conferences, check out the Events page.