Comment: Vehicle electrification is increasing reliance on motion systems

The development of motion systems technology for x-by-wire systems balances the need for precision engineering with the high-volume manufacturing required for the car market, says Thibaut Marqueyrol, maxon’s head of automotive solutions.

Maxon x-by-wire can add electronic control to acceleration, braking and steering
Maxon x-by-wire can add electronic control to acceleration, braking and steering - maxon

The global automotive market is entering one of the most radical changes in its history. With the push towards electrically powered vehicles (EVs), the market is seeing the emergence of a wave of new car brands. Joining the likes of Tesla, there are now a host of start-up EV manufacturers. What’s more, car manufacturers from China are set to gain market share on the global stage.

As result of this shifting market landscape, there are also changes going on in the supply chain structure. Emerging brands from China are bringing on new suppliers from both within and outside of the country, and for the American and European car market, the situation is changing too.

Instead of the traditional, rigid hierarchy led by recognised tier one suppliers, which left little room for entry by smaller players, the emergence of start-up car makers is also bringing opportunities for new suppliers. Crucially, there’s also a need for new suppliers with the expertise required for the EV transition that the existing automotive sector may not yet fully have.

X-by-wire

The involvement of new suppliers doesn’t just end with the car’s electric powertrain. The transition to electric power has though facilitated new capabilities in electronic management. As a result, car designers are increasingly integrating electronic control over critical driving and safety systems.

X-by-wire technology applies electronic and computer control to acceleration, braking, and steering, replacing the traditional mechanical linkages. Providing faster and more precise control, x-by-wire systems are set to improve road safety. Importantly for battery-powered vehicles, this technology also has the potential to increase energy efficiency, thanks to the weight reduction it achieves.

X-by-wire technology has already been introduced on production cars covering acceleration, braking, and now, steering. The 2023 launch of the Tesla Cybertruck included steer-by-wire as standard, and among other manufacturers, Toyota has also developed a fully electronic steering system. Over the next 10 years, x-by-wire control will likely become the norm across all new car designs.

Advances in motion technology

X-by-wire technology relies on electric motion systems. As the car driver operates the steering wheel, throttle, or brake, the electronic control unit sends a corresponding signal to the motion system that actuates the command. The motion system is based around a motor and gearing, plus encoder position sensors, as well as controls to command the speed, torque, and position of the motion capability.

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Electric motors have been used throughout car design for years, from passenger window control to cooling fans, but motors specified for these applications don’t have the capabilities required for safety-critical use. Among wider reasons, these commodity motors are not sufficiently compact or precise, and they are not equipped with the sensors required to provide speed or position feedback.

Considering x-by-wire’s imperative for safety and control, this is placing new demands on motion system designers.

Manufacturing to scale

For the automotive market, the requirement is to match safety-critical motion performance with an upscale in manufacture that can achieve the market’s required cost point. Historically, to realise technology advances in the automotive sector, a common approach has been to bring design expertise in house. However, motion development has a distinct complexity, coupled with the need to guarantee ‘fail-safe’ functionality, and now, ‘fail-operational’ safety, and the redundancy it provides.

To accommodate these requirements, maxon is proposing 3-phase motors for fail-safe applications. Combining two, 3-phase designs, gives the redundancy required for fail-operational requirements.

Driverless cars

While the emergence of the EV is the industry’s biggest development since the first production car in the late 1800s, the next advance is already on its way. Driverless cars are already in use in California, and while x-by-wire is vital to this revolution, so too is the vision system that makes autonomous cars possible.

LiDAR (Light Detection and Ranging) is one of the preferred approaches.  To achieve long-range, 360° vision, LiDAR also relies on motion technology. To achieve the required laser guidance precision to maximise safety and control, the performance of the motion that drives the system is critical.

Micron-level accuracy in motor manufacture, until now not required for the automotive sector, is ensuring a connecting surface between the motor and the laser system, minimising even the smallest traces of vibration, in turn achieving higher accuracy in LiDAR control.

The outlook for the automotive sector

While driverless taxi services are already operating in California, even in the UK, transport secretary Mark Harper has said that self-driving cars could start to be rolled out by 2026. Yet despite the push towards this futuristic automotive market, the debate over battery range and infrastructure means that combustion engine vehicles are by no means obsolete - and their development continues.

Regardless of the technology transition to EVs, there are few barriers to preventing the electrification of driver control. As a result, the continued development of motion technology will be vital to achieve the proliferation of x-by-wire.

Thibaut Marqueyrol, maxon’s head of automotive solutions