Yamaha

Yamaha electric power steering revealed
By Ben Purvis

Yamaha has officially unveiled its electric power steering system for motorcycles - promising to use the system throughout the year on its works machines in the All-Japan Motocross Championship before spreading it across more machines in the future.
You might initially wonder whether power steering is really something that bikes or riders are asking for, but its development is potentially a huge step forward for motorcycle safety systems. Modern electronics can already intervene in braking via ABS, acceleration via traction control and deceleration via electronic engine braking control systems - preventing lock ups or wheelspin, even during cornering with the latest designs assisted by inertial measurement units (IMUs). 

Although less widespread, we've also seen electronically controlled clutches and gearchanges, which leaves steering as the only remaining element of purely human-operated control on some bikes. Yamaha's electric power steering (EPS) means that now there's a way for computers to intervene there, too.
Traditionalists might rail at the idea of a computer stepping in, but when it comes to ABS and TC systems, there's no shortage of evidence that such rider aids can be lifesavers without being obtrusive - and EPS is likely to be the same. That's why its proving ground is motocross, throwing the system directly against the toughest possible challenge.
Mechanically, Yamaha's EPS is quite simple. There's a powerful electric motor attached to the front of the headstock, geared to the steering stem to work as an actuator. 

“The final piece in the rider-aid jigsaw falls into place”

A 'magnetostrictive' torque sensor measures how much effort the rider is putting into moving the bars, while a computer measures that force and decides whether to use the actuator to help.
It's basically the same as the technology used on e-bicycles, which measure the pedalling effort being put in by riders to decide how much electric assistance to add. In its simplest form, the system - which was first run covertly during races in last year's All-Japan Motocross Championship before being publicly adopted by the works team this year - acts as the ultimate steering damper. 

Because it can tell the difference between the rider's inputs at the bars and external influences like bumps that are trying to change the course of the front wheel, it can assist with the former while counteracting the latter. Yamaha says that the power steering side of the system is most significant at low speeds - when large movements at the bars are more common - while at high speeds the steering damper effect is more pronounced.
Even in this, relatively simple form, the system is hugely promising. It should be able to eliminate tankslappers, potentially enabling bike designers to adopt more aggressive steering geometry for sharper responses. As it assists in steering, it also means geometries that would otherwise make the bars harder to turn can also be considered - opening the door to different rake, trail and front wheel and tyre sizes to maximise grip and cornering ability.
Looking further into the future, the system could also become more active, perhaps with programming to step in and help if a rider's inputs are likely to cause an accident. The idea of 'target fixation' - where riders unconsciously steer towards whatever they're looking at - is already well proven, and often blamed for crashes, particularly single-vehicle accidents where a bike runs wide on a corner. With the right combination of active steering control assisted by camera or radar technology, there's potential for a bike to step in and help in those situations.
Yamaha's MOTOBOT project, where a robot rider was given control of an R1 superbike on track, shows that the technology for auto-riding is already available. Honda and BMW have also both demonstrated self-riding bikes with servo-operated steering, and electronics giant Bosch is working on a similar set-up.
Active steering control is coming, and Yamaha's EPS is a huge leap towards getting it onto real-world machines.