Technique: the small “chip” of the electronic suspension (2/2)

In the first part of this file, we had approached basic suspension with electronic adjustment, with presets for the spring and depreciation preload settings, but also semi-active automatic adjustment systems, which automatically adjust the'Depreciation to better adapt to the surface of the road and the driving maneuvers.But since when did it all have?And what motorcycles are equipped with it?

All manufacturers adopt it ...

BMW was one of the first manufacturers to offer an electronic suspensions adjustment, on the K1200S and R in 2004. The ESA suspension electronic adjustment system had a series of presets on the dashboard, for solo, duo and/or With luggage. The ECU sent signals to small electric motors to activate the adjustment devices on the shock absorbers (rear and front teleler), offering a more rigid damping modifying the preload and even the speed of the spring. It was a question here of convenience and ease of adjustment for different charges. On this type of motorcycle, forks and shock absorbers are hidden under plastic panels and are difficult to access. And unlike a more typed sporty motorcycle, it is usual to load a BMW or a goldwing of more than 100 kg for a walk, if we take into account the passenger and the suitcases. It is therefore logical that there is a need for radical changes in the suspension configuration, and they would be really painful without an electronic system. The replacement of the Ergots key and the toolbox of the toolbox with neat push buttons is the perfect solution for a high-end touring motorcycle.

The damping is adjusted using proportional depreciation valves with a "variable annular space and therefore a variable flow for shock absorber oil".These valves make it possible to modify the damping force in a few milliseconds.

The second generation of the German system (ESAII) was born in 2007 and found its place on the K1300S. But it was not until 2013 that BMW really improved its system, by presenting its semi-active dynamic damping control configuration and much more sophisticated on the Superbike HP4 in 2013. It was the first time that the suspension was really adjusted according to the returns of the spring racing sensors, instead of simply playing on predetermined depreciation positions. It was a huge breakthrough that established the standard for the industry using an elastomer jurisdiction stiffness adjuster. A steel axis moves in a material similar to rubber, which actually modifies the effective stiffness of the spring of the mono-pantry. The displacement of this axis out of the elastomer makes it "sweeter", which reduces the overall rigidity of the spring. This is different from the preload setting, and before ESA, it could only be done by exchanging the metal spring itself.

Like the Multistrada, the HP4 has an electronic valve in a single fork arm, while the other has a preload adjuster on top.The calculator obtains all its information from the sensors already on board and part of the ABS and the HP4 control traction: speed, angle of inclination, accelerometers, braking pressure, etc.

Introduced to EICMA in 2012, the semi-active suspension version of Marzocchi entered production in 2015, with the intention that its components are autonomous and can be used as an upgrade on a model already released in series.

The system uses potentiometers and an inertial platform for a complete image of acceleration and positioning angles in the motorcycle.To go further, the GPS is also integrated.A dedicated calculator analyzes all this data, and a smartphone or tablet can be used to make general modifications to the system, direct adjustments to parameters, or even modifications to the actual amortization curves of the fork and the shock absorber.This would make the system much more adjustable and even more suitable for racing applications.

Marzocchi has developed its own semi-active suspension version

The electronic valves developed by Tenneco, the parent company of Marzocchi, are used to control amortization: the response time is less than 10 milliseconds, in the same order as BMW and Ducati systems.Marzocchi works with a variety of manufacturers, including BMW, Ducati, Harley-Davidson, Piaggio (Aprilia) and MV Agusta.Documents on the Marzocchi site show the semi-active system deployed on a brutal MV Agusta model, and it is also used on the MV Agusta Turismo Veloce 800. Ironically, Tenneco has its own semi-active system called electronic suspension(These) which is used in many automotive applications, and the valves these - probably the same as those used in the Marzocchi system - have been developed in collaboration with the Öhlins race department.

We cannot speak high -end suspensions without approaching the Swedish brand, Öhlins.It has been almost 30 years since Öhlins has experienced the semi-active suspension on the Yamaha in Grand Prix for the first time, but technology has since been standard.Öhlins presented its mechatronic system (mechanical and electronic) at the end of 2011 for the BMW R 1200. At the same time, BMW has taken a step beyond its electronic suspension adjustment (ESA) and APublished information on a new Dynamic Depreciation Control System (DDC).The mechatronics and the DDC operate on the same basic principle: change the action of the suspension in real time to better adapt it to the conditions, on the basis of the data collected from various sensors.

Öhlins uses small steps step by step to modify the damping settings in the shock absorber.This is the TTX36 shock absorber offered for the Kawasaki ZX-10R.

The Öhlins mecatronic system begins with TTX shock absorbers, with compression and rebound adjusters replaced by small steps.The technology, nicknamed TTX EC (Electronalely Controlled), has already been used on Yamaha snowmobile models and is part of Ducati's electronic suspension group on Multistrada and Panigale models (1199 then V4), which allows the pilot to modifyThe parameters via the dashboard.The R1M is also equipped with these golden shock absorbers.

With mechatronics, however, step by step engines take their orders from a dedicated calculator.The system was used for the first time by the Yamaha World Superbike team in 2008 (see image below), and is now offered in kit for the R 1200 GS equipped with ESA II - which has a front fork andcan use two TTX shock absorbers.

KTM also has an electronic suspension system, produced by WP.The forks and shock absorbers themselves are built by WP, and the system uses the Bosch electronic control unit, with a software calibration by WP.Its semi-active suspension has mounted on the S adventure (since 2015), as well as on the original 1290 Adventure.The 1190 Adventure is also delivered with an electronic preload adjustment of 2013-16.But KTM does not reserve it only for adventure motorcycles, since the Austrian brand has also installed the electronic suspension on their superduke GT, which proved to be a winning combination.

KTM has equipped the Superduke GT with a semi -active suspension, via its WP subsidiary

Like any technological development, each manufacturer is interested in it, to align in terms of competition. In 2018, it will be Kawasaki's turn to enter the field of electronic suspension, thanks to Showa and an exclusive agreement between the two companies. The 2018 ZX-10R has a brand new semi-active Showa electronic suspension system. The rear mono-amortator and the front forks both have computer-controlled damping adjusters, but they use a new solenoid type adjustment. A large part of the current technology uses small steps, connected to damping screws: a small 12V engine does the work that a mechanic would do with a screwdriver on manual suspension, playing on more or less clicks. But Showa uses a solenoid to adjust the shock absorbers. It is a faster and more direct mechanism that reacts in a few milliseconds.

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Showa suspension elements that equip the Kawasaki ZW-10R is

Showa has also equipped its new race sensor shock absorbers, small electronic devices to measure the movement of the suspension.This information is then returned to the proper calculator of Showa, so that the computer knows what position is the wheels, how much they move and if they accelerate or die.This information is combined with other inputs of the main ECU of the ZX-10R covering the speed, the position of the accelerator, braking-and they also examine the IMU unit of the motorcycle, which indicates the angletilt, as well as its pitch and its lace.Technical, right?

What is the next step ?

Many of the current "dynamic" electronic suspension systems are intelligent - but not so intelligent as we could hope for.They are content to adjust the suspension according to a certain number of factors - speed, accelerator position, braking - but they lack an essential engineering concept called "feedback".In other words, that they do not know exactly what is going on with the wheel, because they do not have a position sensor on the shock absorber.

You've probably seen these types of sensors on MotoGPs, where they are used for data recording.Called LVDT (Differential Variable Linear Transform), these long stems look a little like a steering shock absorber, and they measure the race of the shock against continuously, storing the information so that the technicians can analyze the data when returning to the standsof the pilot.

The “red stem” is an LVDT and is clearly visible on this Yamaha Yzr-M1 with a rear shock absorber

Now, if our electronic suspension system was equipped with it, it could immediately see what is happening at the wheel level, rather than having to interpret it from all other factors.

With a sufficiently rapid calculator and ultra-fast action damping adjusters, it could react much more quickly and effectively to shock, braking and acceleration than ever.

The Showa configuration on the new ZX-10R has been delivered with this type of configuration: racing sensors in the fork and the shock absorber, and a new mechanism of amortization adjustment in Solenoid, which promises to react in a few millisecondes.

What about competition?

All this is very practical, but even if the weight was not a problem, why do MotoGP pilots not use it?The answer is quite simple: the suspension of a high -level competition motorcycle is properly configured for a given race track, little bumpy and known to suspended technicians.This is a fairly simple problem to solve to configure a motorcycle for a driver and its piloting style.Indeed, technicians could undoubtedly obtain a slightly better configuration for each turn with an electronic adjustment.

But would that compensate the mass, cost, complexity and the necessary additional configuration time?Probably not.In any case, the regulations are massively opposed to electronic suspension configurations.In World Superbike, they can only be used if they are also present on the approved version of the machine-and, above all, only the approved configuration can be used, without modification of the ECU or the shock absorbers themselves ('Exception of valves and fluid changes).

GPS - or any other information about the position of the motorcycle on the track - is not allowed for setting suspensions.This means that it is not possible to have an adjustment that adjusts the parameters of the suspension for each curve.Also, this means that in WSBK, the drivers must pilot a motorcycle with an additional weight, with a road motorcycle adjustment and that it is not possible to modify it specifically for the race.This is why we see so little on the track.

In 2008, Noriyuki Haga used a semi-active Öhlins suspension on his WSBK Yamaha YZF-R1, with a shock absorber controlled by this ECU (the golden box) nestled inside the saddle shell.In this application, three -axis gyroscopes help determine when and how to adjust depreciation.

In Grand Prix, it is even simpler: no electronic suspension is authorized, whether in Moto3, Moto2 or MotoGP. What limits the introduction of such technology is above all its exorbitant cost of development, which would dig even more the gap between the stables with large budgets and the small satellite teams. Nevertheless, you should never say. If suspension manufacturers (Öhlins, Showa, WP, etc.) spend more and more money to develop this kind of systems, they may well start to put them in the world of competition. The interest of the race is, after all, to develop new technologies to adapt them to standard motorcycles, but also to publicize a brand for the commercial side. Thus, the presence of a super intelligent semi-active suspension on a MotoGP prototype would make this system more attractive on a standard motorcycle. For the moment, we can only presume, but as electronic suspension becomes the standard on road superbikes, we can only assume that we will see them one day in competition. As for high series motorcycles, it may become the norm in a decade at most.

Sources: BMW, Ducati, Aprilia, Bwi Group, Öhlins, Marzocchi, WP, Sachs, etc.