The major leap forward which Honda's MotoGP bike has taken in the
past two seasons has come in two distinct areas, the chassis and the
electronics. Much of the work of sorting out the RC212V's chassis was
done during the 2010 season, when the factory tried out five different
chassis variations and several different swingarms, before getting the
bike right early in the 2011 season. Parallel to the chassis, Honda
spent two years improving their MotoGP bike's electronics, after
poaching two of Yamaha's key staff to work on HRC's electronics package.
The resulting machine, in the hands of Casey Stoner, proved unbeatable
throughout the 2011 season.
A
photo posted on Twitter by
Augusto Moreno de Carlos, editor of the Spanish
magazine Motociclismo, provides an insight into how the development of
technology can take interesting paths. The photo shows how
ASIMO, the robot Honda has built as a
technology demonstrator and R&D project, provided
some of the crucial technology for HRC's MotoGP machine. The
multidimensional inclinometer used by the RC212V to detect the
attitude of the bike is a direct development of the
system used by ASIMO to monitor the robot's balance as it walks and
runs. The inclinometer, consisting of a collection of gyroscopes and
accelerometers, provides information on how the position of the bike is
changing: Is the bike banked over in a turn? Is the bike wheelying under
power, or pitched forward on the brakes? How hard are the braking
forces? How fast is the bike being tipped into the corner?
On the basis of this information, the electronics package on the
RC212V can change the engine power characteristics to help the riders
control the bike better. By sensing that the bike is braking hard -
especially by combining brake pressure information with data from the
inclinometer about the attitude the bike is in - the electronics can
regulate the amount of engine braking to apply. By sensing that the bike
is leaned hard over, power delivery can be made smoother to prevent the
rear tire from breaking traction too harshly. By sensing that the bike
is being stood up hard on corner exit, power delivery can be ramped up
more quickly, allowing the bike to accelerate harder as the rider gets
the bike onto the fat part of the tire.
Although entirely logical when viewed in hindsight, it is fascinating
that the electronics required to monitor a MotoGP bike should be
derived from a walking robot. Bipedal motion - walking on two legs - is a
massively complex undertaking, requiring managing a constantly shifting
center of gravity, as the
technical manual Honda issued about
ASIMO shows in some detail. Though the speeds involved are much
lower - ASIMO's top speed is 9 km/h while
running, a little over a brisk walk - the
complexities and the required speed of data processing are broadly
similar; the fact that the two wheels of a motorcycle are relatively
rigidly fixed together mean that transitioning between physical
positions is gradual. The fact that the human legs and torso which ASIMO
is copying have multiple degrees of freedom in their movements means
that the number of variables involved are greater, and change at a much
greater rate.
While the achievements of Honda in building the RC212V's electronics
management package are many, their package does not by any means give
them an insuperable advantage. The electronics used by both Yamaha and
Ducati are equally complex, with Yamaha revealing at Valencia that the
electronics package uses predictive algorithms to adjust levels of
control to accommodate tire wear and fuel consumption patterns as the
laps tick off. The Yamaha's electronics package constantly monitors the
response of the tire and bike against the behavior calculated using data
from practice sessions. Electronics strategies are constantly changed
to adapt to the feedback coming from the bike, and new strategies
calculated for the following laps based on that feedback. Yamaha, like
Honda, uses gyros and accelerometers to detect bike behavior and adapt
to it: two years ago, Yamaha switched their anti-wheelie strategy from
data coming from the suspension travel sensors to gyros registering bike
pitch. That meant that the wheelie was being detected before the front
wheel left the ground and the front forks were fully extended, and power
could be cut earlier, but by less.
What both the data from Honda and Yamaha show is that limiting
electronics on MotoGP bikes - as Carmelo Ezpeleta is set on doing for
2013 onwards - is not simple. Data on bike attitude from gyros and
accelerometers has become increasingly important, as demonstrated by the
marginal effect that banning the use of GPS data has had this season.
Arguably, banning data from inclinometer packages would have a much
greater impact on bike control than banning GPS ever did. With no data
from accelerometers, wheelie control would be more difficult, and the
factories would have to rely on supension data again. With no data from
gyros, there would be limited information on how far the bike was being
leaned over, making it more difficult to alter throttle response and the
way that power feeds in based on the angle of the bike. More control
would be handed back to the riders, and away from the electronics.
Given the freedom to program ECUs as they wish, electronics
programmers would soon work their way around the problem. Though precise
data on lean angle and acceleration might be missing, data collected
through the data acquisition packages can be used to simulate bike
attitude quite closely. Using just the data from the brakes, engine
revs, throttle position, selected gear and gear ratios, the position of
the bike can be plotted remarkably accurately. Using that data,
programmers can take a very good guess at the attitude of the bike, and
adjust throttle response and engine mapping as required. It won't be as
accurate as using inclinometers, but it will be more than good enough.
Even physically enforcing a ban on inclinometer data could be very
difficult. Anyone carrying a modern smartphone is carrying an
accelerometer and a gyroscope, as the ability to switch display modes as
you tilt and turn the phone will show. The size of the sensors required
is already tiny: one commonly used
triple-axis digital gyroscopic sensor measures just
4mm x 4mm x 0.9mm. Cost is also not an issue: mounted on a printed
circuit board, the sensor can be purchased for
under $50. As sensors get smaller, they become easier
to hide, leaving the only option for controlling their use monitoring
the data coming into the ECU, or imposing a spec ECU on the series and
restricting the parameters available to the programmers.
Controlling the growth of electronics in motorcycle racing is not
easy, and given the technology crossovers between racing and other areas
- as shown by the use of technology from a walking robot on a MotoGP
bike - certainly goes against the wishes of the factories. Finding a
compromise which allows the factories to perform useful R&D while
allowing spectacular racing is going to be hard. But given the dire
nature of the racing during the fuel-starved 800cc era, it is also going
to be absolutely necessary.
