Is this the future of R/C?
Horizon Hobby’s Active Vehicle Control could be a game-changer;
our friends at RC Car Action take a closer look at the technology
BY PETER VIEIRA
E
ver since Mercedes Benz and BMW
debuted vehicles with electronic stability control in 1995, the technology
of electronically maintaining traction
and mitigating slides has continued to
advance and trickle down to more affordable cars — as you’ve no doubt noticed
when attempting to drift your Alamo rental out of the lot, only to have the electronic
stability system step in before the rear end
gets a chance to step out.
With the advent of Spektrum’s new Active
Vehicle Control system (AVC for short), similar technology is now available for R/C cars
and trucks. Instead of spinning out, AVC
helps your car hold its line. Instead of getting sideways on the start, AVC will keep
your machine tracking true. That’s the
objective anyway — does it really work?
The new Losi TEN-Rally X RTR Rally Car
and the Vaterra Hälix 4WD Monster Truck
are the first models to get AVC, and we
drove them both to get the full experience.
What is Active Vehicle Control?
Before we get to what AVC is, let’s get to
what it isn’t. It’s not a robot, and it doesn’t
drive the car for you.
AVC simply helps your vehicle maintain
the course you set for it. As you drive, AVC
interprets data from accelerometers (like
the ones in your phone that allow the
screen to “flip” depending on its position)
Vaterra’s 1:10-scale Hälix 4WD Monster Truck with Active Vehicle Control
was initially unveiled at the 2013 iHobby Expo in Schaumburg, Ill.
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and microelectromechanical (MEM) gyros
(like those used to stabilize R/C helicopters) to determine the vehicle’s altitude,
direction and acceleration.
AVC compares this data against the commands the receiver is sending to the steering and throttle channels. If your car is
AVC IS NOT A ROBOT, AND
IT DOESN’T DRIVE THE
CAR FOR YOU. IT SIMPLY
HELPS YOUR VEHICLE
MAINTAIN THE COURSE
YOU SET FOR IT.
behaving as commanded, AVC stays in the
background. But if your commands and
the data AVC collects from the accelerometers and gyros don’t jibe, AVC will step in
with corrective steering inputs and even
throttle commands, if needed.
But unlike the electronic stability system
in the Alamo rental you were trying to pitch
sideways, AVC does not dramatically “take
over.” It makes minute corrections 180 times
per second and operates so transparently,
you simply feel like you’re an awesome driver, not a driver being electronically assisted.
How active is Active Vehicle Control?
Out of the box, the Vaterra Hälix 4WD
Monster Truck and Losi TEN-Rally X RTR
include Spektrum DX2E transmitters.
To accommodate AVC, the radio system
is set up so the Dual Rate Steering dial
allows you to dial up as much or as little
AVC as you like by simply twisting the
knob — full counterclockwise is “off,” full
clockwise delivers maximum AVC effect.
Much like the variable settings of many
high-performance road cars’ electronic stability systems, which allow a certain level
of honing without the intervention of the
electronic nanny, dialing down the AVC
allows you to control how wild and crazy
the system will allow the car to get.
MODEL RETAILER
2014
© 2014MARCH
Kalmbach
Publishing Co. This material may not be reproduced in any
form without permission from the publisher. www.ModelRetailer.com
Racing with AVC
Sorry, not allowed, you’ll have to climb out
of the C-main on your own.
“But how will anyone know if I’m using
AVC or not? I could always turn it up after
the race starts ...”
The answer, you cheater, is the AVC’s
“blinky” mode. When the receiver is programmed for “AVC off,” it will blink to confirm AVC is indeed inactive, and cranking up the transmitter’s AVC-assigned
knob won’t turn it back on. All the race
director (or a suspicious competitor) needs to do to confirm you’re not using
any electronic assistance is look for the
blinking LED. If the receiver is blinking,
AVC is off. Easy.
AVC in action
We tested the AVC system on both of the
models in which Horizon Hobby has
debuted the system: the Vaterra Hälix 4WD
Monster Truck and the Losi TEN-Rally X RTR
Rally Car. The cars handle very differently,
but AVC has the same effect on both vehicles: It makes them very easy to drive.
With AVC on, the Hälix and Rally simply
drove like they were very well set up. Handling was predictable, and both machines
were extremely stable. There were no
“there it goes, I felt the AVC kick in” moments. Hand the transmitter to someone
without telling them the cars have an elec-
The Losi TEN-Rally X RTR Rally Car is
one of two vehicles initially released
from Horizon Hobby that features
Active Vehicle Control.
tronic stability control system, and they’ll
never know — they’ll just be able to tear it
up and have fun more easily than if they
drove “unassisted.”
The effectiveness of AVC became very
apparent when compared to driving models with AVC switched off. Without AVC,
much smaller inputs with more precise
timing were required to match the “with
AVC” performance, but “match” isn’t a fair
word — it’s a challenge to be as smooth as
AVC for a single lap on an off-road course,
but to maintain AVC-grade control lap
after lap is something very few of us would
be able to do (and those of you who can,
please say hello to Adam Drake, Dakota
Phend, Dustin Evans and the rest of your
pro buddies for us).
The biggest change in vehicle dynamics
with AVC off was throttle feel. Without
traction control, the Rally and Hälix were
free to unleash full power without regard
for traction, making both feel like more
powerful beasts, as far as dirt-roosting displays go. Actual speeds were slower since
so much power was being lost to wheelspin, but there was a greater impression of
hold-onto-your-hat performance. This is
where the ability to adjust the “amount” of
AVC intervention is a real plus — you can
set just how much “out of control” you
want your driving experience to have.
Not just for corners
AVC’s most noticeable and practical effect
is greater control in corners that might
otherwise see your car spin out, but AVC
also does its thing on the straights with its
Heading Hold function.
Any time the steering wheel is at neutral,
the AVC system will make necessary input
to keep the car tracking straight. This is
especially useful in bumpy conditions that
otherwise make it hard to keep a straight
heading. “Now lining up and hitting that big
jump just became as easy as punching the
trigger,” is how Spektrum crystallizes the
driving experience, and that’s pretty much
spot-on. Bumps can still knock the car off
line, that’s just physics — what’s uncanny is
how the car instantly resumes its straight
heading in the originally commanded direction without any input from the wheel.
Performance on the straights and under
acceleration is also aided by AVC’s tractionenhancing capabilities, which are just as
effective when driving in a straight line as
they are when cornering. You can park the
car on a loose surface, pin the throttle and
launch with minimal wheelspin. The combination of Heading Hold and traction
control make the TEN-Rally X and Hälix the
most rock-solid straight-line machines
we’ve ever driven.
Independent steering and throttle AVC
As mentioned previously, the Spektrum
DX2E transmitter included with the TENRally X and Hälix allows you to easily adjust
the level of AVC intervention by simply
turning it “up” or “down” like a volume
knob. Turning the dial adjusts the steering
Spektrum’s AVC technology is not yet
compatible with all ESCs and should
only be sold as a replacement receiver
for the Hälix and TEN-Rally X.
and throttle channels together. For a finer
level of control you can upgrade to a fourchannel Spektrum DSMR transmitter and
adjust AVC for steering and throttle independently. It would be unusual to want a
lot of AVC on one channel and only a little
on the other (not that we won’t try it ...),
but the ability to fine-tune the relationship
between the two represents another level
of control with which we’re looking forward to experimenting.
Peter Vieira is the editorial director of the surface group at Air Age Media. This article was
compiled from the January 2014 issue of RC
Car Action.
Matt Gunn takes a closer look at the TENRally X in Product Spotlight, page 24.
ALL FOR FUN
When RC Car Action broke the news on
our Facebook page that Spektrum was
bringing electronic stability control to
R/C, I was surprised by how passionately
some decried Active Vehicle Control as a
disturbance in the Force worthy of making Obi-Wan grab his seat on the Falcon.
The feeling was that AVC is a cheat, a
means of allowing new or less-skilled
drivers to experience something they
haven’t “earned.”
I couldn’t disagree more. They’re toy
cars, folks, designed and manufactured
expressly for fun. R/C isn’t a life skill, a
career builder or something that’s going
to help you survive the zombie apocalypse. It’s just fun, whether your idea of
fun is banging around an empty lot or
putting in three qualifiers and a Main at
the track.
As with all things fun, I can’t get
behind the idea that R/C needs any rites
of passage to be enjoyed. With AVC, you
can drive a faster, more powerful model
over rougher terrain more easily than
your skills would likely allow. That’s the
real rub for someone who has a chip on
their shoulder about what an awesome
driver they are.
Another Facebook commenter likened
AVC to aim-assist in video games, as
though that was something wrong,
because it’s an important life skill to be
able to aim accurately in a video game.
Do you want to live in a world where
kids can’t pull off an unassisted head
shot on an alien invader? I have no problem with it. And I have no problem with
AVC. It’s not going to harm the hobby,
and if it’s not for you, someone else
enjoying AVC won’t diminish your enjoyment of driving without it, I assure you.
More fun is more fun, and I’m always
on the side of more fun. — P. V.
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