december2021 - 48

ADAS
The human side of
assistance-guided repairs
Performing static calibrations in-house
and what you need to consider.
By Dave Hobbs
I
f you're delaying getting into servicing ADAS
(advanced driver assistance systems), don't
delay too long. Government safety agencies like
the National Highway Traffic Safety Administration
(NHTSA) and every vehicle manufacturer agree
that ADAS save lives and reduce collision damage.
This means they're here to stay and will continue
to become more commonplace than ever in your
bays. Many advanced (and profitable) repair shops
are maneuvering their way through the complicated
maze of ADAS sensor diagnostics and calibrations.
But this will not be a simple or inexpensive endeavor.
ADAS service joins a long list of other complicated
technology challenges we've faced and conquered
over the years in our wrenching careers.
Today we'll focus on the " human " side of ADAS:
static calibrations.
CALIBRATING SENSORS:
THE 'HUMAN' SIDE OF ADAS
If every ADAS-equipped vehicle could calibrate itself
as well as it robotically performs its advanced driverassist
duties, those of us contemplating working on these
vehicles could breathe a big sigh of relief. There is an
overwhelming number of complicated calibration procedures
and tools to juggle. There are two main types of
ADAS sensor calibration procedures:
* Static: vehicle parked/
system learning
* Dynamic: vehicle driven/
system learning
In most cases, both types of calibrations will require
an enhanced OEM level aftermarket scan tool or true
factory (dealer) scan tool. Some manufacturers require
either static or dynamic calibrations, while others require
both. Static calibrations (typically in your bay) require
the most equipment, shop floor space, and time. If you
are just beginning to do your research on what type and
brand of static calibration equipment fits your needs
(and budget) I must advise you of two big factors.
First, the equipment is costly. Whether you opt for a
collection of pure OEM tools (as used by the dealers) or a
choice from a growing list of aftermarket providers, plan
on spending tens of thousands of dollars if you desire
to calibrate multiple vehicle brands. But please keep in
perspective that diagnosing pre-OBD vehicle drivability
problems was best accomplished via a big box engine
analyzer 35 years ago. The Sun machine my father purchased
(and I used) in the 1980s cost more than $27,000.
We made the ROI in a reasonable timeframe. With inflation
factored in, that same investment would be around
$87,000 today. That's more than enough to handle your
48 Fleet Maintenance | December 2021
Radar sensors use a reflective
metal surface for calibrations. This
pyramid-shaped metal reflector is
common to Toyota and several other
OEMs. Others use a flat plate for a
static calibration reflector.
Photos courtesy of Dave Hobbs
ADAS equipment needs with money to spare. Variations
and choices are abundant in ADAS camera/radar static
calibration equipment. The choices can be broken down
into several categories and subcategories starting with
OEM and aftermarket.
* OEM/dealer equipment: OEMs mostly use a geometry-based
target placement process using common
carpentry tools such as a plumb bob to find the exact
center of the front (and back) of the vehicle. This
allows a technician to locate and mark the vehicle's
geometric center. Lines are then drawn on the shop
floor (i.e., chalk lines/tape/markers) along with
various angles to set the camera static calibration
target(s) and radar sensor reflector (mounted on
stands) at precise position/distances in relation to
the vehicle. A factory scan tool is then connected
to issue bidirectional requests to the ADAS sensor
being calibrated. The scan tool tells it to lock on to
that target to finish the static calibration process.
Laser measurement instruments may be employed
to speed up this time-consuming process.
* Aftermarket - Stand-alone target frame: An aluminum
" frame " with arms to mount targets, lasers,
and tape measures is set in place in front of the sensor
being calibrated. As with OEM's static calibration
equipment, the position of the visual (camera)
target(s) and/or reflector (radar) target must be precise.
Wheel-mounted heads (with clamping brackets
resembling chassis alignment heads) in conjunction
with tape measures/lasers may speed up the process
of finding the center of the vehicle. This is required
to geometrically place the calibration targets in the
precise location in front of the vehicle. This emulates
the vehicle manufacturer's target placement position
but can often take less time to accomplish compared
to some OEM methods.
* Aftermarket - Target frame with chassis alignment
equipment integration: Because ADAS calibration
procedures require the vehicle to be on a level surface,
alignment racks (which must keep the vehicle
perfectly level anyway) have recently become a handy
piece of equipment to add ADAS calibration tools to.
Several chassis alignment equipment companies are
getting into the ADAS calibration tool market. Some
aftermarket stand-alone ADAS calibration systems
(i.e., Autel) can adjust the height of their target frame
arms (and tool calibration software) to accommodate
the raised height of the vehicle WHILE parked on
an alignment rack.
The second consideration is weighing OEM vs.
aftermarket ADAS calibrations. Some deem this a
modern-day Hatfields vs. McCoys. While the OEM
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