TRUCK & OFF-HIGHWAY ENGINEERING June 2019 23UNITED STATES STEEL CORP.
Free Info at http://info.hotims.com/73019-718lation (ANC) system in a cab demonstrator, which was drawing a lot
of attention at the bauma booth, according to Trippel.
The system is attached to the headrest. Microphones pick up the
sound frequencies, and software generates phase-shifted sound
waves in real time and outputs them through speakers to cancel out
the unwanted noise. Sensors detect where the operator’s head is to
create a “quiet zone.” An app is used to configure the system to the
specific cab during installation and also can be used to control it.
The ANC system targets low-frequency noise from about 80-500 Hz.“You hear collisions, things that your implements
come into contact with, but the low frequencies of en-
gine noise, for example, are damped out, providing an
overall more-comfortable and safer environment that
might be more productive if the operator can hear the
things that they want to hear,” Trippel explained.
The noise level in the demonstrator was reduced by
8 to 10 dBA. Greater reductions can be achieved, de-
pending on the sound being canceled.
The technology is still in development, but Recalm
expects to start selling the system by year end, in the
aftermarket and as original equipment.
Worthington also is working on more conventional
ways to reduce noise in the cab, such as cab-mounting
technologies, sound-absorbing layers within the glass
and noise-insulating materials in the cab. The AHSS
concept employed a rubberized coating on the entire
interior of the cab that’s still in the experimental stage,
Trippel said.
“There’s only so much we can do from a cab per-
spective. You’re really dealing with the symptoms of
the problem,” he said. “Dealing with the noise-emis-
sion source is always where we’d like to start, but low-
hanging fruit exists in the cab.”EXECUTIVE VIEWPOINTSGen3 steels may not have the elongation of Gen2 steels, but they cost less and are
more weldable.