Family provides simplified development for versatile short-range measurement applications.

by Richard Quinnell, EiC

There is a growing market for sensors to monitor the
position and speed of objects, and not many flexible alternatives. Ultrasonic
sensors cannot sense through glass or other solid barriers and optical sensors,
including lidar and cameras, have difficulty with fog, dust, and darkness. But
radar using millimeter wavelengths can overcome all these and offer high
accuracy to boot. Now millimeter wave sensing is becoming easy enough to use
that developers should consider exploring the new options available.

The rising interest in advanced driver assistance systems
(ADAS) and autonomous automobile design has created a market for low-power
radar using millimeter wavelengths. These radars work at short ranges,
typically from 30 to 200 meters, and are used for both object detection and
collision avoidance. They typically operate in the 76GHz to 81 GHz range with
an output power up to 150 mW.

But automotive applications to detect obstacles are not the
only use for such radar systems. They produce chirped signal bursts that can also be used in industrial settings to
precisely measure position, angle, and velocity of a target. According to
Sameer Wasson, general manager for radar and analytics processing at Texas
Instruments, the range accuracy possible with millimeter wave sensors Ti is now
introducing is as fine as 100 micrometers – the width of a human hair.

Speaking with Electronic
Products
in a phone briefing, Wasson described the new family millimeter-wave
sensor systems that TI is offering that has on-board signal processing as well
as the full radio system in a single chip. Two families are available: the AWR
series for automotive and the IWR series for industrial. The series include the
AWR1243 radar front end intended for connection to an external signal
processor, sensors with MCUs built in, and sensors with DSPs built in. All the
devices work from a common software base, giving developers portability across
a range of performance options.

 

Millimeter-wave sensor

With the entire RF system and signal processing integrated into a single chip, precision millimeter-wave angle, position, and velocity measurement fits into a 25mm square package.

The common software base and system integration these
sensors offer bring another advantage, Wasson pointed out: simplified
development.  The software development
kit (SDK) supporting these sensors include sample algorithms, software
libraries, and a dedicated design tool that, Wasson said, lets developers get
their applications up and running in 30 minutes or less. An understanding of RF
is still important, he noted, but not the level of expertise that such system
designs have required in the past. And TI is offering online training to help
out.

If this product introduction were just a reduction of size
and development effort for ADAS systems, it would be worth noting. But these
single-chip systems offer such a significant increase in accuracy that they
open the possibility of applications not seen before. With the onboard
processing available, Wasson pointed out, a millimeter-wave system is able to
detect a person’s respiration even if they are otherwise not moving. This sensitivity
would allow an application such as an automobile that, as an additional safety
measure, prevented locking the doors with a sleeping infant inside. In
industrial applications such as level sensing, millimeter-wave sensing beats
existing technologies by an order of magnitude. Other potential industrial uses
might be traffic monitoring, precision obstacle avoidance for robotic systems,
and the like.