Based
on a market study conducted by Intechno Consulting, the world sensor market
(all sensing principles) is growing steadily with an average annual growth rate
of seven percent from $20 B in 1994 to $40 B by 2004. An emerging
segment of this huge market is related to microwave sensors. According to
market forecasts from Frost & Sullivan and ABI Inc., radar applications are
expected to build to a $1 B market within five years, as shown in Figure 1
. Clearly, the commercial microwave sensor market is experiencing a boom. Radar
technology provides what the market needs: a reliable, accurate and noncontact
sensing of distance, movement and presence.
segment of this huge market is related to microwave sensors. According to
market forecasts from Frost & Sullivan and ABI Inc., radar applications are
expected to build to a $1 B market within five years, as shown in Figure 1
. Clearly, the commercial microwave sensor market is experiencing a boom. Radar
technology provides what the market needs: a reliable, accurate and noncontact
sensing of distance, movement and presence.
Industrial
Sensors
A significant
industrial application of radar sensor technology is the measurement of liquid
or solid material level in process tanks. Most level measurement principles
require a mechanical contact to the process, but use of contactless measurement
principles is increasing rapidly. Radar offers the best performance in terms of
robustness to extreme temperature, pressure, dust and aggressive chemicals.
World revenues from shipments of radar level-sensing instruments are growing 15
percent per year and are expected to reach $280 M by 2003.
New
competitors are currently entering this market, creating a market growth that
puts price pressure on radar level-sensing instruments, which originally were
high profit products. The majority of installed radar level meters operate at
5.8 and 10 GHz. However, the next generation of radar systems with 24 GHz
technology pose strong competition to the existing products for two reasons:
The 24 GHz level gauge can be built smaller and lighter. Hence, it can be
mounted to narrow tank flanges and is much easier to handle. In addition, sharp
antenna patterns that maximize the level echo while minimizing disturbing
reflections are possible, providing high accuracy and measurement reliability.
The
new 24 GHz systems not only utilize advanced microwave technology, they also
incorporate modern digital signal processing (DSP) features such as
self-calibration, self-diagnosis and automatic parameter setup, which provide
the user with easy installation and low maintenance. Besides level sensing,
radar technology is used in several industrial niche applications such as
turbine diagnosis, moisture measurement in paper production and object
detection within manufacturing lines. Figure 2 shows an increasingly common
contactless measurement gauge.
Automotive
Sensors
In the
automotive industry, a highly competitive car market exists. Advanced features
are used to distinguish cars while safety is a major consideration in new car
purchases. It is not surprising that radar technology has gained strong support
from leading members of the automobile industry. The automotive radar market is
expected to dynamically grow to a volume of roughly $300 M to $500 M by 2003.
The
revolutionary approach of automotive distance warning systems is to use
front, side and backup radar systems to monitor obstacles, as shown in Figure
3 . This car vision system determines distance from and speed of detected
objects and alerts drivers if they are too close to an obstacle. Radar appears
to be the best sensor principle since alternatives such as laser and ultrasound
fail under bad weather conditions when they are needed most.
front, side and backup radar systems to monitor obstacles, as shown in Figure
3 . This car vision system determines distance from and speed of detected
objects and alerts drivers if they are too close to an obstacle. Radar appears
to be the best sensor principle since alternatives such as laser and ultrasound
fail under bad weather conditions when they are needed most.
The
first 77 GHz adaptive cruise control (ACC) radar was scheduled to be available
in Mercedes Benz S-class cars this spring. Besides the forward-looking radar,
increasing interest is being expressed in short-distance sensor functions such
as lane-change aid, park distance control (PDC), precrash detection, occupant
sensing and a stop-and-go option for second-generation ACC radar systems. It is
not yet clear at which frequencies these novel automotive sensors will operate,
but the 24 GHz band could be a good choice with respect to production maturity
and cost. The in-car sensor functions are likely to be realized using an
optical basis.
The
parking aid is a well-established car option that was introduced by BMW in
1991. All PDC systems shipped currently are based on an ultrasonic principle.
However, ultrasound is likely to be replaced as soon as radar is offered at the
same price level. As a customer benefit, radar is more robust and the microwave
modules are mounted invisibly behind the bumper.
Airbag
systems are another potential application for radar and light detection and
ranging technology. Conventional airbag systems are triggered by acceleration
or pressure sensors. Sophisticated signal processing is required to determine
very quickly whether or not an accident occurred and at what time the airbags
must be deployed. A precrash detection using radar could help to further
improve the reliability of airbags, especially with respect to the side airbag,
which is the most critical type. An additional idea behind adaptive inflation
of the so-called smart airbag is the use of an in-car sensor to determine the
shape and position of the occupant on each seat. The technology for future
optical three-dimensional (3-D) camera chips for passenger detection is
currently in development.
Although
the car sensor functions discussed in this article are not yet completely
mature, it is not difficult to imagine microwave and optical vision systems
making their way into future automobiles. A survey of the automobile industry
has determined that an appropriately priced device designed to reduce
collisions could become as popular as other safety devices such as airbags and
automatic braking systems, which have gained an impressive market share.
Consumer
Sensors
Consumer
applications, a very fragmented market, have put the strongest price pressure
on sensor devices. The sensor element is only a small portion of the end
product. Here, radar again competes with less-expensive principles such as
ultrasound and infrared sensors. Despite the technical advantages of radar, it
cannot be successful unless ultra-low cost microwave sensor elements become
feasible.
The
most popular radar application is motion sensing. Typical end-customer products
are door openers and automatic light switches. Microwave sensors can be mounted
invisibly behind dielectric covers, which is a clear advantage over other
technologies. Radar motion sensors have been available for some time and it is
now possible to produce a simple planar 2.4 or 5.8 GHz Doppler radar module for
roughly $5. However, this cost is still higher than an IR sensor. The
semiconductor industry is working on radar chips capable of operation to 100
GHz. In parallel, optical 3-D camera technology is being established. The
higher the frequency, the better the sensor resolution and the smaller and
cheaper the sensor element can be. The industrial, scientific and medical band
at 61 GHz would be suitable for low cost sensors such as proximity switches.
Future
$3 sensor elements will open up the market for interesting products in
household applications. An intelligent home environment may contain functions
ranging from smart doors and lights, enhanced safety alarm features, wireless
identification and data transmission to more sophisticated products such as 3-D
imaging cameras for cleaning robots and smart cooking.
没有评论:
发表评论