Imaging sensors located inside and outside automobiles offer new market opportunities in the course of improving highway safety and vehicle control. Some of these applications are being driven by government safety regulations such as the Federal Motor Vehicle Safety Standard 208, which requires that 2006 models of automobiles sold in the United States must be capable of distinguishing whether a small child is located in the front passenger seat so that airbag deployment can be adjusted. With new imaging-sensor technologies, automakers are also beginning to install accident-avoidance and guidance features such as camera-aided maneuvering, lane-departure warning systems, and autonomous cruise control.
The growing market for automotive imaging devices that can perform these functions should reach almost 7 million units, or $40 million, by 2008, according to Strategy Analytics (www.strategyanalytics.com). The total market for automotive cameras is expected to grow at a compound average annual growth rate of more than 100% from 2005 until 2010-still a small fraction of the growth of digital cameras.
To meet the stringent automotive requirements for temperature and dynamic range, several sensors and cameras are available. Established CMOS sensor vendors such as FillFactory (www.fillfactory.com), Melexis (www.melexis.com), Micron Technology (www.micron.com), and ZMD (www.zmd.de) are developing automotive-specific products, and more-focused companies such as SMaL Camera Technologies (www.smalcamera.com) and IMS Vision (www.hdrc.com) are also targeting this market.
Apart from the stringent temperature specifications (roughly -40°C and +125°C) required by automotive suppliers, the technical specifications demanded of imagers are very application specific. These include operation over a range of light intensities and detection of objects that may move quickly in both day and nighttime conditions. Juggling these factors with the need to produce low-cost, integrated, and programmable devices, most of the vendors to the automotive market have opted for imaging sensors fabricated using the CMOS process.
Although the dynamic range of linear CMOS sensors is often less than their CCD counterparts, CMOS vendors developing parts for the automotive market are boosting the dynamic range with devices that feature logarithmic or logarithmic-like responses. In these sensors, voltage response is presented as the logarithm of the light intensity. This produces dynamic ranges often in excess of 120 dB, making the devices useful in relative contrast measurements.
Just cruising
Cameras for adaptive cruise control must identify highway lane markings so that the system can determine whether a vehicle detected by the auto’s on-board radar occupies the same lane. Canesta (www.canesta.com), fuses image ranging and recognition functions to create a 3-D image for this purpose (see Laser Focus World, October 2004, Inside Imaging).
It may be that image-analysis software expertise will really make the difference in determining who succeeds. Early market leaders include second-tier automotive suppliers such as Valeo (www.valeo.com) and Iteris (www.iteris.com), which jointly developed the AutoVue lane-departure warning system for Nissan; and Aisin Seiki (www.aisin.com), which developed the intelligent parking system used on the hybrid Prius from Toyota (www.toyota.com).
Strategy Analytics believes that lane-departure warning systems will be deployed initially in the SUV and minivan market. Rapid adoption of lane-departure warning technology would require ease of system integration and, ideally, laws mandating this new safety feature. The U.S. Congress has discussed the provision of financial incentives to buyers of vehicles that include such safety-oriented technologies.
The typical lane-departure warning system uses a forward-looking camera mounted behind the windshield to continuously track visible lane markings. This is interfaced to a computer with image-recognition software to analyze vehicle speed, yaw, and steering angles.
As automobiles incorporate more imaging technology, drivers, passengers, law enforcement officials, and insurance companies may all come to like the smoother and safer flow of traffic.
