Automotive Radar And Video Sensor Fusion Advances Pedestrian Safety
This 'sensor fusion' technology uses the forward-looking radar to cue the video, greatly reducing the amount of real-time processing required. Cambridge Consultants has exploited this to develop a system that can run on a low-cost DSP (digital signal processor) developed for mass consumer appliances - making the technology suited to the cost demands of the automobile industry.
This low cost focus is complemented by Cambridge Consultants' radar technology, CCL-Softcar, which operates at the low frequency of 5.8 GHz - reducing system costs compared with conventional automobile radar technologies operating at 24 or 77 GHz.
The new software performs object classification. It uses radar scatter information, object movement information, shape and color matching and other techniques to distinguish humans from other moving objects.
Analysis is performed in real-time. Results from the company's prototype system, which is based on a low-cost DSP, are currently generated at a typical rate of 10 to 20 Hz (or every 100 to 50 milliseconds). Combined with the radar system's 20 to 25 meter range, this provides the time margin required to initiate active safety measures. Among the impact mitigation measures under discussion by the industry are tilting the hood to lessen the severity of impact, firing external airbags, and assisting braking.
It's likely that the final object classification rate will be increased to around 50 Hz for commercial use - by selecting higher clock speed versions of the DSP - to match the new generations of fast, low-cost image sensors currently being developed for automotive applications.
Cambridge Consultants' sensor fusion technology is equally applicable to improving the performance of next-generation reversing aids, by providing the driver with a full color display where the object classification software automatically identifies objects, along with approximate distance information, to help drivers take necessary action.
"Active safety systems are a highly desirable accessory for automobiles, but so far the cost of this remarkable technology has limited its application to the luxury vehicle sector", says Gordon Oswald of Cambridge Consultants. "We believe that the cost-sensitive features of our new technology - which allows a video and radar system to be implemented for a bill of materials cost of less than $100 - provides the breakthrough that makes it possible to incorporate active safety in mass production vehicles."
This new development is a valuable enhancement of the CCL-Softcar anti-collision radar technology announced in 2003. CCL-Softcar is a pulsed radar system working in the 5.8 GHz band, rather than the 24 or 77 GHz bands used in alternative anti-collision radar approaches. The effect of this relatively low frequency is to reduce the cost of the components required to build a system, and avoid the time and cost overhead which precision assembly of higher frequency equipment imposes. With this technology, just four radar modules and one electronic control unit (ECU) are required to provide 360 degree protection for an automobile - further reducing the bill of materials compared with alternative approaches, which can require two or more modules to be installed on every side of a vehicle.
The new video-equipped CCL-Softcar demonstration system is installed in a mid-range car, and is currently being shown to automobile and accessory manufacturers.
SOURCE: Cambridge Consultants, Inc.