Enabling the latest in traffic monitoring and enforcement technology
This is where Kria with its T-EXSPEED traffic enforcement system comes in. The T-EXSPEED detects red light, speeding, and trajectory based violations and includes ALPR (automatic license plate recognition). And it does all this only through cameras—supplied by Allied Vision—without inductive loop detectors, radars, or lasers. That makes it a first in the ITS industry.
T-EXSPEED: A First in the ITS Industry
Stefano Arrighetti, CEO and President, founded Kria in 2003 in Italy to design, develop, and supply automatic recognition systems based on computer vision technology. ITS applications encompass numerous objectives that are completed by separate systems, such as speed measurement, red light violations and automatic license plate recognition. These traffic enforcement systems usually depend on inductive loop detectors, radars, or lasers. However, Kria’s T-EXSPEED is capable of completing multiple objectives in one system without dependence on detectors or radars. The advantage of the T-EXSPEED is that it “only” requires cameras to capture images and information needed for analysis. That also means the cameras must meet Kria’s exacting standards for speed, resolution, ruggedness, reliability, size, range of features, and multi-spectrum capabilities.
The system is composed of three units: the acquisition unit, processing unit, and central unit.
The T-EXSPEED’s acquisition unit is a compact IP66 housing (40 cm x 50 cm x 25 cm) that contains two monochrome cameras and one color camera in a stereo arrangement. The monochrome cameras capture images in the infrared spectrum for automatic license plate readings. Kria selected Allied Vision’s Prosilica GT4907 and Prosilica GT6600 Gigabit Ethernet (GigE) cameras as options for the monochrome cameras. The choice in camera is dependent on the number of lanes to be framed. The Prosilica GT4907 is equipped with OnSemi’s KAI-16070 sensor delivering a resolution of 16 Megapixels; the Prosilica GT6600 contains OnSemi’s KAI-29050 sensor offering a resolution of 29 Megapixels. Both cameras are designed to operate in extreme environments, offer numerous features, such as camera temperature monitoring and color correction and provide Power over Ethernet (PoE) capabilities. The color camera is a Prosilica GT1920C used in the visible spectrum. The Prosilica GT1920 utilizes Sony’s ICX674 ExView HAD CCD II sensor and has a resolution of 2.8 Megapixels. Kria equipped the camera with a wide-angle lens to complete the automatic recognition of vehicles and provide context imaging when violations are detected at a site. The camera also obtains an image of the traffic light. Capturing images in both spectrums produces high quality and unquestionable documentations of violations.
The Right Camera Was Critical
Kria CEO Arrighetti explains why specifying the right camera was so critically important to the T-EXSPEED’s success. “The main camera features needed for the T-EXSPEED were image, resolution, dynamic range, and global shutter,” says Arrighetti. “Furthermore, the cameras needed to withstand varying environmental conditions and provide universal time synchronization to certify exactly when the image was acquired. Allied Vision’s Prosilica GT cameras not only provided an extended temperature range, they contained I/O ports that made camera and lighting synchronization possible. In addition, the GigE connections allowed for short and long distance installations at reasonable costs.”
The T-EXSPEED can complete four and six lane monitoring and traffic violation recognition using Kria’s own real-time image processing software, which is performed in the processing unit. Kria’s research and development team developed the software’s capabilities, including:
- Multi-lane ALPR
- 3D vehicle reconstruction
- Trajectory-based behavior detection (speeding, red light violations, etc.)
- Camera exposure control
- Image compression and encryption
All these tasks occur in real-time, allowing for continuous acquisition and analysis of images captured by the cameras. The system works by capturing a vehicle’s license plate through a series of images that are fed into the software processing unit. The vehicle’s speed is determined by emulating depth perception and analyzing the estimated travel distance over time. If a violation is detected, the images are forwarded to the central unit. The central unit receives the images in an encrypted format and stores them in archives. Typically located in a police control room, an operator can extract the images and decrypt them for post-processing, such as when searching for information about the vehicle’s owner or determining driver behavior based on 3D vehicle trajectory. According to Arrighetti, the goal of the T-EXSPEED was to enter the ITS enforcement market and replace conventional sensors with machine-vision cameras and computervision technologies. The market already has well-accepted and regulated speeding and red light applications. By introducing computer vision technologies into these applications, Arrighetti says, “We can increase the number of functions, merging different traffic applications in one system. Cameras play a central role in our application because they are not only used for event documentation, but their images are used for vehicle detection, identification, and speed measurement. In a sense, calibrated cameras are not only image sensors; they are certified metrology devices.”
Value beyond Cameras
What made working with Allied Vision appealing, however, was much more than just the company’s extensive camera offerings. “There were many times when assistance from Allied Vision engineers proved invaluable,” Arrighetti says. “For example, I remember when a crucial technical improvement was called for during a trial with the Singapore Traffic Authority. Allied Vision provided it the very next day. We worked with Allied Vision not only because of the quality of their cameras, but also because of the quality of their service. At the beginning of every new project we systematically set up technical discussions with Allied Vision engineers who provided us with details and sample units necessary for our application.” Technical challenges relating to real-time image processing, mechanical design, and lighting were a few of the topics discussed.
A Look to the Future
Kria’s T-EXSPEED is currently in its third generation. This and earlier generations did not go through prototyping phases. Instead, Kria relied on real-time customer feedback to refine designs and fuel growth. “Until now we have played the role of the pioneer in a new field,” Arrighetti says. “Because the T-EXSPEED was intended for use in a totally uncontrolled environment, a similar system has never been conceived in conventional machine-vision applications, such as automation or robotics. So our focus was always to prove device function, reliability, and accuracy. In our third generation we look to go from proving to improvement—in compactness, the number of lanes monitored, and the wide range of software functions. The pioneer era is over. It is now time for market expansion.” To date, Kria has received certifications from METAS, the Swiss Federal Institute of Metrology, and the Italian Ministry of Transportation. Systems have been sold in various countries such as Italy, Switzerland, and Canada. Next steps, Arrighetti says, will include further system miniaturization and product line expansion, in close partnership with Allied Vision.
“We will work on the processing unit miniaturization and include new sensors that will expand the T-EXSPEED family range. A motion version may also be completed that will be able to measure vehicle speed from another moving vehicle. This will probably be the next chapter of the story and—with Allied Vision’s help—we are ready to start writing it.”