The Adaptive Traffic Control System (ATCS) is expected to improve busy urban traffic. With the help of microwave radar, the traffic conditions at intersections can be mastered and traffic lights adjusted appropriately. This text will describe the current development of ATCS and introduce ADI Company's DEMORAD microwave radar solution.
Microwave radar is the best solution for ATCS
ATCS is a self-calibrating control solution that can automatically adjust the time of traffic lights according to real-time traffic conditions in order to optimize traffic flow, which makes it a key component of rapidly growing Intelligent Traffic Systems (ITS) market. The current global ITS market is valued at $4 billion and is expected to grow to $22 billion by 2022 at the compound annual growth rate (CAGR) of 33%.
ATCS has become an increasingly important investment field with the growth of traffic demand and the increasing popularity of smart city planning. The value of lost economic productivity due to wasted time in traffic as well as the associated effects of fuel waste and air pollution is in excess of billions of dollars. Therefore, solutions for managing traffic flow are urgently needed.
ATCS is usually used to optimize the time of traffic lights according to the traffic queue length, average traffic flow speed, traffic time/delay of main lines, number of times for vehicle stops, intersection delay, unforeseen circumstances (such as accidents, construction or vehicle failure), pedestrian movement and other conditions.
With the adoption of ATCS, traffic flow is expected to increase by 50% and mobile traveling time will be reduced by 25%. The number of times for vehicle stops, accidents and car accidents will also be reduced. It can respond to various traffic conditions and fluctuations more rapidly, reduce fuel consumption and air pollution, and is expected to improve the driver's mood due to the reduction of traffic delay. The economic productivity can also be improved due to the reduction of the time wasted in traffic.
Common ATCS detection technologies include inductive loops, video camera, microwave radar and aggregated cell phone signals, among which microwave radar has more advantages. ATCS adopting multichannel microwave radar is a cost-effective solution because of its simple installation and extremely low maintenance requirements. It can support the distance up to 200 meters, which will not be affected by light conditions, dust, dirt or moisture. In addition to the function of monitoring traffic flow of multiple lanes at the same time, multichannel system can also detect, track and monitor the speed and direction of a moving object, and can detect objects as small as 70 cm.
Take ADI Company’s ATCS solutions based on 24 GHz radar as an example. It is an full-signal chain solution which adopts the complete bit-to-antenna solution from the same supplier. Multichannel system can conduct detection and tracking for multiple objects with wider vision. Compared with using multiple single channel radar chip, it has the most advanced performance of lower cost, the best angular resolution, 1.5 times the detection range, 2 times the sensitivity and low power consumption etc. Different with fully integrated single chip radar, it has unlimited design choices and can be easily extended to multiples of four channels with excellent flexibility and extendibility.
In order to accelerate the development of the microwave radar system for customers, ADI Company has launched a 24 GHz radar system-level prototype solution named DEMORAD, which has a full-system reference design of application development hardware and software in order to deal with the challenges of those companies devoting themselves to develop RF radar as a sensing technology. DEMORAD system of 24 GHz radar is a new type microwave radar evaluation platform, which can easily launch the radar sensor in a few minutes with the out-of-the-box software sample. DEMORAD supports rapid prototype design of radar sensor products, which can measure the real-time information of the existence, movement, angular position, speed and range of the sensor’s target/object.
System hardware solutions include RF antenna and complete RF-to-baseband signal chain, as well as ADF5904 (receive), ADF5901 (transmit), ADF4159 (PLL), ADAR7251 (AFE), and ADI’s ADSP-BF707 DSP, which can be quickly connected to a laptop/PC with easy-to-use graphical user interface and radar algorithm software. Blackfin® DSP library provides radar FFT and control firmware, which only needs a few minutes for the user to plug the platform system into the computer with loaded software. The database using the software of GUI and DSP radar support can provide a comprehensive software support of 24 GHz radar chip and can use MATLAB® tool to conduct original data post-processing on PC, which can be applied in radar sensor software design such as 2D/3D radar FFT, CFAR and classification algorithm.
The sensor of DEMORAD contains a single PCB, which is connected to a 24 GHz RF chipset on the obverse side with the integration of 2 transmitters / 4 receiver antennas, and conducts a data collection of ADC and DSP on the reverse side. Therefore, customers can build their final product design on the basis of this reference design.
DEMORAD uses FMCW radar to monitor the range and speed of objects, with the farthest distance of 200 m and the resolution ratio of about 75 cm. According to the antenna array design, the azimuth angle of field of view (FOV) is about 120° and the elevation is about 15°. Through combining antennae in digital beam forming (DBF), DEMORAD uses DBF to calculate angle information in the FOV.
DEMORAD can be used in the products like traffic monitoring, parking, UAV/UAV collision avoidance and altimeter, monitoring and fail-safe system etc. The product packaging contains DEMORAD sensor, USB key containing software, USB mini cable and power cable.