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Noise pollution is a growing problem in large cities, affecting the quality of life of the population. To address this challenge, a French company is testing an innovative sound radar that identifies excessively noisy vehicles and allows automatic fines to be issued.
Noise pollution in traffic is a growing problem. To combat it, technology is advancing with increasingly precise solutions. The “Hydre” sound radar is an example of this. Developed by the French company Noiseparif, it combines acoustic sensors and cameras to identify vehicles that exceed the permitted noise limits.
How Hydre Radar Works
Hydre consists of two acoustic modules that work together. Each module has four microphones capable of measuring sound 25 times per second. These measurements allow the intensity of the noise and its origin to be calculated.
To ensure accuracy, the sensors are protected by acoustically transparent metal cages, preventing damage and vandalism.
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The system also has three cameras. A wide-angle camera captures the entire scene of the moment of the possible infraction.
Two other cameras automatically read vehicle license plates (ALPR), both at the front and rear. This allows us to accurately identify which vehicle generated the excessive noise.
All components are housed in a secure metal enclosure. Data processing and transmission are performed directly on the device. Information is encrypted to ensure security and integrity.
Identification and recording of violations
The Hydre radar operates according to a rigorous process. First, the sensors determine the dominant noise level every 40 milliseconds.
They then cross-reference this information to identify the sound source and calculate the distance from the vehicle. This adjusts the recorded value to a standard reference of 7,6 meters, ensuring standardization in measurements.
If the corrected noise exceeds the established limit, and if the environmental conditions are suitable, a possible violation file is created. The system then analyzes videos and images before and after the moment considered critical. This helps to correctly identify the offending vehicle.
The next step is to compare the trajectory of the dominant sound with the trajectories of vehicles in the scene. If there is any doubt about which vehicle generated the noise, the case is discarded. The system excludes situations where there are multiple vehicles heading towards the sound source, avoiding confusion.
If the violation is confirmed, an image of the vehicle is extracted. In it, a frame marks the identified car, and a circle indicates the origin of the noise.
The system then consults the ALPR cameras to retrieve images of the license plate and automatically read the number. All of these elements make up the violation file, which is sent electronically to a monitoring center.
Initial testing and results
Between January and October 2022, the first phase of Hydre testing was carried out in France. The experiment involved installing prototypes in eight locations, distributed across seven communities.
The objective was to evaluate the performance of the technology in real conditions, but without applying fines at this stage. The results were considered encouraging.
The device was able to detect noisy vehicles within a radius of 15 meters in each direction, even in places with heavy traffic.
During testing, the radar identified between 10 and 44 vehicles per day that exceeded the 83 dB(A) limit. This value was defined only for the experimental phase.
There is still no decision on what the final limit set by the Ministry will be, but it is estimated to be between 83 e 90 dB(A). The higher the limit, the fewer violations will be recorded.
The future of sound monitoring
Hydre radar technology represents a breakthrough in traffic noise monitoring. With precise measurements and automation, it can help control noise pollution and improve urban quality of life.
The next step will be to define the rules for applying fines, making this technology an effective tool for managing noise in cities.
How wonderful! I hope it comes to Brazil soon. I hate noise!!
Finally an invention that really isn't just to rob us.
My dream is to put a lot of them where I live... and motorcycles day, night, dawn, even the rain DOESN'T keep them away...
Hatred of open discharges by a few destroying the peace of a population