Content of the case study
Impacts of SED use in the streets of Pilsen
SED – Sound Event Detector
On Sunday evening, an operational officer of the Pilsen Municipal Police was alerted by an alarm from the SED detector on the city’s CCTV system to a possible incident in Pilsen on Americká třída. The officer immediately determined that the impulse to trigger the allert was a shouting man entering the roadway.
This man was immediately attacked by a group of people and was left lying motionless on the sidewalk. However, City Police patrols were already on their way to the scene prior to the assault. At the same time, the Czech Police were immediately notified of the incident and arrived.
The patrols managed to catch the suspicious group on the spot, but they defended themselves by saying that they had only resisted the man’s attack. During the scuffle, the man sustained injuries that required medical treatment.
At approximately a quarter to 2 a.m., an operations officer dispatched a City Police patrol to Republic Square based on a recorded audible alarm. The trigger for the alert was a group of seven persons disturbing public order. On the video footage it was clear that some of those present were trying to attack each other. The patrol at the scene found that no violation ultimately occurred.
This is a new technology used by the Pilsen Municipal Police, which is able to detect possible illegal actions based on audio input from the location.
Source: Municipal Police of Pilsen
Sound Event Detector (SED) installation targets
▶️ Night Order Solution.
▶️Immediate summoning of security forces in case of conflicts.
▶️ Streamlining the work of the operations centre.
▶️ Analysis of the places with the highest crime rates.
Problem solving
| 01 Procedure for solving the order | The initial analysis consisted in identifying the problem locations of the MP. Subsequently, a study of the coverage of the localities was carried out, where three options (conservative, medium and full coverage) were proposed, the client chose the medium option to cover the areas. The areas are fully covered for the purpose of scream and gunshot detection during nighttime hours, have limited function during the day and when covered for glass breakage. |
| 02 What a concrete solution | Based on the coverage study, feasibility and evaluation of alternative solutions, outdoor SED sensors (25 in total) were selected for the first three areas in the validation phase of the project for crime prevention purposes. |
| 03 Reasons for the chosen solution | 3 of the 6 sites identified have good coverage of camera points, so for the initial 25pc verification phase, sites were selected as far as the operator could see. The remaining sites cannot be fitted with cameras, only a SED is deployed, the operator responds to a short 1s audio demonstration of the problem and calls the patrol according to experience and assessment of the situation. |
| 04 Solving problems | The installation company installed the SED in several places on a non-functioning VO, a change of location was necessary, in another case the sensor was installed in a place next to a waterfall, where it showed a shortened range due to the traffic in the vicinity |
Design solutions in time
6 to 7 sites identified for detector deployment, coverage study of identified sites delivered.
First phase of installation, ordering 25 devices to cover 3 sites.
Installation of 25 SED devices.
Positive evaluation of the project – order placed for 25 more SEDs to cover the remaining sites.
Installation of 25 pieces of SED equipment.
The first service update of the device was performed with modifications for the customer’s specific environment.
Coverage study
Coverage design procedure
MP and city representatives selected a total of 5 areas:
- The area around Americká Street (problem area, large number of bars).
- The area around the main train station (problem area, homeless people).
- CAN and its immediate surroundings (problem area).
- The Thirty-Fifth Avenue, the square and the area around the synagogue (potentially problematic location, large number of people, protection of soft targets).
- City Ring Road (no CCTV, no surveillance, potentially problem area).
- University campus (strategic location, protection of soft targets).
Map of coverage
Results of the case study
- Cost of implementation of 50 Sound Event Detectors (SED): CZK 1,250,000.
- The total implementation of the contract, including preparations, took about 12 months.
- The Municipal Police identified 6 locations, which were subsequently covered by 50 SED devices.
- After only a few days of operation, the SED devices were able to repeatedly warn of various illegal acts (fights, assaults, destruction of cars and other illegal acts).
- SED has helped to significantly streamline the operation of the operations centre.
- Significantly shorter response times to various crimes → recorded cases of street fights and destruction of private property.
- The devices evaluate an average of 3,000 pulse events per device per day. Our deep neural network algorithms operate with an exceptional 99.9% accuracy.
- Streamlining the work of the operations centre – operators in Pilsen now work only with alerts from the SED and no longer actively monitor the camera system.
- Approximately 20 new locations were covered – this was mainly due to the unique SED technology with the possibility of mobile installation and the city saved approximately EUR 500,000 for the installation of camera points in these locations.
- Of the 54 devices, the police receive approximately 35 to 45 alarms per day, of which less than 10% are reported as false alarms.
