New sensor developed in Flow project
The Flow Project is an innovation project investigating how to gather data using sensor technology and then connect the data together on a digital platform. One goal has been to be able to make traffic flow measurements efficiently to replace manual traffic counting and metering with hoses across the road. Therefore, early in the project, participants began to think about opportunities with the project member The Acconeers radar sensor. The radar sensor is effective at measuring passes, but then did not have the ability to determine the direction and speed of passing objects.
- We have solved this by placing four radar sensors from Acconeer together in a fan shape,” says Knut Mårtensson at MiThings, which has had the task of making an optimized solution of the sensor. By measuring how what passes is moved from one sensor to the next, it is possible to create data on direction and speed.
In order to be able to interpret the data from the combined sensors, Acconeer has created an associated software specifically for this sensor.
- Based on an algorithm developed by Acconeer, it is possible to combine several radar sensors to obtain data showing the direction and speed of passing objects, says Martin Hoff, Acconeer. During the project, the product was tested several times at various locations in Lund and Malmö to collect data on the number of passing people and vehicles. The idea of the system is based on the fact that it can be placed with ease and is not affected by static movement from the surrounding environment.
The advantage of sensors in a fan shape over, for example, cameras is that the data handled can never be anything other than completely anonymous. In addition, the sensor is so low in energy consumption that it could be powered by solar cells in the future. But not all parts are in place yet, so the sensors in the project are initially powered by power. During the winter of 2024/25 they have been tested in Veberöd, because Smart Villages there has a test bed where it is possible to get power from a lamppost. The devices would then be linked to the cellular mobile network, but would also be able to tap into the municipality's WiFi. A future option is to send the signals over the LoRa network and the solution provided by the project party Sensative has done.
In the test in Veberöd, it is possible to track how many cyclists and pedestrians pass by the sensor. The sensor sits in the centre of the village near a bus stop. It records all passes, both from left and right, on the bike lane closest to the sensor. The graph shows, among other things, when traffic starts in the morning and when it stops in the evening.
- It looks a little different in both directions, and that probably depends, among other things, on where you get off the bus, says Knut Mårtensson. Now this is only a test, of course, in order to produce data as a basis for decisions, you need to do a more extensive survey.
The sensors that fit together in a fan shape have been developed during the Flow project and discussed during project meetings — just like other sub-projects where other actors have been involved.
- It has given us at MiThing many insights to be part of FLOW, says Knut Mårtensson. The exchange of information with the other parties has been very rewarding and we have had the opportunity to discuss many aspects with the other actors. It has given many impulses, ideas and thoughts on how to follow traffic flows.
For Acconeer, the meetings have been an opportunity to develop the scope of application of its sensor.
- The project was a good opportunity to explore and develop our radar and its applications and test our sensor in a real environment with many objects in motion, concludes Martin Hoff.
Footnote: A goal of FLOW has been that traffic flow measurements should be continuous and real-time based and that the techniques developed should have a high potential to be cost-effective so that they could replace the technologies used today (such as manual traffic counting and counting using hose). New solutions are primarily important for urban planning and traffic management, but can also be used in other parts of public activities such as logistics and environmental planning. Project time was Feb 2022 to Dec 2024. The financier of the project is IoT Sweden.
