[Resolved] Multiple people detection

Discussion in 'Presence Sensor' started by Spiderixius, Feb 6, 2019.

  1. Spiderixius

    Spiderixius New Member

    Hello community, as I mentioned a little bit in this thread https://www.xethru.com/community/threads/regarding-tracking-multiple-object-position.470/ we are able to track the presence of two persons, by looking at the Fast Movement column from the movement item list csv file. We simply detect how many peaks there are, however the issue arises when people are at the same distance to the sensor.

    Any ideas to what could be done to find two persons at the same distance to the sensor?

    We are using one X4M300 sensor. We were thinking to maybe use two and sync the data between the two sensors to detect the presence of multiple objects at the same distance to the sensor.
     
  2. Charlie Shao

    Charlie Shao Moderator Staff Member

    XeThru Radar module is one-dimensional sensor, which means reflection radar pulse from the same distance is mixed together, no angle information, so it is not able to distinguish two persons at the same distance. It is possible to use a multi-chip system for this case, we have customers working in this direction, but there is no ready-to-use product by far.
     
  3. Spiderixius

    Spiderixius New Member

    Hello Charlie Shao

    What if we used two sensors and synced the data using Python. Do you think it could help us distinguish between multiple people? One sensor would give the data for one axis and another sensor for another axis. Then maybe use the timestamp to sync the data and 2D lateration to see how many people are present?
     
  4. NSANGOU CHOUAIBOU

    NSANGOU CHOUAIBOU Active Member

    Hi Spiderixius,
    You will end up with data from two transmitters and two receivers completely uncorrelated.

    B.R,
    Chouaibou.
     
  5. Spiderixius

    Spiderixius New Member

    Yes, but I was thinking it could maybe be possible to correlate the data using the timestamp. Also are you able to suggest alternative UWB radars for the purpose of sensing multiple persons?
     
  6. NSANGOU CHOUAIBOU

    NSANGOU CHOUAIBOU Active Member

    Hi Spiderixius,
    Timestamp just give you data with time as tag each time the data is generated by the SoC. But it doesn't tell you that your sensors will be acquiring data synchroneously. You are not losing anything to try and see what result you will get.

    UWB radar sensor can sense multiple persons in an area, but it based on intense DSP algorithms, system and antennas design, etc... For the X4M300 module, it is designed for presence detection of a single target based on movement (when moving) or respiration when still. The development kit X4M03 is made for people who want to design their own custom UWB-IR radar based applications. The result guarantee depends on your algorithm and perimeter of your application.

    B.R,
    Chouaibou.
     
    Last edited: Feb 28, 2019
  7. Spiderixius

    Spiderixius New Member

    Thank you very much Chouaibou. We will try with two X4M300's and see what we can do about it.