Template sensor and automation to track speed / acceleration from GPS device tracker

Configuration
1

Hi all, I am working on a project that uses GPS data from my phone to track speed.

It works OK but I do get crazy data from time to time and this creates spikes in speed that are incorrect. I have tried different ways to filter the data and my latest idea is to calculate acceleration between each speed data point. To do this I need the following:

  1. current speed (I have this)
  2. time stamp for current speed (I have this)
  3. time since last GPS/speed (I have this)

So I can create input number helpers for this data and then use them to calculate acceleration etc when I receive new data. But this is clunky as for each device i will need to create multiple input number helpers.

I have been trying to create a template sensor that holds all the data I need as attributes but I can’t find a way to hold the data from the previous speed/gps data.

I tried using this.state and this.attributes.name and states(entity) as I hoped one would have the previous data. Here is my working/testing yaml.

Any advice appreciated

- sensor:
    - name: "Jago iPhone Acceleration Test"
      unique_id: jago_iphone_acc_test
      icon: "mdi:speedometer"
      state: >
        {% set speed = states('sensor.jago_iphone_speed') | float(0) %}
        {% set gps_age = states('sensor.jago_gps_age') | float(0) %}
        {% set speed_last = state_attr('sensor.jago_iphone_acc_test', 'speed_last') %}
        {% if speed_last == 'None' %}{% set acc = 0 %}{% else %}{% set acc = ((speed - speed_last) / gps_age) | int(2) %}{% endif %} 
        "{{ acc }}"       
      attributes:
        speed_last: "{{ states('sensor.jago_iphone_speed') | float(0) }}"
        gps_age_last: "{{ states('sensor.jago_gps_age') | float(0) }}"
        time_last: "{{ state_attr('device_tracker.jago_iphone_2', 'last_seen') }}"
        acc_last: "{{ states('jago_iphone_acc_test') | float(0) }}"
2

I am looking to do the same (for just speed) and am thinking of an automation that on a location update works out the distance travelled over the time since the last update. I’m not sure if this data is in the trigger though.

3

@sshaikh - happy to help but I warn you that it was not easy generally and getting acceptable/accurate data took a load of work.

Let me know if you want any help. I learnt a load and have a system that works quite well now.

There is an integration that I use that takes multiple device trackers into one and has built-in speed sensors. It’s a good place to start.

Here is a view that displays raw data, cleaned data with speed limit and a log of speeding events…

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4

Actually I think that composite sensor is already doing what I’m thinking of doing. I’d just wrap one tracker in it though.

5

Nice.

The composite tracker is a great integration. Works fine with one tracker. I use a couple in my setup to get better home/away tracking but only one tracker has GPS data for speed calcs.

I think you might find quite a bit of noise/false speed data depending on the frequency of GPS data. This is the tricky bit to clean up if you want only good data.

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