IMU

IMU Position Estimator User Guide

Overview


The IMU Position Estimator app allows you to compare the results obtained by using multiple inertial measurement unit (IMU) sensors from a predefined list containing ADI’s sensors, such as:


1

Sensor not yet released; scheduled early 2022. Please reach out to your local sales representative for more information about our automotive solutions.

In addition to ADI’s sensors, the app also contains competitors' sensors marked as Competitor A, Competitor B, and Competitor C.


Using the app, you can simulate the results and get the position error trajectory graph by customizing the following variables:

  • Trajectory
  • Iterations
  • Sampling Frequency



Getting Started


  • Access the vLab page and navigate to Apps.
  • Select the IMU Position Estimator app.
  • Click Open App.

Once a new project is created, you can see the Configuration field to your left and the Navigation Path View on your right.


/assets/user-guides/imu-overview.png

Figure 1. New project



Configure


1. Choose the IMU Sensor(s)


You can choose one or more IMU sensors from a predefined list containing ADI’s sensors, together with competitors' sensors.


ADI’s sensors available for comparison are:

  • ADIS16507 – compact size and performance IMU for applications such as last-mile delivery and drones.
  • ADIS16550 – auto performance, auto qualified IMU targeted towards L4 applications.

Competitors' sensors are marked as:

  • Competitor A – this sensor has a medium cost and a medium performance.
  • Competitor B – this sensor has a high cost and a medium performance.
  • Competitor C – this sensor has a low cost and a low performance.

2. Add the Trajectory Inputs


Once you selected the IMU sensor(s), you can add the parameters for Trajectory Inputs.


2.1. Choose a Trajectory for the IMU from the dropdown menu:

  • Straight road with constant velocity 30 m/s
  • Turn at constant speed 24 m/s (to stay below 0.4g friction limit)
  • Soft brake, starting velocity 30 m/s, brake at 0.3g, no pitch angle
  • Braking while turning, starting velocity 30 m/s, brake at 0.3g, no bank angle
  • Road roughness, velocity 5 m/s, potholes or speed breakers create shocks

Note: You can select only one option.


2.2. The Iterations must be configured considering the following:

  • Only numerical values are accepted.
  • Decimal numbers are not valid.
  • The number of iterations must be between 25 and 100.
  • Iterations lower than 50 are not recommended because the sigma position error output will not show very accurate results.

2.3. Enter the Sampling Frequency to determine the error domination considering the following:

  • Only numerical values are accepted.
  • Decimal numbers are not valid.
  • The unit of measurement is hertz (Hz).
  • The sampling frequency must be between 25 and 1 000 Hz.
  • Sampling frequency lower than 300 is not recommended because it leads to faster error accumulation.

/assets/user-guides/imu-configuration.png

Figure 2. Trajectory Inputs



Run the Simulation


After inputting (and double-checking) the values in your configuration, click Run.


Within a few seconds, the IMU Position Estimator app will analyze the parameters you offered, and it will simulate the results in the Trajectory Output tab.




Analyze Results


In the Trajectory Output tab, you will find the trajectory graph for each selected IMU sensor.


The graph will display the time (X-axis) and the 1 sigma position error (Y-axis).


/assets/user-guides/imu-analyze.png

Figure 3. Trajectory Outputs



Additional Features


  • To look at graphs in more detail, you can click on the fullscreen icon to show the graphs on the entire screen.

  • If you want to remove all the entered values from all the fields, click the reset icon on the top right corner of the Configuration panel.

  • To download the Trajectory Output graph as CSV, click the download icon above the graph.