LCR Calibration Guide - directedmachines/customer-support GitHub Wiki

Table of Contents

Overview

Calibration records the magnetometer readings from the inertial measurement unit (IMU) while rotating to determine the direction of magnetic north. The calibration is tied to a GPS coordinate and temperature, and multiple calibrations can be saved on an LCR to account for different locations and temperature conditions.

Prerequisites

  • First Use Guide
  • A device (phone, tablet, PC) connected to the LCR WiFi
  • The device locked in portrait mode (to prevent page refreshes when it is tilted)
  • A web browser open with the LCR dashboard page loaded

Safety

Please make sure the LCR is free to rotate in place, far from any people, animals or obstacles. Level ground away from ferro-magnetic objects is preferred. Please select an area where in place rotation for a minute or more will not damage the ground.

Instructions

  1. From any screen in the LCR UI that has a compass (bar magnet) indicator on the upper right, tap/click the compass indicator
  1. The Pose estimator service will load. Tap/click the "Configure" button to expand the options.

  1. Tap/click the "calibrate sensors" button.

  2. Determine if you want to "Reset" the calibration (delete all previous calibrations and create a new one) or add an additional calibration. If you are unsure, skip the reset. Otherwise click on the "reset" button.

  1. The LCR will rotate in place, ensure it is free of obstacles.

  2. Press "Start" to begin calibration.

Calibrations Instructions

In the Calibration UI, tap/click the "reset" button. It will self-disable in a few seconds.

Stand and remain at least 10 feet clear of the LCR. Press the "start" button.

Wait until the LCR stops rotating. It will do a clockwise rotation for a minimum of 30 seconds and will stop when calibration is complete.

after calibration, robot must move forward, in straight line, at least at 15% speed, for GPS correction to be learned.

Verify the compass indicator points towards the approximate magnetic heading the LCR is facing.

Pose Estimator UI after Calibration:

image

Note correctionDeg is 19deg, which is added to mag heading, to give us a nice due to east heading.

Troubleshooting

  • If the LCR was not able to rotate smoothly during the calibration because of the terrain it is on, you need to click "Configure Calibration" and raise the rotation speed and try again. The default rotation speed is 0.11 (11% power). Raise it to 0.12 and repeat the Calibrations Instructions.
  • If motion is disabled you will need to enable in the manual control UI

Next Steps