Misty II has eight time-of-flight sensors; three facing forward, one facing backward, and four facing downward (two in front and two in rear). These sensors are located on the base of the robot, and are likely to become dirty over time. Dirty time-of-flight sensors (especially downward-facing time-of-flight sensors) can compromise the performance of the robot’s built-in hazards system, causing the hazards system to perceive false-positives, or leading the robot to fall and cause harm or become damaged.
If your robot has started running into objects that she would normally avoid, you can follow these steps to ensure the sensors are functioning properly:
- Connect Misty to the Command Center. (Check the docs for details on how to do this.)
- Scroll down to the Sensor Data section.
- Check the boxes to subscribe to Misty’s time-of-flight sensors.
- Position each sensor at incrementally larger distances away from a wall other large object that the sensor an easily detect. Compare the sensor’s return values to the actual physical distance of the object. Start at 100mm, and run the same test at 500mm and 800mm away from the sensor.
Note: You may see some incorrect values due to faulty sensor readings, but if most values are close to the measured distance, then the sensor is working correctly.
For best performance, we recommend cleaning the time-of-flight sensor covers daily by blowing them clean with low-pressure compressed air. Do not use liquid or aerosol cleaning agents, thinners, alcohol, cleaning products containing ammonia or chemical hydrocarbon based solvents (like gasoline, naphtha, carbon tetra-chloried, or acetone), or any other abrasive or corrosive materials to clean the sensor covers, or any other part of the robot, as these agents can damage the finish of the sensor cover, harm the sensor’s optical properties, and reduce sensor clarity.