|
THS
|
Robots /
Lab 2 IR Sensor Experiments1. Try using the IR sensor. Can you get the IR sensor to change values using some common IR sources in the lab or around your home? You may also use the virtual walls and docking station as IR sources.-->Amber 2. How does the Docking Station Work? -->Lorraine Amber Stangroom: Blue Cohort Purpose/Description of experiments: The purpose of this lab was to test the sensitivity of the bump, wheel drop, and IR sensors. To test the bump sensor, the Create was held in a vertical position and nickels were placed on the bumper until the bump sensor was activated. Then, the mass of the nickels was measured. To test the wheel drop sensor, the Create was held in different positions, checking the sensor readings frequently. To test the IR sensor, we used various IR sources such as remote controls, a virtual wall, and a docking station and observed if any infrared light was detected. Results/Conclusions: The bump sensor was activated under a mass of only 110 grams plus the force of gravity. That isn't very much, seeing as many things are measured in kilograms since grams are so small. It can be concluded that the bump sensor is fairly effective at detecting obstructions. The wheel drop sensors were very sensitive. As expected, when the robot was lying flat on a surface none of the wheel drop sensors were activated. I found it suprising that when you turn the robot upside down and keep it level, all of the wheel drop sensors still activate. I would think since because they all fall to their highest position within the robot that none would activate. This may be so because the pressure of gravity probably doesn't push the wheels as far in as the pressure of the floor on the wheels. When slight amounts of pressure are released, the wheel drop will still be activated. IR sources from around the home have no effect on the Create's IR sensors. We used three different types of remotes and none produced any readings from the IR sensors. We also tried to to see if there was a response from the virtual wall sensors but the results were the same. This is because they send out different codes. The virtual wall was very effective, as long as you cover the sides and back of the IR sensor on the Create. Without it covered, the Create senses the IR, but there is no way for the Create to identify which direction the IR source is coming from. This worked especially well for the virtual wall demo. When the Create senses the virtual wall, it will drive towards the IR source. It worked so well that the Create pushed the virtual wall across the floor. The docking base sends out its own IR for the robot to drive towards when it senses its battery is low. It is sent in a way to form 2 buoys of "force". Different positions around the docking station result in codes that tell which specific buoys are detected.
255= no IR detected 240-254= docking station buoys or force field detected 0= no virtual wall 1= virtual wall |