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Bump

1. What force is required to activate the bump sensor?: Annelise

2. How sensitive is the bump sensor? Tina

Name Annelise Mesler

Purpose/Description of Experiment The purpose of my experiment was to determine the sensitivity of the iRobot's bump sensors. The bump sensor is operated by a spring that holds the robot's bumper. When the bumper is pushed, the spring compresses and the sensor is turned on. I wanted to know what force would be required to compress the springs. I accomplished this by holding the robot perpendicular to the floor and placing standard weights (nickels) on the bumper until the sensor was turned on.

Diagram

Results It took an average of 110 grams (22 nickels) to compress the spring on the front bumper. This weight is equivilant to 1.1 Newtons, a relatively small value. This shows that the bump sensors are very sensitive! However, I did not take the weight of the bumper itself into account, so the actual force required may be slightly higher than my results suggest.

Name : Tina (You Kyung) Choi

3. How sensitive are the bump and wheel drop sensors? 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.

Purpose

Purpose of this lab is to find out how sensitive the bumper and wheel drop sensors.

Hypothesis

The bumper sensor of the robot will be very sensitive and it will even detect very light force applied to the Robot.

Materials

Robot, RealTerm, Ruler, pencil, paper

Procedure

1. On the piece of paper, draw 1mm mark for 30mm

2. Place the robot on top of the paper and send the bumper sensor command.

     [142] [7]

3. Start to push slowly until the robot sends back information when it senses something on the bump.

4. Repeat this step 2 more times and try from the right and left side of the Robot as well.

Results/Data

Front bumper

Left bumper

Right bumper

Observation/Conclusion

As I have expected, the robot's bumper was very sensitive. The robot detected a very minimum push on the bumper. One thing I noticed was that robot senses the bumper sensor when there is a "click" sound. I assume that it is a sound that is made when a part of the material from bumper sensor touches part of the main body part of the robot.