Accelerometer: Centripetal Acceleration
Figure 1. Students building their activity robots.Copyright 2011 Jennifer S. Haghpanah, Polytechnic Institute of NYU
Students work as physicists to understand centripetal acceleration concepts. They also learn about a good robot design and the accelerometer sensor. They also learn about the relationship between centripetal acceleration and centripetal force—governed by the radius between the motor and accelerometer and the amount of mass at the end of the robot's arm. Students graph and analyze data collected from an accelerometer, and learn to design robots with proper weight distribution across the robot for their robotic arms. Upon using a data logging program, they view their own data collected during the activity. By activity end, students understand how a change in radius or mass can affect the data obtained from the accelerometer through the plots generated from the data logging program. More specifically, students learn about the accuracy and precision of the accelerometer measurements from numerous trials.
**Note: This activity uses the retired LEGO NXT robot which is no longer available for purchase.
Understanding centripetal forces is important for engineers who design devices that follow curved paths, such as airplanes, satellites, space ships, cars and amusement park rides. The key factors that affect centripetal force and acceleration—mass, radius and velocity—all play important roles in how engineers design equipment that is counted on to work correctly and safely every day, all over the world. Civil engineers apply their understanding of centripetal acceleration to design highways that are safe for cars traveling at high speeds. Other engineers apply their understanding of centripetal acceleration to make sure that satellites follow the right path and accurately provide people with directions via GPS.
After this activity, students should be able to:
- Describe the parts of a robot.
- Design a LEGO-based arm.
- Explain how data logging works, as well as how to acquire data from data logging and record that data using sensors.
- Program a robot with LEGO MINDSTORMS NXT software.
- Understand how to program an accelerometer and monitor it in data logging.
- Know how to manipulate the mass and radius of the accelerometer.
- Accurately monitor the change in acceleration when the mass on the arm and the radius from the motor to the accelerometer are changed.
Figure 2. Accelerometer sensor on a robotic arm, used to monitor tilt across three axes.Copyright 2011 Jennifer S. Haghpanah, Polytechnic Institute of NYU