Encoder needed? Vex Inverted Pendulum Robot V1.0

This video shows how well our vex pendulum robot balances with and without encoder wheel rate. The motor command is generated from three state feedbacks:
tilt_angle, tilt_angle_rate and symmetric_motor_rate. The symmetric_motor_rate is the average of left and right wheel motor rate derived from encoders geared to the motors.
The motor command is

u=k1*tilt_angle + k2*tilt_angle_rate + k3* symmetric_motor_rate.

This video starts with k3=0 and shows unstable behavior. We then show a stable balance with k3 normal.

More info at Vex Forum http://www.vexforum.com/showthread.php?t=1593
Vamfun Blog:
http://vamfun.wordpress.com/2009/05/29/why-did-i-use-encoders-in-vex-inverted...
Chris S.
Mentor RoboDox Team 599 , Granada Hills, Ca.

Category:

Entertainment

Tags:

• Pendulum
• Inverted
• robot
• self
• balancing
• gyro
• accelerometer
• imu
• robodox
• 599
• vex
• encoder
• bbot
• vamfun
• segway
• vegway

[k2kingy]

Ours does not use encoder feedback.

[allenrl]

what are you using to get the tilt angle and tilt angle rate from the arm? ie encoder or accelerometer or gyro or what?

[paintball718]

fun

[deadlyfalcon89]

nice! is this just for fun or for a competition?