EE471 Design

Inverted Pendulum System

with Balance Drive

This project will determine 25% of your grade.

The goal: to create an inverted pendulum control system.

PHASE I (the weeks of September 21 through October 5)

There are four major tasks to be accomplished:

1. model the inverted pendulum system and design a pendulum position sensing system
2. model the motor and the drive train--an iterative process
3. evaluate the PIC chips available and choose one (see www.microchip.com)
4. determine the numerical methods required and implement PID control for the PIC chip

The PID Control Equation

Each task will be the responsibility of one group. Groups 1 and 2 will work closely together, as will groups 3 and 4. There will be some interaction between groups 1 and 3 and groups 2 and 3.

PHASE II (the weeks of October 12 through October 19)

Once the four major tasks have been completed, all of the subsystems must be put together.

The PIC chip must be ready to accept PID tuning parameters.

PHASE III (the week of October 26)

Each person, now individually, will determine the tuning parameters based on the fully documented inverted pendulum control system.

Specifications

1. The pendulum position sensor will be an optical encoder and must operate using gray code and LED sensors.
2. The pendulum will have 90^o of rotation, 45^o on each side of vertical.
3. Eight AA batteries will be used to power the system.
4. Pulse width modulation (PWM) will be used to control the motor speed.
5. A 2N2222, or similar device, will be used to power the servo motor.
6. If the pendulum should fall either way, the system will stop.
7. The pendulum will only move through one plane.
8. A PIC microprocessor from Microchip must be used.

Requirements

• Every aspect of each task shall be documented.
• For groups 1 and 2, the characteristics of their respective responsibilities will be expressed mathematically, so that the system may be simulated in MatLAB.
• You can't divide the decisions up but you can divide the work up.
• Division of work will be based on each person's ability and number of hours they are taking. However, everyone shall have equal responsibility. No one in a group shall do all the work.
• Group meetings and as much work as possible will be done in lab following the normal lab.
• Each group will give a presentation on what they have accomplished so far at each lab meeting.
• A weekly report is due. Formatting unimportant, only content is important, though it should be arranged in some logical manner.

Statements

• The inverted pendulum is by nature an unstable system.
• I don't care where you get your information, as long as it is correct.
• You should see if others have already solved your problem and not solve it yourself, if possible.
• It is time to get honest with everyone, including yourself. A healthy mix of conservativeness and ambition should be sought before committing yourself to any task within your group. Drop the starry eyed vision in which you do everything right and on time.