Project 4: Height Control and Finite State Machines

Project Goals

• implement controllers that manipulate multiple, independent degrees of freedom,
• design and implement a finite state machine in software,
• use a finite state machine for control.

Hardware Overview

Project Overview

In brief, your code must:

• command the heli to maintain the designated orientation and height,
• respond to new commands by changing the orientation and height goals in the specified manner (using a finite state machine),
• indicate the current state of your FSM using a set of 3 LEDs.

Project Components

Part 1: Microcontroller Circuit

• Designate two additional digital input pins. Call these C1 and C0 (you may choose any 2 pins).
• Connected these pins to +5V through a 10K ohm resistor (one resistor for each pin).
• Connect a wire from each of these pins to ground. Configure the wire such that it is easy to remove/replace. When connected, the pin will read "0"; when disconnected, the pin will read "1"

Part 2: Height Maintenance

Note: you may need to use a different position gain depending on whether you have a positive or negative error (it is a lot easier to get the craft to descend than it is to get it to rise).

Part 3: Finite State Machine

• Assign each state a unique integer between 0 and 5
• The numbers on the transitions represent events as indicated by input command lines C1 and C0 (and "xx" means any value for each)
• Implement this FSM in software using these events
• Display the state of the FSM using a set of 3 LEDs

Note: Develop this FSM independently of Part 2. You should be able to see the FSM state change as you alter C1 and C0.

Part 4: Finite State Machines for Control

• Each state will have its own height and orientation goals.
• Transitions may only occur after the height and orientation goals are achieved. For example, starting from hover 4, if 11 is commanded, this will take the FSM to hover 1. Only after its goals are achieved, may the FSM transition to hover 3

The goals for each state are as follows:

• wait: stay on ground

• land:
  • height: 0
  • orientation: maintain last orientation

• hover 1:
  • height: 1m
  • orientation: maintain last orientation
• hover 2:
  • height: maintain last height
  • orientation: 90 degrees
• hover 3:
  • height: 2m
  • orientation: 180 degrees
• hover 4:
  • height: 1.5m
  • orientation: 225 degrees

References

• Atmel HOWTO
• OU-XUFO hardware specification
• Devantech sonar sensor unit

What to Hand In

• Demonstration/Presentation: All group members must be present.
  • Demonstrate your final product.
  • Present your design and implementation (5 minutes). The group is responsible for assembling a short presentation consisting of 3-4 slides (on computer or in printed form). Describe the design including: your general approach to solving the problem, the circuit, any key software algorithms (how the general problems are solved in code), and the software organization (describe how the software problem is split into different separable sub-problems, and how the different components interact).
• Code: Turn in your documented code to the project 3 digital dropbox on D2L (text format). Only hand in one copy of the code per group.
• Group report: Augment your presentation with any details that do not fit within the allotted time. You may use your presentation format (e.g., powerpoint) for this report. Turn in one copy per group.
• Personal report: One submission per person to the project 3 digital dropbox. State the relative contribution of you and your group members (in terms of percentage of effort) (text format only!)

Grading

• 40%: Project implementation
• 30%: Demonstration/presentation of working project (to either of the TAs or the instructor). This demonstration is due at the same time as the reports
• 30%: Code documentation and group report

Grades for individuals will be based on the group grade, but weighted by the assessed contributions of the group members.

fagg [[at]] ou.edu

Last modified: Wed Apr 9 22:10:25 2008