AME 3623: Project 10: Finite State Machines II

• All components of the project are due by Thursday, May 5th at 9:00 am
• Groups are the same as for project 1.
• Discussion within groups is fine.
• Discussion across groups may not be about the specifics of the solution (general programming/circuit issues are fine to discuss).

At the end of this project, you should be able to:

• design a finite state machine (FSM) for complex, mission-level control,
• translate the FSM design into C code, and
• debug both FSM designs and code.

Project Outline

1. At the beginning of a test run, your hovercraft will be placed in either the 1, 2 or 3 configuration shown (it will be placed in the middle of the hallway). Your program will not be given any information about which configuration it is in.

2. On start up, your program should first record the state of the switch.

3. Phase 1: your hovercraft must navigate from its initial configuration to a subgoal:
   • If started in 1, then end in B
   • If started in 2, then end in B
   • If started in 3, then end in A

   Note: "ending" at a location is very liberal; if your hovercraft stops within 2 feet of the end of the designated hallway, then it is considered as as having arrived successfully.

4. Phase 2: depending on the state of the switch at the beginning of your run, the craft must navigate to a second specific subgoal:
   • If 0, then navigate to A
   • If 1, then navigate to C

Component 1: Hardware

Component 2: Finite State Machine Design

Design your FSM on paper. This FSM must accomplish all of the above steps, including handling the start and the stopped states.

In particular, you must:

• List the actions. How the actions relate to control signals? For example, an action such as brake requires the reversal of the middle fan and a large middle fan duty cycle for a brief period of time.

• List the events. How do the events relate to internal or external information? For example, an event such as obstacle requires that the value of one of the distance sensors is within some range.

• Draw the FSM diagram with states, events and actions listed. Include this FSM diagram as part of your report.

Component 3: Software

Notes

• Implement your FSM incrementally: get one piece working well first and then grow it.

• Draw your FSM before you implement it in code. If you change your implementation, make the change on the diagram first, then work on the code.

• You can do a lot of testing with your craft being held by a group member. This will help you separate the problems of debugging high- and low-level code (but, in the end, it must all work together).

• Your hovercraft can easily accumulate a lot of momentum. You can "burn" this off using a number of techniques. Reducing middle fan thrust in general can cause the craft to drag a little against the ground, effectively giving you a form of linear damping. You can also explicitly have states in your FSM dedicated to powering down the middle fan to stop the craft before continuing with the next phase of the task.

• This is an involved project. Start early.

• Keep your batteries charged.

• By rotating your lateral fans slightly inward (so their thrust vector is perpendicular to the vector from the middle of the fan to the center of mass), you can generate more rotation and less forward acceleration.

What to Hand In

• Demonstration/Code Review: All group members must be present. Given time, this can be done during class. The demonstration must be completed by Monday, May 9th. It is our expectation that you will make every attempt to complete your demonstration by May 6th.

• Check in the following to your project 10 area of your subversion tree:
  • Documented code: See the project 1 specification for detailed documentation requirements.

  • FSM diagram. Submit in pdf format.

• Personal report: There is no personal report due for this project.

Grading

• Each person must accumulate at least three personal programming credits over the course of the semester. This project offers one.

• To receive credit, you must be the primary designer, implementer and debugger of the component. This does not mean that your other group members should not be looking over your shoulder. But: you must do the "driving."

• 35%: Project implementation
• 30%: Demonstration of working project (to either of the TA or the instructor)
• 35%: Documentation

Group Grading Rubric

Grades for individuals will be based on the group grade, but weighted by the assessed contributions of the group members to the non-personal programming items.

References

• OUlib documentation

andrewhfagg -- gmail.com

Last modified: Tue May 3 15:19:09 2016