Self-Cleaning Particulate Filter Project Filter II Team Presenters: Roger Ostrander Steve Van Neste Demo given by: Roger Ostrander

Unique Feature of System: The Voltage Regulator A controller subsystem that controls current the heating elements during the Cleaning Sequence. Components of unique feature: Timer. Regulator of pulsed current. Element incrementer.

What does feature support? Functionality of Voltage Regulator: controls the ramp-up and ramp down of current to currently selected functional elements. Sample scenario description: (see normal sequence diagram in D.D.)

Key Model The System Monitor Checks the values of the system and says when and when not to clean the filters It is key because Illustrates the primary control logic Demonstrates RPM change functionality Shows the concurrency needs and peer-to- peer relationship requirements

[PressStart = true RevStart = true RPMStart = true GetCS() == false] /BeginCleaningSequence [RPMStart = true GetCS() == true] /BeginCleaningSequence Element Checking RPM Checking Revolutions Checking Pressure Checking

Critical Properties Required Element Failures Required Response to the Failed Element Required Response to Pressure Abnormalities Required Cleaning Sequence Start, Execution and Continuation

Promela and XSpin Results of analysis Both the starting and cleaning functionality of the system was modeled Assertion statements were used to verify that the system started properly, a failed element would be skipped during cleaning, and that the ramp down of current began properly Discussion of results All three critical properties were verified without errors The model ran in Xspin until it ran out of memory

Demo of Prototype High-level features of User Interface: Start/Stop Engine Everything changeable (RPM, etc) “Defaults” button

Scenarios Cleaning Sequence is initiated. Executor check, then send message to Voltage Regulator to start the Cleaning Cycle. Voltage Regulator receives the message to start, it will repeatedly pulse and increment the current until the System Monitor senses the current is between amps. System Monitor sends warning message to Executor.

Scenarios Voltage Regulator begin the ramping down process. Voltage Regulator calls ‘increment current element’ function. The Executor checks if it is >=8, then set Cleaning Sequence to ‘false’. Error encountered(no temperature change ). System Monitor stores failed elements and Voltage Regulator stops Cycle. Voltage Regulator calls Executor to increment the current, when =8, Cleaning Sequence is ended until it is next initiated.