Water Pump Object Unobservable Event that causes fault

Water Pump Object Unobservable Event that causes fault (debatable whether we need these) ? WP Water Pump on off F_WP_RPM Water Pump RPM Fault Ok stuck at prev stuck at unknown degrading ? WP_RPM Water Pump RPM (revs per minute) Continuous value (range? ? ) F_S_WP_RPM WP RPM Sensor Fault Ok stuck at prev stuck at unknown degrading S_WP_RPM WP RMP Sensor Continuous value (range? ? ) P_WP_OUT Output pressure Continuous value (range? ? )

Water Pump (plus) DBN LL LL’ Tank’s Liquid Leve Continuous value (range? ? )l S_LL’ Tank’s Liquid Level Sensor Continuous value (range? ? ) ? ? ’ WP F_WP_RPM ? WP’ F_WP_RPM’ ? WP_RPM F_S_WP_RPM’ F_S_WP_RPM’ P_WP_OUT’

Solenoid Valve Object Unobservable Event that causes fault (debatable whether we need these) ? F_SV Solenoid Valve Fault ok stuck open stuck closed degrading leaking Solenoid Valve open closed CMD SV Controller Command On off P_IN Input Pressure Continuous value (range? ? ) P_SV_OUT Output Pressure Continuous value (range? ? )

Solenoid Valve (plus) DBN ? ? F_SV CMD SV F_SV P_IN P_SV_OUT CMD SV P_IN P_SV_OUT’

Some Questions How do we model faults? - external variable (as illustrated) vs. stochastic transition F_S_WP_RPM How does the sensor fail? - what types of failures does it have (stuck at, random, noisy) - how does the failure evolve over time (persistent, unpredicted) F_WP_RPM How does the water pump fail? - what types of failures does it have (stuck at, random, noisy) - how does the failure evolve over time (persistent, unpredicted)

Electrolyzer ? Command turn-on turn-off Fault in Electrol OK Stuck-at-off Stuck-at-on Degrading F_EL CMD Electrolyzer on off FL_H 2 O_DEIONIZER_OUT EL CMD_EL_VOLTS Elec. voltage requested (Cont. value Current Cont. value Electrolyzer Current Sensor Fault Ok ? stuck at prev stuck at unknown degrading F_S_EL_CUR Input flow, water Cont value (range? ? ) FL_H 2 O_EL_IN Output flow, H 2 Contin. value (range? ? ) linear fn. of amps ? FL_H 2 O_EL_UP_OUT Output flow, O 2 Cont. value (range? ? ) linear fn. of amps FL_H 2 O_EL_LOW_OUT Output flow, H 20 (w/ H 2) Cont value FL_H 2_EL_UP_OUT FL_O 2_EL_LOW_OUT ? FL_H 2 O_EL_OUT F_S_EL_CUR H 2 Mass Flow Rate Cont. value (range? ? ) S_EL_CUR_A 7 Output flow. H 20 (w/ O 2) Cont value Output flow, H 20 Cont value S_FL_H 2_R 5/R 6 F_S_EL_CUR S_FL_O 2_R 5/R 6 O 2 Mass Flow Rate Cont. value (range? ? )

Output flow, water Continuous value (range? ? ) P_H 2_OUT Extra Electrolyzer Stuff Electrolyser Current being consumed Continuous value (range? ? ) Output pressure, hydrogen Continuous value (range? ? ) Electrolyzer Current Sensor Fault Ok stuck at prev stuck at unknown degrading F_S_TEMP_UP_T 8 F_S_TEMP_LOW_T 7 TEMP_UP TEMP_LOW S_TEMP_UP_T 8 S_TEMP_LOW_T 7

Deionizer Out press. WP 1 Cont. Value ? P_WP 1_OUT ? WP 1 Press Sensor Fault Ok stuck at prev stuck at unknown degrading F_WP 1_OUT_P 10 F_DEIONIZER Deionize Fault Ok degrading S_WP 1_OUT_P 10 DEIONIZER WP 1 Output Pressue Cont. Value FL_H 2 O_DEIONIZER_OUT Output flow Deionizer Cont. Value