The descriptions of the copying events of each level of the tree are omitted here.
C.2.1 Initial model
Event name Description
INPUT the input phase
RESULT the decision phase
C.2.2 First refinement
Event name Description
INPUT checking the failure of the voltage supplied to CCU RESULT transition to
manual steering mode
transition to the ‘Manual Steering’ mode when the failure is detected
RESULT normal mode keeping in the normal mode when no failure is de-tected
C.2.3 Second refinement
Event name Description
INPUT inverter failure detecting the failure of the voltage supplied to the inverter
INPUT predriver failure checking the failure of the voltage supplied to the pre-driver
INPUT no failure detecting no failure RESULT transition to
manual steering mode
transition to the ‘Manual Steering’ mode when one of the failure is detected
RESULT normal mode keeping in the normal mode when no failure is de-tected
C.2.4 Third refinement
Event name Description RESULT sending demand
to manual steering
sending demand for transition to the ‘Manual Steer-ing’ mode without failure when one of the failure is detected
RESULT receiving demand to manual steering
receiving the demand when it is sent without failure RESULT transition to
manual steering mode
transition to the ‘Manual Steering’ mode when the demand is received
RESULT not sending demand to manual steering
not sending the demand for transition to the ‘Manual Steering’ mode when no failure is detected
RESULT not receiving demand to manual steering
not receiving the demand for transition to the ‘Manual Steering’ mode when it is not sent
RESULT normal mode keeping in the normal mode when no demand for tran-sition to the ‘Manual Steering’ mode is received
C.2.5 Fourth refinement
Event name Description RESULT power supply
stops
stopping the power supply when the demand for tran-sition to the ‘Manual Steering’ mode is received RESULT motor stops stopping the motor when the power supply stops RESULT transition to
manual steering mode
transition to the ‘Manual Steering’ mode when the motor stops
RESULT power supply works
turning the power supply on when the demand for transition to the ‘Manual Steering’ mode is not re-ceived
RESULT motor works actuating the motor when the power supply works RESULT normal mode keeping in the normal mode when the motor works
C.2.6 Fifth refinement
Event name Description
RESULT predriver stops stopping the pre-driver when the demand for transi-tion to the ‘Manual Steering’ mode is received
RESULT motor relay stops stopping the motor relay when the demand for tran-sition to the ‘Manual Steering’ mode is received RESULT fail safe relay
stops
stopping the fail-safe relay when the demand for tran-sition to the ‘Manual Steering’ mode is received RESULT power supply
stops
stopping the power supply when one of the compo-nents stops
RESULT predriver motor relay fail safe relay work
keeping all the three components working when the demand for transition to the ‘Manual Steering’ mode is not received
RESULT power supply works
turning the power supply on all the three components work
C.2.7 Sixth refinement
Event name Description RESULT predriver stop
signal sent
sending the stop signal to the pre-driver without fail-ure when the demand for transition to the ‘Manual Steering’ mode is received
RESULT predriver stop signal received
receiving the stop demand when it is sent without failure
RESULT predriver stops stopping the pdriver when the stop demand is re-ceived
RESULT motor relay open circuit demand sent
sending the open circuit demand to the motor relay without failure when the demand for transition to the
‘Manual Steering’ mode is received RESULT motor relay
open circuit demand received
receiving the open cicuit demand when the demand is sent without failure
RESULT motor relay stops
stopping the motor relay when open circuit demand is received
RESULT fail safe relay open circuit demand sent
sending the open circuit demand to the fail-safe relay without failure when the demand for transition to the
‘Manual Steering’ mode is received RESULT fail safe relay
open circuit demand received
receiving the open circuit demand when the demand is sent without failure
RESULT fail safe relay stops
stopping the fail-safe relay when the open circuit de-mand is received
RESULT not sending any stop signals
not sending any stop demand and open circuit de-mand when the dede-mand for transition to the ‘Manual Steering’ mode is not received
RESULT not receiving any stop signals
not receiving any stop demand and open circuit de-mand when none of them is sent
RESULT predriver motor relay fail safe relay work
keeping all the three components working when no stop signal and open circuit demand is received
C.2.8 Seventh refinement
Event name Description RESULT predriver enable
signal not sent
not sending the enable signal to the pre-driver when the demand for transition to the ‘Manual Steering’
mode is received RESULT predriver enable
signal not received
not receiving the enable signal when it is not sent RESULT predriver stops stopping the pre-driver when the enable signal is not
received RESULT motor relay
enable signal not sent
not sending the enable signal to the motor relay when the demand for transition to the ‘Manual Steering’
mode is received RESULT motor relay
enable signal not received
not receiving the enable when the demand is not sent RESULT motor relay
stops
stopping the motor relay when the enable signal is not received
RESULT fail safe relay enable signal not sent
not sending the enable to the fail-safe relay when the demand for transition to the ‘Manual Steering’ mode is received
RESULT fail safe relay enable signal not received
not receiving the enable signal when the demand is not sent
RESULT fail safe relay stops
stopping the fail-safe relay when the enable signal is not received
RESULT sending all enable signals
sending all enable signals to all the three components without failure when the demand for transition to the
‘Manual Steering’ mode is not received RESULT receiving all
enable signals
receiving all enable signals when all of them are sent without failure
RESULT predriver motor relay fail safe relay work
keeping all the three components working when all enable signals are received