| 摘要 |
A method of detecting faults in an injector arrangement in an engine. The injector arrangement comprises at least one fuel injector (12a,12b) having a piezoelectric actuator (16a,16b), and the method comprises: charging the piezoelectric actuator (16a,16b) during a charge phase (t C ); attempting to recharge the piezoelectric actuator (16a,16b) during a test phase (t T ) which commences after a time interval (”t) following the end of the charge phase (t C ); sensing a current (I S ) that flows through the piezoelectric actuator (16a,16b) during the test phase (t T ); and generating a short circuit fault signal if the sensed current (I S ) reaches a first predetermined threshold current (I SC ) which is indicative of a short circuit in the piezoelectric actuator (16a,16b).
The method also consists in monitoring the voltage drop or the voltage gradient over time across the piezoelectric actuator. |
