Abnormality diagnosis system and control system for internal combustion engine
First Claim
1. An abnormality diagnosis system for diagnosing abnormality of an internal combustion engine, which has an actuator operable to control a controlled variable of an object to be controlled to a target value, when fuel is converted to rotational energy, the abnormality diagnosis system comprising:
- means for changing the target value forcibly; and
determination means for determining presence or absence of an abnormality in a response characteristic of the actuator by checking, under a condition that a target value of either one of the operating quantity and the controlled variable is changed, whether a maximum value of a time differential value of a detection value of either one of the operation quantity of the actuator and the controlled variable of the object is within a predetermined normal range defined by an upper limit and a lower limit of the maximum value or whether a minimum value of the time differential value is within a predetermined normal range defined by an upper limit and a lower limit of the minimum value.
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Accused Products
Abstract
An ECU (60) for an engine (10, 70) monitors a change of an actual fuel pressure (NPC), when a target fuel pressure (PFIN) is changed stepwise. In one abnormality, the time required for the actual fuel pressure to reach the target fuel pressure is equal to that when an actuator (34) operates normally. However, the maximum value of a differential value (dNPC/dt) with respect to time of the actual fuel pressure is different from that when the actuator operates normally. For this reason, a normal range is set in advance for the maximum value of the differential value with respect to time of the actual fuel pressure and when the maximum value of the differential value with respect to time of the actual fuel pressure is out of the normal range, it is determined that the actuator operates abnormally.
15 Citations
19 Claims
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1. An abnormality diagnosis system for diagnosing abnormality of an internal combustion engine, which has an actuator operable to control a controlled variable of an object to be controlled to a target value, when fuel is converted to rotational energy, the abnormality diagnosis system comprising:
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means for changing the target value forcibly; and determination means for determining presence or absence of an abnormality in a response characteristic of the actuator by checking, under a condition that a target value of either one of the operating quantity and the controlled variable is changed, whether a maximum value of a time differential value of a detection value of either one of the operation quantity of the actuator and the controlled variable of the object is within a predetermined normal range defined by an upper limit and a lower limit of the maximum value or whether a minimum value of the time differential value is within a predetermined normal range defined by an upper limit and a lower limit of the minimum value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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Specification