Vehicle control computer apparatus having self-diagnosis function

• US 20010008987A1
• Filed: 01/02/2001
• Published: 07/19/2001
• Est. Priority Date: 01/14/2000
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Wada, Yasutake, Suzuki, Takano
• Granted Patent: US 6,502,021 B2
• Time in Patent Office: Days
• US Class Current: 701/29
• CPC Class Codes: B60W 2050/021 Means for detecting failure or malfunction
• CPC Class Codes: B60W 50/0205 Diagnosing or detecting failures; Failure detection models

Abstract

In a vehicle control computer apparatus, information operation processing is performed by a RISC-type microcomputer so that a storage area necessary in diagnosis is reduced and the number of designing steps of processing program is reduced. Status data within the range “0” to “179” is used for storing a determination status indicating the result of diagnosis. That is, a first normal status is stored as “1”, a second normal status as “2” to “38”, or “130” to “166”, a third normal status as “39”, “40”, “166” or “168”, a temporary normal status as “50”, “51”, “178” or “179”, and an abnormal status as “41”. The status is changed by increasing/decreasing the status data, and output control is performed in correspondence with the determination status.

Claims

1. A vehicle control apparatus having a diagnosis function comprising:

detection means for detecting a predetermined diagnostic item as normal or abnormal during a trip period of a vehicle as a running period from a point in which an ignition switch is turned on to a point in which the ignition switch is turned off;

determination status decision means for deciding a determination status indicating the result of diagnosis of the diagnostic item, based on the result of detection by the detection means;

storage means for storing the determination status decided by the determination status decision means; and

output control means for performing output control in accordance with the result of diagnosis, based on the determination status decided by the determination status decision means,

wherein the determination status decision means decides the determination status by performing status transition processing to change a determination status during a previous trip period stored in the storage means to a new determination status when necessary, characterized in that

the determination status is stored into the storage means, as a numerical value set in correspondence with each determination status while avoiding mutual numerical overlap.

2. The apparatus as in

claim 1

, wherein:

the numerical value stored in the storage means is within a range of 0 to 255 which can be defined by a single byte.

3. The apparatus as in

claim 1

, wherein:

the numerical value corresponding to the determination status is set as a value within a predetermined range corresponding to each determination status; and

the status transition processing is made by increasing or decreasing the numerical value in accordance with the numerical value corresponding to the determination status stored in the storage means.

4. The apparatus as in

claim 3

, wherein:

the numerical value corresponding to the determination status is incremented or decremented by a predetermined value at every trip period of the vehicle in the status transition processing, when the determination status is changed by counting the number of continuation of the trip period in which the detection result of the detection means remains the same.

5. The control apparatus as in

claim 4

, wherein:

the numerical value corresponding to the determination status is changed by a predetermined value each time the diagnostic item is decided as normal in the status transition processing, when the determination status is changed from a fully abnormal state to a fully normal state.

6. The control apparatus as in

claim 5

, wherein:

the numerical value corresponding to the determination status is changed by a predetermined value in the status transition processing until the numerical value reaches a value indicative of the fully normal status, when the diagnostic item is determined as normal by the decision means.

7. The control apparatus as in

claim 4

, wherein:

the numerical value corresponding to the determination status is changed only at a first determination in the status transition processing thereby to change the numerical value at every trip period, even when the detection means detects the same status repeatedly within the trip period.

8. The control apparatus as in

claim 1

, wherein:

the storage means includes a battery backup volatile memory or an electrically rewritable non-volatile memory.

9. The control apparatus as in

claim 1

, wherein:

the output control means at least on/off-controls a warning light to notify an abnormality and controls output of abnormality code indicating the content of the abnormality.

10. The control apparatus as in

claim 1

, wherein:

a numerical value indicating an undetected status is stored as the determination status in the storage means until the determination status decision means decides the determination status during a first trip period.

11. A computer-readable recording medium containing a computer program for causing a computer system to function as the detection means, the determination status decision means and the output control means of the vehicle control apparatus according to any one of

claims 1

to

10

.