Vehicle communication control apparatus and method

• US 6,321,148 B1
• Filed: 03/26/1998
• Issued: 11/20/2001
• Est. Priority Date: 03/31/1997
• Status: Expired due to Fees

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Leung, Sherman
• Primary Examiner(s): LOUIS JACQUES, JACQUES H
• Application Number:
  US09/048,618
• Time in Patent Office: 1,335 Days
• Field of Search: 701/29, 701/30, 701/33, 701/34, 701/35, 701/31, 701/32, 701/114, 701/115, 340/825.06, 340/825.08, 340/825.16, 340/825.1, 340/825.5, 340/825.51, 375/259, 375/220, 731/173, 731/181, 123/339.1, 123/361, 370/216, 370/221, 370/225, 370/241, 370/242, 370/243, 370/248, 370/249, 370/252, 370/464, 370/471, 714/1, 714/25, 714/724, 714/736, 714/746-749
• US Class Current: 701/29
• CPC Class Codes: B60R 16/0232 for measuring vehicle parameters and indicating critical, abnormal or dangerous conditions

Abstract

A communication control apparatus and method for controlling communication between a plurality of electronic control units (ECUs) provided in a vehicle and a diagnostic apparatus. Each of the ECUs determines whether it is ready to send a positive response to the diagnostic apparatus within a predetermined response time after receiving a request signal from the diagnostic apparatus. A negative response signal is sent to the diagnostic apparatus by any ECU that is not ready. The negative response signal indicates that the sending ECU is not ready and allows the other ECUs to respond to the diagnostic apparatus. The diagnostic apparatus sends a further request signal directed specifically to an ECU that send a negative response signal.

Claims

1. A communication control apparatus for controlling communication between a plurality of electronic control units provided in a vehicle and a diagnostic device, wherein the diagnostic device diagnoses each of set of electronic control units, the apparatus comprising:

a determiner in each control unit that determines whether a positive response can be issued to the diagnostic device within a predetermined response time after receiving a first request signal from the diagnostic device; and

a transmitter in each control unit of the set that transmits a negative response signal including a message header indicating a negative response to the diagnostic device when the determiner determines that a positive response to the diagnostic device cannot be issued, wherein the negative response signal allows another control unit of the set to respond to the diagnostic device and generates a second request signal from the diagnostic device to retrieve each control unit operation previously by-passed.

2. The communication control apparatus according to claim 1, wherein the diagnostic device sends the second request signal directed to a negatively responding control unit after all the control units in the set have responded to the request.

3. The communication control apparatus according to claim 2, wherein each of the control units stores diagnostic data used for diagnosis and is connected to the other control units to construct a communication network, wherein the diagnostic device is connected to the network to communicate with and read out the diagnostic data stored in each of the control units.

4. A communication control apparatus for controlling communication between a diagnostic device and a set of electronic control units including a first ECU and a second ECU over a network, the apparatus comprising:

a general requestor in the diagnostic device the issues a general request signal to the set of ECUs via the network;

a determiner in each of the first and second ECUs that determines readiness to respond to the general request signal within a predetermined period of time from receipt of the request signal from the network;

a transmitter in each control unit of the set that transmits a response signal, including a message header indicating that the response signal is either negative or positive, to the diagnostic device via the network when the associated determiner determines unreadiness or readiness, respectively, wherein a negative response signal from the first ECU does not prevent the second ECU from responding to the diagnostic device via the network, and wherein the negative response signal generates a specific request signal from the diagnostic device to retrieve each control unit operation previously by-passed.

5. The apparatus according to claim 4 further comprising:

a one-to-one transmitter in the diagnostic device that sends the specific request signal over the network directed specifically to a negatively responding ECU; and

an identifier in the diagnostic device that permits the diagnostic device to identify which, if any, ECU has responded negatively.

6. The apparatus according to claim 5, wherein the diagnostic device sends the specific request signal only if all control units in the set have responded to the general request signal and if a negative response signal has been issued by a control unit and received by the diagnostic device.

7. A method for controlling communication between a plurality of electronic control units provided in a vehicle and a diagnostic device, wherein the diagnostic device diagnoses each of a set of electronic control units, the method comprising:

determining whether each control unit is able to respond positively to the diagnostic device within a predetermined response time after receiving a first request signal from the diagnostic device; and

transmitting a negative response signal including a message header indicating a negative response to the diagnostic device from each control unit of the set that is not ready to positively respond to the diagnostic device, wherein the negative response signal allows another control unit of the set to respond to the diagnostic device, and wherein the negative response signal generates a second request signal from the diagnostic device to retrieve each control unit operation previously by-passed.

8. The method according to claim 7 further comprising sending the second request signal directed to a negatively responding control unit from the diagnostic device after the diagnostic device has received a response from all the control units of the set if the diagnostic device receives a negative response signal.