Method for controlling AMT system including speed sensor signal fault detection and tolerance

• US 5,050,427 A
• Filed: 10/14/1988
• Issued: 09/24/1991
• Est. Priority Date: 04/07/1986
• Status: Expired due to Term

• Current Assignee: Eaton Corp. (Wisconsin) (Eaton Corporation PLC.)
• Original Assignee: Eaton Corp. (Wisconsin) (Eaton Corporation PLC.)
• Inventors: Cote, William F., Speranza, Donald
• Primary Examiner(s): RAEVIS, ROBERT R
• Application Number:
  US07/258,287
• Time in Patent Office: 1,075 Days
• Field of Search: 364/429.01, 73/118.1
• US Class Current: 73/115.02
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/11 Stepped gearings
• CPC Class Codes: B60W 2050/021 Means for detecting failure or malfunction
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2510/102 Input speed change rate
• CPC Class Codes: B60W 2510/104 Output speed
• CPC Class Codes: B60W 2540/12 Brake pedal position
• CPC Class Codes: B60W 30/18 Propelling the vehicle
• CPC Class Codes: B60W 50/0205 Diagnosing or detecting failures; Failure detection models
• CPC Class Codes: F16H 2061/1208 with diagnostic check cycles; Monitoring of failures
• CPC Class Codes: F16H 2061/122 Avoiding failures by using redundant parts
• CPC Class Codes: F16H 2061/1284 the failing part is a sensor
• CPC Class Codes: F16H 59/36 Inputs being a function of speed
• CPC Class Codes: F16H 59/38 of gearing elements
• CPC Class Codes: F16H 59/40 Output shaft speed
• CPC Class Codes: F16H 59/42 Input shaft speed
• CPC Class Codes: F16H 61/02 characterised by the signals used for shift actuators F16H61/28, for continuously variable gearings F16H61/66
• CPC Class Codes: F16H 61/12 Detecting malfunction or potential malfunction, e.g. fail safe in control of hydrostatic gearing F16H61/4192; Circumventing or fixing failures

Abstract

A method for controlling an AMT system (10) is provided including sensing and identifying faulty input signals (ES, IS, OS) from the engine speed sensor (28), the input shaft speed sensor (32) and/or the output shaft speed sensor (36) and, if only one of the speed signals (ES, IS or OS) is faulty, modifying the logic method of control (42) to a logic method tolerant of the identified faulty input signal.

Claims

1. An abnormality determination system for revolution speed sensors comprising:

a first speed sensor for detecting a revolution speed of one shaft of an automatic transmission and for outputting a first speed signal corresponding to the speed;

a second speed sensor for detecting a revolution speed of another shaft of said automatic transmission and for outputting a second speed signal corresponding to the speed;

abnormality determination means for determining if either of said speed sensors is abnormal by comparing the first signal from said first speed sensor with the second speed signal from said second speed sensor, and for outputting an abnormality determination signal if it is determined that one of said speed sensors is abnormal;

shifting detection means for detecting that said automatic transmission is shifting and for outputting a shifting indication signal which denotes that a shift of the automatic transmission is being executed; and

abnormality determination halt means for halting the abnormality determination executed by said abnormality determination means when the shifting indication signal is received.

2. The abnormality determination system for revolution speed sensors according to claim 1, wherein:

the automatic transmission includes an Electronic Control Unit (ECU), and

the shifting detection means includes means for detecting that a shift of the automatic transmission is being executed, via a shift command signal generated by the ECU.

3. The abnormality determination system for revolution speed sensors according to claim 1, wherein:

the abnormality determination means changes a condition for comparing speed signals from both of the first and the second speed sensors, in response to current gear ratio of the automatic transmission.

4. An abnormality determination system for revolution speed sensors comprising:

a first speed sensor for detecting a revolution speed of one shaft of an automatic transmission and for outputting a first speed signal corresponding to the speed;

a second speed sensor for detecting a revolution speed of another shaft of said automatic transmission and for outputting a second speed signal corresponding to the speed;

abnormality determination means for determining if either of said speed sensors is abnormal by comparing the first speed signal from said first speed sensor with the second speed signal from said second speed sensor, and for outputting an abnormality determination signal if it is determined that one of said speed sensors is abnormal;

detection means for detecting that said automatic transmission is not in a known gear ratio; and

abnormality determination halt means for halting the abnormality determination executed by said abnormality determination means when the detection means is detecting that said automatic transmission is not in a known gear ratio.

5. An abnormality determination system for revolution speed sensors comprising:

a first speed sensor for detecting a revolution speed of one shaft of an automatic transmission and for outputting a first speed signal corresponding to the speed;

a second speed sensor for detecting a revolution speed of another shaft of said automatic transmission and for outputting a second speed signal corresponding to the speed;

abnormality determination means for determining if either of said speed sensors is abnormal by comparing the first signal from said first speed sensor with the second speed signal from said second speed sensor, and for outputting an abnormality determination signal if it is determined that one of said speed sensors is abnormal;

shifting detection means for detecting that said automatic transmission shafts are not interconnected and for outputting an indication signal which denotes that said shafts are not inter-connected; and

abnormality determination halt means for halting the abnormality determination executed by said abnormality determination means when the indication signal is received.

6. An abnormality determination system for revolution speed sensors comprising:

a first speed sensor for detecting a revolution speed of one shaft of an automatic transmission and for outputting a first speed signal corresponding to the speed;

a second speed sensor for detecting a revolution speed of another shaft of said automatic transmission and for outputting a second speed signal corresponding to the speed;

abnormality determination means for determining if either of said speed sensors is abnormal by comparing the first signal from said first speed sensor with the second speed signal from said second speed sensor, and for outputting an abnormality determination signal if it is determined that one of said speed sensors is abnormal;

shifting detection means for detecting that said automatic transmission is shifting by detecting whether said transmission is in a known gear ratio and for outputting a shifting indication signal which denotes that a shift of the automatic transmission is being executed; and

abnormality determination halt means for halting the abnormality determination executed by said abnormality determination means when the shifting indication signal is received.

7. An abnormality determination system for revolution speed sensors comprising:

a first speed sensor for detecting a revolution speed of one shaft of an automatic transmission and for outputting a first speed signal corresponding to the speed;

a second speed sensor for detecting a revolution speed of another shaft of said automatic transmission and for outputting a second speed signal corresponding to the speed;

abnormality determination means for determining if either of said speed sensors is abnormal by comparing the first signal from said first speed sensor with the second speed signal from said second speed sensor, and for outputting an abnormality determination signal if it is determined that one of said speed sensors is abnormal;

shifting detection means for detecting that said automatic transmission is shifting by detecting whether said shafts of said transmission are not interconnected and for outputting a shifting indication signal which denotes that a shift of the automatic transmission is being executed; and

abnormality determination halt means for halting the abnormality determination executed by said abnormality determination means when the shifting indication signal is received.