Method for controlling AMT system including speed sensor signal fault detection and tolerance
AssigneeEaton Corporation
InventorsWilliam F. Cote, Donald Speranza
Life of this patent
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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.
Claims42
A method for controlling an automatic mechanical transmission system for devices having a throttle-controlled engine, a transmission having a plurality of gear ratio combinations selectively engageable between a transmission input shaft and a transmission output shaft, said transmission input shaft being operatively connected to said engine by means of a selectably engagable and disengagable coupling providing a substantially nonslipping driving connection between said engine and said input shaft in the fully engaged condition thereof, said automatic mechanical transmission system comprising an information processing unit having means for receiving a plurality of input signals including (1) an input signal indicative of the fully engaged condition of the coupling;
- (2) an input signal indicative of the currently engaged gear ratio of the transmission;
- (3) an input signal indicative of the rotational speed of the engine, and (4) an input signal indicative of the rotational speed of the transmission input shaft;
- and (5) an input signal indicative of the rotational speed of the transmission output shaft, said processing unit including means for processing said input signals in according with a program and for generating output signals whereby said transmission system is operated in accordance with said program, and means associates with said transmission system effective in actuate said transmission system effective to actuate said transmission system to effect engagement of said gear ratio combinations in response to said output signals from said processing unit, the method characterized by:
- when said transmission is engaged in a known gear ratio and said coupling is fully engaged, sensing the presence or absence of faulty input signals indicative of the rotational speeds of said engine, input shaft and output shaft if the following relationship is false:
- ES=IS=GR*OS
- where:
- ES=the value of the input signal indicative of rotational engine speed,
- IS=the value of the input signal indicative of rotational input shaft speed,
- OS=the value of the input signal indicative of rotational output shaft speed, and
- GR=a signal indicative of the known currently engaged gear ratio, and
- if only one of said input signals indicative of the rotational speeds of said engine, input shaft and output shaft is determined to be faulty, modifying said program by ignoring said identified faulty input signal and processing the remainder of said input signals in accordance with predetermined logic rules to determine an acceptable value for the identified faulty input signal.
A control system for controlling an automatic mechanical transmission system for devices having a throttle-controlled engine, a transmission having a plurality of gear ratio combinations selectively engagable between a transmission input shaft and a transmission output shaft, said transmission input shaft being operatively connected to said engine by means of a selectably engagable and disengagable coupling providing a substantially nonslipping driving connection between said engine and said input shaft in the fully engaged condition thereof, said automatic mechanical transmission system comprising an information processing unit having means for receiving a plurality of input signals including (1) an input signal indicative of the fully engaged condition of the coupling;
- (2) an input signal indicative of the currently engaged gear ratio of the transmission;
- (3) an input signal indicative of the rotational speed of the engine, and (4) an input signal indicative of the rotational speed of the transmission input shaft;
- and (5) an input signal indicative of the rotational speed of the transmission output shaft, said processing unit including means for processing said input signals in accordance with a program and for generating output signals whereby said transmission system is operated in accordance with said program, and means associated with said transmission system effective to actuate said transmission system effective to actuate said transmission system to effect engagement of said gear ratio combinations in response to said output signals from said processing unit, the control system characterized by:
- means defining logic rules effect when said transmission is engaged in a known gear ratio and said coupling is fully engaged to sense the presence or absence of faulty input signals indicative of the rotational speeds of said engine, input shaft and output shaft if the following relationship is false:
- ES=IS=GR * OS
- wherein:
- ES=the value of the input signal indicative of rotational engine speed,
- IS=the value of the input signal indicative of rotational input shaft speed,
- OS=the value of the input signal indicative of rotational output shaft speed, and
- GR=a signal indicative of the known currently engaged gear ratio;
- and
- means defining logic rules effective if only one of said input signals indicative of the rotational speeds of said engine, input shaft and output shaft is determined to be faulty, to ignore said identified faulty input signal and to process said remaining input signals to determine an acceptable value for the identified faulty input signal.
Dependencies are inferred from the claim text.