Start ratio engagement control system and method
First Claim
1. A method of controlling a semi-automatic mechanical change gear transmission system (10) comprising a manual fuel throttle control (24), a fuel throttle controlled engine (14), a multiple speed change gear mechanical transmission (12) having a lowest grouping of gear ratios (1st-5th) suitable for start from stop operation and having a specific ratio within said lowest grouping of ratios determined to be the predetermined start ratio, a friction master clutch (16) interposed the engine and transmission, a master clutch control (3), a central processing unit (38) for receiving inputs indicative of vehicle speed and for processing same according to predetermined logic rules to issue command output signals to non-manually controlled operators including a fuel throttle control operator (26), and a transmission operator (34), said processing unit sensing conditions indicative of selection of a downshift directly from a higher gear ratio into the predetermined start ratio and for implementing same upon sensing predetermined enabling conditions, said method comprising:
- selecting a desired target engine speed, andsequencing initiation of a direct shift into the preselected start ratio to achieve completion thereof when the product of the numerical gear ratio of the preselected start ratio (GR) multiplied by the expected output shaft rotational speed (OS) is substantially equal to the target engine speed.
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Accused Products
Abstract
A control system and method for a vehicular semi-automatic mechanical transmission system (10) is provided for allowing controller or operator request for a direct downshift into a preselected start ratio, under certain predefined conditions. The direct downshift into the preselected start gear ratio is sequenced such that the target synchronous engine speed (OS*GR) at target gear ratio engagement is substantially equal to a preselected desirable, preferably constant, value for all selectable start ratios.
30 Citations
20 Claims
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1. A method of controlling a semi-automatic mechanical change gear transmission system (10) comprising a manual fuel throttle control (24), a fuel throttle controlled engine (14), a multiple speed change gear mechanical transmission (12) having a lowest grouping of gear ratios (1st-5th) suitable for start from stop operation and having a specific ratio within said lowest grouping of ratios determined to be the predetermined start ratio, a friction master clutch (16) interposed the engine and transmission, a master clutch control (3), a central processing unit (38) for receiving inputs indicative of vehicle speed and for processing same according to predetermined logic rules to issue command output signals to non-manually controlled operators including a fuel throttle control operator (26), and a transmission operator (34), said processing unit sensing conditions indicative of selection of a downshift directly from a higher gear ratio into the predetermined start ratio and for implementing same upon sensing predetermined enabling conditions, said method comprising:
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selecting a desired target engine speed, and sequencing initiation of a direct shift into the preselected start ratio to achieve completion thereof when the product of the numerical gear ratio of the preselected start ratio (GR) multiplied by the expected output shaft rotational speed (OS) is substantially equal to the target engine speed. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A system for controlling a semi-automatic mechanical change gear transmission system (10) comprising a manual fuel throttle control (24), a fuel throttle controlled engine (14), a multiple speed change gear mechanical transmission (12) having a lowest grouping of gear ratios (1st-5th) suitable for start from stop operation and having a specific ratio within said lowest grouping of ratios determined to be the predetermined start ratio, a friction master clutch (16) interposed the engine and transmission, a master clutch control (3), a central processing unit (38) for receiving inputs indicative of vehicle speed and for processing same according to predetermined logic rules to issue command output signals to non-manually controlled operators including a fuel throttle control operator (26), and a transmission operator (34), said processing unit sensing conditions indicative of selection of a downshift directly from a higher gear ratio into the predetermined start ratio and for implementing same upon sensing predetermined enabling conditions, said system comprising:
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means for selecting a desired target engine speed, and means for sequencing initiation of a direct shift into the preselected start ratio to achieve completion thereof when the product of the numerical gear ratio of the preselected start ratio (GR) multiplied by the expected output shaft rotational speed (OS) is substantially equal to the target engine speed. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification