System for controlling downshift points of automatically selectable transmission gears
First Claim
1. A system for controlling downshifting of an automatically selectable gear of a transmission coupled to an internal combustion engine of a vehicle, comprising:
- means for determining one of engine and vehicle deceleration;
means for determining one of a commanded throttle percentage and engine load;
means for determining a downshift engine RPM of an automatically selectable gear of a transmission coupled to an internal combustion engine based on a comparison of a rate of said one of engine and vehicle deceleration with at least one predefined deceleration rate and on said one of commanded throttle percentage and engine load; and
means for controlling downshifting of said automatically selectable gear of said transmission based on said downshift engine RPM.
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Accused Products
Abstract
A system for controlling automatic transmission downshift points includes a control computer for electronically controlling an internal combustion engine and a transmission having at least one automatically selectable gear. The control computer is responsive to at least a throttle signal, provided by either a manually actuatable accelerator pedal or a cruise control system, to compute an engine load value, and is further responsive to either an engine speed signal or a vehicle speed signal to compute a deceleration value. The control computer is operable to compute a downshift engine RPM value based on the deceleration value and either the throttle signal or the engine load value, wherein the downshift engine RPM value is lower than a default downshift engine RPM if the deceleration value indicates a relatively slow deceleration rate and the throttle signal or the engine load value indicates high throttle or engine load. Conversely, the downshift engine RPM value is higher than the default downshift engine RPM value if the deceleration value indicates a relatively high deceleration rate and the throttle signal or the engine load indicates high throttle or engine load.
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Citations
19 Claims
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1. A system for controlling downshifting of an automatically selectable gear of a transmission coupled to an internal combustion engine of a vehicle, comprising:
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means for determining one of engine and vehicle deceleration; means for determining one of a commanded throttle percentage and engine load; means for determining a downshift engine RPM of an automatically selectable gear of a transmission coupled to an internal combustion engine based on a comparison of a rate of said one of engine and vehicle deceleration with at least one predefined deceleration rate and on said one of commanded throttle percentage and engine load; and means for controlling downshifting of said automatically selectable gear of said transmission based on said downshift engine RPM. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A system for controlling downshifting of an automatically selectable gear of a transmission coupled to an internal combustion engine of a vehicle, comprising:
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an internal combustion engine carried by a vehicle; means for determining one of engine RPM and vehicle speed and producing a speed signal corresponding thereto; a fuel system responsive to a fueling signal to supply fuel to said engine; means for producing a throttle signal; a transmission coupled to said engine and having at least one automatically selectable gear; and a control computer responsive to said throttle signal to produce said fueling signal, said control computer determining an engine load value based on said fueling signal and a current deceleration rate based on said speed signal, said control computer determining a downshift engine RPM of said at least one automatically selectable gear based on a comparison of said current deceleration rate with a predefined deceleration rate and on one of said throttle signal and said engine load value, said control computer controlling downshifting of said at least one automatically selectable gear based on said downshift engine RPM. - View Dependent Claims (11, 12, 13, 14, 15)
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16. A method of controlling downshifting of an automatically selectable gear of a transmission coupled to an internal combustion engine of a vehicle, comprising the steps of:
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determining one of an engine and vehicle deceleration rate; determining one of a commanded throttle percentage and engine load; determining a downshift engine RPM of an automatically selectable gear of a transmission coupled to an internal combustion engine of a vehicle based on a comparison of said one of engine and vehicle deceleration rate with at least one predefined deceleration rate and on said one of commanded throttle percentage and engine load; and controlling downshifting of said automatically selectable gear of said transmission based on said downshift engine RPM. - View Dependent Claims (17, 18, 19)
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Specification