# US 8,771,144 B2 · Manual downshift control method for automatic transmission > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,771,144 B2 - Document ID: US8771144B2 - Status: Granted - Kind: B2 - Application number: 12/176,455 - Filed: 2008-07-21 - Published: 2010-01-21 - Granted: 2014-07-08 - Earliest claimed: 2008-07-21 - Assignees: Honda Motor Co., Ltd. - Applicants: Mike Dickinson; Aaron Dorn - Inventors: Mike Dickinson; Aaron Dorn - Web page: https://patentgrep.com/patent/US8771144B2 ## CPC - F16H 61/061: {using electric control means} - F16H 63/502: {for smoothing gear shifts} - F16H 2061/0496: {for low engine torque, e.g. during coasting, sailing or engine braking} - F16H: GEARING ## Abstract A control system and a method for controlling an automatic transmission that determines the disengagement of an off-going clutch and the engagement of an on-coming clutch by monitoring the corresponding hydraulic clutch pressures, and/or the calculated gear ratios with or without the assistance of off-pressure timer controls, or both. ## Claims ### Claim 1 A method comprising the steps of: (a) providing a vehicle having a vehicle frame, an engine and an automatic transmission that is mounted to the vehicle frame and operatively connected to the engine; (b) determining a first hydraulic fluid pressure during an off-coming clutch phase; (c) triggering an increase in the engine power due to the first hydraulic fluid pressure reaching a first predetermined level; (d) determining a second hydraulic fluid pressure; and, (e) triggering a reduction in the engine power substantially fully due to the second hydraulic fluid pressure reaching a second predetermined level. ### Claim 2 (depends on 1) The method of claim 1, wherein step (a) further comprises the step of: transmitting a first input to a control unit, wherein the first input indicates the initiation of a manual downshift. ### Claim 3 (depends on 1) The method of claim 1, wherein step (a) further comprises the step of: transmitting at least a first input to a control unit, wherein the first input indicates the initiation of a manual downshift at a low accelerator pedal opening. ### Claim 4 (depends on 1) The method of claim 1, wherein step (b) further comprises the step of: determining that a first hydraulic line pressure switch has changed from an on state to an off state. ### Claim 5 (depends on 1) The method of claim 1, wherein step (d) further comprises the step of: determining that a second hydraulic line pressure switch has changed from an off state to an on state. ### Claim 6 (depends on 1) The method of claim 1, wherein step (b) further comprises the steps of: initiating a first delay; and, determining the expiration of the first delay. ### Claim 7 (depends on 6) The method of claim 6 wherein: the expiration of the first delay triggers a “timer expired” signal; and the increase in the engine power in step (c) occurs only if the “timer expired” signal has also been triggered. ### Claim 8 (depends on 1) The method of claim 1, wherein step (d) further comprises the step of: determining an effective gear ratio, wherein the effective gear ratio is substantially equal to or greater than a predetermined value. ### Claim 9 (depends on 8) The method of claim 8 wherein the effective gear ratio is determined by comparing a first gear ratio with a second gear ratio; wherein the first gear ratio is determined during step (b) at the time of and due to the first hydraulic pressure reaching a first predetermined level; and wherein the second gear ratio is determined during step (d) at the time of and due to the second hydraulic fluid pressure reaching a second predetermined level. ### Claim 10 (depends on 1) The method of claim 1, wherein step (d) further comprises the step of: determining an effective gear ratio, wherein the effective gear ratio is substantially equal to or less than a predetermined value. ### Claim 11 (depends on 1) The method of claim 1, wherein step (d) further comprises the step of: determining an effective gear ratio, wherein the effective gear ratio is greater than a predetermined value. ### Claim 12 (depends on 1) The method of claim 1, wherein step (d) further comprises the step of: determining an effective gear ratio, wherein the effective gear ratio is less than a predetermined value. ### Claim 13 A vehicle comprising: a vehicle frame; an engine; an automatic transmission, wherein the automatic transmission is mounted to the vehicle frame and operatively connected to the engine; a control system for use in controlling the engine power when a pressure switch device: (1) determines that an off-going clutch is substantially released within the automatic transmission; and, (2) determines when an on-coming clutch is substantially fully engaged within the automatic transmission; and a throttle control device that: (1) increases engine power triggered by the off-going clutch becoming substantially released; and, (2) reduces engine power triggered by the on-coming clutch becoming substantially engaged. ### Claim 14 (depends on 13) The vehicle of claim 13 wherein the automatic transmission comprises: a timer device for causing a first delay, wherein the control system initiates the first delay due to the pressure switch device indicating the disengaging of the off-going clutch, and wherein the throttle control device increases engine power due to the expiration of the first delay. ### Claim 15 (depends on 13) The vehicle of claim 13 wherein the automatic transmission comprises: a gear ratio device for determining when the on-coming clutch is substantially fully engaged. ### Claim 16 (depends on 15) The vehicle of claim 15, wherein the gear ratio device determines when the on-coming clutch is substantially fully engaged by comparing a first gear ratio to a second gear ratio. ### Claim 17 (depends on 16) The vehicle of claim 16, wherein the first gear ratio is determined when a first hydraulic line pressure switch changes from a first on state to a first off state and the second gear ratio is determined when a second hydraulic line pressure switch changes from a second off state to a second on state.