# US 9,873,431 B2 · Vehicle transmission brake launch system and method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,873,431 B2 - Document ID: US9873431B2 - Status: Granted - Kind: B2 - Application number: 15/409,909 - Filed: 2017-01-19 - Published: 2017-07-20 - Granted: 2018-01-23 - Earliest claimed: 2016-01-20 - Assignees: Fca US LLC - Applicants: Michael D Sowards; James M Wilder; Joseph M Johnson - Inventors: Michael D Sowards; James M Wilder; Joseph M Johnson - Web page: https://patentgrep.com/patent/US9873431B2 ## CPC - B60W 30/18027: {Drive off, accelerating from standstill} - B60W 10/06: including control of combustion engines - B60W 10/115: with planetary gears - B60W 10/184: with wheel brakes - B60W 50/14: Means for informing the driver, warning the driver or prompting a driver intervention - F16H 61/0059: {Braking of gear output shaft using simultaneous engagement of engaging means, e.g. clutches or brakes, applied for different gear ratios} - B60W 2050/146: {Display means} - B60W 2710/0666: Engine torque - B60W 2710/1005: Transmission ratio engaged - B60Y 2300/18025: Drive off, accelerating from standstill - F16H 3/66: composed of a number of gear trains without drive passing from one train to another - F16H 2200/006: the gear ratios comprising eight forward speeds - F16H 2200/2012: with four sets of orbital gears - F16H 2200/2043: with five engaging means - F16H 2200/2046: with six engaging means - F16H 2312/02: Driving off - B60W: CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT - F16H: GEARING - B60Y: INDEXING SCHEME RELATING TO ASPECTS CROSS-CUTTING VEHICLE TECHNOLOGY ## Abstract A transmission launch system includes a control system and a transmission having a plurality of clutches, where actuation of combinations of a predetermined number of clutches provides powerflow for different transmission drive gears. The control system is configured to initiate a performance launch of the vehicle where the transmission is commanded to engage a combination of the predetermined number of clutches corresponding to a forward drive gear. The transmission is then commanded to engage an additional clutch to lock its output shaft such that engine torque is prevented from being transferred to vehicle drive wheels. The engine generates drive torque greater than a capacity of a vehicle brake system and the control system then commands release of the additional clutch thereby unlocking the output shaft and allowing powerflow in the forward drive gear such that the generated engine drive torque is transferred to the drive wheels to propel the vehicle. ## Claims ### Claim 1 A vehicle transmission brake launch system, comprising: a transmission having a plurality of clutches and an output shaft, wherein actuation of different combinations of a predetermined number of clutches of the plurality of clutches provides powerflow for corresponding different transmission forward drive gears; a control system configured to: receive a command to initiate a performance launch of the vehicle; command the transmission to engage a combination of the predetermined number of clutches corresponding to a predetermined forward gear; command the transmission to engage an additional clutch of the plurality of clutches, thereby resulting in the transmission being in a state where the output shaft is bound and torque from an engine is prevented, by the transmission, from being transferred to drive wheels of the vehicle; command the engine to generate drive torque, the generated drive torque being greater than a predetermined torque capacity of a foundation brake system of the vehicle; and upon receipt of a command to launch the vehicle, command release of the additional clutch thereby unbinding the output shaft of the transmission and allowing powerflow in the predetermined forward gear such that the generated drive torque is transferred to the drive wheels to propel the vehicle. ### Claim 2 (depends on 1) The system of claim 1, wherein the control system is further configured to: confirm the foundation brakes are applied and vehicle brake torque is above a predetermined brake threshold; after commanding the transmission to engage the combination of the predetermined number of clutches corresponding to the predetermined forward gear and before commanding the transmission to engage the additional clutch, command the engine to generate a predetermined amount of torque that is less than the generated drive torque and less than the torque capacity of the foundation brake system; and transfer the predetermined amount of torque to the drive wheels through a driveline of the vehicle with the vehicle foundation brake system preventing movement of the drive wheels to thereby capture the predetermined amount of torque in the driveline to i) remove lash from the driveline, ii) preload bushings and one or more shafts of the driveline, and iii) torque an axle of the driveline against associated travel limiters. ### Claim 3 (depends on 2) The system of claim 2, wherein the control system is further configured to: maintain the brake torque above the predetermined brake threshold to keep driveline torque captured until the transmission is commanded to release the addition clutch, upon which an electronic stability control system of the vehicle is commanded to release the brake torque. ### Claim 4 (depends on 3) The system of claim 3, wherein the control system is further configured to: cause a message to be displayed via a user interface associated with an interior of the vehicle, the message instructing a brake pedal of the vehicle to be released; and maintain the brake torque above the predetermined brake threshold independent of application of the brake pedal so as to keep driveline torque captured until the transmission is commanded to release the addition clutch. ### Claim 5 (depends on 1) The system of claim 1, wherein the predetermined forward gear is first gear. ### Claim 6 (depends on 1) The system of claim 1, wherein the predetermined forward gear is one of first gear and second gear; and wherein the control system is further configured to determine whether the launch will be initiated with the transmission in first gear or second gear before commanding the transmission to engage the combination of the predetermined number of clutches corresponding to the predetermined forward gear. ### Claim 7 (depends on 1) The system of claim 1, wherein the plurality of clutches includes only five clutches, the transmission being free of any additional clutches utilized to make forward drive gears of the transmission. ### Claim 8 (depends on 7) The system of claim 7, wherein the combination of the predetermined number of clutches corresponding to the predetermined forward gear and the additional clutch are utilized in providing powerflow for first and second gears of the transmission. ### Claim 9 (depends on 7) The system of claim 7, wherein the combination of the predetermined number of clutches corresponding to the predetermined forward gear are utilized in providing powerflow for first gear of the transmission, and the additional clutch is utilized in providing powerflow for second gear and not for first gear. ### Claim 10 (depends on 7) The system of claim 7, wherein the combination of the predetermined number of clutches corresponding to the predetermined forward gear are utilized in providing powerflow for second gear of the transmission, and the additional clutch is utilized in providing powerflow for first gear and not for second gear. ### Claim 11 (depends on 1) The system of claim 1, wherein: the predetermined forward gear is first gear; the combination of the predetermined number of clutches corresponding to the predetermined forward gear includes two brake clutches and one rotating clutch; and the additional clutch is a rotating clutch that, when utilized in the different combinations of the predetermined number of clutches of the plurality of clutches to provide powerflow for different forward drive gears of the transmission, provides powerflow for second through fourth and sixth gears of the transmission. ### Claim 12 (depends on 1) The system of claim 1, wherein: the predetermined forward gear is second gear; the combination of predetermined number of clutches corresponding to the predetermined forward gear includes two brake clutches and one rotating clutch; and the additional clutch is a rotating clutch that, when utilized in the different combinations of the predetermined number of clutches of the plurality of clutches to provide powerflow for different forward drive gears of the transmission, provides powerflow for first, third and fifth through seventh gears of the transmission. ### Claim 13 (depends on 1) The system of claim 1, wherein the control system is further configured to determine a tractive effort threshold where greater torque applied to the wheels would result in wheel slip and, based on this determined tractive effort threshold, command the predetermined forward gear to be first gear or second gear. ### Claim 14 (depends on 1) The system of claim 1, wherein the predetermined number of clutches of the plurality of clutches is three clutches such that when the additional clutch is commanded to be engaged, four clutches are engaged.