# US 11,441,673 B2 · Eco-friendly vehicle and transmission hydraulic pressure control method for the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,441,673 B2 - Document ID: US11441673B2 - Status: Granted - Kind: B2 - Application number: 16/696,444 - Filed: 2019-11-26 - Published: 2020-09-10 - Granted: 2022-09-13 - Earliest claimed: 2019-03-08 - Assignees: Hyundai Motor Company; Kia Motors Corporation - Applicants: Hyundai Motor Company; Kia Motors Corporation - Inventors: Kyung Su Kim; Hyeon Jun Kim; Yong Hyun Kim - Web page: https://patentgrep.com/patent/US11441673B2 ## CPC - F16H 61/0025: {Supply of control fluid; Pumps therefor} - B60W 10/04: including control of propulsion units - B60W 10/30: including control of auxiliary equipment, e.g. air-conditioning compressors or oil pumps - B60W 20/00: Control systems specially adapted for hybrid vehicles {(hybrid vehicle design, B60K6/00; electric vehicles B60L)} - F04C 28/28: Safety arrangements; Monitoring - F16H 57/0412: {Cooling or heating; Control of temperature} - F16H 59/18: dependent on the position of the accelerator pedal - B60W 2510/30: Auxiliary equipments - B60W 2540/10: Accelerator pedal position - B60W 2710/0666: Engine torque - B60W 2710/083: Torque - F01M 2001/0215: {Electrical pumps} - F01M 2011/1473: {by considering temperature} - F16H 59/72: dependent on oil characteristics, e.g. temperature, viscosity - F16H: GEARING - 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 - F04C: ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS (engines F03C); ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS - F01M: LUBRICATING OF MACHINES OR ENGINES IN GENERAL; LUBRICATING INTERNAL COMBUSTION ENGINES; CRANKCASE VENTILATING ## Abstract An eco-friendly vehicle and a transmission hydraulic pressure control method for the same are provided. The vehicle includes an oil pump that estimates an inner temperature without using a temperature sensor. The method includes determining a driver request output and determining a required hydraulic pressure corresponding to the request output. A temperature of an oil pump unit is estimated to operate an electric oil pump to supply a hydraulic pressure to a transmission, based on the required hydraulic pressure and driving status information. An output torque is then adjusted based on the estimated temperature. ## Claims ### Claim 1 A transmission hydraulic pressure control method for an eco-friendly vehicle, comprising: determining, by a controller, a driver request output; determining, by the controller, a required hydraulic pressure that corresponds to the request output; estimating, by the controller, a temperature of an oil pump unit to operate an electric oil pump to supply a hydraulic pressure to a transmission, based on the required hydraulic pressure and driving status information; and adjusting, by the controller, an output torque based on the estimated temperature. ### Claim 2 (depends on 1) The transmission hydraulic pressure control method according to claim 1, wherein the driving status information includes a driving time and a request torque. ### Claim 3 (depends on 2) The transmission hydraulic pressure control method according to claim 2, wherein the estimating of the temperature of the oil pump unit is executed using a previously prepared temperature estimation expression. ### Claim 4 (depends on 3) The transmission hydraulic pressure control method according to claim 3, wherein the temperature estimation expression is determined based on a correlation of between a driving time and a temperature according to the request torque on a required hydraulic pressure basis. ### Claim 5 (depends on 1) The transmission hydraulic pressure control method according to claim 1, wherein the adjusting of the output torque includes determining whether the estimated temperature is less than a predetermined protective temperature. ### Claim 6 (depends on 5) The transmission hydraulic pressure control method according to claim 5, further comprising: determining, by the controller, the request torque to be the output torque when the estimated temperature is determined to be less than the predetermined protective temperature, based on results of the determination. ### Claim 7 (depends on 5) The transmission hydraulic pressure control method according to claim 5, further comprising: limiting, by the controller, the output torque to be less than a predetermined protective torque when the estimated temperature is determined to be greater than the predetermined protective temperature, based on results of the determination. ### Claim 8 (depends on 1) A non-transitory computer-readable recording medium recorded with a program to execute the transmission hydraulic pressure control method according to claim 1. ### Claim 9 An eco-friendly vehicle, comprising: an electric oil pump configured to supply a hydraulic pressure to a transmission; and an oil pump unit configured to acquire a driver request output, determine a required hydraulic pressure corresponding to the request output, estimate an inner temperature based on the required hydraulic pressure and driving status information, and adjust an output torque based on the estimated temperature, while operating the electric oil pump. ### Claim 10 (depends on 9) The eco-friendly vehicle according to claim 9, wherein the driving status information includes a driving time and a request torque. ### Claim 11 (depends on 10) The eco-friendly vehicle according to claim 10, wherein the oil pump unit is configured to estimate the inner temperature using a previously prepared temperature estimation expression. ### Claim 12 (depends on 11) The eco-friendly vehicle according to claim 11, wherein the temperature estimation expression is determined based on a correlation of between a driving time and a temperature according to the request torque on a required hydraulic pressure basis. ### Claim 13 (depends on 9) The eco-friendly vehicle according to claim 9, wherein the oil pump unit is configured to determine whether the estimated temperature is less than a predetermined protective temperature. ### Claim 14 (depends on 13) The eco-friendly vehicle according to claim 13, wherein the oil pump unit is configured to instruct a hybrid controller to determine the request torque to be the output torque when the estimated temperature is less than the predetermined protective temperature. ### Claim 15 (depends on 13) The eco-friendly vehicle according to claim 13, wherein the oil pump unit is configured to instruct a hybrid controller to limit the output torque to be less than a predetermined protective torque when the estimated temperature is greater than the predetermined protective temperature.