# US 11,079,011 B2 · Vehicle control system and method on low friction road > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,079,011 B2 - Document ID: US11079011B2 - Status: Granted - Kind: B2 - Application number: 16/668,293 - Filed: 2019-10-30 - Published: 2020-05-07 - Granted: 2021-08-03 - Earliest claimed: 2018-11-02 - Assignees: Hyundai Kefico Corporation - Applicants: Hyundai Kefico Corporation - Inventors: John Ha Lee; Nam Hoon Kim; Se Hoon Son; Seo Yeon Cho - Web page: https://patentgrep.com/patent/US11079011B2 ## CPC - F16H 61/16: Inhibiting {or initiating} shift during unfavourable conditions {, e.g. preventing forward-reverse shift at high vehicle speed, preventing engine overspeed} (F16H61/18 takes precedence) - B60W 10/06: including control of combustion engines - B60W 10/11: Stepped gearings - B60W 30/19: Improvement of gear change, e.g. by synchronisation or smoothing gear shift - B60W 40/068: Road friction coefficient - B60W 50/06: Improving the dynamic response of the control system, e.g. improving the speed of regulation or avoiding hunting or overshoot - F16H 59/66: Road conditions, e.g. slope, slippery - F16H 61/10: Controlling shift hysteresis - B60W 2510/0638: Engine speed - B60W 2510/0676: Engine temperature - B60W 2520/125: Lateral acceleration - B60W 2540/10: Accelerator pedal position - B60W 2540/18: Steering angle - B60W 2552/40: Coefficient of friction - F16H 59/18: dependent on the position of the accelerator pedal - F16H 59/44: dependent on machine speed {, e.g. the vehicle speed} (F16H59/46 takes precedence) - F16H 59/48: Inputs being a function of acceleration - F16H 59/78: Temperature - F16H 2061/161: {by checking feasibility of shifts, i.e. determine if requested shift can be successfully completed and post shift values are in an acceptable range} - Y02T 10/72: Electric energy management in electromobility - 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 - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A vehicle control system and a method for a vehicle running on a low friction road inhibit repetitive gear shifts of a transmission of the vehicle. The vehicle control system of the vehicle includes: one or more sensors for sensing an engine speed of the vehicle, an engine oil temperature, a position of an accelerator pedal, a lateral acceleration of the vehicle, a rotational angle of a steering wheel, or whether a low friction road running mode switch is turned on or off; and a controller for receiving sensor data from the sensors. In particular, the controller determines whether the vehicle satisfies an entry condition for performing a repetitive shift prevention control based on the sensor data, and controls a gear shift of the transmission and an engine torque to inhibit the repetitive gear shifts of the vehicle when the downshift occurs when the vehicle has satisfied the entry condition. ## Claims ### Claim 1 A vehicle control system for inhibiting repetitive gear shifts while a vehicle is running on a low friction road, the vehicle control system comprising: one or more sensors configured to detect an engine speed of the vehicle, a temperature of an engine oil, a position of an accelerator pedal, a lateral acceleration of the vehicle, a rotational angle of a steering wheel, or whether a low friction road running mode switch is turned on or off; and a controller configured to: receive detected data from the one or more sensors, determine whether the vehicle satisfies an entry condition for performing a repetitive shift prevention control based on the received data of the vehicle, and control a gear shift of a transmission and an engine torque of the vehicle to perform the repetitive shift prevention control when a downshift occurs in a state where the vehicle has satisfied the entry condition, wherein the controller comprises: an entry condition determinator configured to determine whether the vehicle has satisfied the entry condition or whether the entry condition has been released during the running of the vehicle based on the data received from the one or more sensors; a shift controller configured to inhibit the gear shift of the transmission when the downshift occurs, after the entry condition has been satisfied; and an engine torque controller configured to request an engine torque limitation when the downshift occurs, after the entry condition has been satisfied. ### Claim 2 (depends on 1) The vehicle control system of claim 1, wherein the one or more sensors comprises: an oil temperature sensor configured to detect the temperature of the engine oil; an accelerator position sensor configured to detect the position of the accelerator pedal; a steering angle sensor configured to detect the rotational angle of the steering wheel; an acceleration sensor configured to detect the lateral acceleration of the vehicle; and an engine speed sensor configured to detect the engine speed of the vehicle. ### Claim 3 (depends on 1) The vehicle control system of claim 1, wherein the entry condition determinator is configured to determine that the vehicle has satisfied the entry condition when: the low friction road running mode switch is turned on, a signal delivered from the one or more sensors is a normal signal, the engine speed is equal to or greater than a predetermined first setting value, the temperature of the engine oil is equal to or greater than a predetermined second setting value, the position of the accelerator pedal is equal to or greater than a predetermined third setting value, and the rotational angle of the steering wheel is equal to or greater than a predetermined fourth setting value. ### Claim 4 (depends on 1) The vehicle control system of claim 1, wherein the controller further comprises a low friction road running determinator configured to determine whether the vehicle has escaped the low friction road based on a value of the lateral acceleration of the vehicle, and wherein the low friction road running determinator is configured to determine that the vehicle has escaped the low friction road when the value of the lateral acceleration is greater than a predetermined fifth setting value. ### Claim 5 (depends on 4) The vehicle control system of claim 4, wherein the controller is configured to determine whether the downshift occurs only when it is determined that the vehicle has not escaped the low friction road, and configured to control the gear shift of the transmission and the engine torque when the downshift has occurred. ### Claim 6 (depends on 1) The vehicle control system of claim 1, wherein the shift controller is configured to inhibit the gear shift of the transmission such that a current gear is maintained during a predetermined time, when the entry condition determinator determines that the entry condition has been released during the running of the vehicle. ### Claim 7 (depends on 1) The vehicle control system of claim 1, wherein the engine torque controller is configured to control the engine torque to be increased with a constant slope during a predetermined time, when the entry condition has been released during the running of the vehicle. ### Claim 8 A vehicle control method for inhibiting repetitive gear shifts of a vehicle while running on a low friction road, the vehicle control method comprising: collecting, by at least one sensor, data of the vehicle including at least one of an engine speed of the vehicle, a temperature of an engine oil, a position of an accelerator pedal, a lateral acceleration of the vehicle, a rotational angle of a steering wheel, or ON/OFF data of a low friction road running mode switch; determining, by a controller, whether the vehicle satisfies an entry condition for performing a repetitive shift prevention control or whether the entry condition has been released during the running of the vehicle based on the collected data; inhibiting, by the controller, a gear shift of a transmission of the vehicle when a downshift occurs after it has been determined that the entry condition has been satisfied; and controlling, by the controller, an engine to limit an engine torque when the downshift occurs after it has been determined that the entry condition has been satisfied. ### Claim 9 (depends on 8) The vehicle control method of claim 8, further comprising: prior to controlling the gear shift of the transmission or the engine torque, determining, by the controller, whether the vehicle has escaped the low friction road based on the lateral acceleration data of the vehicle. ### Claim 10 (depends on 9) The vehicle control method of claim 9, wherein determining that the vehicle has escaped the low friction road when a value of the lateral acceleration of the vehicle is greater than a predetermined setting value. ### Claim 11 (depends on 8) The vehicle control method of claim 8, further comprising: when the entry condition has been released during the running of the vehicle, inhibiting the gear shift of the transmission such that a current gear is maintained during a predetermined time, or controlling the engine torque to be increased with a constant slope during a predetermined time.