# US 11,077,835 B2 · Control apparatus for vehicle and control method for vehicle > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,077,835 B2 - Document ID: US11077835B2 - Status: Granted - Kind: B2 - Application number: 16/241,001 - Filed: 2019-01-07 - Published: 2019-10-03 - Granted: 2021-08-03 - Earliest claimed: 2018-03-28 - Assignees: Subaru Corporation - Applicants: Subaru Corporation - Inventors: Yuya Maeda; Noeru Sato; Fumiya Sato - Web page: https://patentgrep.com/patent/US11077835B2 ## CPC - B60T 8/1763: responsive to the coefficient of friction between the wheels and the ground surface (B60T8/1764 takes precedence) - B60T 8/171: Detecting parameters used in the regulation; Measuring values used in the regulation - B60T 8/172: Determining control parameters used in the regulation, e.g. by calculations involving measured or detected parameters {(B60T8/17551 takes precedence)} - B60W 40/068: Road friction coefficient - B60W 50/0098: {Details of control systems ensuring comfort, safety or stability not otherwise provided for} - B60T 2210/12: Friction - B60W 2050/0075: {Automatic parameter input, automatic initialising or calibrating means} - B60W 2420/403: Image sensing, e.g. optical camera - B60W 2520/28: Wheel speed - B60T: VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL (electrodynamic brake systems for vehicle, in general B60L; brakes per se, i.e. devices where braking effect occurs, including ultimate brake actuators, F16D); ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES - 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 ## Abstract A control apparatus for a vehicle includes: a first road surface friction coefficient calculator; a second road surface friction coefficient calculator; and a braking and driving force controller. The first road surface friction coefficient calculator calculates a first road surface friction coefficient that is a friction coefficient of a road surface in a contact with a wheel. The second road surface friction coefficient calculator calculates a second road surface friction coefficient on a basis of a detection value from a contactless sensor that contactlessly detects a road surface state. ## Claims ### Claim 1 A control apparatus for a vehicle, the control apparatus comprising: a processor configured to: calculate a first road surface friction coefficient that is a friction coefficient of a road surface in a contact with a wheel; calculate a second road surface friction coefficient on a basis of a detection value from a contactless sensor capable of contactlessly detecting a road surface state; control a braking and driving force of the vehicle on a basis of the first road surface friction coefficient at a normal time, and control the braking and driving force of the vehicle on a basis of the second road surface friction coefficient in a case where it is determined on the basis of the second road surface friction coefficient that a low friction road surface having a low friction coefficient is present in front of the vehicle; calculate the second road surface friction coefficient in each predetermined control cycle, including: calculating a previous second road surface friction coefficient from a previous control cycle; and calculating a current second road surface friction coefficient from a current control cycle, wherein the previous control cycle immediately precedes the current control cycle; compare the previous second road surface friction coefficient with the current second road surface friction coefficient; and determine that the low friction road surface is present in front of the vehicle when the current second road surface friction coefficient is less than the previous second road surface friction coefficient. ### Claim 2 (depends on 1) The control apparatus for a vehicle according to claim 1, wherein the processor is configured to: control the braking and driving force within a range of a friction circle decided in accordance with the first road surface friction coefficient at the normal time, and control the braking and driving force within the range of the friction circle while shrinking the friction circle before the vehicle reaches the low friction road surface in the case where it is determined that the low friction road surface is present in front of the vehicle. ### Claim 3 (depends on 2) The control apparatus for a vehicle according to claim 2, wherein the processor is configured to reduce a size of the friction circle from a size corresponding to the first road surface friction coefficient to a size corresponding to the second road surface friction coefficient before the vehicle reaches the low friction road surface. ### Claim 4 (depends on 2) The control apparatus for a vehicle according to claim 2, wherein the processor is configured to: determine whether the low friction road surface is present in front of the vehicle, calculate the second road surface friction coefficient in each predetermined control cycle, and determine that the low friction road surface is present in front of the vehicle in a case where a value of the second road surface friction coefficient is smaller in a current control cycle than in a previous control cycle. ### Claim 5 (depends on 3) The control apparatus for a vehicle according to claim 3, wherein the processor is configured to: determine whether the low friction road surface is present in front of the vehicle, calculate the second road surface friction coefficient in each predetermined control cycle, and determine that the low friction road surface is present in front of the vehicle in a case where a value of the second road surface friction coefficient is smaller in a current control cycle than in a previous control cycle. ### Claim 6 (depends on 1) The control apparatus for a vehicle according to claim 1, wherein the processor is configured to control the braking and driving force of the vehicle on a basis of the second road surface friction coefficient in a case where it is determined at least twice that the low friction road surface is present while the vehicle is traveling a predetermined distance. ### Claim 7 (depends on 4) The control apparatus for a vehicle according to claim 4, wherein the processor is configured to control the braking and driving force of the vehicle on a basis of the second road surface friction coefficient in a case where it is determined at least twice that the low friction road surface is present while the vehicle is traveling a predetermined distance. ### Claim 8 (depends on 5) The control apparatus for a vehicle according to claim 5, wherein the processor is configured to control the braking and driving force of the vehicle on a basis of the second road surface friction coefficient in a case where it is determined at least twice that the low friction road surface is present while the vehicle is traveling a predetermined distance. ### Claim 9 (depends on 1) The control apparatus for a vehicle according to claim 1, wherein the processor is configured to lower a torque of a driving force of a front wheel and raise a toque of a rear wheel on a basis of the second road surface friction coefficient in a case where it is determined that the low friction road surface is present in front of the vehicle. ### Claim 10 (depends on 1) The control apparatus for a vehicle according to claim 1, wherein the processor is configured to calculate the first road surface friction coefficient on a basis of a detection value from a hub unit sensor provided to an axle. ### Claim 11 (depends on 2) The control apparatus for a vehicle according to claim 2, wherein the processor is configured to calculate the first road surface friction coefficient on a basis of a detection value from a hub unit sensor provided to an axle. ### Claim 12 (depends on 3) The control apparatus for a vehicle according to claim 3, wherein the processor is configured to calculate the first road surface friction coefficient on a basis of a detection value from a hub unit sensor provided to an axle. ### Claim 13 (depends on 1) The control apparatus for a vehicle according to claim 1, wherein the processor is configured to calculate the first road surface friction coefficient on a basis of a detection value from a hub unit sensor provided to an axle. ### Claim 14 (depends on 4) The control apparatus for a vehicle according to claim 4, wherein the processor is configured to calculate the first road surface friction coefficient on a basis of a detection value from a hub unit sensor provided to an axle. ### Claim 15 (depends on 5) The control apparatus for a vehicle according to claim 5, wherein the processor is configured to calculate the first road surface friction coefficient on a basis of a detection value from a hub unit sensor provided to an axle. ### Claim 16 A control method for a vehicle, the control method comprising: calculating a first road surface friction coefficient that is a friction coefficient of a road surface in a contact with a wheel; calculating a second road surface friction coefficient on a basis of a detection value from a contactless sensor capable of contactlessly detecting a road surface state; and controlling a braking and driving force of the vehicle on a basis of the first road surface friction coefficient at a normal time, and controlling the braking and driving force of the vehicle on a basis of the second road surface friction coefficient in a case where it is determined on the basis of the second road surface friction coefficient that a low friction road surface having a low friction coefficient is present in front of the vehicle, calculating the second road surface friction coefficient in each predetermined control cycle, including: calculating a previous second road surface friction coefficient from a previous control cycle; and calculating a current second road surface friction coefficient from a current control cycle, wherein the previous control cycle immediately precedes the current control cycle; comparing the previous second road surface friction coefficient with the current second road surface friction coefficient; and determining that the low friction road surface is present in front of the vehicle when the current second road surface friction coefficient is less than the previous second road surface friction coefficient. ### Claim 17 A control apparatus for a vehicle, the control apparatus comprising: circuitry configured to calculate a first road surface friction coefficient that is a friction coefficient of a road surface in a contact with a wheel, calculate a second road surface friction coefficient on a basis of a detection value from a contactless sensor capable of contactlessly detecting a road surface state, and control a braking and driving force of the vehicle on a basis of the first road surface friction coefficient at a normal time, and control the braking and driving force of the vehicle on a basis of the second road surface friction coefficient in a case where it is determined on the basis of the second road surface friction coefficient that a low friction road surface having a low friction coefficient is present in front of the vehicle, calculate the second road surface friction coefficient in each predetermined control cycle, including: calculating a previous second road surface friction coefficient from a previous control cycle; and calculating a current second road surface friction coefficient from a current control cycle, wherein the previous control cycle immediately precedes the current control cycle; compare the previous second road surface friction coefficient with the current second road surface friction coefficient; and determine that the low friction road surface is present in front of the vehicle when the current second road surface friction coefficient is less than the previous second road surface friction coefficient.