# US 12,600,408 B2 · Turning control device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,600,408 B2 - Document ID: US12600408B2 - Status: Granted - Kind: B2 - Application number: 18/359,721 - Filed: 2023-07-26 - Published: 2023-11-23 - Granted: 2026-04-14 - Earliest claimed: 2021-01-29 - Assignees: Denso Corporation - Applicants: Denso Corporation - Inventors: Akira Takesaki - Web page: https://patentgrep.com/patent/US12600408B2 ## CPC - B62D 6/002: {computing target steering angles for front or rear wheels (B62D7/159 takes precedence)} - B62D 7/159: {characterised by computing methods or stabilisation processes or systems, e.g. responding to yaw rate, lateral wind, load, road condition} - B62D 15/025: {Active steering aids, e.g. helping the driver by actively influencing the steering system after environment evaluation (B62D1/28 takes precedence)} - B62D: MOTOR VEHICLES; TRAILERS (steering, or guiding on a desired track, of agricultural machines or implements A01B69/00; wheels, castors, axles, increasing wheel adhesion B60B; vehicle tyres, tyre inflation or tyre changing B60C; connections between vehicles of a train or the like B60D; vehicles for use on rail and road, amphibious or convertible vehicles B60F; suspension arrangements B60G; heating, cooling, ventilating or other air treating devices B60H; windows, windscreens, non-fixed roofs, doors or similar devices, protective coverings for vehicles not in use B60J; propulsion plant arrangements, auxiliary drives, transmissions, controls, instrumentation or dashboards B60K; electric equipment or propulsion of electrically-propelled vehicles B60L; power supply for electrically-propelled vehicles B60M; passenger accommodation not otherwise provided for B60N; adaptations for load transportation or to carry special loads or objects B60P; arrangement of signalling or lighting devices, the mounting or supporting thereof or circuits therefor, for vehicles in general B60Q; vehicles, vehicle fittings or vehicle parts not otherwise provided for B60R; servicing, cleaning, repairing, supporting, lifting, or manoeuvring, not otherwise provided for, B60S; brake arrangements, brake control systems or parts thereof B60T; air-cushion vehicles B60V; motor-cycles, accessories therefor B62J, B62K; testing of vehicles G01M) ## Abstract A turning control device is for a vehicle having four wheels that are mechanically separated and steered independently. The four wheels are left and right wheels of a front row and a rear row. The turning control device controls four steering actuators corresponding to the four wheels. The turning control device includes a controller that performs feedback control of the four steering actuators to reduce a deviation for each of the four wheels. The deviation is a difference between a state parameter convertible into a turning angle and a target value of the state parameter set according to steering of a steering wheel. The controller executes a responsiveness changing process of changing a responsiveness of the feedback control so that the deviation is likely to be smaller in a vehicle straight traveling state than in a vehicle non-straight traveling state. ## Claims ### Claim 1 A turning control device for a vehicle having four wheels that are mechanically separated and steered independently, the four wheels being left and right wheels of a front row and a rear row, the turning control device being configured to control four steering actuators corresponding to the four wheels, the turning control device comprising a controller configured to perform feedback control of the four steering actuators to reduce a deviation for each of the four wheels, the deviation being a difference between a state parameter convertible into a turning angle and a target value of the state parameter set according to steering of a steering wheel, wherein the controller is configured to execute a responsiveness changing process of changing a responsiveness of the feedback control so that the deviation is likely to be smaller in a vehicle straight traveling state than in a vehicle non-straight traveling state, except when the vehicle satisfies a predetermined application exclusion requirement. ### Claim 2 (depends on 1) The turning control device according to claim 1, wherein the controller is configured to set, in the responsiveness changing process, an integral term of the feedback control to be larger in the vehicle straight traveling state than in the vehicle non-straight traveling state. ### Claim 3 (depends on 2) The turning control device according to claim 2, wherein the controller is configured to set, in the responsiveness changing process, the integral term of the feedback control to be smaller with increase in vehicle speed in the vehicle straight traveling state. ### Claim 4 (depends on 2) The turning control device according to claim 2, wherein the controller is configured to set, in the responsiveness changing process, the integral term of the feedback control to be larger with decrease in difference between a turning angle and a neutral position in the vehicle straight traveling state. ### Claim 5 (depends on 1) The turning control device according to claim 1, wherein the controller is configured to execute the responsiveness changing process independently for each of the four steering actuators corresponding to the four wheels. ### Claim 6 (depends on 1) The turning control device according to claim 1, wherein the controller is configured to determine that the vehicle is in the vehicle straight traveling state when an absolute value of the state parameter is equal to or less than a straight traveling determination threshold. ### Claim 7 (depends on 1) The turning control device according to claim 1, wherein the application exclusion requirement includes a speed condition which is met when the vehicle speed is less than a vehicle speed threshold, and the controller is configured to perform the feedback control in the vehicle straight traveling state with the same responsiveness as that in the vehicle non-straight traveling state when the speed condition is met. ### Claim 8 (depends on 1) The turning control device according to claim 1, wherein the controller is configured to execute the responsiveness changing process of changing the responsiveness of the feedback control so that a fluctuation of the deviation is to be smaller in a vehicle straight traveling state than in a vehicle non-straight traveling state, except when the vehicle satisfies a predetermined application exclusion requirement.