# US 10,246,128 B2 · Travel control device for vehicle > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,246,128 B2 - Document ID: US10246128B2 - Status: Granted - Kind: B2 - Application number: 15/229,401 - Filed: 2016-08-05 - Published: 2017-02-09 - Granted: 2019-04-02 - Earliest claimed: 2015-08-07 - Assignees: Toyota Jidosha Kabushiki Kaisha - Applicants: Toyota Jidosha Kabushiki Kaisha - Inventors: Takahiro Kojo - Web page: https://patentgrep.com/patent/US10246128B2 ## CPC - B62D 6/002: {computing target steering angles for front or rear wheels (B62D7/159 takes precedence)} - B62D 5/008: {Changing the transfer ratio between the steering wheel and the steering gear by variable supply of energy, e.g. by using a superposition gear} - B62D 5/0463: {calculating assisting torque from the motor based on driver input} - B62D 5/0472: {for damping vibrations} - B62D 6/06: responsive only to vehicle vibration dampening arrangements (steering dampers for cycles B62K21/08) - 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 travel control device for vehicle (10) includes a steering transmission ratio variable device (14), a steering transmission ratio control device (16) configured to carry out such control that an actual relative rotational angle (θre) of the steering transmission ratio variable device reaches a target value (θret), a power steering device (18), a steering assist torque control device (20) configured to control the power steering device, and a driving support device (22) configured to correct a target steering assist torque so that an actual steering angle of steered wheels (19FL, 19FR) reaches a target steering angle for driving support. When the driving support device is in operation (Step 140), the magnitude of a change in a relative rotational angle generated by the control of the steering transmission ratio variable device is decreased (Step 150 to 200) compared to a case in which the driving support device is not in operation. ## Claims ### Claim 1 A travel control device for a vehicle, comprising: a steering transmission ratio variable device, which is installed in a steeling transmission system between a steeling wheel and steered wheels, and is configured to rotate a lower steeling shaft with respect to an upper steering shaft, to thereby change a steering transmission ratio; a steering transmission ratio controller, which is configured to calculate a target value of a relative rotational angle between the upper steering shaft and the lower steeling shaft, which is required to achieve a target steering transmission ratio, and to control the steering transmission ratio variable device so that an actual relative rotational angle conforms to the target value; a power steering device, which is installed in the steeling transmission system between the steered wheels and the steering transmission ratio variable device, and is configured to generate a steering assist torque; a steering assist torque controller, which is configured to calculate a target steeling assist torque, and to control the power steering device so that an actual steering assist torque conforms to the target steeling assist torque; and a driving support controller, which is configured to calculate a target steering angle of the steered wheels for causing the vehicle to travel along a predetermined travel path, and to correct the target steeling assist torque so that an actual steering angle of the steered wheels conforms to the target steeling angle, wherein the steering transmission ratio controller is configured to decrease a range of the relative rotational angle controlled by the steeling transmission ratio variable device when the driving support controller is engaged compared to when the driving support controller is not engaged. ### Claim 2 (depends on 1) The travel control device according to claim 1, wherein the steering transmission ratio controller is configured to calculate the target value of the relative rotational angle to be 0 for every speed of the vehicle when the driving support controller is engaged. ### Claim 3 (depends on 1) The travel control device according to claim 1, wherein the steering transmission ratio controller is configured to acquire, when the driving support controller starts an operation thereof, a current value of the relative rotational angle, and calculate, when the driving support controller is engaged, the target value of the relative rotational angle to be the current value, to thereby cause the change in the relative rotational angle controlled by the steering transmission ratio variable device to be 0 for every speed of the vehicle. ### Claim 4 (depends on 1) The travel control device according to claim 1, wherein: the steering transmission ratio variable device comprises a lock device configured to block a relative rotation between the upper steering shaft and the lower steering shaft; and the steering transmission ratio controller is configured to operate, when the driving support controller is engaged, the lock device so that the change in the relative rotational angle controlled by the steering transmission ratio variable device is 0 for every speed of the vehicle. ### Claim 5 (depends on 1) The travel control device according to claim 1, wherein the steering transmission ratio controller is configured to apply, based on the target value of the relative rotational angle and a current value of the relative rotational angle, feedback control to the steering transmission ratio variable device so that a magnitude of a difference between the target value of the relative rotational angle and the current value of the relative rotational angle decreases, and to decrease a gain of the feedback control when the driving support controller is engaged compared to when the driving support controller is not engaged. ### Claim 6 (depends on 1) The travel control device according to claim 1, wherein: the vehicle comprises a switch to be operated by an occupant, configured to switch between an engaged position in which the driving support controller is engaged and a non-engaged position in which the driving support controller is not engaged; and the steering transmission ratio control device is configured to determine that the driving support controller is engaged when the switch is in the engaged position. ### Claim 7 (depends on 6) The travel control device according to claim 6, wherein: the driving support controller is configured to calculate, even when the switch is in the non-engaged position, a target steering angle of the steered wheels required for an emergency avoidance, and carry out emergency avoidance steering of correcting the target steering assist torque so that the actual steering angle of the steered wheels conforms to the target steering angle; and the steering transmission ratio controller is configured to determine, also when the emergency avoidance steering is being carried out, that the driving support controller is engaged.