US-12617460-B2 - Vehicle and hands-off state detection method thereof

US12617460B2US 12617460 B2US12617460 B2US 12617460B2US-12617460-B2

Abstract

A hands-off state detection method of a vehicle includes determining a difference between a pinion angle and a column angle of a motor-driven power steering (MDPS) system of the vehicle, and determining a hands-off state of a steering wheel of the vehicle based on the difference between the pinion angle and the column angle.

Inventors

Dongseob Lee

Assignees

HYUNDAI MOTOR COMPANY
KIA CORPORATION

Dates

Publication Date: 20260505
Application Date: 20231017
Priority Date: 20221102

Claims (12)

1 . A hands-off state detection method of a vehicle comprising: determining a difference between a pinion angle and a column angle of a motor-driven power steering (MDPS) system of the vehicle; determining whether a state of a steering wheel of the vehicle is a hands-off state based on the difference between the pinion angle and the column angle, the hands-off state indicating that hands of a driver of the vehicle are spaced apart from the steering wheel; and controlling the vehicle based on the determining of the hands-off state.
2 . The hands-off state detection method according to claim 1 , further comprising: determining, based on a determination that the difference between the pinion angle and the column angle is 0 degrees for a preset number of times or more for a preset time, the state of the steering wheel as the hands-off state.
3 . The hands-off state detection method according to claim 2 , further comprising, determining, based on the state of the steering wheel not being the hands-off state, strength of grasp of the driver on the steering wheel according to a difference between (i) distribution of the difference between the pinion angle and the column angle and (ii) the 0 degree.
4 . The hands-off state detection method according to claim 1 , further comprising determining the state of the steering wheel as the hands-off state while the vehicle is in a driving assist control mode.
5 . The hands-off state detection method according to claim 4 , wherein the driving assist control mode comprises a lane keeping assist control mode.
6 . The hands-off state detection method according to claim 1 , wherein the motor-driven power steering (MDPS) system is provided in a rack mounting method (R-MDPS).
7 . A vehicle comprising: a torque angle sensor provided to detect a difference between a pinion angle and a column angle of a motor-driven power steering (MDPS) system of the vehicle; and an electronic controller configured to: determine the difference between the pinion angle and the column angle of the motor-driven power steering (MDPS) system, and determine whether a state of a steering wheel of the vehicle is a hands-off state based on the difference between the pinion angle and the column angle, the hands-off state indicating that hands of a driver of the vehicle are spaced apart from the steering wheel.
8 . The vehicle according to claim 7 , wherein the electronic controller is configured to determine, based on a determination that the difference between the pinion angle and the column angle is 0 degrees for a preset number of times or more for a preset time, the state of the steering wheel as the hands-off state.
9 . The vehicle according to claim 8 , wherein the electronic controller is configured to determine, based on the state of the steering wheel not being the hands-off state, strength of grasp of the driver on the steering wheel according to a difference between (i) distribution of the difference between the pinion angle and the column angle and (ii) the 0 degree.
10 . The vehicle according to claim 7 , wherein the electronic controller is configured to determine the state of the steering wheel as the hands-off state while the vehicle is in a driving assist control mode.
11 . The vehicle according to claim 10 , wherein the driving assist control mode comprises a lane keeping assist control mode.
12 . The vehicle according to claim 7 , wherein the motor-driven power steering (MDPS) system is provided in a rack mounting method (R-MDPS).

Description

CROSS-REFERENCE TO RELATED APPLICATION(S) This application is based on and claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2022-0144531, filed on Nov. 2, 2022, in the Korean Intellectual Property Office, the disclosure of which is incorporated by reference herein in its entirety. TECHNICAL FIELD The disclosure relates to a vehicle and a hands-off state detection method thereof. BACKGROUND A steering angle signal of a vehicle serves in various aspects of driving. For example, it plays a role in ensuring safety through the operation of key safety devices, such as steering systems, electronic stability control (ESC), and steering collision avoidance systems (SCAS). Moreover, the steering angle signal also facilitates the function of driver convenience systems, including smart parking assistant systems (SPAS) and smart cruise control (SCC). A steering angle sensor used for calculating a steering angle is installed on a steering system to measure and convert a physical signal into an electrical signal. The electrical signal is then transmitted to an electrical control unit (ECU) so as to determine steering angle information of a driver. SUMMARY The present the disclosure is directed to a vehicle capable of more accurately detecting a hands-on/off state of a steering wheel of the vehicle, and a hands-off state detection method thereof. In accordance with an aspect of the disclosure, a hands-off state detection method of a vehicle includes determining a difference between a pinion angle and a column angle of a motor-driven power steering (MDPS) system of the vehicle, and determining a hands-off state of a steering wheel of the vehicle based on the difference between the pinion angle and the column angle. The hands-off state detection method may further include determining as the hands-off state in which a driver takes the hands of the driver off the steering wheel when it is detected that the difference between the pinion angle and the column angle is 0 degrees for a preset number of times or more for a preset time. The hands-off state detection method may further include, when it is not the hands-off state, determining the strength of the driver's grasp of the steering wheel according to the difference between the distribution of the difference between the pinion angle and the column angle and the 0 degree. The hands-off state detection method may further include detecting the hands-off state of the steering wheel while the vehicle is driving in a driving assist control mode. The driving assist control mode may include a lane keeping assist control mode. The motor-driven power steering (MDPS) system may be provided in a rack mounting method (R-MDPS). In accordance with another aspect of the disclosure, a vehicle includes a torque angle sensor provided to detect a difference between a pinion angle and a column angle of a motor-driven power steering (MDPS) system of the vehicle, and an electronic control unit configured to determine the difference between the pinion angle and the column angle of the motor-driven power steering (MDPS) system, and determine a hands-off state of a steering wheel of the vehicle based on the difference between the pinion angle and the column angle. The electronic control unit may determine as the hands-off state in which a driver takes the hands of the driver off the steering wheel when it is detected that the difference between the pinion angle and the column angle is 0 degrees for a preset number of times or more for a preset time. The electronic control unit may determine that, when it is not the hands-off state, the strength of the driver's grasp of the steering wheel according to the difference between the distribution of the difference between the pinion angle and the column angle and the 0 degree. The electronic control unit may determine detect the hands-off state of the steering wheel while the vehicle is driving in a driving assist control mode. The driving assist control mode may include a lane keeping assist control mode. The motor-driven power steering (MDPS) system may be provided in a rack mounting method (R-MDPS). BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram illustrating an example of an MDPS system of a vehicle. FIG. 2 is a diagram illustrating an example of a torque angle sensor and an electronic control unit. FIG. 3 is a flowchart illustrating an example of a method of detecting a hands-off state of the vehicle. FIGS. 4A and 4B are diagrams illustrating example distributions of differences between pinion angles and column angles depending on a hands-on/off state of a steering wheel. FIG. 5 is a graph illustrating an example of control values (LKA) and steering torques (TOR) in a lane keeping assist control mode, and differences (DIF) between pinion angles and column angles, in a case where a driver grips the steering wheel with the hands of the driver in a state in which the lane keeping assist control mode is activated (LKA-on state