CONTROL DEVICE FOR VEHICLE SEAT BELT

• US 20200130642A1
• Filed: 08/22/2019
• Published: 04/30/2020
• Est. Priority Date: 10/29/2018
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Nezaki, Takuya, Hayakawa, Koki, Sugiyama, Motoki, Komeno, Fumihito
• Granted Patent: US 11,364,873 B2
• Time in Patent Office: Days
• CPC Class Codes: B60R 2021/01272 Belt tensioners
• CPC Class Codes: B60R 2021/01304 monitoring rough road condition
• CPC Class Codes: B60R 2021/01313 monitoring the vehicle steering system or the dynamic control system
• CPC Class Codes: B60R 2022/4685 with means to adjust or regulate the tensioning force in relation to external parameters
• CPC Class Codes: B60R 2022/4808 Sensing means arrangements therefor
• CPC Class Codes: B60R 21/013 including means for detecting collisions, impending collisions or roll-over
• CPC Class Codes: B60R 21/0132 responsive to vehicle motion parameters , e.g. to vehicle longitudinal or transversal deceleration or speed value
• CPC Class Codes: B60R 22/46 Reels with means to tension the belt in an emergency by forced winding upelectrical circuits for triggering safety arrangements B60R21/01 ; tensioners using reels only guiding the belt during normal use, e.g. splitted reels B60R22/195
• CPC Class Codes: B60R 22/48 Control systems, alarms, or interlock systems, for the correct application of the belt or harness

Abstract

A control device for a vehicle seat belt, includes: a retraction unit that is configured to retract a seat belt through use of a driving force of a motor and to stop retracting the seat belt when the motor is stopped from being driven; an acceleration measurement unit that is configured to measure an acceleration of a vehicle; a state detection unit that is configured to detect whether or not the vehicle is in a stable state while running; and a control unit that is configured to stop driving the motor when the acceleration measured by the acceleration measurement unit during driving of the motor has remained lower than a first set acceleration for at least a first set time and the vehicle has remained in the stable state detected by the state detection unit for at least a second set time.

Claims

1. A control device for a vehicle seat belt, comprising:

a retraction unit that is configured to retract a seat belt through use of a driving force of a motor and to stop retracting the seat belt when the motor is stopped from being driven;

an acceleration measurement unit that is configured to measure an acceleration of a vehicle;

a state detection unit that is configured to detect whether or not the vehicle is in a stable state while running; and

a control unit that is configured

to stop driving the motor when the acceleration measured by the acceleration measurement unit during driving of the motor has remained lower than a first set acceleration for at least a first set time and the vehicle has remained in the stable state detected by the state detection unit for at least a second set time, and

to continue to drive the motor at least either when the acceleration has remained lower than the first set acceleration for a time shorter than the first set time, or when the vehicle has remained in the stable state detected by the state detection unit for a time shorter than the second set time.

2. The control device for the vehicle seat belt according to claim 1, further comprising:

a vehicle speed sensor that is configured to measure a speed of the vehicle; and

a steering angle sensor that is configured to measure a steering angle of the vehicle, wherein

the state detection unit is configured to detect a running state of the vehicle as the stable state when an estimated acceleration obtained based on the speed and the steering angle is equal to or lower than a second set acceleration, and to detect the running state of the vehicle as an unstable state when the estimated acceleration is higher than the second set acceleration.

3. The control device for the vehicle seat belt according to claim 1, wherein

the vehicle is further provided with a side skid suppression unit configured to suppress a side skid of the vehicle and to output an actuation signal to the state detection unit in suppressing the side skid, and

the state detection unit is configured to detect a running state of the vehicle as the stable state when the actuation signal is not input to the state detection unit, and to detect the running state of the vehicle as an unstable state when the actuation signal is input to the state detection unit.

4. The control device for the vehicle seat belt according to claim 1, further comprising:

a friction coefficient estimation unit that is configured to estimate a friction coefficient of a road surface on which the vehicle runs, wherein

the control unit is configured to reduce the first set acceleration when the friction coefficient estimated by the friction coefficient estimation unit is lower than a set friction coefficient.

5. The control device for the vehicle seat belt according to claim 4, wherein

the control unit is configured to lengthen at least one of the first set time and the second set time when the friction coefficient estimated by the friction coefficient estimation unit is lower than the set friction coefficient.

6. The control device for the vehicle seat belt according to claim 1, further comprising:

a friction coefficient estimation unit that is configured to estimate a friction coefficient of a road surface on which the vehicle runs, wherein

the control unit is configured to lengthen at least one of the first set time and the second set time when the friction coefficient estimated by the friction coefficient estimation unit is lower than a set friction coefficient.