BRAKE CONTROL METHOD AND BRAKE CONTROL DEVICE

• US 20080114520A1
• Filed: 11/14/2007
• Published: 05/15/2008
• Est. Priority Date: 11/14/2006
• Status: Active Grant

• Current Assignee: Yokohama Rubber Company Limited
• Original Assignee: Yokohama Rubber Company Limited
• Inventors: Miyashita, Naoshi, Hashimura, Yoshiaki, Matsuda, Jun, Kitazaki, Tsuyoshi
• Granted Patent: US 7,957,879 B2
• Time in Patent Office: Days
• US Class Current: 701/82
• CPC Class Codes: B60T 2210/12 Friction
• CPC Class Codes: B60T 8/172 Determining control parameters used in the regulation, e.g. by calculations involving measured or detected parameters B60T8/17551 takes precedence
• CPC Class Codes: B60T 8/17616 Microprocessor-based systems
• CPC Class Codes: Y10T 152/10 Tires, resilient
• CPC Class Codes: Y10T 152/10279 Cushion

Abstract

A brake control device is provided to a wheel equipped with a tire, which has a function of applying a brake force to the wheel to put a brake thereon while adjusting the brake force. In the device, an acceleration sensor outputs acceleration data in a radial direction of the rotating tire, a predetermined detection range is set with respect to the acceleration data, a threshold value is set with respect to a corresponding part of the acceleration data falling within the detection range, the corresponding part of the acceleration data falling within the detection range is specified. Values of the specified acceleration data are compared with the threshold value, and a control signal for causing a braking device to adjust the brake force thereof is output in a case where some values of the acceleration data are larger than the threshold value.

Claims

1. A brake control method for a braking device having a function of applying a brake force to a wheel equipped with a tire to put a brake on a vehicle while adjusting the brake force, the brake control method comprising the steps of:

acquiring, in time series, acceleration data of acceleration applied to the tire in a radial direction of the tire;

setting a predetermined detection range with respect to the acceleration data and setting a threshold value with respect to values of corresponding part of the acceleration data falling within the predetermined detection range;

specifying the corresponding part of the acceleration data falling within the predetermined detection range; and

controlling, when a value or values of the specified part of the acceleration data exceeds or exceed the threshold value, the brake force to be applied to the wheel as a control target.

2. The brake control method according to claim 1, wherein in the step of setting the predetermined detection range, when a timing at which a leading peak in the acceleration data occurs in a vicinity of a leading edge of a contact region of the tire on a ground is determined to be set as a first timing, a timing at which a trailing peak in the acceleration data occurs in a vicinity of a trailing edge of the contact region of the tire is determined to be set as a second timing, and a midway timing between the first timing and the second timing is set as a reference timing, a certain section accounting for 10 to 100% of a section defined between the first timing and the second timing with the reference timing being located in a center of the section is defined, and the defined certain section is set as the predetermined detection range.

3. The brake control method according to claim 2, wherein:

in the step of specifying the corresponding part of the acceleration data falling within the predetermined detection range, a start timing and a finish timing of the predetermined detection range are associated with peak positions in an output signal which has a predetermined number of peaks which are generated in one rotation of the wheel, to thereby specify the corresponding part of the acceleration data.

4. The brake control method according to claim 1, wherein the threshold value corresponds to a certain value falling within a range which accounts for 10 to 100% of a value of the leading peak or a value of the trailing peak in the acceleration data, in a state where the wheel is not applied with a brake force.

5. A brake control device, comprising:

a braking device provided to a wheel equipped with a tire, the braking device having a function of applying a brake force to the wheel to put a brake thereon while adjusting the brake force;

an acceleration sensor for outputting time series acceleration data of acceleration acting on the tire in a radial direction of the tire;

a control unit provided with a detection range setting unit to which the acceleration data is supplied, the detection range setting unit setting a predetermined detection range with respect to the supplied acceleration data and setting a threshold value with respect to values of a corresponding part of the acceleration data falling within the predetermined detection range, the control unit specifying the corresponding part of the acceleration data falling within the predetermined detection range, comparing a value or values of the specified part of the acceleration data with the threshold value, and outputting, in a case where the value or the values of the specified part of the acceleration data exceeds or exceed the threshold value, a control signal for causing the braking device to adjust the brake force.

6. The brake control device according to claim 5, wherein,

in the acceleration data, when a timing at which a leading peak occurs in a vicinity of a leading edge of a contact region of the tire on a ground is generated is set as a first timing, a timing at which a trailing peak occurs in a vicinity of a trailing edge of the contact region of the tire is set as a second timing, and a midway timing between the first timing and the second timing is set as a reference timing, the detection range setting unit defines a certain section accounting for 10 to 100% of a section defined between the first timing and the second timing with the reference timing being located in a center of the section and sets the section as the predetermined detection range.

7. The brake control device according to claim 6, wherein:

the control unit specifies the corresponding part of the acceleration data falling within the predetermined detection range, by obtaining an output signal which has a predetermined number of peaks generated in one rotation of the wheel, and by associating a start timing and a finish timing of the predetermined detection range with peak positions in the output signal.

8. The brake control device according to claim 5, wherein the threshold value corresponds to a certain value falling within a range which accounts for 10 to 100% of a value of the leading peak or a value of the trailing peak in the acceleration data, in a state where the wheel is not applied with a brake force.