Method for correcting the vehicle G sensor output value and for detecting G sensor failure

• US 6,253,602 B1
• Filed: 12/21/1998
• Issued: 07/03/2001
• Est. Priority Date: 12/24/1997
• Status: Expired due to Fees

• Current Assignee: Nisshinbo Industries, Inc. (Kawasaki Heavy Industries Limited)
• Original Assignee: Nisshinbo Industries, Inc. (Kawasaki Heavy Industries Limited)
• Inventors: Uchida, Kazuma
• Primary Examiner(s): Dombroske, George
• Application Number:
  US09/216,846
• Time in Patent Office: 925 Days
• Field of Search: 731/16, 731/172, 731/173, 731/181, 73/11.3, 73/13.7, 701/29, 701/30, 701/31, 701/34, 701/35, 701/124
• US Class Current: 73/115.08
• CPC Class Codes: B60T 17/221 Procedure or apparatus for checking or keeping in a correct functioning condition of brake systems hydraulic pressure systems in general F15B19/00, F15B21/04; testing structures or apparatus G01M
• 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: G01P 15/00 Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration

Abstract

A method for correction of the G sensor output of a vehicle. The method is for a vehicle equipped with a G sensor, a wheel speed sensor to detect the rotational speed of a wheel of the vehicle, and an electronic control device conducting computations from the signals received from the G sensor and the wheel speed sensor. The method includes steps of determining the acceleration/deceleration at every predetermined time and the G sensor output value, determining the G sensor zero point from the G sensor output value, and determining the current G sensor zero point based on the G sensor zero point which is determined before the predetermined time.

Claims

1. A method for correcting a G sensor output value for a vehicle, the vehicle including a G sensor, a wheel speed sensor determining wheel rotational speed for a wheel of the vehicle, and an electronic control device receiving signals form the G sensor and the wheel speed sensor and conducting computations therefrom, the method comprising the steps of:

determining the zero point of the G sensor from wheel acceleration/deceleration and an output value of the G sensor for each predetermined cycle; and

determining a current zero point of the G sensor for a current cycle based on the zero point of the G sensor determined in a cycle prior to the current cycle and the zero point of the G sensor determined in a cycle prior to said cycle prior to the current cycle.

2. A method for correcting the G sensor output value claimed in claim 1, wherein the method further comprises a step of:

determining the zero point of the G sensor by applying to the wheel acceleration/deceleration and the G sensor output value, the formula, Zero Point of G Sensor=(Wheel Acceleration/Deceleration)/Slope Coefficient+G Sensor Output Value.

3. A method for correcting the G sensor output value as claimed in claim 1, wherein the method further comprises a step of:

determining the zero point of the G sensor only when the difference between the wheel speed of a wheel with the maximum wheel speed and the wheel speed of a wheel with the minimum wheel speed is less than a predetermined value.

4. A method for correcting the G sensor output value as claimed in claim 1, wherein

the G sensor output value is an average value determined within a predetermined short period of time and

the acceleration/deceleration is an average acceleration/deceleration within the predetermined short period of time.

5. A method for determining acceleration/deceleration of a vehicle, the vehicle including a G sensor, a wheel speed sensor determining wheel rotational speed, and an electronic control device receiving signals from the G sensor and the wheel speed sensor and conducting computations, wherein the method comprises the steps of:

determining the wheel acceleration/deceleration and a G sensor output value at every predetermined interval,

determining the differences of the wheel acceleration/deceleration before and after the predetermined interval and the differences of the G sensor output value,

determining the slope coefficient for the G sensor based on the ratio of the differences, and

determining the vehicle acceleration/deceleration from the G sensor output value modified by the slope coefficient.

6. A method for determining acceleration/deceleration of a vehicle as claimed in claim 5, wherein the method further comprises the steps of:

determining maximum wheel speed and minimum wheel speed at every vehicle wheel and

determining the slope coefficient of the G sensor whenever the speed difference between said maximum and minimum wheel speeds is less than a predetermined value.

7. A method for determining acceleration/deceleration of a vehicle as claimed in claim 5, wherein the G sensor output value is an average value determined within the predetermined interval.

8. A method for determining acceleration/deceleration of a vehicle as claimed in claim 5, wherein the method further comprises the step of:

determining a slope coefficient when the G sensor output value before and after the predetermined interval or the absolute value of the wheel acceleration/deceleration difference is larger than a predetermined value.

9. A method for detecting the G sensor failure for a vehicle, the vehicle including a G sensor, a wheel speed sensor determining wheel rotational speed and an electronic control device receiving signals from the G sensor and the wheel speed sensor and conducting computations, wherein the method comprises the steps of:

determining a wheel acceleration/deceleration and a G sensor output value at every predetermined interval,

determining differences of the wheel acceleration/deceleration before and after the predetermined interval,

determining the differences of the G sensor output value,

determining the slope coefficient of the G sensor based on the ratio of the differences, and

detecting the G sensor failure whenever the slope coefficient is determined to be outside a predetermined value range.

10. A method for detecting the G sensor failure for a vehicle, the vehicle including a G sensor, a wheel speed G sensor determining wheel rotation speed, and an electronic control device receiving signals from the G sensor and the wheel speed sensor and conducting computations, wherein the method comprises the steps of:

determining a value at the zero point of the G sensor processed by a low pass filter when the value of the zero point of the G sensor is approximately same as the absolute value determined by the G sensor and a vehicle speed is larger than a predetermined value and

detecting said G sensor failure in case of said value determined by the low pass filter is not within a predetermined value range.