In-vehicle device for detecting driving condition and computer program product for use in the same

• US 20070118257A1
• Filed: 08/08/2006
• Published: 05/24/2007
• Est. Priority Date: 11/18/2005
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Iida, Masahiro
• Granted Patent: US 7,603,213 B2
• Time in Patent Office: Days
• US Class Current: 701/29
• CPC Class Codes: G07C 5/085 using electronic data carriers

Abstract

An in-vehicle device for detecting a driving condition includes: first and second sensors for detecting one of acceleration and angular speed; first and second determination units for determining whether a detection signal from each sensor is varied with a frequency equal to or larger than a predetermined determination frequency and with a variation amount larger than a predetermined variation threshold; and a vibration noise removal unit for determining that a vibration noise is superimposed on each detection signal. The vibration noise removal unit removes the vibration noise from each detection signal.

Claims

1. An in-vehicle device for detecting a driving condition of an automotive vehicle comprising:

a first sensor for detecting one of acceleration of the vehicle and angular speed of the vehicle, wherein the angular speed is defined around a predetermined axis of the vehicle;

a second sensor for detecting one of the acceleration of the vehicle and the angular speed of the vehicle;

a first determination unit for determining whether a first detection signal from the first sensor is varied with a first frequency equal to or larger than a predetermined first determination frequency and with a first variation amount larger than a predetermined first variation threshold;

a second determination unit for determining whether a second detection signal from the second sensor is varied with a second frequency equal to or larger than a predetermined second determination frequency and with a second variation amount larger than a predetermined second variation threshold; and

a vibration noise removal unit for determining that a vibration noise caused by vertical vibration of the vehicle is superimposed on each detection signal of the first and second sensors when both of the first and second determination units determine that each detection signal is varied with the frequency equal to or larger than the determination frequency and with the variation amount larger than the variation threshold, wherein

the vibration noise removal unit removes the vibration noise from each detection signal when the vibration noise removal unit determines that the vibration noise is superimposed on each detection signal, and

the vibration noise is defined by the determination frequency and the variation threshold.

2. The device according to claim 1, wherein

each of the first and second determination units samples multiple sampling data from each detection signal in a predetermined sampling period corresponding to the determination frequency,

each of the first and second determination units calculates a difference between a maximum sampling data and a minimum sampling data in multiple sampling data, and

each of the first and second determination units determines that the vibration noise is superimposed on each detection signal when the difference is larger than the variation threshold.

3. The device according to claim 2, wherein

the vibration noise removal unit calculates first and second center data in multiple sampling data, and

the vibration noise removal unit removes the vibration noise in such a manner that the first and second center data are set to be current first and second detection data from the first and second sensors.

4. The device according to claim 1, further comprising:

an image capture unit for capturing an image around the vehicle; and

a vehicle vibration determination unit for determining whether the vehicle vibrates with a vehicle vibration frequency and with a vehicle vibration amount on the basis of a change of the image from the image capture unit, wherein vibration of the vehicle with the vehicle vibration frequency and the vehicle vibration amount affects each detection signal from the first and second sensors, wherein

the vibration noise removal unit removes the vibration noise from each detection signal when the vehicle vibration determination unit determines that the vibration of the vehicle affects each detection signal from the first and second sensors and when the vibration noise removal unit determines that the vibration noise is superimposed on each detection signal.

5. The device according to claim 4, wherein

each of the first and second determination units samples multiple sampling data from each detection signal in a predetermined sampling period corresponding to the determination frequency,

each of the first and second determination units calculates a difference between a maximum sampling data and a minimum sampling data in multiple sampling data,

each of the first and second determination units determines that the vibration noise is superimposed on each detection signal when the difference is larger than the variation threshold,

the first determination frequency is substantially equal to the second determination frequency, and

the first determination frequency is substantially equal to the vehicle vibration frequency.

6. The device according to claim 5, wherein

the vibration noise removal unit calculates first and second center data in multiple sampling data, and

the vibration noise removal unit removes the vibration noise in such a manner that the first and second center data are set to be current first and second detection data from the first and second sensors.

7. The device according to claim 1, wherein

the in-vehicle device is a part of a navigation device.

8. An in-vehicle device for detecting a driving condition of an automotive vehicle comprising:

a sensor for detecting one of acceleration of the vehicle and angular speed of the vehicle, wherein the angular speed is defined around a predetermined axis of the vehicle;

an image capture unit for capturing an image around the vehicle;

a determination unit for determining whether a detection signal from the sensor is varied with a frequency equal to or larger than a predetermined determination frequency and with a variation amount larger than a predetermined variation threshold;

a vehicle vibration determination unit for determining whether the vehicle vibrates with a vehicle vibration frequency and with a vehicle vibration amount on the basis of a change of the image from the image capture unit, wherein vibration of the vehicle with the vehicle vibration frequency and the vehicle vibration amount affects the detection signal from the sensor; and

a vibration noise removal unit for determining that a vibration noise caused by vertical vibration of the vehicle is superimposed on the detection signal when the determination unit determines that the detection signal is varied with the frequency equal to or larger than the determination frequency and with the variation amount larger than the variation threshold and when the vehicle vibration determination unit determines that the vibration of the vehicle affects the detection signal from the sensor, wherein

the vibration noise removal unit removes the vibration noise from the detection signal when the vibration noise removal unit determines that the vibration noise is superimposed on each detection signal, and

the vibration noise is defined by the determination frequency and the variation threshold.

9. The device according to claim 8, wherein

the determination unit samples multiple sampling data from the detection signal in a predetermined sampling period corresponding to the determination frequency,

the determination unit calculates a difference between a maximum sampling data and a minimum sampling data in multiple sampling data, and

the determination units determines that the vibration noise is superimposed on the detection signal when the difference is larger than the variation threshold.

10. The device according to claim 9, wherein

the vibration noise removal unit calculates a center data in multiple sampling data, and

the vibration noise removal unit removes the vibration noise in such a manner that the center data is set to be a current detection data from the sensor.

11. The device according to claim 8, wherein

the in-vehicle device is a part of a navigation device.

12. A computer program product in a computer readable medium for use in an in-vehicle device for detecting a driving condition of an automotive vehicle, the product comprising:

an instruction for detecting one of acceleration of the vehicle and angular speed of the vehicle with a first sensor, wherein the angular speed is defined around a predetermined axis of the vehicle;

an instruction for detecting one of the acceleration of the vehicle and the angular speed of the vehicle with a second sensor;

an instruction for determining with a first determination unit whether a first detection signal from the first sensor is varied with a first frequency equal to or larger than a predetermined first determination frequency and with a first variation amount larger than a predetermined first variation threshold;

an instruction for determining with a second determination unit whether a second detection signal from the second sensor is varied with a second frequency equal to or larger than a predetermined second determination frequency and with a second variation amount larger than a predetermined second variation threshold; and

an instruction for determining with a vibration noise removal unit that a vibration noise caused by vertical vibration of the vehicle is superimposed on each detection signal when both of the first and second determination units determine that each detection signal is varied with the frequency equal to or larger than the determination frequency and with the variation amount larger than the variation threshold, wherein

the vibration noise removal unit removes the vibration noise from each detection signal when the vibration noise removal unit determines that the vibration noise is superimposed on each detection signal, and

the vibration noise is defined by the determination frequency and the variation threshold.

13. A computer program product in a computer readable medium for use in an in-vehicle device for detecting a driving condition of an automotive vehicle, the product comprising:

an instruction for detecting one of acceleration of the vehicle and angular speed of the vehicle with a sensor, wherein the angular speed is defined around a predetermined axis of the vehicle;

an instruction for capturing an image around the vehicle with an image capture unit;

an instruction for determining with a determination unit whether a detection signal from the sensor is varied with a frequency equal to or larger than a predetermined determination frequency and with a variation amount larger than a predetermined variation threshold;

an instruction for determining with a vehicle vibration determination unit whether the vehicle vibrates with a vehicle vibration frequency and with a vehicle vibration amount on the basis of a change of the image from the image capture unit, wherein vibration of the vehicle with the vehicle vibration frequency and the vehicle vibration amount affects the detection signal from the sensor; and

an instruction for determining with a vibration noise removal unit that a vibration noise caused by vertical vibration of the vehicle is superimposed on the detection signal when the determination unit determines that the detection signal is varied with the frequency equal to or larger than the determination frequency and with the variation amount larger than the variation threshold and when the vehicle vibration determination unit determines that the vibration of the vehicle affects the detection signal from the sensor, wherein

the vibration noise removal unit removes the vibration noise from the detection signal when the vibration noise removal unit determines that the vibration noise is superimposed on each detection signal, and

the vibration noise is defined by the determination frequency and the variation threshold.