Moving state detecting device

• US 10,012,672 B2
• Filed: 04/19/2010
• Issued: 07/03/2018
• Est. Priority Date: 05/19/2009
• Status: Active Grant

• Current Assignee: Furuno Electric Co, Ltd
• Original Assignee: Furuno Electric Co, Ltd
• Inventors: Toda, Hiroyuki, Yoshitake, Ken
• Primary Examiner(s): Kuan, John
• Application Number:
  US13/265,762
• Publication Number:
  US 20120041702A1
• Time in Patent Office: 2,997 Days
• CPC Class Codes: G01C 21/185 for gravity
• CPC Class Codes: G01P 21/00 Testing or calibrating of apparatus or devices covered by the preceding groups

Abstract

To accurately calculate an attached angle of an accelerometer and accurately correct an acceleration that is obtained from the accelerometer: a frequency analyzing module of an acceleration corrector divides a sensor coordinate system acceleration into a bias frequency component, a gravity frequency component, a movement acceleration frequency component, and a noise frequency component, through a wavelet transform. The frequency analyzing module outputs a sum component of the gravity frequency component and the movement acceleration frequency component to an attached angle estimating module and a correcting operation module. The attached angle estimating module estimation-calculates the attached angle of an accelerometer and outputs it to the correcting operation module. The correcting operation module corrects the acceleration, which is including of the sum component of the gravity frequency component and the movement acceleration frequency component, based on the estimation-calculated attached angle to calculate a movable body coordinate system acceleration.

Claims

1. A moving state detecting device, comprising:

an accelerometer installed in a vehicle, the accelerometer being configured to detect acceleration components of a measured acceleration of the vehicle as measured by the accelerometer, with

a front-and-rear direction acceleration component,

a left-and-right direction acceleration component, and

an up-and-down direction acceleration component, all of which are perpendicular to each other respectively; and

processing circuitry configured

to divide, for a plurality of frequency bands, the measured acceleration that is obtained from the accelerometer, and

to estimate an attached angle, at which the accelerometer is physically attached to the vehicle, based on

a gravity frequency component, and

a movement acceleration frequency component that are formed by predetermined frequency band components, respectively,

the processing circuitry being further configured

to evaluate movement of the vehicle based on the acceleration components detected by the accelerometer,

to determine that the vehicle is traveling straight in a front-and-rear direction when the left-and-right direction acceleration component is below a predetermined threshold,

to select, based on the evaluated movement of the vehicle, one of performing vehicle straight traveling processing to correct the estimated attached angle of the accelerometer when the vehicle is traveling straight and refraining from performing the vehicle straight traveling processing, and

upon selecting to perform the vehicle straight traveling processing, perform, while the vehicle is traveling straight, at least one of

an azimuth direction estimation of the attached angle in an azimuth direction based on the front-and-rear direction acceleration component and the left-and-right direction acceleration component, and

a pitch direction estimation of the attached angle in a pitch direction based on the front-and-rear direction acceleration component and the up-and-down direction acceleration component, and

the processing circuitry being further configured to, upon selecting to perform the vehicle straight traveling processing;

correct the estimated attached angle of the accelerometer based on at least one of the azimuth direction estimation and the pitch direction estimation to generate a corrected estimated attached angle, and

correct the measured acceleration of the vehicle based on the corrected estimated attached angle to provide a corrected acceleration value representing the acceleration of the vehicle;

wherein the moving state detecting device further comprises a vehicle navigation system configured to provide real-time navigation guidance for the vehicle based on the corrected acceleration value.

2. The moving state detecting device of claim 1, wherein

the processing circuitry estimates at least one of the attached angle in the azimuth direction and the attached angle in the pitch direction when the left-and-right direction acceleration component is below the predetermined threshold.

3. The moving state detecting device of claim 1, wherein

when the left-and-right direction acceleration component is above the predetermined threshold, the processing circuitry estimates a roll direction attached angle of the vehicle.

4. The moving state detecting device of claim 1, wherein

the accelerometer is configured to detect the acceleration components in each of a plurality of axes;

and

the processing circuitry is configured to estimate the attached angle of the accelerometer when the acceleration components indicate that the vehicle is traveling straight or turning.

5. A moving state detecting device, comprising:

an accelerometer installed in a vehicle,

the accelerometer being configured to detect acceleration components of a measured acceleration of the vehicle as measured by the accelerometer, with a front-and-rear direction acceleration component, a left-and-right direction acceleration component, and an up-and-down direction acceleration component, all of which are perpendicular to each other respectively; and

processing circuitry configured to

divide, for a plurality of frequency bands, an acceleration that is obtained from the accelerometer, and

estimate an attached angle, at which the accelerometer is physically attached to the vehicle, based on a gravity frequency component and a movement acceleration frequency component that are formed by predetermined frequency band components, respectively,

the processing circuitry being further configured

to evaluate movement of the vehicle based on the acceleration components detected by the accelerometer, to determine that the vehicle is traveling straight in a front-and-rear direction when the left-and-right direction acceleration component is below a predetermined threshold, and to determine that the vehicle is turning when the left-and-right direction acceleration component is above the predetermined threshold,

to select, based on the evaluated movement of the vehicle, one of performing vehicle straight traveling processing to correct the estimated attached angle of the accelerometer when the vehicle is traveling straight and performing vehicle turning processing to correct the estimated attached angle of the accelerometer when the vehicle is turning,

upon selecting to perform the vehicle straight traveling processing, the processing circuitry;

estimating, while the vehicle is traveling straight, an azimuth direction estimation of the attached angle in an azimuth direction based on the front-and-rear direction acceleration component and the left-and-right direction acceleration component,

estimating, while the vehicle is traveling straight, a pitch direction estimation of the attached angle in a pitch direction based on the front-and-rear direction acceleration component and the up-and-down direction acceleration component, and

correcting the estimated attached angle of the accelerometer based on the azimuth direction estimation and the pitch direction estimation to generate a corrected estimated attached angle;

upon selecting to perform the vehicle turning processing, the processing circuitry;

estimating, while the vehicle is turning, a roll direction estimation of the attached angle in a roll direction based on the front-and-rear direction acceleration component, the left-and-right direction acceleration component, the up-and-down direction acceleration component, and the pitch direction estimation of the attached angle, and

correcting the estimated attached angle of the accelerometer based on the roll direction estimation to generate the corrected estimated attached angle; and

to correct the measured acceleration of the vehicle based on the corrected estimated attached angle to provide a corrected acceleration value representing the acceleration of the vehicle;

wherein the moving state detecting device further comprises a vehicle navigation system configured to provide real-time navigation guidance for the vehicle based on the corrected acceleration value.

6. The moving state detecting device of claim 5, wherein

when the left-and-right direction acceleration component is below the predetermined threshold, the processing circuitry estimates at least one of the attached angle in the azimuth direction and the attached angle in the pitch direction.

7. The moving state detecting device of claim 5, wherein

the accelerometer is configured to detect the acceleration components in each of a plurality of axes;

and

the processing circuitry is configured to estimate the attached angle of the accelerometer when the acceleration components indicate that the vehicle is traveling straight or turning.

8. A moving state detecting device, comprising:

an accelerometer installed in a vehicle to detect a measured acceleration of the vehicle as measured by the accelerometer; and

processing circuitry configured to divide, for a plurality of frequency bands, the measured acceleration that is obtained from the accelerometer, estimate an attached angle, at which the accelerometer is physically attached to the vehicle, based on a gravity frequency component and a movement acceleration frequency component that are formed by predetermined frequency band components, respectively, and correct the measured acceleration of the vehicle based on the attached angle to provide a corrected acceleration value representing the acceleration of the vehicle; and

the processing circuitry being further configured to select, based on a physical operating condition of the vehicle, to calculate a speed of the vehicle, a traveling pitch angle of the vehicle serving as an up-and-down direction inclination angle of the vehicle, or both the speed of the vehicle and the traveling pitch angle of the vehicle, based on the corrected acceleration as corrected by the processing circuitry, and when the processing circuitry selects to calculate the traveling pitch angle, the processing circuitry calculates a divided value of the gravity frequency component by a gravity acceleration and corrects the calculated traveling pitch angle at which the vehicle is traveling based on the divided value to generate a corrected traveling pitch angle value representing a pitch angle at which the vehicle is traveling;

wherein the moving state detecting device further comprises a vehicle navigation system configured to provide real-time navigation guidance for the vehicle based on the corrected acceleration value.

9. The moving state detecting device of claim 8, wherein

the processing circuitry is configured to correct the calculated traveling pitch angle by performing a weight averaging processing between the traveling pitch angle and the corrected traveling pitch angle.

10. A moving state detecting device, comprising:

an accelerometer installed in a vehicle to detect a measured acceleration of the vehicle as measured by the accelerometer; and

processing circuitry configured to divide, for a plurality of frequency bands, the measured acceleration that is obtained from the accelerometer, estimate an attached angle, at which the accelerometer is physically attached to the vehicle, based on a gravity frequency component and a movement acceleration frequency component that are formed by predetermined frequency band components, respectively, and correct the measured acceleration of the vehicle based on the attached angle to provide a corrected acceleration value representing the acceleration of the vehicle;

the processing circuitry being further configured to sequentially store the estimated attached angle as well as correct the estimated attached angle through time averaging processing, and, to select whether to reduce a weight of a previously estimated attached angle in the time average processing or to refrain from reducing the weight of the previously estimated attached angle in the time average processing, by evaluating if a latest estimated attached angle is different from the previously estimated attached angle by a predetermined angle or above, and the processing circuitry reduces the weight of the previously estimated attached angle in the time averaging processing when the processing determines by the evaluating that the latest estimated attached angle is different from the previously estimated attached angle by the predetermined angle or above;

wherein the moving state detecting device further comprises a vehicle navigation system configured to provide real-time navigation guidance for the vehicle based on the corrected acceleration value.

11. A moving state detecting device, comprising:

an accelerometer installed in a vehicle and configured to detect multi-axial acceleration components of a measured acceleration of the vehicle as measured by the accelerometer; and

processing circuitry configured;

to evaluate movement of the vehicle based on the acceleration components detected by the accelerometer, to determine that the vehicle is traveling straight in a front-and-rear direction when a left-and-right direction acceleration component is below a predetermined threshold,

to select, based on the evaluated movement of the vehicle, one of performing vehicle straight traveling processing to correct an estimated attached angle of the accelerometer when the vehicle is traveling straight and refraining from performing the vehicle straight traveling processing, and

upon selecting to perform the vehicle straight traveling processing, the processing circuitry;

dividing, for a plurality of frequency bands, the measured acceleration of the vehicle that is obtained from the accelerometer,

estimating the attached angle, at which the accelerometer is physically attached to the vehicle, at least in a pitch direction based on a gravity frequency component and a movement acceleration frequency component while the vehicle is traveling straight, and

correcting the measured acceleration of the vehicle based on the attached angle to provide a corrected acceleration value representing the acceleration of the vehicle;

wherein the moving state detecting device further comprises a vehicle navigation system configured to provide real-time navigation guidance for the vehicle based on the corrected acceleration value.

12. A moving state detecting device comprising:

an accelerometer installed in a vehicle and configured to detect multi-axial acceleration components of a measured acceleration of the vehicle as measured by the accelerometer; and

processing circuitry configured;

to evaluate movement of the vehicle based on the acceleration components detected by the accelerometer, to determine that the vehicle is traveling straight in a front-and-rear direction when a left-and-right direction acceleration component is below a predetermined threshold, and to determine that the vehicle is turning when the left-and-right direction acceleration component is above the predetermined threshold,

to select, based on the evaluated movement of the vehicle, one of performing vehicle straight traveling processing to correct an estimated attached angle of the accelerometer when the vehicle is traveling straight and performing vehicle turning processing to correct the estimated attached angle of the accelerometer when the vehicle is turning,

upon selecting to perform the vehicle straight traveling processing, the processing circuitry;

estimating the attached angle, at which the accelerometer is physically attached to the vehicle, in a yaw direction based on front-and-end direction acceleration components and left-and-right direction acceleration components while the vehicle is traveling straight, and

estimating the attached angle of the accelerometer in a pitch direction based on the front-and-end direction acceleration components and up-and-down direction acceleration components while the vehicle is traveling straight,

upon selecting to perform the vehicle turning processing, the processing circuitry estimating the attached angle of the accelerometer in a roll direction based on the front-and-end direction acceleration components, the left-and-right direction acceleration components, the up-and-down direction acceleration components, and the attached angle of the accelerometer in a pitch direction, and

to correct the measured acceleration of the vehicle based on the estimated attached angle in the yaw direction, the pitch direction and the roll direction to provide a corrected acceleration value representing the acceleration of the vehicle;

wherein the moving state detecting device further comprises a vehicle navigation system configured to provide real-time navigation guidance for the vehicle based on the corrected acceleration value.