EP-4741769-A1 - OFFSET ERROR CALCULATION FOR A THREE-AXIS ACCELERATION SENSOR

Abstract

To provide an attitude estimation system for an automobile and an offset error calculation method for a three-axis acceleration sensor for correcting an error caused depending on the mounting attitude of an acceleration sensor with respect to an automobile, using a three-axis acceleration sensor, a Roll angle Roll_A and a Pitch angle Pitch_A are measured in a state where an automobile is parked with a forward orientation in a parking lot, where a Roll angle Roll_B and a Pitch angle Pitch_B are measured in a state where the automobile is parked with an opposite orientation in the parking lot, and the average of Roll_A and Roll_B is set as an offset error in the Roll direction, and the average of Pitch_A and Pitch_B is set as an offset error in the pitch direction.

Inventors

• Obara, Masanori

Assignees

• Alps Alpine Co., Ltd.

Dates

Publication Date

20260513

Application Date

20251027

Claims (5)

1. An attitude estimation system, comprising: a three-axis acceleration sensor fixed to an automobile; a processor; and a memory, wherein the processor is configured to: calculate a roll angle of the automobile, using the three-axis acceleration sensor; set an offset error for roll angle measurement for the automobile using the three-axis acceleration sensor; and correct the calculated roll angle of the automobile such that the offset error is canceled, and wherein, when setting the offset error, the processor is configured to set, as the offset error, an average of a first roll angle measured using the three-axis acceleration sensor in a state where the automobile is parked at a first location with a first orientation and a second roll angle measured using the three-axis acceleration sensor in a state where the automobile is parked at the first location with a second orientation opposite to the first orientation.
2. An attitude estimation system, comprising: a three-axis acceleration sensor fixed to an automobile; a processor; and a memory, wherein the processor is configured to: calculate a pitch angle of the automobile, using the three-axis acceleration sensor; set an offset error for pitch angle measurement for the automobile using the three-axis acceleration sensor; and correct the calculated pitch angle of the automobile such that the offset error is canceled, and wherein, when setting the offset error, the processor is configured to set, as the offset error, an average of a first pitch angle measured using the three-axis acceleration sensor in a state where the automobile is parked at a first location with a first orientation and a second pitch angle measured using the three-axis acceleration sensor in a state where the automobile is parked at the first location with a second orientation opposite to the first orientation.
3. An attitude estimation system, comprising: a three-axis acceleration sensor fixed to an automobile; a processor; and a memory, wherein the processor is configured to: calculate a roll angle and a pitch angle of the automobile, using the three-axis acceleration sensor; set an offset error for roll angle measurement and an offset error for pitch angle measurement for the automobile using the three-axis acceleration sensor; and correct the calculated roll angle of the automobile such that the offset error for the roll angle measurement is canceled, and correct the calculated pitch angle of the automobile such that the offset error for the pitch angle measurement is canceled, and wherein, when setting the offset errors, the processor is configured to set, as the offset error for the roll angle measurement, an average of a first roll angle measured using the three-axis acceleration sensor in a state where the automobile is parked at a first location with a first orientation and a second roll angle measured using the three-axis acceleration sensor in a state where the automobile is parked at the first location with a second orientation opposite to the first orientation, and to set, as the offset error for the pitch angle measurement, an average of a first pitch angle measured using the three-axis acceleration sensor in a state where the automobile is parked at the first location with the first orientation and a second pitch angle measured using the three-axis acceleration sensor in a state where the automobile is parked at the first location with the second orientation.
4. The attitude estimation system according to one of claims 1 to 3, wherein the processor is further configured to: guide a driver of the automobile to park at the first location with the first orientation, and guide the driver to park at the first location with the second orientation, where the first location is a parking lot bounded by delimiting lines.
5. An offset error calculation method for a three-axis acceleration sensor used in the attitude estimation system of one of claims 1 to 4, the offset error calculation method comprising: measuring an inclination angle with respect to a horizontal direction as a first inclination angle, using a three-axis acceleration sensor fixed to the automobile, in a state where the automobile is parked at a first location with a first orientation; measuring an inclination angle with respect to the horizontal direction as a second inclination angle, using the three-axis acceleration sensor, in a state where the automobile is parked at the first location with a second orientation opposite to the first orientation; and calculating an average of the first inclination angle and the second inclination angle, as an inclination angle offset error of the inclination angle measured by the three-axis acceleration sensor with respect to the horizontal direction of the automobile.

Description

The present application claims priority to Japanese Patent Application No. 2024-196055, filed November 8, 2024. The present invention relates to an attitude estimation system for an automobile. As a technique related to an attitude estimation system for estimating the attitude of an automobile, a technique known in a system for calculating the pitch angle of an automobile using an acceleration sensor determines the attitude of the acceleration sensor when mounted on the automobile (the mounting attitude, the attitude with respect to the automobile) such that the amount of azimuth change measured using a GPS receiver and the amount of azimuth change measured using a gyro sensor fixed on the same base as that on which the acceleration sensor is fixed will match, and corrects the pitch angle calculated using the acceleration sensor in accordance with the determined mounting attitude (for example, JP 2004-20207A) . According to the above-described technique for calculating the mounting attitude of the acceleration sensor with respect to the automobile and correcting the pitch angle calculated using the acceleration sensor, the gyro sensor and the GPS receiver are required for the correction, and a relatively large amount of time and processing is required for calculating the mounting attitude. Therefore, it is an object of the present invention to correct, with a simple configuration, an error caused depending on the mounting attitude of the acceleration sensor with respect to the automobile in the calculation of the attitude of the automobile using the acceleration sensor. The present disclosure relates to an attitude estimation system for an automobile according to the appended claims. Embodiments are disclosed in the dependent claims. According to an aspect, the present invention provides an attitude estimation system for an automobile, including: a three-axis acceleration sensor fixed to an automobile;a processor; anda memory,wherein the processor is configured to: calculate a roll angle of the automobile, using the three-axis acceleration sensor;set an offset error for roll angle measurement for the automobile using the three-axis acceleration sensor; andcorrect the calculated roll angle of the automobile such that the offset error is canceled, andwherein, when setting the offset error, the processor sets, as the offset error, an average of a first roll angle measured using the three-axis acceleration sensor in a state where the automobile is parked at a first location with a first orientation and a second roll angle measured using the three-axis acceleration sensor in a state where the automobile is parked at the first location with a second orientation opposite to the first orientation. According to a further aspect, the present invention provides an attitude estimation system for an automobile, including: a three-axis acceleration sensor fixed to an automobile;a processor; anda memory,wherein the processor is configured to: calculate a pitch angle of the automobile, using the three-axis acceleration sensor;set an offset error for pitch angle measurement for the automobile using the three-axis acceleration sensor; andcorrect the calculated pitch angle of the automobile such that the offset error is canceled, andwherein, when setting the offset error, the processor sets, as the offset error, an average of a first pitch angle measured using the three-axis acceleration sensor in a state where the automobile is parked at a first location with a first orientation and a second pitch angle measured using the three-axis acceleration sensor in a state where the automobile is parked at the first location with a second orientation opposite to the first orientation. According to a further aspect, the present invention provides an attitude estimation system for an automobile, including: a three-axis acceleration sensor fixed to an automobile;a processor; anda memory,wherein the processor is configured to: calculate a roll angle and a pitch angle of the automobile, using the three-axis acceleration sensor;set an offset error for roll angle measurement and an offset error for pitch angle measurement for the automobile using the three-axis acceleration sensor; andcorrect the calculated roll angle of the automobile such that the offset error for the roll angle measurement is canceled, and correct the calculated pitch angle of the automobile such that the offset error for the pitch angle measurement is canceled, andwherein, when setting the offset errors, the processor sets, as the offset error for the roll angle measurement, an average of a first roll angle measured using the three-axis acceleration sensor in a state where the automobile is parked at a first location with a first orientation and a second roll angle measured using the three-axis acceleration sensor in a state where the automobile is parked at the first location with a second orientation opposite to the first orientation, and sets, as the offset error for