CN104677355B - Virtual gyro and method based on Multi-sensor Fusion - Google Patents

Abstract

The invention discloses a virtual gyroscope based on multi-sensor fusion and its method, wherein the method includes the following steps: setting a first accelerometer whose detection direction is orthogonal in the same plane; setting a first accelerometer parallel to one of the detection directions, But the second accelerometer in different positions, and the third accelerometer parallel to the other detection direction but not in the same position form an acceleration combination sensor; a gyroscope is set at any position on the plane, and its detection direction is perpendicular to the plane ; Output the measured value of the combined acceleration sensor and gyroscope. The output of the optimized angular velocity is obtained by data fusion through the combination of the accelerometer and the output of the gyroscope. The angular velocity measurement accuracy of the entire system can be greatly improved.

Description

Virtual gyroscope and method based on multi-sensor fusion

technical field

The invention relates to the technical field of sensors, in particular to a virtual gyroscope and method based on multi-sensor fusion.

Background technique

With the increasing demand for inertial sensors, the requirements for the accuracy and power consumption of gyroscopes (angular velocity sensors) are also getting higher and higher. Although MEMS gyroscopes have the advantages of low cost and easy digitization, compared with accelerometers and other sensors, their power consumption is significantly higher. At the same time, with the enrichment of applications, the demand for high-precision gyroscopes is also increasing. The accuracy requirements of the current MEMS gyroscopes are gradually unable to meet their needs.

In order to make up for the deficiencies of MEMS gyroscopes in these aspects, several methods have been proposed. Someone once proposed to use a multi-gyroscope data fusion method to realize the scheme of using low-cost gyroscopes to build high-precision gyroscopes. But its disadvantage is that the power consumption of the multi-gyroscope system is too high. There are also proposals to use accelerometer calculations to build a gyro-free inertial system. The disadvantage is that the acceleration layout requires a three-dimensional layout, which not only requires high positional accuracy of the accelerometer layout, but also has a large volume for the entire system.

Contents of the invention

The technical problem to be solved by the present invention is to provide a virtual gyroscope technology based on multi-sensor fusion for the high power consumption and insufficient precision of the virtual gyroscope in the prior art. Fusion, the output of the optimized angular velocity value can be obtained, which can greatly improve the angular velocity measurement accuracy of the entire system.

The technical solution adopted by the present invention to solve its technical problems is:

A method for realizing a virtual gyroscope based on multi-sensor fusion is provided, comprising the following steps:

The first accelerometer whose detection direction is orthogonal in the same plane is set;

In this plane, a second accelerometer parallel to one of the detection directions but not at the same position, and a third accelerometer parallel to the other detection direction but not at the same position are arranged to form an acceleration combined sensor;

Outputs the measured values of the combined acceleration sensor and gyroscope.

In the method of the present invention, also comprise step:

According to the output measurement value, the state update and time update equations are constructed to perform Kalman filtering.

In the method of the present invention, the first accelerometer is a dual-axis accelerometer or two single-axis accelerometers with a co-location and an orthogonal detection direction in the same plane.

In the method of the present invention, the two detection directions of the first accelerometer are respectively along the X-axis direction and the Y-axis direction of the preset coordinate system, and the distance between the second accelerometer on the X-axis and the first accelerometer is The position of d1, the direction is parallel to the Y axis, the third accelerometer is placed on the Y axis at a distance of d2 from the first accelerometer, the direction is parallel to the X axis, and the detection direction of the gyroscope is along the Z axis.

In the method of the present invention, d1 is set equal to d2.

The present invention also provides a virtual gyroscope based on multi-sensor fusion, including a substrate on which an acceleration combination sensor and a gyroscope are arranged;

The combined acceleration sensor comprises: a first accelerometer whose detection direction is orthogonal in the same plane; a second accelerometer which is parallel to a detection direction of the first accelerometer in this plane but not at the same position; a third accelerometer , within the plane, parallel to the other detection direction of the first accelerometer, but not in the same position;

The gyroscope is arranged at any position on the plane, and its detection direction is perpendicular to the plane;

In the virtual top of the present invention, the virtual top also includes:

The calculation unit is used to calculate the angular acceleration according to the measurement value of the acceleration combination sensor, and combine the output of the gyroscope to construct the state update and time update equations and perform Kalman filtering.

In the virtual gyroscope of the present invention, the first accelerometers are two single-axis accelerometers or two-axis accelerometers whose detection directions are in the same plane and whose detection directions are orthogonal in the same plane.

In the virtual gyroscope of the present invention, the second accelerometer and the third accelerometer are both single-axis accelerometers.

In the virtual gyroscope of the present invention, the two detection directions of the first accelerometer are respectively along the X-axis direction and the Y-axis direction of the preset coordinate system, and the second accelerometer is placed on the X-axis at a distance from the first accelerometer is the position of d1, the direction is parallel to the Y-axis, the third accelerometer is placed on the Y-axis at a distance of d2 from the first accelerometer, the direction is parallel to the X-axis, and the detection direction of the gyroscope is along the Z-axis direction.

In the virtual gyroscope of the present invention, the distance between the second accelerometer on the X-axis and the first accelerometer is equal to the distance between the third accelerometer on the Y-axis and the first accelerometer.

The beneficial effects produced by the present invention are: the present invention arranges a pair of accelerometers in the same plane with a common position and orthogonal detection directions, two pairs of accelerometer detection directions are parallel but not in the same position, and a gyroscope, and builds the state according to the output Update and time update equations, perform Kalman filtering, combine the output characteristics of the accelerometer and gyroscope, and select a suitable covariance matrix to achieve an optimized angular velocity output, and its accuracy will be greatly increased. Low, and only one gyroscope is used, which is significantly lower than the power consumption of multiple gyroscopes in the prior art.

Description of drawings

The present invention will be further described below in conjunction with accompanying drawing and embodiment, in the accompanying drawing:

Fig. 1 is a flow chart of a method for realizing a virtual gyroscope based on multi-sensor fusion in an embodiment of the present invention;

Fig. 2 is a schematic diagram of the structure of a virtual gyroscope based on multi-sensor fusion according to an embodiment of the present invention.

detailed description

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

The invention utilizes the combination of the accelerometer and the gyroscope for data fusion to obtain the output of the optimized angular velocity value and improve the measurement accuracy of the angular velocity.

The virtual gyroscope based on multi-sensor fusion in the embodiment of the present invention includes a substrate, and an acceleration combination sensor and a gyroscope arranged on the substrate;

The combined acceleration sensor comprises: a first accelerometer whose detection direction is orthogonal in the same plane; a second accelerometer which is parallel to a detection direction of the first accelerometer in this plane but not at the same position; a third accelerometer , within the plane, parallel to the other detection direction of the first accelerometer, but not in the same position;

The gyroscope is arranged at any position on the plane, and its detection direction is perpendicular to the plane.

The virtual gyroscope also includes a calculation unit, which can be set on the substrate and connected to the combined acceleration sensor and the gyroscope, and is used to calculate the angular acceleration according to the measured value of the combined acceleration sensor, and combine the output of the gyroscope to construct the state update and time update equations , for Kalman filtering.

The calculation unit can also be set outside the virtual gyroscope, such as through an external single-chip microcomputer, or through a host computer.

In one embodiment of the present invention, the first accelerometer is two single-axis accelerometers or two-axis accelerometers whose co-location and detection directions are orthogonal in the same plane; the second accelerometer and the third accelerometer The gauges are single-axis accelerometers.

In one embodiment of the present invention, as shown in FIG. 2 , the biaxial accelerometer 1 is arranged at a corner of the substrate 4 , and the directions of the two axes are respectively along the X-axis and Y-axis of a preset coordinate system. The uniaxial accelerometer 2 a is arranged on the X axis at a distance d1 from the biaxial accelerometer 1 , and its direction is parallel to the Y axis. The uniaxial accelerometer 2b is arranged at a distance d2 from the biaxial accelerometer 1 on the Y axis, and its direction is parallel to the X axis. The gyroscope 3 is arranged at any position coplanar with each accelerometer, and its detection direction is the Z-axis direction.

In one embodiment of the present invention, the distance between the second accelerometer on the X axis and the first accelerometer can be set to be equal to the distance between the third accelerometer on the Y axis and the first accelerometer.

Under the above layout scheme, it is assumed that the outputs of the biaxial accelerometer 1 in the X-axis direction and the Y-axis direction are A1 and A2 respectively, the output of the uniaxial accelerometer 2a is A3, and the output of the uniaxial accelerometer 2b is A4, through the following The angular acceleration is obtained by solving the formula

get Finally, combined with the output ω of the gyroscope, the following equation is constructed for Kalman filtering:

(time update equation)

(state update equation)

Among them, ω _k is the angular velocity value at time k, is the angular acceleration value at k moment, ω _zk is the angular velocity measurement value at k moment, is the angular acceleration measurement value at time k, T is the sampling interval time, Q ₁ and Q ₂ are the systematic errors of the angular velocity value and the angular acceleration value, respectively, R ₁ and R ₂ are the measurement errors of the angular velocity value and the angular acceleration value, respectively.

Combining the output characteristics of the accelerometer and gyroscope, and selecting a suitable covariance matrix, the optimized angular velocity output can be achieved, and its accuracy will be greatly increased.

In order to realize the virtual gyroscope of the foregoing embodiment, the embodiment of the present invention realizes the method for virtual gyroscope based on multi-sensor fusion, as shown in FIG. 1 , comprising the following steps:

S1, setting the first accelerometer whose detection direction is orthogonal in the same plane;

S2. In the plane, set a second accelerometer parallel to one of the detection directions but not in the same position, and a third accelerometer parallel to the other detection direction but not in the same position to form an acceleration combination sensor;

S3. Install a gyroscope at any position on the plane, and its detection direction is perpendicular to the plane;

S4. Outputting the measured values of the combined acceleration sensor and the gyroscope.

The method of the present invention further includes the step: S5. According to the output measurement value, construct state updating and time updating equations, and perform Kalman filtering.

The first accelerometer is a dual-axis accelerometer or two single-axis accelerometers with a common location and a detection direction orthogonal to the same plane.

In the present invention, the quantity of acceleration value output is 4 and above (the first accelerometer is recorded as 2 acceleration value outputs, and the second and the third accelerometer are each recorded as 1 acceleration value output), and the arrangement of the accelerometer is in In the same plane, there is a pair of accelerometers with the same position and the detection direction is orthogonal; there are two pairs of accelerometers with parallel detection directions but not with the same position.

In one embodiment of the present invention, the two detection directions of the first accelerometer are respectively along the X-axis direction and the Y-axis direction of the preset coordinate system, and the distance between the second accelerometer placed on the X-axis and the first accelerometer is The position of d1, the direction is parallel to the Y axis, the third accelerometer is placed on the Y axis at a distance of d2 from the first accelerometer, the direction is parallel to the X axis, and the detection direction of the gyroscope is along the Z axis. Among them, d1 can be set equal to d2.

In summary, the output of the optimized angular velocity value is obtained by data fusion through the combination of the accelerometer and the output of the gyroscope. The angular velocity measurement accuracy of the entire system can be greatly improved.

Claims (10)

1. A method for realizing virtual gyroscope based on multi-sensor fusion, is characterized in that, comprises the following steps: The first accelerometer whose detection direction is orthogonal in the same plane is set; In this plane, a second accelerometer that is parallel to one of the detection directions of the first accelerometer but not co-located, and a second accelerometer that is parallel to the other detection direction of the first accelerometer but not co-located a third accelerometer forming an acceleration combination sensor; Set the gyroscope at any position on the plane, and its detection direction is perpendicular to the plane; Outputs the measured values of the combined acceleration sensor and gyroscope. 2. The method according to claim 1, further comprising the steps of: According to the output measurement value, the state update and time update equations are constructed to perform Kalman filtering. 3. The method according to claim 1, wherein the first accelerometer is a dual-axis accelerometer whose detection direction is orthogonal in the same plane, or a co-located, detection direction orthogonal in the same plane Two uniaxial accelerometers. 4. method according to claim 1 is characterized in that, two detection directions of the first accelerometer are respectively along the X-axis direction and the Y-axis direction of the preset coordinate system, and the second accelerometer is placed on the X-axis from The distance of the first accelerometer is d1, the detection direction is parallel to the Y axis, the third accelerometer is placed on the Y axis at a distance of d2 from the first accelerometer, and the detection direction is parallel to the X axis, the detection of the gyroscope The direction is along the Z-axis direction. 5. The method according to claim 4, characterized in that d1 is set equal to d2. 6. A virtual gyroscope based on multi-sensor fusion is characterized in that it comprises a substrate on which an acceleration combination sensor and a gyroscope are arranged; The combined acceleration sensor comprises: a first accelerometer whose detection direction is orthogonal in the same plane; a second accelerometer which is parallel to a detection direction of the first accelerometer in this plane but not at the same position; a third accelerometer , within the plane, parallel to the other detection direction of the first accelerometer, but not in the same position; The gyroscope is arranged at any position on the plane, and its detection direction is perpendicular to the plane. 7. The virtual top according to claim 6, wherein the virtual top also comprises: The calculation unit is used to calculate the angular acceleration according to the measurement value of the acceleration combination sensor, and combine the output of the gyroscope to construct the state update and time update equations and perform Kalman filtering. 8. The virtual gyroscope according to claim 6, characterized in that, the first accelerometer is two uniaxial accelerometers or biaxial accelerometers with a common position and detection directions orthogonal in the same plane; Both the second accelerometer and the third accelerometer are single-axis accelerometers. 9. The virtual gyroscope according to claim 6, wherein the two detection directions of the first accelerometer are respectively along the X-axis direction and the Y-axis direction of the preset coordinate system, and the second accelerometer is placed on the X-axis The distance from the first accelerometer is d1, the detection direction is parallel to the Y axis, the third accelerometer is placed on the Y axis, and the distance from the first accelerometer is d2, the detection direction is parallel to the X axis, and the gyroscope The detection direction is along the Z-axis direction. 10. The virtual gyro according to claim 9, wherein the second accelerometer is placed on the X-axis at a distance from the first accelerometer and the third accelerometer is placed on the Y-axis at a distance equal to the first accelerometer .