KR20160061814A - Inertial sensor module - Google Patents

Abstract

The present invention relates to an inertial sensor module. According to an embodiment of the present invention, the module comprises: an inertial sensor unit detecting inertial displacement and outputting inertial data which shows the inertial displacement; a temperature sensor outputting a temperature value by sensing a temperature; a temperature conversion unit updating a reference value as the sensed temperature value, if the temperature value exceeds a threshold range of the reference value; and a compensation unit loading temperature coefficients stored in a memory and calculating and outputting compensation data based on the temperature coefficients, the reference value, and the inertial data. According to an embodiment of the present invention, provided is the inertial sensor module configured to make hardware efficient by reducing degradation caused by the noise of the sensed temperature.

Description

Inertial Sensor Module {INERTIAL SENSOR MODULE}

The present invention relates to an inertial sensor module.

The inertial sensor is divided into an acceleration sensor capable of measuring linear motion and an angular velocity sensor capable of measuring rotational motion.

The angular velocity sensor measures the Coriolis force and converts it into an electric signal such as a signal having a voltage, a current, and a frequency. The acceleration sensor measures movement of an object in consideration of gravity acceleration and converts it into an electrical signal.

In general, all sensors do not have the same characteristics due to manufacturing process tolerances such as micro electro mechanical systems (MEMS), packaging, and the like during manufacture of the sensor, and deviations occur.

On the other hand, the inertial sensor detects displacement in proportion to the physical quantity externally applied, and is classified into a piezoresistive type, a piezoelectric type, and a capacitive type according to the detection method of the displacement. Materials suitable for each method are selected, do.

Since the physical properties of the materials are affected by the temperature, the structure of the inertial sensor composed of the selected materials also has temperature characteristics.

Korean Patent Laid-Open Publication No. 2014-0026149

According to an embodiment of the present invention, there is provided an inertial sensor module that reduces deterioration due to noise of a measured temperature and divides the compensation by temperature to improve hardware efficiency.

According to an embodiment of the present invention, there is provided an inertial sensor unit that detects inertial displacement and outputs inertial data representing the inertial displacement; A temperature sensor for sensing a temperature and outputting a temperature value; A temperature converter for updating the reference value with the sensed temperature value when the temperature value is out of a threshold range of the reference value; And a compensation unit for loading temperature coefficients stored in the memory and computing and outputting compensation data based on the temperature coefficients, the reference value and the inertia data.

The inertial sensor module according to an embodiment of the present invention has the effect of reducing the deterioration due to noise of the measured temperature and performing hardware division by calculating the compensation by the temperature.

1 is a block diagram briefly showing an inertial sensor module according to an embodiment of the present invention.
2 is a block diagram illustrating an inertial sensor module according to an embodiment of the present invention.
3 is a block diagram illustrating a compensation unit of the inertial sensor module according to an embodiment of the present invention.
FIG. 4 and FIG. 5 are graphs showing a temperature treatment simulation of the inertial sensor module according to an embodiment of the present invention.
6 is a memory map of the temperature coefficient stored in the memory of the inertial sensor module according to an embodiment of the present invention.
7 is a temperature coefficient loading timing diagram of the inertial sensor module according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

However, the embodiments of the present invention can be modified into various other forms, and the scope of the present invention is not limited to the embodiments described below. Further, the embodiments of the present invention are provided to more fully explain the present invention to those skilled in the art. It should be understood that the various embodiments of the present invention are different, but need not be mutually exclusive. For example, certain features, structures, and characteristics described herein may be implemented in other embodiments without departing from the spirit and scope of the invention in connection with an embodiment.

Also, to "include" an element means that it may include other elements, rather than excluding other elements, unless specifically stated otherwise.

1 is a block diagram briefly showing an inertial sensor module according to an embodiment of the present invention.

Referring to FIG. 1, the inertial sensor module according to an embodiment of the present invention may include an inertial sensor unit 100, a temperature sensor 200, a temperature converter 300, and a compensator 400.

Also, the memory 500 may be included in the inertial sensor module, or may be a memory external to the inertial sensor module.

The inertial sensor unit 100 may detect the inertial displacement and convert it into inertial data, which is a digital signal, and output the inertial data to the compensation unit 400.

The temperature sensor 200 may sense the temperature and the temperature converter 300 may update the reference value to the sensed temperature value when the sensed temperature value is out of the threshold range of the reference value.

That is, the reference value may be set by updating the reference value to the sensed temperature value when the temperature value sensed by the temperature sensor 200 is out of the threshold range from the set reference value.

Thus, deterioration due to noise at the measurement temperature, which is generated when the temperature value near the boundary of the reference value is continuously sensed, and whose reference value is unintentionally fluctuated by noise, can be prevented.

The compensation unit 400 receives the inertial data, compensates the inertial data using the reference value and temperature coefficients stored in the memory 500, and outputs the compensated inertial data as compensation data.

2 is a block diagram illustrating an inertial sensor module according to an embodiment of the present invention.

2, the inertial sensor module according to an embodiment of the present invention includes an inertial sensor unit 100, a temperature sensor 200, a temperature converter 300, a compensator 400, a driver 600, And an output unit 700.

Also, the memory 500 may be included in the inertial sensor module, or may be a memory external to the inertial sensor module.

The inertial sensor unit 100 may include at least one of an angular velocity sensor 110 and an acceleration sensor 120 and may include an A / D converter 130.

More specifically, the inertial sensor unit 100 includes an angular velocity sensor 110 capable of detecting a plurality of (for example, three) axial angular velocities, or an acceleration sensor capable of detecting a plurality of axial accelerations (120).

The angular velocity sensor 110 and the acceleration sensor 120 generate signals corresponding to inertial displacements corresponding to motions such as movement and rotation, and the generated signals are converted into inertial data by an A / D converter 130, .

That is, the inertial sensor unit 100 detects the inertial displacement and converts the inertial data into inertial data, which is a digital signal, and outputs the inertial data to the compensation unit 400.

The angular velocity sensor 110 and the acceleration sensor 120 may include a driving mass. The driving mass may resonate and vibrate according to the driving voltage applied by the driving unit 600.

The temperature sensor 200 can sense the temperature and output it to the temperature converter 300.

The temperature converter 300 may use a moving average filter to remove noise from the sensed temperature value.

However, since the noise component may remain after the noise removal process using the moving average filter, the temperature converter 300 may update the reference value to the temperature value when the temperature value is out of the threshold range of the reference value. have.

That is, the reference value may be set by updating the reference value to the temperature value when the temperature value after the noise removal process is out of the threshold range from the set reference value.

Accordingly, even when the temperature value sensed by the temperature sensor 200 continuously changes due to the noise of the measurement temperature or the like, the reference value used for temperature compensation is not changed unless the variation width (variation) exceeds the critical range, It is possible to prevent the inertial sensor module from being deteriorated by the noise of the measurement temperature.

The output unit 700 may include a filter unit 710 and a communication unit 720.

The filter unit 710 can remove the noise included in the compensation data, and the communication unit can transmit the noise-canceled compensation data by communicating with the host (not shown). The filter unit 710 may include a low pass filter.

3 is a block diagram illustrating a compensation unit of the inertial sensor module according to an embodiment of the present invention.

Referring to FIG. 3, the compensation unit 400 of the inertial module sensor according to an embodiment of the present invention may include a temperature coefficient calculation unit 410 and a compensation calculation unit 420.

The temperature coefficient calculator 410 may load the temperature coefficients stored in the memory 500 in a segmentation manner and receive a reference value output from the temperature converter 300.

Here, the segment unit is a set of temperature coefficients for computing one compensation data

For example, the temperature coefficients for calculating the compensation data in the X-axis direction of the angular velocity sensor among the compensation data include temperature coefficients for obtaining the sensitivity coefficient Sxx (T) for compensating the inertia data in the X-axis direction (sxx_a, sxx_b, sxx_c) for obtaining the sensitivity coefficient (Sxy (T)) for compensating the inertia data in the Y-axis direction, a sensitivity coefficient (Off_a, off_b, off_c) for obtaining temperature coefficients (sxz_a, sxz_b, sxz_c) for obtaining the temperature coefficient Sxz (T) and a sensitivity coefficient Ox .

The temperature coefficient calculator 410 may calculate the sensitivity coefficients by polynomials of the temperature coefficients and the reference values loaded in units of segments, and output the calculated sensitivity coefficients to the compensation calculator 420.

In one embodiment, a polynomial for a reference value that is a coefficient of temperature coefficients for calculating the sensitivity coefficient Sxx (T) may be expressed by the following equation (1).

Here, sxx_a, sxx_b, and sxx_c are temperature coefficients corresponding to the sensitivity coefficient among the temperature coefficients loaded in units of segments from the memory 500, T is a reference value updated to the sensed temperature value by the temperature conversion unit 300, Sxx (T) is a sensing coefficient for temperature-compensating the inertia data of the angular velocity sensor in the X-axis direction in order to calculate the compensation data in the X-axis direction.

Other detection coefficients of the polynomial equation can be calculated by an equation similar to the equation (1). In this case, the temperature coefficients selected from the temperature coefficients loaded from the memory are selected according to the detection coefficient to be calculated. For example, in the case of calculating the detection coefficient Sxy (T) for temperature compensation of the inertia data in the Y axis direction of the angular velocity sensor to calculate the compensation data in the X axis direction, The temperature coefficients sxy_a, sxy_b and sxy_c corresponding to the coefficient Sxy (T) are selected and the temperature coefficients sxy_a, sxy_b and sxy_c are substituted into the equation (1) )) Can be calculated.

Gx_raw, Gz_raw, and Ax_raw, which are digital signals of a plurality of (for example, three) axial angular velocities and a plurality of axial direction acceleration displacements detected by the inertial sensor unit 100, , Ay_raw, Az_raw).

Here, the inertia data (Gx_raw, Gy_raw, Gz_raw, Ax_raw, Ay_raw, Az_raw) can detect angular velocities in a plurality of (for example, three (X, Y, Z)) axial directions included in the inertia sensor unit 100 And the data corresponding to the inertial displacement detected by the acceleration sensor 120 capable of detecting the plurality of axial accelerations.

The compensation operation unit 420 generates compensation data TC_Gx, TC_Gy, TC_Gz, and TC_Ax by using the inertia data Gx_raw, Gy_raw, Gz_raw, Ax_raw, Ay_raw, Az_raw and the temperature compensation matrix using the sensitivity coefficients as an element. , TC_Ay, TC_Az) can be calculated and output.

The inertia data for calculating the compensation data (TC_Gx, TC_Gy, TC_Gz) for the angular velocity among the compensation data (TC_Gx, TC_Gy, TC_Gz, TC_Ax, TC_Ay and TC_Az) The temperature compensation matrix can be expressed by the following equation (2).

Here, Sxx (T) to Szz (T) and Ox (T) to Oz (T) are the sensitivity coefficients calculated by the temperature coefficient arithmetic unit 410, Gx_raw to Gz_raw are inertia data (Gx_raw, Gy_raw, Gz_raw) corresponding to the inertial displacement of the angular velocity sensor among the Gx_raw, Gy_raw, Gz_raw, Ax_raw, Ay_raw and Az_raw.

FIG. 4 and FIG. 5 are graphs showing a temperature treatment simulation of the inertial sensor module according to an embodiment of the present invention.

Referring to FIG. 4, the inertial sensor module according to an embodiment of the present invention updates the baseline to a sensed temperature value when a sensed temperature value is out of a threshold range of a baseline It can be confirmed that the baseline is adjusted to the sensed temperature value.

That is, the baseline may be set by updating the baseline with the sensed temperature value when the temperature sensed by the temperature sensor 200 (FIG. 1) deviates from a preset reference value have.

Accordingly, when the temperature value near the boundary of the reference value is continuously sensed, deterioration due to noise of the measurement temperature at which the reference value unintentionally fluctuates due to noise can be prevented.

Referring to FIG. 5, a graph (a) with respect to time of a temperature value before using a moving average filter and a graph (b) with respect to time after use are compared with each other to remove noise from sensed temperature values , It can be seen that the variation of the temperature value with respect to time is improved from about 20 LSB to 10 LSB.

6 is a memory map of the temperature coefficient stored in the memory of the inertial sensor module according to an embodiment of the present invention.

Referring to FIG. 6, it can be seen that the temperature coefficients are stored in the memory 500 (FIG. 3) in a segmentation segment corresponding to the inertia data.

3) can load the temperature coefficients stored in the memory 500 (Fig. 3) on a segment basis, and the temperature conversion unit 300 (Fig. 3) The reference value to be output can be input.

The temperature coefficient calculator 410 (FIG. 3) may calculate the sensitivity coefficients by polynomials of the temperature coefficients and the reference values loaded in units of segments, and output the calculated sensitivity coefficients to the compensation calculator 420 (FIG. 3).

3) of the angular velocity sensor in the X-axis direction will be described as an example. The temperature coefficient calculator 410 (Fig. 3) calculates the inertia data of the angular velocity sensor in the X- (TC_Gx, Fig. 3) in the X-axis direction of the angular velocity sensor by loading the temperature coefficients (sxx_a to c, sxy_a to c, sxz_a to c, offx_a to c) The coefficients can be calculated.

7 is a temperature coefficient loading timing diagram of the inertial sensor module according to an embodiment of the present invention.

Referring to FIG. 7, it can be seen that the compensation unit 400 (FIG. 3) included in the inertial sensor module according to an embodiment of the present invention sequentially loads temperature coefficients stored in the memory 500 (FIG. 3) have.

Here, sm1_a-c, sm2_a-c, and sm3_a-c correspond to the temperature coefficients included in one segment unit.

Accordingly, the hardware can be efficiently operated by sequentially loading the temperature coefficients required to divide the compensation by the temperature.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, Those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Therefore, the spirit of the present invention should not be construed as being limited to the above-described embodiments, and all of the equivalents or equivalents of the claims, as well as the following claims, I will say.

100: inertia sensor unit
200: Temperature sensor
300: temperature conversion unit
400:
500: Memory

Claims (20)

An inertial sensor unit for detecting an inertial displacement and outputting inertia data representing the inertial displacement;
A temperature sensor for sensing a temperature and outputting a temperature value;
A temperature converter for updating the reference value with the sensed temperature value when the temperature value is out of a threshold range of the reference value; And
A compensation unit for loading the temperature coefficients stored in the memory and calculating and outputting compensation data based on the temperature coefficients, the reference value and the inertia data,
And an inertial sensor module.
The method according to claim 1,
Wherein the inertial sensor unit includes at least one of an angular velocity sensor and an acceleration sensor.
The method according to claim 1,
Wherein the compensation unit computes the inertia data by a temperature compensation matrix including coefficients calculated by polynomials of temperature coefficients and a temperature value to output compensation data.
The method according to claim 1,
Wherein the compensation unit sequentially loads the temperature coefficients stored in the memory in units of segments.
The apparatus according to claim 1,
A temperature coefficient operating unit for loading the temperature coefficients in units of segments and outputting the sensitivity coefficients calculated in a polynomial equation for the reference value;
And outputting the compensation data calculated by the temperature compensation matrix using the inertia data and the sensitivity coefficients as an entry,
And an inertial sensor module.
The method according to claim 1,
Wherein the temperature coefficients are stored in the memory in segment units corresponding to the inertial data.
The apparatus according to claim 1,
Wherein the inertia data is calculated by a temperature compensation matrix and the elements of the temperature compensation matrix are calculated by a second order polynomial with respect to a temperature whose coefficients are the temperature coefficients.
The method according to claim 1,
And a driving unit for applying a driving voltage to drive the inertial sensor unit.
The method according to claim 1,
Wherein the temperature converter uses a moving average filter to remove noise from the sensed temperature value.
The method according to claim 1,
Wherein the inertial sensor unit includes an A / D converter for converting a signal corresponding to the inertial displacement into inertial data that is a digital signal.
An inertial sensor unit for detecting an inertial displacement and outputting inertia data representing the inertial displacement;
A temperature sensor for sensing a temperature and outputting a temperature value;
A temperature converter for updating the reference value with the sensed temperature value when the temperature value is out of a threshold range of the reference value; And
A compensation unit for loading temperature coefficients stored in the memory, computing and outputting compensation data based on the temperature coefficients, the reference value, and the inertia data; And
An output unit for receiving and receiving compensation data,
And an inertial sensor module.
12. The method of claim 11,
Wherein the inertial sensor unit includes at least one of an angular velocity sensor and an acceleration sensor.
12. The method of claim 11,
Wherein the compensation unit computes the inertia data by using a temperature compensation matrix including temperature coefficients and sensitivity coefficients calculated by a polynomial equation for the reference value to output compensation data.
12. The method of claim 11,
Wherein the compensation unit sequentially loads the temperature coefficients stored in the memory in units of segments.
12. The apparatus according to claim 11,
A temperature coefficient operating unit for loading the temperature coefficients in units of segments and outputting the sensitivity coefficients calculated by a polynomial for the reference value;
And outputting the compensation data calculated by the temperature compensation matrix using the inertia data and the sensitivity coefficients as an entry,
And an inertial sensor module.
12. The method of claim 11,
Wherein the temperature coefficients are stored in the memory in segment units corresponding to the inertial data.
12. The apparatus according to claim 11,
Wherein the inertia data is calculated by a temperature compensation matrix and the elements of the temperature compensation matrix are calculated by a second order polynomial with respect to a temperature whose coefficients are the temperature coefficients.
12. The method of claim 11,
And a driving unit for applying a driving voltage to drive the inertial sensor unit.
12. The method of claim 11,
Wherein the temperature converter uses a moving average filter to remove noise from the sensed temperature value.
12. The method of claim 11,
Wherein the inertial sensor unit includes an A / D converter for converting a signal corresponding to the detected inertial displacement into inertial data as a digital signal.

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