Inertial measurement device and laser detector combined calibration method

Abstract

The invention belongs to the technical field of sensor calibration, and particularly relates to a joint calibration method for an inertial measurement device and a laser detector, which is used for calibration of guidance equipment. The method mainly comprises the following steps of: marking on a curtain by using a communicating vessel at the same height as the rotation center of a rotary table; adjusting the laser spot position to coincide with the curtain mark; adjusting the turntable to enable the laser spot to be located at the central position of the laser detector, and recording a pitch angle output by the inertial measurement device; the turntable inner frame is rotated by 90 degrees, and the other direction is calibrated. The method has the advantages that errors caused by non-coincidence of coordinate axes of the inertial measurement device and the laser detector are eliminated, and the calibration precision is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of sensor calibration, and in particular relates to a joint calibration method of an inertial measurement device and a laser detector. Background Art

[0002] Inertial measurement units and laser detectors are key components for achieving guidance functions. Inertial measurement units are devices that measure acceleration and angular velocity. Laser detectors are devices that measure the angle of laser targets. In order to measure accurately, both inertial measurement units and laser detectors need to be calibrated to correct the measurement values ​​and reduce errors.

[0003] In the prior art, the inertial measurement device is calibrated separately, and the laser detector is calibrated separately. After the two are calibrated separately, they are assembled together. Due to structural processing errors and assembly errors, the coordinate axes of the inertial measurement device and the laser detector do not coincide, resulting in additional guidance errors. The prior art has errors caused by the misalignment of the coordinate axes, which causes a decrease in guidance accuracy. Summary of the invention

[0004] 1. Technical issues to be resolved

[0005] The technical problem to be solved by the present invention is: how to eliminate the error caused by the misalignment of the coordinate axes of the inertial measurement device and the laser detector to improve the calibration accuracy.

[0006] (II) Technical solution

[0007] In order to solve the above technical problems, the present invention provides a method for joint calibration of an inertial measurement device and a laser detector, the method comprising the following steps:

[0008] Step 1: Place one end of the communicating vessel at the rotation center of the turntable, and the other end of the communicating vessel on the reflective curtain, so that the liquid level in the communicating vessel is at the same height as the rotation center of the turntable, and mark the liquid level on the curtain;

[0009] Step 2: Adjust the irradiation position of the laser irradiator so that the center of the laser spot coincides with the mark on the screen;

[0010] Step 3: Adjust the turntable so that the laser spot is located at the center of the laser detector and record the pitch angle output by the inertial measurement unit;

[0011] Step 4: Rotate the inner frame of the turntable 90 degrees, and then repeat step 3.

[0012] In order to calibrate the coordinate axis misalignment error between the inertial measurement device and the laser detector, the center axis of the laser detector needs to be located in the horizontal direction. For this purpose, a horizontal reference is established with the help of a communicating vessel.

[0013] Among them, in step one, one end of the communicating vessel is placed at the rotation center of the turntable, and the other end of the communicating vessel is placed on the reflective curtain; the liquid levels at both ends of the communicating vessel are at the same height; the position of the communicating vessel or the amount of water in the communicating vessel is adjusted so that the liquid level in the communicating vessel is at the same height as the rotation center of the turntable; the liquid level height is marked on the curtain; according to the characteristics of the communicating vessel, the curtain mark and the rotation center of the turntable are at the same height, and the line connecting the two is the horizontal reference.

[0014] Wherein, the communicating vessel adopts a polyvinyl chloride (PVC) transparent hose.

[0015] Among them, in the step 2, the irradiation position of the laser irradiator is adjusted so that the center position of the laser spot coincides with the mark on the curtain; at this time, the line connecting the laser spot and the rotation center of the turntable is in the horizontal direction.

[0016] Among them, in the step three, the turntable is adjusted so that the laser spot is located at the center of the laser detector; at this time, the axis of the laser detector is located in the horizontal direction; the pitch angle output by the inertial measurement device is recorded; this angle is the non-coincidence error between the coordinate axes of the inertial measurement device and the laser detector in the Y direction.

[0017] Wherein, in the step 4, the inner frame of the turntable is rotated 90 degrees, and then step 3 is repeated; in step 3, the coordinate axis misalignment error in the Y direction has been measured; step 4 is to measure the coordinate axis misalignment error in the X direction.

[0018] Wherein, the laser detector comprises a four-quadrant photoelectric sensor; the laser detector comprises a lens and a four-quadrant photoelectric sensor element; the laser spot is imaged on the four-quadrant photoelectric sensor; the four-quadrant photoelectric sensor measures the light intensity of the four quadrants, V1, V2, V3, and V4, and the measured value in the Y direction is

[0019] Y=(V1+V2-V3-V4) / (V1+V2+V3+V4);

[0020] The measured value in the X direction is

[0021] X=(V1-V2-V3+V4) / (V1+V2+V3+V4).

[0022] Among them, in the step three, the turntable is adjusted so that the measurement value in the X direction and the measurement value in the Y direction are both 0, so that the axis of the laser detector is located in the horizontal direction.

[0023] Among them, the method measures the coordinate axis misalignment errors of the inertial measurement device and the laser detector in two directions; by compensating these two errors through software, a higher-precision guidance function can be achieved.

[0024] (III) Beneficial effects

[0025] Compared with the prior art, the present invention calibrates the coordinate axis misalignment error of the inertial measurement device and the laser detector, and can improve the guidance accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of step one and step two of the present invention.

[0027] Figure 2 It is a laser detector using a four-quadrant photoelectric sensor. DETAILED DESCRIPTION

[0028] In order to make the purpose, content, and advantages of the present invention more clear, the specific implementation methods of the present invention are further described in detail below in conjunction with the accompanying drawings and examples.

[0029] In order to solve the above technical problems, the present invention provides a method for joint calibration of an inertial measurement device and a laser detector, the method comprising the following steps:

[0030] Step 1: Place one end of the communicating vessel at the rotation center of the turntable, and the other end of the communicating vessel on the reflective curtain, so that the liquid level in the communicating vessel is at the same height as the rotation center of the turntable, and mark the liquid level on the curtain;

[0031] Step 2: Adjust the irradiation position of the laser irradiator so that the center of the laser spot coincides with the mark on the screen;

[0032] Step 3: Adjust the turntable so that the laser spot is located at the center of the laser detector and record the pitch angle output by the inertial measurement unit;

[0033] Step 4: Rotate the inner frame of the turntable 90 degrees, and then repeat step 3.

[0034] In order to calibrate the coordinate axis misalignment error between the inertial measurement device and the laser detector, the center axis of the laser detector needs to be located in the horizontal direction. For this purpose, a horizontal reference is established with the help of a communicating vessel.

[0035] Among them, in step one, one end of the communicating vessel is placed at the rotation center of the turntable, and the other end of the communicating vessel is placed on the reflective curtain; the liquid levels at both ends of the communicating vessel are at the same height; the position of the communicating vessel or the amount of water in the communicating vessel is adjusted so that the liquid level in the communicating vessel is at the same height as the rotation center of the turntable; the liquid level height is marked on the curtain; according to the characteristics of the communicating vessel, the curtain mark and the rotation center of the turntable are at the same height, and the line connecting the two is the horizontal reference.

[0036] Wherein, the communicating vessel adopts a polyvinyl chloride (PVC) transparent hose.

[0037] Among them, in the step 2, the irradiation position of the laser irradiator is adjusted so that the center position of the laser spot coincides with the mark on the curtain; at this time, the line connecting the laser spot and the rotation center of the turntable is in the horizontal direction.

[0038] Among them, in the step three, the turntable is adjusted so that the laser spot is located at the center of the laser detector; at this time, the axis of the laser detector is located in the horizontal direction; the pitch angle output by the inertial measurement device is recorded; this angle is the non-coincidence error between the coordinate axes of the inertial measurement device and the laser detector in the Y direction.

[0039] Wherein, in the step 4, the inner frame of the turntable is rotated 90 degrees, and then step 3 is repeated; in step 3, the coordinate axis misalignment error in the Y direction has been measured; step 4 is to measure the coordinate axis misalignment error in the X direction.

[0040] Wherein, the laser detector comprises a four-quadrant photoelectric sensor; the laser detector comprises a lens and a four-quadrant photoelectric sensor element; the laser spot is imaged on the four-quadrant photoelectric sensor; the four-quadrant photoelectric sensor measures the light intensity of the four quadrants, V1, V2, V3, and V4, and the measured value in the Y direction is

[0041] Y=(V1+V2-V3-V4) / (V1+V2+V3+V4);

[0042] The measured value in the X direction is

[0043] X=(V1-V2-V3+V4) / (V1+V2+V3+V4).

[0044] Among them, in the step three, the turntable is adjusted so that the measurement value in the X direction and the measurement value in the Y direction are both 0, so that the axis of the laser detector is located in the horizontal direction.

[0045] Among them, the method measures the coordinate axis misalignment errors of the inertial measurement device and the laser detector in two directions; by compensating these two errors through software, a higher-precision guidance function can be achieved.

[0046] Example 1

[0047] In order to calibrate the coordinate axis misalignment error of the inertial measurement device and the laser detector in this embodiment, it is necessary to make the central axis of the laser detector in the horizontal direction. Figure 1 As shown, a horizontal reference is established by means of the connecting vessel 2.

[0048] In step 1, one end of the communicating vessel 2 is placed at the rotation center of the turntable 4, and the other end of the communicating vessel 2 is placed on the reflective curtain 1. The liquid levels at both ends of the communicating vessel 2 are at the same height. Adjust the position of the communicating vessel 2 or adjust the amount of water in the communicating vessel 2 so that the liquid level in the communicating vessel 2 is at the same height as the rotation center of the turntable 4. Mark the liquid level on the curtain 1. According to the characteristics of the communicating vessel 2, the mark on the curtain 1 is at the same height as the rotation center of the turntable 4, and the line connecting the two is the horizontal reference.

[0049] In a preferred solution, the communicating vessel 2 is made of a polyvinyl chloride (PVC) transparent hose, which is easy to bend and adjust its position; in addition, the PVC transparent hose is easy to observe the liquid level.

[0050] In step 2, the irradiation position of the laser irradiator 3 is adjusted so that the center position of the laser spot coincides with the mark on the curtain 1. At this time, the line connecting the laser spot and the rotation center of the turntable 4 is in the horizontal direction.

[0051] In step 3, adjust the turntable 4 so that the laser spot is located at the center of the laser detector 5. At this time, the axis of the laser detector 5 is in the horizontal direction. Record the pitch angle output by the inertial measurement device 6. This angle is the non-coincidence error between the coordinate axes of the inertial measurement device 6 and the laser detector 5.

[0052] In step 4, the inner frame of the turntable 4 is rotated 90 degrees, and then step 3 is repeated. In step 3, the coordinate axis misalignment error in the Y direction has been measured; step 4 is to measure the coordinate axis misalignment error in the X direction.

[0053] The present invention measures the coordinate axis misalignment errors in two directions of the inertial measurement device 6 and the laser detector 5. The software compensates for these two errors to achieve a higher precision guidance function.

[0054] In a preferred solution, the laser detector includes a four-quadrant photoelectric sensor. The laser detector includes a lens, a four-quadrant photoelectric sensor and other components. The laser spot is imaged on the four-quadrant photoelectric sensor. Figure 2 , the four-quadrant photoelectric sensor measures the light intensity of the four quadrants, V1, V2, V3, V4, then the measured value in the Y direction is

[0055] Y=(V1+V2-V3-V4) / (V1+V2+V3+V4)

[0056] The measured value in the X direction is

[0057] X=(V1-V2-V3+V4) / (V1+V2+V3+V4)

[0058] In step three, adjust the turntable so that the X-direction measurement value and the Y-direction measurement value are both 0, which means that the axis of the laser detector is in the horizontal direction.

[0059] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for joint calibration of an inertial measurement device and a laser detector, characterized in that: The method comprises the following steps: Step 1: Place one end of the communicating vessel at the rotation center of the turntable, and the other end of the communicating vessel on the reflective curtain, so that the liquid level in the communicating vessel is at the same height as the rotation center of the turntable, and mark the liquid level on the curtain; Step 2: Adjust the irradiation position of the laser irradiator so that the center of the laser spot coincides with the mark on the screen; Step 3: Adjust the turntable so that the laser spot is located at the center of the laser detector and record the pitch angle output by the inertial measurement unit; Step 4: Rotate the inner frame of the turntable 90 degrees, and then repeat step 3.

2. The method for joint calibration of an inertial measurement device and a laser detector as claimed in claim 1, characterized in that: In order to calibrate the coordinate axis misalignment error between the inertial measurement unit and the laser detector, the central axis of the laser detector needs to be located in the horizontal direction. For this purpose, a horizontal reference is established with the help of a communicating vessel.

3. The method for joint calibration of an inertial measurement device and a laser detector as claimed in claim 2, characterized in that: In step one, one end of the communicating vessel is placed at the rotation center of the turntable, and the other end of the communicating vessel is placed on a reflective curtain; the liquid levels at both ends of the communicating vessel are at the same height; the position of the communicating vessel or the amount of water in the communicating vessel is adjusted so that the liquid level in the communicating vessel is at the same height as the rotation center of the turntable; the liquid level height is marked on the curtain; according to the characteristics of the communicating vessel, the curtain mark and the rotation center of the turntable are at the same height, and the line connecting the two is the horizontal reference.

4. The method for joint calibration of an inertial measurement device and a laser detector as claimed in claim 1, characterized in that: The communicating vessel adopts a polyvinyl chloride (PVC) transparent hose.

5. The method for joint calibration of an inertial measurement device and a laser detector as claimed in claim 3, characterized in that: In the step 2, the irradiation position of the laser irradiator is adjusted so that the center position of the laser spot coincides with the mark on the curtain; at this time, the line connecting the laser spot and the rotation center of the turntable is in the horizontal direction.

6. The inertial measurement device and laser detector joint calibration method according to claim 5, characterized in that: In step three, the turntable is adjusted so that the laser spot is located at the center of the laser detector; at this time, the axis of the laser detector is located in the horizontal direction; the pitch angle output by the inertial measurement device is recorded; this angle is the non-coincidence error between the coordinate axes of the inertial measurement device and the laser detector in the Y direction.

7. The method for joint calibration of an inertial measurement device and a laser detector as claimed in claim 6, characterized in that: In the step 4, the inner frame of the turntable is rotated 90 degrees, and then step 3 is repeated; in step 3, the coordinate axis misalignment error in the Y direction has been measured; step 4 is to measure the coordinate axis misalignment error in the X direction.

8. The method for joint calibration of an inertial measurement device and a laser detector as claimed in claim 7, characterized in that: The laser detector includes a four-quadrant photoelectric sensor; the laser detector includes a lens and a four-quadrant photoelectric sensor element; the laser spot is imaged on the four-quadrant photoelectric sensor; the four-quadrant photoelectric sensor measures the light intensity of the four quadrants, V1, V2, V3, and V4, and the measured value in the Y direction is Y=(V1+V2-V3-V4) / (V1+V2+V3+V4); The measured value in the X direction is X=(V1-V2-V3+V4) / (V1+V2+V3+V4).

9. The method for joint calibration of an inertial measurement device and a laser detector as claimed in claim 8, characterized in that: In the step three, the turntable is adjusted so that the measured values ​​in the X direction and the measured values ​​in the Y direction are both 0, so that the axis of the laser detector is located in the horizontal direction.

10. The inertial measurement device and laser detector joint calibration method according to claim 8, characterized in that: The method measures the coordinate axis misalignment errors of the inertial measurement device and the laser detector in two directions; by compensating these two errors through software, a higher precision guidance function can be achieved.

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