A real-time angle calculation method for the telescope's pitch axis based on a linear accelerometer

Abstract

The present invention discloses a real-time angle calculation method for the elevation axis of a telescope based on a linear accelerometer. The specific steps are as follows: First, place the elevation axis of the telescope in a vertical state and any other state, record the measurement values of the linear accelerometer respectively and calculate the gravity values received; then use the arcsine relationship between the gravity values received to obtain the angle values affected by gravity. Since there is a situation of erect and inverted telescopes in the actual system, by pulling the single rod in the positive direction, compare the angle values affected by gravity to determine the erect and inverted states of the telescope, so as to obtain the true angle of the elevation axis. The method of the present invention has a fast calculation speed, is easy to implement, and has stable performance. It can give an alarm in time when the encoder data of the elevation axis of the telescope is incorrect, and give the approximate angle information of the telescope.

Description

Technical Field

[0001] The present invention relates to the technical field of ground-based telescope tracking control, and particularly relates to a method for real-time calculation of the angle of the elevation axis of a telescope based on a linear accelerometer. Background Art

[0002] In the precision tracking control system of a ground-based telescope, due to system design requirements, the encoder acquisition board cannot save the zero position correction value. Additionally, when the software sends a zero position correction command through the network port after self-starting, since a switch with three-layer protocol functions is used, it is slower than the startup time of the operating software. In this way, there will sometimes be a phenomenon where zero position correction cannot be performed normally, and the telescope cannot work properly, which not only brings trouble to the operator but also causes difficulties in tracking control.

[0003] Currently, when performing the method before correcting the error of the erect and inverted mirrors: the operator walks to the equipment, first observes the position of the elevation axis, then rotates the equipment to the horizontal position of the erect mirror, and finally walks to the operation console, sets the elevation axis encoder angle to 0 degrees at this time, and then takes the erect and inverted mirrors to correct the error.

[0004] Since this method requires the operator to walk to the equipment, it increases the workload of the operator in actual work and makes the work efficiency very low; at the same time, in actual work, when rotating the equipment to the horizontal position of the erect mirror, the operator also needs to have the ability to identify the erect and inverted mirrors of the equipment, which requires relevant training, consumes a large amount of manpower and valuable time, and cannot achieve automatic processing.

[0005] With the development of tracking control technology, the requirements for the automation process of equipment are becoming increasingly stringent, so higher requirements are put forward for zero position correction; at the same time, for the system during the test period, before each task is executed, it is necessary to correct the error by taking the erect and inverted mirrors in the field to ensure the smooth execution of the task. Therefore, a calculation method for automatic processing with strong adaptability and low requirements for the environment and auxiliary conditions is needed. The existing methods are difficult to meet the requirements in terms of both efficiency and automation. Summary of the Invention

[0006] The purpose of the present invention is to provide a method for real-time calculation of the angle of the elevation axis of a telescope based on a linear accelerometer, which is used to give an alarm in time when the encoder data of the elevation axis of the telescope is incorrect and give the approximate angle information of the telescope.

[0007] The technical solution adopted by the present invention is as follows: A method for real-time calculation of the angle of the elevation axis of a telescope based on a linear accelerometer has the following steps:

[0008] Step (1): The first accelerometer 100 - A and the second accelerometer 100 - B are symmetrically installed on the telescope turntable 101 and fixedly connected to the turntable. The two accelerometers are at the same distance from the rotation center and have the same sensitive direction, which is the tangential direction of the turntable rotation.

[0009] Step (2): Place the telescope pitch axis in a vertical state and record the measured value accA of the first accelerometer 100 - A, Max and take it as the gravity value Gacc max received.

[0010] Step (3): Place the telescope pitch axis in any state, record the measured value accA of the first accelerometer 100 - A, and calculate the angle α affected by gravity on the pitch axis using the gravity value.

[0011] Step (4): Pull the single rod to move the pitch axis upward, record the measured value accA of the first accelerometer 100 - A and the measured value accB of the second accelerometer 100 - B, and calculate the instrument linear velocity value Vacc and the gravity value Gacc received by the first accelerometer 100 - A.

[0012] Step (5): Calculate the angle value α1 affected by gravity on the first accelerometer 100 - A using the arcsine relationship between the gravity values Gacc and Gacc max received by the first accelerometer 100 - A.

[0013] Step (6): There are normal and inverted mirror situations for the telescope pitch axis. Denote the angle value α1 as the normal mirror angle, and the angle β1 with a complementary relationship as the inverted mirror angle.

[0014] Step (7): If the angle value α1 gradually increases relative to the angle α, the device is in the normal mirror state, and the true angle of the pitch axis is α1; otherwise, the device is in the inverted mirror state, and the true angle of the pitch axis is β1.

[0015] Furthermore, in step (2), when the telescope pitch axis is placed in a vertical state, the gravity received by the first accelerometer 100 - A is the maximum gravity, and its gravity value is equal to the measured value. This state only needs to be calibrated once.

[0016] Furthermore, in step (3), when the device is in a stationary state, the measured value accA of the first accelerometer 100 - A is the projection of the maximum gravity received in the sensitive direction, and the angle affected by gravity can be solved using the arcsine function.

[0017] Furthermore, in step (4), when the device is in a moving state, first separate the linear velocity of the device, and then calculate the gravity value received by the accelerometer.

[0018] Further, in step (5), when the device is in a moving state, the angular values of the accelerometer affected by gravity at different positions are solved in real time in the same way as in step (2).

[0019] Further, in step (6), since there is a situation of erect and inverted telescopes for the elevation axis of the telescope, the calculated angle may be for an erect telescope or an inverted telescope. The angles of the erect and inverted telescopes are complementary.

[0020] Further, in step (7), when pulling the single rod to lift the elevation axis upward, if the telescope is in the erect position, the angle gradually increases; if the telescope is in the inverted position, the angle gradually decreases. Thus, the erect and inverted telescope information is obtained, and the true elevation axis angle is obtained.

[0021] The advantages of the present invention compared with the prior art are as follows:

[0022] (1) According to the measured values of the accelerometer, the present invention calculates and solves the real-time angle of the elevation axis of the telescope, avoiding the association with the telescope encoder, and the calculation process is simple and easy to implement.

[0023] (2) The present invention can solve the time-consuming and laborious problems of the previous operators observing and manually operating beside the device, making the work process automated and simplified.

[0024] (3) The present invention can calculate and solve the elevation axis angle in real time at any azimuth of the telescope, with few required conditions, strong adaptability, and fast calculation speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the installation of the accelerometer for implementing the present invention. Among them, 101 is the telescope turntable, 102 is the torque motor, 103 is the photoelectric encoder, 104 is the base, 100-A is the first accelerometer, and 100-B is the second accelerometer;

[0026] Figure 2 It is a schematic diagram for solving the angles affected by gravity of the erect and inverted telescopes of the accelerometer of the present invention in a static state;

[0027] Figure 3 It is a processing flow chart of a method for real-time calculation and solution of the elevation axis angle of a telescope based on a linear accelerometer according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0028] The following describes in detail the specific embodiments of the present invention with reference to the accompanying drawings.

[0029] The specific process of a method for real-time calculation and solution of the elevation axis angle of a telescope based on a linear accelerometer according to the present invention is as Figure 3 shown, and the specific steps are as follows:

[0030] Step (1), as Figure 1 shown, it includes a telescope turntable 101, a torque motor 102, an optoelectronic encoder 103, a base 104, a first accelerometer 100-A, and a second accelerometer 100-B; the first accelerometer 100-A and the second accelerometer 100-B are fixedly installed on the telescope turntable 101 in pairs. The distances of the two accelerometers from the rotation center are the same, and the sensitive directions are the same. The sensitive direction is the tangential direction of the turntable rotation.

[0031] Step (2), place the telescope pitch axis in a vertical state, and record the measurement value accA of the first accelerometer 100-A Max . At this time, the gravity received by the first accelerometer 100-A is the maximum gravity Gacc max , and its value is equal to the measurement value accA Max ;

[0032] Step (3), place the telescope pitch axis in any position, record the measurement value accA of the first accelerometer 100-A. At this time, the accelerometer is in a stationary state, and the measurement value accA of the first accelerometer 100-A is the projection of the maximum gravity Gacc max received in the sensitive direction. As Figure 2 shown, the angle α affected by gravity can be solved using the arcsine function;

[0033] α = arcsin(accA / Gacc max ) (1)

[0034] Step (4), pull the single rod to make the pitch axis move upward, record the measurement value accA of the first accelerometer 100-A and the measurement value accB of the second accelerometer 100-B. First, strip out the instrument linear velocity value Vacc, and then subtract the instrument linear velocity value Vacc from the measurement value accA of the first accelerometer 100-A to obtain the gravity value Gacc received by the first accelerometer 100-A;

[0035] Vacc = (accA - accB) / 2 (2)

[0036] Gacc = accA - Vacc (3)

[0037] Step (5), calculate the angle value α1 affected by gravity of the first accelerometer 100-A using the arcsine relationship between the gravity values Gacc and Gacc max received by the first accelerometer 100-A;

[0038] α1 = arcsin(Gacc / Gacc max ) * 180 / PI (4)

[0039] Step (6): Since there is a situation of erect and inverted telescopes for the elevation axis of the telescope, the angle value α1 is denoted as the erect telescope angle, and the β1, which is a complementary relationship, is denoted as the inverted telescope angle;

[0040] β1 = 180 - α1 (5)

[0041] Step (7): When pulling the single rod to lift the elevation axis upward, if the angle value α1 gradually increases relative to α, the device is an erect telescope, and the actual angle of the elevation axis is α1; otherwise, the device is an inverted telescope, and the actual angle of the elevation axis is β1.

[0042] The method of the present invention has a fast calculation speed, is easy to implement, and has stable performance. It can give an alarm in time when the encoder data of the elevation axis of the telescope is incorrect and provide approximate angle information of the telescope.

[0043] The above is only the specific implementation manner in the present invention, but the protection scope of the present invention is not limited thereto. Any transformation or replacement that can be understood and conceived by those familiar with the technology within the technical scope disclosed by the present invention should be covered within the scope of the present invention. The content not described in detail in this specification belongs to the prior art well-known to those skilled in the art.

Claims

1. A real-time angle calculation method for the telescope pitch axis based on a linear accelerometer, characterized in that: The method has the following steps: Step (1): The first accelerometer (100-A) and the second accelerometer (100-B) are symmetrically installed on the telescope turntable (101), fixedly connected to the turntable. The two accelerometers are at the same distance from the rotation center and have the same sensitive direction, and the sensitive direction is the tangential direction of the turntable rotation; Step (2): Place the telescope elevation axis in a vertical state and record the measured value accA of the first accelerometer (100-A). Max Take it as the gravity value Gacc max ; Step (3): Place the telescope pitch axis in an arbitrary state, record the measured value accA of the first accelerometer (100-A), and calculate the angle α affected by gravity on the pitch axis using the gravity value; Step (4): Pull the single rod to move the pitch axis upward, record the measured value accA of the first accelerometer (100-A) and the measured value accB of the second accelerometer (100-B), and calculate the instrument linear velocity value Vacc and the gravity value Gacc received by the first accelerometer (100-A); Step (5), calculate the angle value α1 affected by gravity of the first accelerometer (100-A) using the arcsine relationship between the gravity value Gacc and Gacc received by the first accelerometer (100-A). max between to calculate the angle value α1 affected by gravity of the first accelerometer (100-A). Step (6): There are erect and inverted positions for the telescope pitch axis. Denote the angle value α1 as the erect position angle, and the β1 that is in a complementary relationship as the inverted position angle; Step (7): If the angle value α1 gradually increases relative to the angle α, the device is in the erect position, and the true angle of the pitch axis is α1; otherwise, the device is in the inverted position, and the true angle of the pitch axis is β1.

2. The real-time angle calculation method for the telescope pitch axis based on a linear accelerometer according to claim 1, characterized in that: In step (2), when the telescope pitch axis is placed in the vertical state, the gravity received by the first accelerometer (100-A) is the maximum gravity, and its gravity value is equal to the measured value. This state only needs to be calibrated once.

3. The real-time angle calculation method for the telescope pitch axis based on a linear accelerometer according to claim 1, characterized in that: In step (3), when the device is in the stationary state, the measured value accA of the first accelerometer (100-A) is the projection of the maximum gravity received in the sensitive direction. The angle value affected by gravity can be solved using the arcsine function.

4. The real-time angle calculation method for the telescope pitch axis based on a linear accelerometer according to claim 1, characterized in that: In step (4), when the device is in the moving state, first strip out the linear velocity of the device, and then calculate the gravity value received by the accelerometer.

5. The real-time angle calculation method for the telescope pitch axis based on a linear accelerometer according to claim 1, characterized in that: In step (5), when the device is in the moving state, solve the angle value affected by gravity at different positions of the accelerometer in real time in the same way as step (2).

6. The real-time angle calculation method for the telescope pitch axis based on a linear accelerometer according to claim 1, characterized in that: In step (6), due to the existence of erect and inverted positions for the telescope pitch axis, the calculated angle may be for the erect position or the inverted position. The angles of the erect and inverted positions are in a complementary relationship.

7. The real-time angle calculation method for the telescope pitch axis based on a linear accelerometer according to claim 1, characterized in that: In step (7), here pull the single rod to lift the pitch axis upward. If the telescope is in the erect position, the angle gradually increases; if the telescope is in the inverted position, the angle gradually decreases. Thus, the erect and inverted position information of the telescope is obtained, and then the true angle of the pitch axis is obtained.

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