A dome azimuth angle measuring device and method

Abstract

The present invention discloses a dome azimuth angle metering device and method. The device comprises a magnetic steel installed on the circumference of a transmission wheel and two Hall sensors fixed outside the transmission wheel. The spacing between the two Hall sensors enables the two Hall sensors to detect the sequence of corresponding valid signals when the magnetic steel rotates synchronously with the transmission wheel or the transmission wheel shaft. The device also comprises a baffle installed on the dome shaft and a zero point detection switch fixed outside the dome. When the baffle rotates synchronously with the dome or the dome shaft to the corresponding position of the zero point detection switch, the baffle is in contact with the zero point detection switch. The dome azimuth angle metering device and method can effectively solve the problem of complicated or inaccurate dome azimuth angle metering devices in the prior art. Even when the transmission ratio of the transmission device is unknown or the accuracy is poor, the dome azimuth angle can still be accurately measured.

Description

Technical Field

[0001] The present invention relates to the technical field of astronomical instruments, and in particular to a device and method for measuring the azimuth angle of a dome. Background Art

[0002] The measurement of dome azimuth angle refers to the measurement of dome azimuth angle by means of a measuring device. Pulse equivalent is an important parameter for the measurement of large dome azimuth angle. It is the minimum rotation angle that can be identified for the dome azimuth, also known as angular resolution.

[0003] At present, many large dome azimuth transmission devices are composed of multi-stage transmissions such as pulleys, reducers, and chains. The angle detection element of the device is usually installed at the motor end or the reducer input end. The pulse equivalent of the dome azimuth is calculated by the resolution and transmission ratio of the angle detection element. This method is not very reliable and relies on the transmission ratio and accuracy of the transmission device. It is difficult to achieve high accuracy. In addition, each set of dome equipment needs to input the corresponding transmission ratio at the beginning. Once the transmission ratio data is lost or forgotten, it is difficult to obtain the pulse equivalent of the corresponding dome azimuth. Summary of the invention

[0004] In order to overcome the above-mentioned deficiencies of the prior art, the present invention provides a method and device for measuring the azimuth angle of the dome, so as to solve the problem of inaccurate dome pulse equivalent data in the prior art. Even when the transmission ratio of the transmission device is unknown or the accuracy is poor, the azimuth angle of the dome can still be accurately measured.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A dome azimuth angle metering device comprises a motor, a transmission wheel and a dome, wherein the motor transmits torque to the dome through the transmission wheel, wherein at least one set of magnetic induction mechanism is arranged at the transmission wheel, wherein the magnetic induction mechanism comprises a magnet installed on the circumference of the transmission wheel or the circumference of the transmission wheel shaft and two Hall sensors fixed outside the transmission wheel, wherein the two Hall sensors are arranged at intervals along the circumferential direction, and the interval distance enables the two Hall sensors to detect the sequence of corresponding effective signals when the magnet rotates synchronously with the transmission wheel or the transmission wheel shaft, wherein a zero point detection mechanism is arranged at the dome, wherein the zero point detection mechanism comprises a baffle installed on the circumference of the dome or the circumference of the dome shaft and a zero point detection switch fixed outside the dome, and when the baffle rotates synchronously with the dome or the dome shaft to the corresponding position of the zero point detection switch, the baffle is in contact with and connected to the zero point detection switch.

[0007] Furthermore, the output signal of one Hall sensor, the output signal of another Hall sensor, and the output signal of the zero point detection switch are respectively connected to the external interrupt 0, external interrupt 1, and external interrupt 2 input ports of the microprocessor.

[0008] Furthermore, the transmission wheel includes a pulley driving wheel and a pulley driven wheel, the pulley driving wheel is driven to rotate by a motor, the pulley driving wheel and the pulley driven wheel are driven by a belt, and the magnetic induction mechanism is arranged at the pulley driven wheel.

[0009] Furthermore, it also includes a reducer, which has a reducer input shaft and a reducer output shaft, the transmission wheel is installed on the reducer input shaft, a pinion is installed on the reducer output shaft, a rack extending along the circumferential direction is fixedly provided on the circumferential or dome rotating shaft, and the pinion is installed in meshing with the rack.

[0010] A method for measuring dome azimuth angle, comprising:

[0011] Step 1: Set the first Hall sensor, the second Hall sensor and the zero point detection switch to the pull-down mode at the same time, and enable their corresponding external interrupt ports;

[0012] Step 2: Use the status of the two Hall sensors to detect the signal to determine the rotation direction of the dome;

[0013] When the magnet passes through the first Hall sensor and the second Hall sensor, if the second Hall sensor detects a signal change before the first Hall sensor, the dome rotates clockwise; if the second Hall sensor detects a signal change after the first Hall sensor, the dome rotates counterclockwise;

[0014] Step 3: N is recorded as the count pulses of the two Hall sensors. When the dome rotates continuously clockwise, when any one of the two Hall sensors detects a valid signal from the magnet, the count pulse N increases by 1 and keeps increasing. When the dome rotates continuously counterclockwise, when any one of the two Hall sensors detects a valid signal from the magnet, the count pulse N decreases by 1 and keeps decreasing.

[0015] Step 4: Initially rotate the dome in a certain direction. When the zero-point detection switch detects a valid signal for the first time, the counter N is cleared. Continue to rotate. When a valid signal is detected for the second time, the current counter value N is recorded as N1. N1 is the total number of pulses for one rotation of the dome. At the same time, the counter N is cleared.

[0016] Step 5: Based on the total number of pulses in one circle of the dome, the pulse equivalent of the dome orientation can be obtained: The unit is arc seconds;

[0017] Step 6: When the dome rotates again, the current counter value N is recorded as N2, and the two Hall sensors and magnets are used to determine the rotation direction of the dome; when the dome rotates clockwise, the pulse number N2 keeps increasing; when the dome rotates counterclockwise, the pulse number N2 keeps decreasing, and the current dome azimuth angle is obtained. Angular measurement of dome orientation is achieved.

[0018] Furthermore, the pulse equivalent is reduced by increasing the number of Hall sensors or magnets at the transmission wheel.

[0019] Furthermore, when multiple magnets are installed, the magnets are evenly distributed.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] In view of the deficiencies in the prior art, the present invention proposes a device and method for realizing the pulse equivalent of a dome. Compared with the prior art, the complexity of the system is simplified, the cost of the system is reduced, and the accuracy of the pulse equivalent is improved. Even if the transmission device in the transmission system has poor accuracy or the transmission ratio is unknown, the angle of the dome orientation can still be accurately measured. At the same time, the pulse equivalent can be reduced by increasing the number of Hall sensors or magnets. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the dome pulse equivalent realization device.

[0023] Figure 2 This is a schematic diagram of the dome zero switch installation.

[0024] Markings in the figure: 1. reducer; 2. belt; 3. pulley driving wheel; 4. magnet; 5. first Hall sensor; 6. second Hall sensor; 7. pulley driven wheel; 8. dome; 9. zero point detection switch; 10. baffle; 11. reducer output shaft; 12. pinion; 13. reducer input shaft; 14. skylight; 15. telescope true north baseline; 16. fixed axis of the dome. DETAILED DESCRIPTION

[0025] The present invention will be further described in detail below in conjunction with the accompanying drawings.

[0026] The present embodiment provides a measuring device for the azimuth angle of a dome, which mainly includes a reducer 1, a belt 2, a pulley driving wheel 3, a magnetic steel 4, a first Hall sensor 5, a second Hall sensor 6, a pulley driven wheel 7, a dome 8, a zero point detection switch 9, a baffle 10, a reducer output shaft 11, a pinion 12, and a reducer input shaft 13.

[0027] The working process of the dome azimuth transmission system is as follows: first, the pulley driving wheel 3 installed on the servo motor drives the pulley driven wheel 7 installed on the reducer input shaft 13 to rotate through the belt 2, and at the same time, the reducer input shaft 13 drives the pinion installed on the reducer output shaft 11 through the reducer 1, and then drives the dome 8 to rotate synchronously through the transmission device in which the pinion 12 and the rack on the dome 8 are meshed. The transmission system of this embodiment is only an example of the existing transmission system and is not used to limit the structure of the transmission system. When the transmission system only includes one transmission wheel, the motor can also directly drive the dome 8 to rotate synchronously by driving the transmission wheel.

[0028] A magnet 4 is attached to a certain position on the circumference of the pulley driven wheel 7 (or on the circumference of the rotating shaft of the pulley driven wheel 7), and a first Hall sensor 5 and a second Hall sensor 6 are fixedly installed near the magnet 4. The two Hall sensors should maintain a certain distance to ensure the order in which the two Hall sensors detect corresponding valid signals when the magnet rotates synchronously with the pulley driven wheel 7. It can be understood that when the transmission system only includes one transmission wheel, the magnet 4 is installed on the circumference of the transmission wheel or the circumference of the transmission wheel rotating shaft, and the two Hall sensors are fixed outside the transmission wheel. In addition, a baffle 10 is installed at a suitable position on the circumference of the rotating shaft of the dome 8 (or on the circumference of the dome 8), and a zero point detection switch 9 is installed outside the rotating shaft of the dome 8 (or outside the dome 8). The baffle 10 has a certain width and thickness to ensure that it is reliably connected when it contacts the zero point detection switch 9. Specifically, the zero point detection switch 9 in this embodiment is arranged according to Figure 2 As shown in the figure. The dotted line in the figure serves as the theoretical reference center line of the dome, that is, the true north direction (i.e., the true north baseline 15 of the telescope), which can be determined using the plumb line method. When the sun passes through the south direction of the dome, the plumb line is used as the projection line along the center of the dome as the true north baseline. The skylight 14 rotates synchronously with the dome's rotation axis. A baffle 10 is installed on the dome's rotation axis, and a zero point detection switch 9 is installed in a suitable area around the dome's fixed axis 16 outside the dome's rotation axis. When the dome rotates to the true north position, the center line of the skylight 14 coincides with the dome's telescope true north baseline 15, and at this time the baffle 10 is in contact with the zero point detection switch 9.

[0029] The output signal of the first Hall sensor 5, the output signal of the second Hall sensor 6, and the output signal of the zero point detection switch 9 are respectively connected to the external interrupt 0, external interrupt 1, external interrupt 2 and other input ports of the microprocessor. Here, the effective signals can be defined as high-level signals, and vice versa.

[0030] A method for realizing dome pulse equivalent based on the above device includes:

[0031] Step 1: Initialize the microprocessor program, set the first Hall sensor 5, the second Hall sensor 6 and the zero point detection switch to the pull-down mode at the same time, and open the corresponding external interrupt port.

[0032] Step 2: Use the states of the detection signals of the two Hall sensors to determine the rotation direction of the dome. When the magnet passes through the first Hall sensor 5 and the second Hall sensor 6, if the first Hall sensor 5 detects a signal change before the second Hall sensor 6, the dome rotates counterclockwise. If the first Hall sensor 5 detects a signal change after the second Hall sensor 5, the dome rotates clockwise.

[0033] Step 3: N is recorded as the counting pulses of the first Hall sensor 5 and the second Hall sensor 6. When the dome rotates continuously clockwise, any one of the first Hall sensor 5 or the second Hall sensor 6 detects a valid high-level signal from the magnet, and the counting pulse N increases continuously. When the dome rotates continuously counterclockwise, any one of the first Hall sensor 5 or the second Hall sensor 6 detects a valid high-level signal from the magnet, the counting pulse N decreases by 1 and decreases continuously.

[0034] Step 4: Initially rotate the dome in a certain direction. When the zero-point detection switch 9 detects a valid high-level signal from the sensor for the first time, the counter N is cleared. Continue to rotate. When a valid high-level signal is detected for the second time, the current counter value N is recorded as N1. N1 is the total number of pulses for one rotation of the dome, and the counter N is cleared at the same time.

[0035] Step 5: Based on the total number of pulses in one circle of the dome, the pulse equivalent of the dome orientation can be obtained: The unit is arc seconds.

[0036] Step 6: When the dome rotates again, the current counter value N is recorded as N2, and the Hall sensor and magnet are used to determine the rotation direction of the dome. When the dome rotates clockwise, the pulse number N2 keeps increasing; when the dome rotates counterclockwise, the pulse number N2 keeps decreasing, and the current dome azimuth angle is obtained. Angular measurement of dome orientation is achieved.

[0037] In order to further optimize this solution, the pulse equivalent is reduced and the angular resolution of the dome orientation is improved by increasing the number of Hall sensors or magnets on the pulley driven wheel 7. When installing the magnets, attention should be paid to uniform distribution to improve the accuracy of the pulse equivalent.

[0038] In summary, the invention provides a device and method for measuring the azimuth angle of a dome. The angle detection element installed in the dome azimuth transmission system and the zero point detection switch of the dome outer contour constitute a device for measuring the azimuth angle of the dome. The device is used to implement a method for measuring the azimuth angle of the dome: 1) The rotation direction of the dome is determined by detecting the sequence of magnetic steel signals using two Hall sensors; (2) The dome initially rotates in a certain direction. When the effective signal of the zero position switch is detected for the first time, the counter N is reset to zero, that is, N=0; (2) The dome continues to rotate in the same direction. When the effective signal of the zero position switch is detected for the second time, the current counter value N is recorded as N1, which is the total number of pulses in one circle of the dome azimuth, and the counter N is reset to zero at the same time; (3) According to the total number of pulses in one circle of the dome, the pulse equivalent of the dome azimuth measurement system is obtained: The unit is arc seconds; (4) When the dome rotates again, the current counter value N is recorded as N2. When the dome rotates clockwise, the pulse number N2 increases; when the dome rotates counterclockwise, the pulse number N2 decreases, and the current dome azimuth angle is obtained. The dome azimuth angle measurement is realized. The dome azimuth angle measurement method and measurement device can effectively solve the problem of complex or inaccurate measurement of the dome azimuth angle measurement device in the prior art, and even when the transmission ratio of the transmission device is unknown or the accuracy is poor, the dome azimuth angle can still be accurately measured.

[0039] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent replacement and improvement made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for measuring the azimuth angle of a dome, wherein the measuring device used in the method comprises a motor, a transmission wheel, and a dome, wherein the motor transmits torque to the dome through the transmission wheel, wherein at least one set of magnetic induction mechanisms is arranged at the transmission wheel, wherein the magnetic induction mechanisms comprise a magnet installed on the circumference of the transmission wheel or the circumference of the transmission wheel shaft and two Hall sensors fixed outside the transmission wheel, wherein the two Hall sensors are arranged at intervals along the circumference, and the interval distance enables the two Hall sensors to detect the sequence of corresponding valid signals when the magnet rotates synchronously with the transmission wheel or the transmission wheel shaft, wherein a zero point detection mechanism is arranged at the dome, wherein the zero point detection mechanism comprises a baffle installed on the circumference of the dome or the circumference of the dome shaft and a zero point detection switch fixed outside the dome, wherein when the baffle rotates synchronously with the dome or the dome shaft to the corresponding position of the zero point detection switch, the baffle is in contact with the zero point detection switch, wherein the baffle is connected with the zero point detection switch, wherein the baffle is connected with the zero point detection switch, wherein the baffle is connected with the zero point detection switch, wherein the baffle is connected with the zero point detection switch, wherein the baffle is connected with the zero point detection switch, and ... The method comprises: Step 1: Set the first Hall sensor, the second Hall sensor and the zero point detection switch to the pull-down mode at the same time, and enable their corresponding external interrupt ports; Step 2: Use the status of the two Hall sensors to detect the signal to determine the rotation direction of the dome; When the magnet passes through the first Hall sensor and the second Hall sensor, if the second Hall sensor detects a signal change before the first Hall sensor, the dome rotates clockwise; if the second Hall sensor detects a signal change after the first Hall sensor, the dome rotates counterclockwise; Step 3: N is recorded as the count pulses of the two Hall sensors. When the dome rotates continuously clockwise, when any one of the two Hall sensors detects a valid signal from the magnet, the count pulse N increases by 1 and keeps increasing. When the dome rotates continuously counterclockwise, when any one of the two Hall sensors detects a valid signal from the magnet, the count pulse N decreases by 1 and keeps decreasing. Step 4: Initially rotate the dome in a certain direction. When the zero-point detection switch detects a valid signal for the first time, the counter N is cleared. Continue to rotate. When a valid signal is detected for the second time, the current counter value N is recorded as N1. N1 is the total number of pulses for one rotation of the dome. At the same time, the counter N is cleared. Step 5: Based on the total number of pulses in one circle of the dome, the pulse equivalent of the dome orientation can be obtained: , the unit is arc seconds; Step 6: When the dome rotates again, the current counter value N is recorded as N2, and the two Hall sensors and magnets are used to determine the rotation direction of the dome; when the dome rotates clockwise, the pulse number N2 keeps increasing; when the dome rotates counterclockwise, the pulse number N2 keeps decreasing, and the current dome azimuth angle is obtained. , achieving the angular measurement of the dome orientation.

2. The measuring method according to claim 1, characterized in that: The pulse equivalent can be reduced by increasing the number of Hall sensors or magnets at the transmission wheel.

3. The measuring method according to claim 2, characterized in that: When multiple magnets are installed, the magnets are evenly distributed.

4. The measuring method according to claim 1, characterized in that: An output signal of one of the Hall sensors, an output signal of another Hall sensor, and an output signal of the zero point detection switch are respectively connected to the external interrupt 0, external interrupt port 1, and external interrupt port 2 input ports of the microprocessor.

5. The measuring method according to claim 1, characterized in that: The transmission wheel comprises a pulley driving wheel and a pulley driven wheel. The pulley driving wheel is driven to rotate by a motor. The pulley driving wheel and the pulley driven wheel are driven by a belt. The magnetic induction mechanism is arranged at the pulley driven wheel.

6. The measuring method according to claim 1, characterized in that: It also includes a reducer, which has a reducer input shaft and a reducer output shaft, the transmission wheel is installed on the reducer input shaft, a pinion is installed on the reducer output shaft, a rack extending along the circumferential direction is fixedly provided on the circumferential or dome rotating shaft, and the pinion is installed in meshing with the rack.

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