A radar azimuth positioning device

Abstract

The present invention discloses a device for radar azimuth positioning, comprising: a radar spindle; a speed measuring shaft, which is transmission-connected with the radar spindle; a rotary encoder, which is arranged on the speed measuring shaft; a detection unit and an auxiliary detector, wherein the detection unit is arranged on the radar spindle, and the auxiliary detector is arranged at a relative position to the detection unit, and when the detection unit rotates to the detection area of ​​the auxiliary detector, the auxiliary detector generates an in-position signal. The high-precision azimuth of the radar spindle is achieved without occupying the installation space of the radar spindle and without being able to use the installation position of the radar spindle, thus breaking through the limitation of the installation of the spindle encoder.

Description

Technical Field

[0001] The invention relates to the field of radar engineering, and in particular to a radar azimuth positioning device. Background Art

[0002] Radar is a device that uses electromagnetic waves to detect targets and determine their spatial positions. The azimuth angle measurement accuracy of radar consists of two parts. The first part is the north pointing accuracy, that is, the zero value accuracy of the radar; the second part is the transmission measurement accuracy, that is, when the radar moves from the zero point to the target point, the angle measurement error caused by the transmission chain error and the angle measurement device measurement error. With the rapid development of encoder technology, the measurement accuracy of angle measurement equipment is rapidly improving. Therefore, the north pointing accuracy of radar has become the bottleneck of the radar azimuth angle measurement accuracy.

[0003] There are currently two common solutions to the problem of radar north pointing accuracy: 1. Calibrate the radar immediately after each startup. Each time the radar is turned on, the "sun method" or gyro north finder or GPS is used to calibrate the radar and record the current zero point value. The pointing accuracy of this solution is determined by the measurement method and equipment, and some measurement conditions may not be achieved when the radar is deployed in the field. Each calibration takes a long time. In an emergency, the target may be missed due to the long startup time. Its use is relatively limited and is more suitable for timed radar calibration, but not for radar north finding after each startup; 2. Install the encoder coaxially with the radar main shaft. After the encoder is installed on the radar main shaft, the encoder reading is 1:1 with the radar azimuth and there is no transmission error. When the radar is calibrated after the first installation, the encoder value when the radar points to the north can be recorded as the zero point of the radar. Each time the radar is turned on, the radar directly looks for the recorded encoder zero value point to realize the radar's north pointing. The radar's zero position error has the same accuracy level as the encoder's measurement error. This method is the most economical, practical and effective method, and is also the preferred solution for general radar design. However, due to the particularity of radar equipment, the central spindle of the radar generally has electric slip rings, fiber slip rings, waveguide slip rings, liquid joints and other equipment, which seriously occupy the spindle space. This makes it difficult to install high-precision encoders or only separate encoders with large code disks can be installed, resulting in insufficient positioning accuracy or complex structure and increased volume. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a radar azimuth positioning method, which can locate the radar zero point without installing an encoder on the main shaft, has a simple structure and high measurement accuracy.

[0005] According to the present invention, a radar azimuth positioning device includes: a radar main shaft; a speed measuring shaft, which is connected to the radar main shaft through gear transmission; a rotary encoder, which is arranged on the speed measuring shaft; a detection unit and an auxiliary detector, wherein the detection unit is arranged on the radar main shaft, and the auxiliary detector is arranged at a relative position to the detection unit, and when the detection unit rotates to the detection area of ​​the auxiliary detector, the auxiliary detector generates an in-position signal.

[0006] A radar azimuth positioning device according to an embodiment of the present invention has at least the following beneficial effects: high-precision azimuth of the radar spindle is achieved without occupying the radar spindle installation space and without being able to use the radar spindle installation position, thus breaking through the limitation of the spindle encoder installation.

[0007] According to a radar azimuth positioning device of an embodiment of the present invention, a first gear is installed on the radar main shaft, a second gear is installed on the speed measuring shaft, and the first gear is meshed with the second gear.

[0008] In a radar azimuth positioning device according to an embodiment of the present invention, the second gear is an anti-backlash gear.

[0009] A radar azimuth positioning device according to an embodiment of the present invention further includes a bearing installed on the speed measuring shaft, and the bearing is arranged at the upper end of the anti-backlash gear.

[0010] According to a radar azimuth positioning device of an embodiment of the present invention, a first gear is installed on the radar main shaft, an anti-backlash gear is installed at the bottom of the speed measuring shaft, the anti-backlash gear is meshed with the first gear, the speed measuring shaft is installed in a bearing seat through an angular contact ball bearing, and the bearing seat is arranged at the upper end of the anti-backlash gear.

[0011] In a radar azimuth positioning device according to an embodiment of the present invention, the rotary encoder is an absolute value encoder.

[0012] In a radar azimuth positioning device according to an embodiment of the present invention, the auxiliary detector is a proximity switch, and the detection part is a block.

[0013] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0015] Figure 1 A top view of an embodiment of the present invention;

[0016] Figure 2 is a cross-sectional view of an embodiment of the present invention;

[0017] Figure 3 This is a distribution diagram of encoder reading values ​​corresponding to the radar spindle zero point according to an embodiment of the present invention. DETAILED DESCRIPTION

[0018] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0019] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0020] A radar azimuth positioning device according to an embodiment of the present invention comprises a radar main shaft 7; a speed measuring shaft 4, which is meshed with the radar main shaft 7 through gears; a rotary encoder 5, which can be a photoelectric, magnetoelectric and contact brush encoder, and is arranged on the speed measuring shaft 4; a detection unit 8 and an auxiliary detector 9, wherein the detection unit 8 is arranged on the radar main shaft 7, and the auxiliary detector 9 is arranged at a relative position of the detection unit 8. Specifically, the auxiliary detector 9 can be arranged concentrically with the detection unit 8 and arranged on the outer ring, and the detection unit 8 is arranged on the inner ring. The auxiliary detector 9 can be fixed by a bracket on the radar, and the detection unit 8 rotates with the radar main shaft 4. When the detection unit 8 rotates to the detection area of ​​the auxiliary detector 9, the auxiliary detector 9 generates an in-position signal. The present invention breaks through the limitation of the installation of the main shaft encoder, has high positioning accuracy, and has a high economic effect.

[0021] In some embodiments of the present invention, a first gear 6 is installed on the radar main shaft 7, a second gear is installed on the speed measuring shaft 4, and the first gear 6 is meshed with the second gear. The second gear is an anti-backlash gear 1. In some embodiments, a bearing is also included that is installed on the speed measuring shaft 4, and the bearing is arranged at the upper end of the anti-backlash gear 1.

[0022] See also Figure 1 and Figure 2In one embodiment of the present invention, the speed measuring shaft 4 is installed in the bearing seat of the speed measuring shaft 4 through a pair of angular contact ball bearings 3. A second gear is installed at the tail end of the speed measuring shaft 4. The second gear adopts a pair of mechanical anti-backlash gears 1. The anti-backlash gear 1 uses a torsion spring to provide anti-backlash torque. The speed measuring shaft 4 cooperates with the large gear of the radar main shaft 7 through the anti-backlash gear 1. The angle of the azimuth rotation of the radar main shaft 7 is transmitted to the speed measuring shaft 4 through the gear matching. A rotary encoder 5 is installed on the upper end of the speed measuring shaft 4 in the form of a sleeve. In this embodiment, the encoder adopts an absolute encoder, specifically, a magnetoelectric or contact brush absolute encoder. The rotary encoder 5 is used to record the rotation angle of the speed measuring shaft 4. A detection unit 8 is also installed on the radar main shaft 7, and an auxiliary detector 9 is also installed on the radar. The auxiliary detector 9 adopts a proximity switch, and the detection unit 8 adopts a block. The type of the proximity switch can be inductive, capacitive, Hall, AC, or DC. When the detection unit 8 rotates to the vicinity of the proximity switch, the proximity switch can generate a high-level signal for positioning. The high level continuous angle of the proximity switch does not exceed 360 / (3*m). m is the number of teeth of the anti-backlash gear 1.

[0023] The working principle of the embodiment of the present invention is as follows: Due to the space limitation of the radar structure and the requirements of the transmission system design, the reduction ratio between the anti-backlash gear 1 of the speed measuring shaft 4 and the large gear of the radar main shaft 7 is not 1:1. Therefore, when the radar main shaft 7 rotates to the zero position of each circle, the readings on the absolute encoder are inconsistent. However, after m cycles of the number of teeth of the anti-backlash gear 1, the readings on the absolute encoder begin to repeat. Turn the radar to the position where the proximity switch is a high-level signal, which sets the reading of the encoder on the speed measuring shaft 4 to 0, and determines the first zero positioning point of the radar. See Figure 3 , continue to rotate the radar. When the radar spindle 7 rotates to the next zero point, the reading of the absolute encoder is: │a×n / m│%a. The encoder value of the next zero point is: │2a×n / m│%a. Until the mth zero point, the encoder value is: │(m-1)a*n / m│%a. n and m are the number of teeth of the first gear 6 and the second gear or the anti-backlash gear 1, respectively. a is the value of one rotation of the absolute encoder. After one rotation of the absolute encoder, the value becomes 0. Therefore, multiply a by n / m and then round it. Then take the result modulo a to get the reading of the absolute encoder. The encoder values ​​of these m spindle zero point points divide the encoding code disk into m equal parts. If the high level width and data drift of the auxiliary positioning proximity switch are better than 360 / (3×m) degrees, then the high level point of the auxiliary positioning proximity switch will appear within the range of ±360 / (3×m) degrees of the radar spindle 7 zero point. See Figure 3It can be known that when the high level width and data drift of the auxiliary positioning proximity switch are better than 360 / (3×m) degrees, when the auxiliary positioning proximity switch has a high level signal, the encoder value of the corresponding spindle zero point positioning point is the only fixed one.

[0024] Therefore, when the radar is assembled inside the factory, according to the absolute encoder of the proximity switch and the speed measuring axis 4, the radar's motion controller establishes an encoder reading table of the radar zero point position, which contains a total of m values. When the radar is deployed to the work site, the radar only needs to move to the position where the proximity switch generates a high-level signal to perform north-finding operation, record the encoder reading value, and then match the encoder reading table of the radar zero point position within the range of ±360 / (3×m) degrees of the encoder reading value to determine the unique radar zero point position. The encoder reading value ±360 / (3×m) degrees is converted into the encoder reading value, which is the encoder reading value ±a / (3×m). In this way, the azimuth positioning of the radar can be achieved. The theoretical accuracy of this positioning system is as high as ±(m / n)*LSB, which is much higher than the positioning accuracy of the encoder resolution.

[0025] The present invention achieves high-precision positioning of the radar spindle 7 without occupying the installation space of the radar spindle 7 and without being able to use the installation position of the radar spindle 7, thus breaking through the limitation of the installation of the spindle encoder; without adding additional devices and equipment, the positioning accuracy of the radar spindle 7 higher than the encoder resolution is achieved by using low-precision proximity switches and encoders, thus having extremely high engineering practicability and economic effect.

Claims

1. A radar azimuth positioning device, characterized in that: include: Radar spindle (7); The speed measuring shaft (4) is connected to the radar main shaft (7) via a gear transmission; a first gear (6) is mounted on the radar main shaft (7), a second gear is mounted on the speed measuring shaft (4), the first gear (6) and the second gear are meshed; the second gear is a backlash-eliminating gear (1); A rotary encoder (5) arranged on the speed measuring shaft (4); A detection unit (8) and an auxiliary detector (9), wherein the detection unit (8) is arranged on the radar main shaft (7), and the auxiliary detector (9) is arranged at a relative position to the detection unit (8). When the detection unit (8) rotates to the detection area of ​​the auxiliary detector (9), the auxiliary detector (9) generates an in-position signal. The auxiliary detector (9) is a proximity switch, and the detection unit (8) is a stopper. When the radar rotates to a position where the proximity switch generates a high-level signal, the reading of the encoder on the speed measuring shaft (4) is set to 0, thereby determining the first zero positioning point of the radar. The radar continues to rotate. When the radar main shaft (7) rotates to the next zero point, the reading of the rotary encoder (5) is: │a×n / m│%a, and the encoder value of the next zero point is: │2a×n / m│%a, and the encoder value of the mth zero point is: │(m-1)a*n / m│%a, where n and m are the number of teeth of the first gear (6) and the second gear or the anti-backlash gear (1), respectively, and a is the value of the rotary encoder (5) after one rotation. After the rotary encoder (5) rotates one circle, the value becomes 0. Multiply a by n / m and then round it up, and then find the modulus of a to obtain the reading of the rotary encoder (5).

2. The radar azimuth positioning device according to claim 1, characterized in that: It also includes a bearing mounted on the speed measuring shaft (4), the bearing being arranged at the upper end of the anti-backlash gear (1).

3. The radar azimuth positioning device according to claim 1, characterized in that: A first gear (6) is mounted on the radar main shaft (7), an anti-backlash gear (1) is mounted on the bottom of the speed measuring shaft (4), the anti-backlash gear (1) and the first gear (6) are meshed, the speed measuring shaft (4) is mounted in a bearing seat (2) via an angular contact ball bearing (3), and the bearing seat (2) is arranged on the upper end of the anti-backlash gear (1).

4. The radar azimuth positioning device according to claim 1, characterized in that: The rotary encoder (5) is an absolute value encoder.

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