A total station-based ranging and direction-finding precision method

Abstract

This invention discloses a method for measuring distance and direction accuracy based on a total station, belonging to the field of high-frequency sonar performance measurement. First, the total station is set up, and the measurement target and reference target are deployed. Second, calibration is performed using the reference target. Next, the distance and azimuth of the target are measured. Finally, the distance and direction accuracy are calculated. This invention uses a total station as the tool for measuring the true value of the target. This device has extremely small measurement errors, which do not affect the measurement results. Simultaneously, it proposes an effective and simple method for zero-point calibration of the total station and sonar, eliminating the need to adjust the positions of the total station, sonar, and target to the same direction. Calibration is performed solely through calculation, resulting in high measurement accuracy with negligible error impact. Furthermore, it is easy to implement and computationally simple, effectively solving the problem of measuring high-precision distance and azimuth indicators.

Description

Technical Field

[0001] This invention relates to the field of high-frequency sonar performance measurement technology, and in particular to a distance and direction measurement accuracy method based on a total station. Background Technology

[0002] High-frequency sonar is currently an important instrument for marine target detection, especially for small targets. It is mainly used for the precise location of close-range targets in the ocean, thus requiring high-precision range and azimuth indicators. However, the range and azimuth accuracy of high-frequency sonar is often affected by errors introduced by the environment and measuring tools, which can influence the final measurement results.

[0003] Currently, the main method for improving ranging and direction finding accuracy is to use DGPS on a lake to locate the target and use it as the true value for measurement. However, this device has a large measurement error, which can affect the measurement results of high-frequency sonar. Summary of the Invention

[0004] The purpose of this invention is to provide a method for improving the accuracy of distance and direction measurement based on a total station, so as to solve the problems in the background art.

[0005] To solve the above-mentioned technical problems, the present invention provides a method for measuring distance and direction accuracy based on a total station, comprising:

[0006] Step 1: Set up the total station and place the measurement targets and reference targets;

[0007] Step 2: Calibrate using a reference target;

[0008] Step 3: Measure the distance and orientation of the target.

[0009] Step 4: Calculate the distance and direction finding accuracy.

[0010] In one implementation, step one includes:

[0011] The sonar was installed on a rotating platform and then submerged in water to form array A;

[0012] Total station B should be set up in an open area of ​​the platform, where it is possible to measure the target.

[0013] The measurement target D is placed at a certain distance from the sonar, at the same depth as the sonar entering the water.

[0014] Reference target C is placed at close range to the measurement target and then connected to the platform before being submerged in water.

[0015] In one embodiment, a total station prism is mounted above the water entry point of the measurement target.

[0016] In one implementation, step two includes:

[0017] The zero-point calibration of array A and total station B is performed using reference target C. The calibration steps are as follows:

[0018] Step 1: Set BA as the zero position of the total station and measure the distance L from the total station B to the array A;

[0019] Step 2: Measure the distance L1 from the total station B to the reference target C, and the angle θ between BA and BC using a total station;

[0020] Step 3: Calculate the distance D1 from the base array A to the reference target and the angle γ between BA and AC according to the following formulas;

[0021]

[0022]

[0023] Step 4: Rotate the rotary table to align the sonar zero position with the AC direction.

[0024] In one implementation, step three includes:

[0025] Step 1: The total station measures the distance L2 from the total station B to the target D, and the angle α between BA and BD. At the same time, the sonar directly measures the distance D from the target to the array A and the azimuth Ω, where the azimuth Ω is the angle between AD and AC.

[0026] Step 2: Calculate the distance D2 from the target D to the array A and the angle φ between BA and AD according to the following formula;

[0027]

[0028]

[0029] Step 3: Calculate the angle β between DA and AC using the following formula;

[0030]

[0031] Step 4: Repeat steps 1 to 3 to measure N sets of data.

[0032] In one implementation, step four includes:

[0033] The D2 and β calculated in step three are used as the true values ​​of the measured target and compared with D and Ω obtained directly from the sonar measurement. The ranging accuracy and direction finding accuracy are calculated according to the following formulas:

[0034]

[0035]

[0036] In the distance and direction measurement accuracy method based on a total station provided by this invention, a total station is used as the tool for measuring the true value of the target. The measurement error of this device is extremely small and will not affect the measurement results. At the same time, an effective and simple method for zero-position calibration of the total station and sonar is proposed. It does not require adjusting the positions of the total station, sonar and target to the same direction. Calibration can be performed by calculation. Not only is the measurement result highly accurate and the error influence negligible, but it is also easy to implement and simple to calculate, effectively solving the problem of measuring high-precision distance and azimuth indicators. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of a distance and direction measurement accuracy method based on a total station provided by the present invention.

[0038] Figure 2 This is a schematic diagram of the structure for setting up a total station and deploying various targets. Detailed Implementation

[0039] The following detailed description, in conjunction with the accompanying drawings and specific embodiments, provides a further detailed explanation of the distance and direction measurement accuracy method based on a total station proposed in this invention. The advantages and features of this invention will become clearer from the following description. It should be noted that the accompanying drawings are all in a very simplified form and use non-precise scales, and are only used to facilitate and clarify the illustration of the embodiments of this invention.

[0040] This invention provides a method for improving distance and direction measurement accuracy using a total station, the process of which is as follows: Figure 1 As shown, it includes the following steps:

[0041] Step 1: Set up the total station and deploy various targets

[0042] After the sonar is mounted on the rotating platform and submerged to a certain depth in the water, it forms array A. The total station B is set up in an open area of ​​the platform, sufficient to measure the target. The target D is placed at a certain distance from the sonar, at the same depth as the sonar submersion. A total station prism is mounted above the target's submersion point. The reference target C is placed close to the target and submerged to a certain depth after being connected to the platform. A deployment diagram is shown below. Figure 2 As shown.

[0043] Step 2: Calibrate using a reference target.

[0044] The zero-point calibration of array A and total station B is performed using reference target C. The calibration steps are as follows:

[0045] 1. Set BA as the zero position of the total station, and measure the distance L from the total station B to the base array A;

[0046] 2. Measure the distance L1 from the total station B to the reference target C, and the angle θ between BA and BC using a total station;

[0047] 3. Calculate the distance D1 from the base array A to the reference target and the angle γ between BA and AC according to formulas (1) and (2);

[0048]

[0049]

[0050] 4. Rotate the rotary table to align the sonar zero position with the AC direction.

[0051] At this point, the zero-point calibration of both the total station and the sonar is complete, and the target can be measured.

[0052] Step 3: Measure the distance and orientation of the target.

[0053] After calibration, distance and direction finding are performed on the target. The measurement steps are as follows:

[0054] 1. The total station measures the distance L2 from the total station B to the target D, and the angle α between BA and BD. At the same time, the sonar directly measures the distance D from the target to the array A and the azimuth Ω (i.e. the angle between AD and AC). A total of N sets of measurements are taken.

[0055] 2. Calculate the distance D2 from the target D to the array A and the angle φ between BA and AD according to formulas (3) and (4);

[0056]

[0057]

[0058] 3. Calculate the angle β between DA and AC according to formula (5);

[0059]

[0060] 4. Repeat steps 1 to 3 to measure N sets of data.

[0061] Step 4: Calculate the distance and direction finding accuracy

[0062] The N sets of D2 and β calculated in step three are used as the true values ​​of the measured target. They are compared with the N sets of D and Ω obtained directly by sonar measurement. The ranging accuracy and direction finding accuracy are calculated according to formula (6) and formula (7).

[0063]

[0064]

[0065] The method provided by this invention is simple to implement, does not require adjusting the total station, sonar and target position to be in the same direction, and has extremely small measurement error, which will not affect the ranging and direction finding accuracy of the high-frequency sonar, and can accurately and effectively verify the performance indicators of the high-frequency sonar.

[0066] The above description is merely a description of preferred embodiments of the present invention and is not intended to limit the scope of the present invention in any way. Any changes or modifications made by those skilled in the art based on the above disclosure shall fall within the protection scope of the claims.

Claims

1. A total station-based ranging and direction-finding accuracy method, characterized in that, It includes: Step one, erecting total station and laying measurement target and reference target; Step two, calibration through reference target; Step three, measuring distance and direction of measurement target; Step four, calculating ranging and direction finding accuracy; wherein, The step two includes: Calibration work of base array A and total station B zero position is carried out by using reference target C, and the calibration steps are as follows: Step 1, set BA as total station zero position direction, and measure distance L of total station B to base array A; Step 2, total station measures distance L1 of total station B to reference target C, and BA and BC included angle θ; Step 3, according to the following formula, calculate distance D1 of base array A to reference target and BA and AC included angle γ; Step 4, rotate rotating table to make sonar zero position as AC direction.

2. The total station based distance finding direction of arrival accuracy method as claimed in claim 1 wherein, The step one includes: After sonar is installed on rotating table and enters water, base array A is formed; Total station B is erected on platform open position, and can measure target; Measurement target D is laid outside a certain distance from sonar, and is consistent with sonar entering water depth; Reference target C is laid in close distance from measurement target, and is connected with platform and enters water.

3. The total station based distance finding direction finding accuracy method as claimed in claim 2, wherein, Total station prism is erected above the water entry of measurement target.

4. The total station based distance finding direction of arrival accuracy method as claimed in claim 1 wherein, The step three includes: Step 1, total station measures distance L2 of total station B to measurement target D, and BA and BD included angle α, at the same time, sonar directly measures distance D and direction Ω of measurement target to base array A, and direction Ω is AD and AC included angle; Step 2, the distance D2 of the measurement target D from the array A and the angle between BA and AD are calculated according to the following formula Step 3, according to the following formula, calculate DA and AC included angle β; Step 4, repeat steps 1 to 3, and measure N groups of data.

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