Logometer calibration method, device and medium suitable for uniform variable flow or uniform flow

Abstract

This invention discloses a calibration method, equipment, and medium for a speedometer suitable for uniformly variable or uniformly velocity flow. The method includes: determining whether the water flow is uniform or uniformly variable when the ship is sailing stably; if so, proceeding to the next step; otherwise, re-finding the test area until the test requirements are met; acquiring the equivalent average water velocity, equivalent land velocity, equivalent track direction, and equivalent heading angle of the ship during a first time period while sailing along a certain direction; acquiring the equivalent average water velocity, equivalent land velocity, equivalent track direction, and equivalent heading angle of the ship during a second time period while sailing along another direction; calculating the true water velocity based on the water flow velocity at the end of the first and second time periods; and calculating a correction coefficient based on the true water velocity to complete the calibration of the speed point. This method is simple to operate, requires fewer sailing trips, has a short calibration time, and has low requirements for changes in water flow velocity.

Description

Technical Field

[0001] This invention relates to the field of odometer calibration technology, and more specifically to a odometer calibration method, equipment and medium suitable for uniformly variable flow or uniform flow. Background Technology

[0002] A ship's log is a navigation instrument used to measure a ship's speed and cumulative distance traveled. Logs can be classified into two categories based on their measurement reference coordinate system: relative logs and absolute logs. Relative logs can only measure the ship's speed relative to the water and accumulate distance traveled. All logs require calibration before use to ensure accurate speed measurements, and they must be calibrated again after a period of use.

[0003] The calibration of odometers is usually carried out in accordance with the provisions of GJB 6850.128-2009 "Regulations for Mooring and Navigation Tests of Surface Ships Part 128: Test of Odometers", which adopts the calibration method of running back and forth three times in a "clockwise-counterclockwise-clockwise" manner. This method is currently the internationally recognized calibration method, but it also has shortcomings such as the calibration test process being too complicated and time-consuming.

[0004] To address this problem, this invention proposes a rapid calibration method that simplifies the calibration process, reduces the number of calibration trips, shortens calibration time, and improves the economic efficiency of the speedometer. Summary of the Invention

[0005] In view of this, the present invention provides a method, equipment and medium for calibrating a speedometer suitable for uniformly variable flow or uniform flow. The method is simple to operate, requires fewer navigation trips, has a short calibration time and low requirements for changes in water flow velocity.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a method for calibrating a speedometer suitable for uniformly variable flow or uniform flow, comprising:

[0008] Step 1: When the ship is sailing steadily, determine whether the water flow is uniform or uniformly variable. If it meets the requirements, proceed to the next step; otherwise, find a new test area until the test requirements are met.

[0009] Step 2: Obtain the real-time water speed, real-time land speed, instantaneous track direction, and instantaneous heading angle of the ship during the first time period while sailing along a certain course, and obtain the equivalent average water speed, equivalent land speed, equivalent track direction, and equivalent heading angle during the first time period;

[0010] Step 3: Obtain the real-time water speed, real-time land speed, instantaneous track direction, and instantaneous heading angle of the ship during the second time period while sailing along another course, and obtain the equivalent average water speed, equivalent land speed, equivalent track direction, and equivalent heading angle during the second time period;

[0011] Step 4: Calculate the true velocity of water based on the equivalent average velocity to water, equivalent velocity to land, equivalent track direction and equivalent heading angle in the first time period, the equivalent average velocity to water, equivalent velocity to land, equivalent track direction and equivalent heading angle in the second time period, the water flow velocity at the end of the first time period and the water flow velocity at the end of the second time period.

[0012] Step 5: Based on the correction coefficient calculated for the true water speed, complete the calibration of the speed point.

[0013] Preferably, the specific judgment process in step 1 is as follows:

[0014] If the difference between the ship's real-time velocity relative to the ground and its real-time velocity relative to the water is a fixed value when the ship is sailing steadily, then it is a uniform flow.

[0015] If the difference between the real-time velocity relative to the ground and the real-time velocity relative to the water when the ship is sailing steadily shows an increasing or decreasing trend, it indicates that it is a uniformly variable flow.

[0016] Preferably, the formulas for calculating the equivalent average water velocity, equivalent ground velocity, equivalent course direction, and equivalent heading angle during the first time period are as follows:

[0017]

[0018] Where t2-t1 is the first time period, V J1 V is the equivalent average velocity relative to water over the time interval (t2-t1). D1 Let β1 be the equivalent ground velocity during the time interval (t2-t1), β1 be the equivalent course direction during the time interval (t2-t1), and α1 be the equivalent heading angle during the time interval (t2-t1). J1i V is the real-time water velocity at a certain moment within the time interval (t2-t1). D1i α1i and β 1i These represent the real-time ground velocity, instantaneous heading angle, and instantaneous trajectory at a certain moment within the time interval (t2-t1), respectively, where n represents the total number of instantaneous variables collected within the time interval (t2-t1).

[0019] Preferably, the formulas for calculating the equivalent average water velocity, equivalent ground velocity, equivalent course direction, and equivalent heading angle during the second time period are as follows:

[0020]

[0021] Where t4-t3 is the first time period, V J2 V is the equivalent average velocity relative to water over the time interval (t4-t3). D2 β2 is the equivalent ground velocity during the time interval (t4-t3), α2 is the equivalent course direction during the time interval (t4-t3), and V is the equivalent heading angle during the time interval (t4-t3). J2j V is the real-time water velocity at a certain moment within the time interval (t4-t3). D2j α 2j and β 2j These represent the real-time ground velocity, instantaneous heading angle, and instantaneous trajectory at a certain moment within the time interval (t4-t3), respectively, and m represents the total number of instantaneous variables collected within the time interval (t4-t3).

[0022] Preferably, the water flow velocity V at the end of the first time period L1 The calculation formula is:

[0023] V L1 =V L0 +δ VL ·(t2-t1)

[0024] Among them, V L0 δ represents the water flow velocity at the beginning of the first time interval. VL For water flow acceleration,

[0025] The water flow velocity V at the end of the second time period L2 The calculation formula is:

[0026] V L2 =V L0 +δ VL ·(t4-t3).

[0027] Among them, V L2 The flow rate at the start of the second time period.

[0028] Preferably, the formula for calculating the water velocity is:

[0029]

[0030] Among them, V Z1 To determine the true speed of the water.

[0031] Preferably, the formula for calculating the correction factor is:

[0032] k Z1 =V Z1 / V′ J

[0033]

[0034] Where, kZ1 V′ is the correction factor. J1 and V′ J2 These are the average water flow rates displayed by the speedometer during the first and second time periods, respectively.

[0035] In a second aspect, the present invention provides a computer device, comprising:

[0036] Memory, used to store computer programs;

[0037] A processor is configured to implement the steps of the speedometer calibration method applicable to uniformly variable flow or uniform flow when executing the computer program.

[0038] Thirdly, the present invention provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the speedometer calibration method applicable to uniformly variable flow or uniform flow.

[0039] As can be seen from the above technical solution, compared with the prior art, the present invention discloses a method, equipment and medium for calibrating a speed log suitable for uniformly variable flow or uniform flow. The calibration process of one speed point can be completed by two trips of straight-line navigation with varying heading. This method simplifies the calibration process, reduces the number of calibration trips, shortens the calibration time, and improves the economic efficiency of using the speed log. This method can be used to perform speed log calibration tests under both uniform and uniformly variable flow conditions, improving the environmental adaptability of the speed log. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0041] Figure 1 The present invention provides a flowchart of a speedometer calibration method applicable to uniformly variable flow or uniform flow.

[0042] Figure 2 This is a schematic diagram of the navigation coordinate system and position during the time interval t2-t1 provided by the present invention.

[0043] Figure 3 This is a schematic diagram of the navigation coordinate system and position during the time interval t4-t3 provided by the present invention. Detailed Implementation

[0044] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] This invention discloses a method for calibrating a speedometer suitable for uniformly variable or uniform flow, such as... Figure 1 As shown, it includes:

[0046] Step 1: Start the equipment and wait for the boat to stabilize. Compare the real-time ground speed of the GPS with the real-time water speed of the log to determine whether the water flow is uniform or the flow velocity varies uniformly. If it meets the requirements, proceed to the next step; otherwise, find a new test area until the test requirements are met. Uniform speed means that the difference between the real-time ground speed of the GPS and the real-time water speed displayed by the log approaches a fixed value. Uniform flow velocity means that the difference between the two shows an increasing or decreasing trend.

[0047] Step 2: Obtain the real-time water speed, real-time land speed, instantaneous track direction, and instantaneous heading angle of the ship during the first time period while sailing along a certain course, and obtain the equivalent average water speed, equivalent land speed, equivalent track direction, and equivalent heading angle during the first time period;

[0048] The specific implementation process is as follows:

[0049] like Figure 2 As shown, a ship travels a short distance in an open sea with constant power. If at time t1 the ship is at the origin O, with an equivalent heading angle α1 and an equivalent track angle β1, and at time t2 it reaches point B(x2,y2); if the water flow velocity V L1 If the angle is 0, the ship should travel from the origin O to point A(x1,y1) with an equivalent heading angle α1. Because of the water flow, points A and B do not coincide. Therefore, during the time interval (t2-t1), due to the water flow, the ship undergoes displacements of (x2-x1) and (y2-y1). At this point, according to... Figure 2 Using the coordinate system in the equations, we can obtain the following set of equations for the motion of point AB during navigation:

[0050]

[0051] Among them, V x1 Let V be the average velocity of the ship along the x-axis during the time interval (t2-t1). y1 Let x1 and y1 be the average velocity of the ship along the y-axis within the range (t2-t1). Let x1 and y1 be the coordinates of point A, and x2 and y2 be the coordinates of point B. The coordinates of point B can be obtained from GPS.

[0052] x1 and y1 have the following relationship:

[0053] y1=tan(α1)x1 (2)

[0054] Flow velocity V L1 The flow direction γ1 has the following relationship:

[0055]

[0056] Flow velocity V during time interval t2-t1 L1 Flow direction γ1, equivalent water velocity V J1 Equivalent ground velocity V D1 The following relationship exists:

[0057]

[0058] The above equations can form a system of equations for the navigation process at point AB:

[0059]

[0060] The formulas for calculating the equivalent average water velocity, equivalent ground velocity, equivalent track direction, and equivalent heading angle are as follows:

[0061]

[0062] Among them, V J1i V is the real-time water velocity at a certain moment within the time interval (t2-t1) (obtained through simulation calculation). D1i α 1i and β 1i These represent the real-time ground velocity (obtained via GPS), instantaneous heading angle (obtained via GPS), and instantaneous trajectory (obtained via GPS) at a certain moment within the time interval (t2-t1), respectively, where n represents the total number of instantaneous variables collected within the time interval (t2-t1).

[0063] Step 3: Obtain the real-time water speed, real-time land speed, instantaneous track direction, and instantaneous heading angle of the ship during the second time period while sailing along another course, and obtain the equivalent average water speed, equivalent land speed, equivalent track direction, and equivalent heading angle during the second time period;

[0064] The specific implementation process is as follows:

[0065] Specifically, such as Figure 3 As shown, a ship travels a short distance in an open sea with constant power. If at time t3 the ship is at the origin B, and with an equivalent heading angle α2 and an equivalent track angle β2, it travels to point D(x4,y4) at time t4; if the water flow velocity V L2If the angle is 0, the ship should travel from the origin B to point C(x3,y3) with an equivalent heading angle α2. Due to the current, point C and point D do not coincide. Therefore, during the time interval (t4-t3), the ship experiences displacements of (x4-x3) and (y4-y3) due to the current. At this point, according to... Figure 3 The coordinate system in the equations gives the equations of motion for point CD during its navigation process:

[0066]

[0067] Among them, V x2 Let V be the average velocity of the ship along the x-axis during the time interval (t4-t3). y2 Let x3 and y3 be the average velocity of the ship along the y-axis within the range (t4-t3). x3 and y3 are the coordinates of point C, and x4 and y4 are the coordinates of point D. The coordinates of point D can be obtained from GPS.

[0068] x3 and y3 have the following relationship:

[0069] y3=tan(α2)x3 (8)

[0070] Flow velocity V L2 The flow direction γ2 has the following relationship:

[0071]

[0072] Flow velocity V during time t4-t3 L2 , Flow direction γ2, Equivalent water velocity V J2 Equivalent ground velocity V D2 The following relationship exists:

[0073]

[0074] The above equations can form a system of equations for the navigation process at point CD:

[0075]

[0076] The formulas for calculating the equivalent average speed relative to water, equivalent speed relative to land, equivalent trajectory, and equivalent heading angle are as follows:

[0077]

[0078] Among them, V J2j V represents the real-time water velocity (obtained through simulation calculation) at a certain moment within the time interval (t4-t3). D2j α 2j and β 2jThese represent the real-time ground velocity (obtained via GPS), instantaneous heading angle (obtained via GPS), and instantaneous trajectory (obtained via GPS) at a certain moment within the time interval (t4-t3), respectively, where m represents the total number of instantaneous variables collected within the time interval (t4-t3).

[0079] Step 4: Calculate the true velocity of water based on the equivalent average velocity to water, equivalent velocity to land, equivalent track direction and equivalent heading angle in the first time period, the equivalent average velocity to water, equivalent velocity to land, equivalent track direction and equivalent heading angle in the second time period, the water flow velocity at the end of the first time period and the water flow velocity at the end of the second time period.

[0080] Specifically, under conditions such as short sailing time, it can be assumed that the current direction remains unchanged within the water area during that time. Combining formulas (5) and (11), after calculation and simplification, we can obtain:

[0081]

[0082] The formula for calculating the water flow velocity at the end of the first time period is:

[0083] V L1 =V L0 +δ VL ·(t2-t1) (14)

[0084] The formula for calculating the water flow velocity at the end of the second time period is:

[0085] V L2 =V L0 +δ VL ·(t4-t3) (15)

[0086] Among them, V L0 Let δ be the water flow velocity at the origin 0, i.e., at time t1 when the voyage begins. VL This is the acceleration of the water flow. When this value is 0, it means that the water flow velocity is constant, that is, it is uniform flow. Therefore, this calibration method is also applicable to the case of uniform flow. If it is not 0, it means that the flow velocity changes uniformly.

[0087] Substituting formulas (6), (12), (14), and (15) into formula (13), we obtain the formula for calculating the water velocity:

[0088]

[0089] Among them, V Z1 To determine the true speed of the water.

[0090] Step 5: Based on the correction coefficient calculated for the true water speed, complete the calibration of the speed point.

[0091] The formula for calculating the correction factor is:

[0092] k Z1 =V Z1 / V′ J

[0093]

[0094] Where, k Z1 V′ is the correction factor. J1 and V′ J2 These are the average water flow rates displayed by the speedometer during the first and second time periods, respectively.

[0095] This invention provides a computer device, comprising:

[0096] Memory, used to store computer programs;

[0097] A processor, used to execute a computer program to implement the steps of a speedometer calibration method applicable to uniformly variable flow or uniform flow as described above.

[0098] For a description of the computer device provided by the present invention, please refer to the above method embodiments; the present invention will not be described in detail here.

[0099] The computer-readable storage medium of this invention stores a computer program, which, when executed by a processor, implements the steps of the above-described method for calibrating a speedometer suitable for uniformly variable or uniform flow. The storage medium includes various media capable of storing program code, such as mobile storage devices, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0100] For a description of the computer-readable storage medium provided by the present invention, please refer to the above method embodiments; the present invention will not be described again here.

[0101] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0102] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for calibrating a speedometer suitable for uniformly variable flow or uniform flow, characterized in that, include: Step 1: When the ship is sailing steadily, determine whether the water flow is uniform or uniformly variable. If it meets the requirements, proceed to the next step; otherwise, find a new test area until the test requirements are met. Step 2: Obtain the real-time water speed, real-time land speed, instantaneous track direction, and instantaneous heading angle of the ship during the first time period while sailing along a certain course, and obtain the equivalent average water speed, equivalent land speed, equivalent track direction, and equivalent heading angle during the first time period; Step 3: Obtain the real-time water speed, real-time land speed, instantaneous track direction, and instantaneous heading angle of the ship during the second time period while sailing along another course, and obtain the equivalent average water speed, equivalent land speed, equivalent track direction, and equivalent heading angle during the second time period; Step 4: Calculate the true velocity of water based on the equivalent average velocity to water, equivalent velocity to land, equivalent track direction and equivalent heading angle in the first time period, the equivalent average velocity to water, equivalent velocity to land, equivalent track direction and equivalent heading angle in the second time period, the water flow velocity at the end of the first time period and the water flow velocity at the end of the second time period. Step 5: Based on the correction coefficient calculated for the true water speed, complete the calibration of the speed point; The water flow velocity at the end of the first time period The calculation formula is: in, The water flow velocity at the start of the first time period. For water flow acceleration, This is the first time period; The water flow velocity at the end of the second time period The calculation formula is: The formula for calculating the true velocity of water is: in, To determine the true speed of the water, for Equivalent velocity to Earth over a time period for Equivalent flight path within a time period, for Equivalent heading angle over the time period for Equivalent velocity to Earth over a time period for Equivalent flight path within a time period, for Equivalent heading angle over the time period This is the second time period.

2. The method for calibrating a speedometer suitable for uniformly variable flow or uniform flow according to claim 1, characterized in that, The specific judgment process for step 1 is as follows: If the difference between the ship's real-time velocity relative to the ground and its real-time velocity relative to the water is a fixed value when the ship is sailing steadily, then it is a uniform flow. If the difference between the ship's real-time velocity relative to the ground and its real-time velocity relative to the water shows an increasing or decreasing trend when the ship is sailing steadily, it indicates that the flow is uniformly accelerated.

3. The method for calibrating a speedometer suitable for uniformly variable flow or uniform flow according to claim 1, characterized in that, The formulas for calculating the equivalent average water velocity, equivalent land velocity, equivalent trajectory, and equivalent heading angle during the first time period are as follows: in, The first time period for Equivalent average velocity over the time period for Equivalent velocity to Earth over a time period for Equivalent flight path within a time period, for Equivalent heading angle over the time period for Real-time water velocity at a specific moment within a time period , and They are respectively Real-time ground velocity, instantaneous heading angle, and instantaneous trajectory at a specific moment within a time period. express The total number of instantaneous variables collected within a time period.

4. The method for calibrating a speedometer suitable for uniformly variable flow or uniform flow according to claim 3, characterized in that, The formulas for calculating the equivalent average water velocity, equivalent land velocity, equivalent trajectory, and equivalent heading angle during the second time period are as follows: in, This is the second time period. for Equivalent average velocity over the time period for Equivalent velocity to Earth over a time period for Equivalent flight path within a time period, for Equivalent heading angle over the time period for Real-time water velocity at a specific moment within a time period , and They are respectively Real-time ground velocity, instantaneous heading angle, and instantaneous trajectory at a specific moment within a time period. express The total number of instantaneous variables collected within a given time period.

5. The method for calibrating a speedometer suitable for uniformly variable flow or uniform flow according to claim 4, characterized in that, The formula for calculating the correction factor is: in, For correction factor, and These are the average water flow rates displayed by the speedometer during the first and second time periods, respectively.

6. A computer device, characterized in that, include: Memory, used to store computer programs; A processor, configured to execute the computer program to implement the steps of a calibrator method for uniformly variable or uniform flow as described in any one of claims 1 to 5.

7. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of a speedometer calibration method as described in any one of claims 1 to 5, applicable to uniformly variable flow or uniform flow.

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