A method for measuring the length of a hull on a tilted cradle
By marking straight lines on the slipway and setting up targets, and using a total station to adjust the target angle, the problem of decreased accuracy in hull length measurement was solved, and high-precision measurement under different temperature differences and seasons was achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HUDONG ZHONGHUA SHIPBUILDINGGROUP
- Filing Date
- 2022-11-04
- Publication Date
- 2026-06-09
AI Technical Summary
Traditional methods for measuring the length of a ship on an inclined slipway are affected by the thermal expansion and contraction of the slipway, resulting in decreased measurement accuracy, especially with larger errors when there are different temperature differences and seasonal temperature changes.
Draw straight lines on the slipway and set up stern, bow, and intermediate targets. Use a total station to adjust the target center angle to measure the hull length, avoiding the influence of temperature changes.
It improves the accuracy of hull length measurement, provides accurate hull length data under different temperature differences and seasons, and reduces measurement errors.
Smart Images
Figure CN115628708B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of shipbuilding technology, and in particular relates to a method for measuring the length of a ship's hull on an inclined slipway. Background Technology
[0002] With the advancement of modern shipbuilding methods, shipbuilding efficiency is constantly improving, and ships are becoming increasingly larger. The slipway grid lines, which serve as the basis for section mounting, positioning, and measurement during shipbuilding, are also increasingly affected by temperature differences along the length of the slipway.
[0003] The traditional method for measuring the length of a ship on an inclined slipway involves marking grid lines on the slipway before the ship sections are hoisted onto the slipway. These grid lines, marking the bow and stern endpoints of the hull, serve as the baseline for length measurement. After the hull construction is completed, a total station is used to measure the relative position difference between the bow and stern endpoints and their corresponding positions on the slipway grid lines, and the hull length is calculated. In practice, the slipway, being a large reinforced concrete structure, is subject to thermal expansion and contraction, especially along its length. There is typically a time lag of several months between marking the slipway grid lines and measuring the hull length. Furthermore, the length between the bow and stern endpoints of the grid lines can vary due to the construction cycle of the hull sections and seasonal temperature changes, leading to increased errors and decreased accuracy in length measurement. Summary of the Invention
[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for measuring the length of a ship on an inclined slipway. The method of this invention measures the length of the ship by marking a straight section line on the slipway and setting up a stern target, a bow target and a midships target on the straight section line. This avoids the influence of ship construction cycle and seasonal temperature on the error of the hull length measurement and improves the accuracy of the hull length measurement.
[0005] To achieve the above-mentioned objectives, the technical solution provided by this invention patent is as follows:
[0006] A method for measuring the length of a ship's hull on an inclined slipway, the method specifically includes the following steps:
[0007] The first step is to use a total station to draw the center line of the slipway on the inclined slipway, which coincides with the mid-longitudinal section of the hull.
[0008] The second step is to use a total station to draw straight sections on the inclined slipway after the center line of the slipway is drawn.
[0009] The third step is to set up stern and bow targets on the straight section line of the slipway after the straight section line is drawn. Then, use a total station to adjust the center of the stern and bow targets so that the inclination angle of the line containing the center of the stern and bow targets is the same as the inclination angle of the slipway.
[0010] The fourth step is to set up an intermediate target on the straight section line of the slipway between the bow and stern targets after the bow and stern targets are set up. The center of the intermediate target is adjusted by a total station so that the center of the intermediate target is on the same straight line as the center of the stern target and the center of the bow target.
[0011] Fifth step: After the stern target, bow target, and intermediate target are set up, a stern reflector is installed at the stern of the hull, and a bow reflector is installed at the bow of the hull. The stern length is measured using a total station based on the positions of the stern target, intermediate target, and stern reflector. The bow length is measured using a total station based on the positions of the bow target, intermediate target, and bow reflector.
[0012] The sixth step is to add the measured bow and stern lengths together to obtain the hull length, thus completing the measurement of the hull length.
[0013] The longitudinal section of the hull in the first step above is the section of the hull midway along the length of the hull.
[0014] In the second step above, the straight section line of the slipway is parallel to the center line of the slipway, and the distance between the straight section line of the slipway and the center line of the slipway is greater than half the width of the hull.
[0015] The specific steps for setting up the stern and bow targets in the third step above are as follows: The stern target is set up along the hull's vertical section line where the stern section is located. A first total station is set up outside this line. Using the hull's vertical section line as a reference line, the first total station is used to measure and adjust the target's center so that it coincides with the vertical plane containing the hull's vertical section line, thus completing the stern target setup. The bow target is set up along the hull's vertical section line... The bow target is erected. A second total station is set up outside the straight section line of the hull where the bow is located. Using the straight section line of the hull as a reference line, the second total station is used to measure and adjust the center of the bow target so that the center of the bow target coincides with the vertical plane where the straight section line of the hull is located, thus completing the erection of the bow target. At the same time, the first total station is used to measure and adjust the center of the stern target so that the inclination angle of the line containing the center of the stern target and the center of the bow target is the same as the inclination angle of the slipway.
[0016] The specific steps for setting up the intermediate target in the fourth step above are as follows: After the stern target and bow target are set up, the intermediate target is set up on the straight section line of the hull where the middle of the hull is located. The center of the intermediate target is measured and adjusted using a first total station so that the center of the intermediate target coincides with the center line. The stern target, bow target and intermediate target are on the same straight line.
[0017] The specific steps for measuring the stern length and bow length in step five above are as follows: A first total station is set up outside the straight section line of the hull where the stern is located. The position of the first total station allows for the measurement of the stern reflector, stern target, and center target. The first total station is used to measure the target center line of the center target and the stern target. Using the target center line as a reference line and the target center of the center target as a reference point, the first total station measures the projection of the stern reflector and the center target onto the target center line. The distance is used to obtain the stern length; a second total station is set up outside the straight section line of the hull where the bow is located. The location of the second total station can measure the bow reflector, bow target and intermediate target. The second total station is used to measure the target center line where the center of the intermediate target and the target center of the bow target are located. The second total station uses the target center line as the reference line and the target center of the intermediate target as the reference point to measure the projected distance between the bow reflector and the intermediate target on the target center line, thereby obtaining the bow length.
[0018] When measuring the stern length and bow length, the first total station and the second total station simultaneously measure the stern length and bow length, respectively.
[0019] Based on the above technical solution, the method for measuring the length of a ship's hull on an inclined slipway, as described in this invention patent, has achieved the following technical advantages through practical application:
[0020] 1. The present invention provides a method for measuring the length of a ship's hull on an inclined slipway. By marking a straight section line on the slipway and setting up a stern target, a bow target, and a midships target on the straight section line, the method avoids the influence of ship construction cycle and seasonal temperature on the error of hull length measurement, thereby improving the accuracy of hull length measurement.
[0021] 2. Compared with the prior art, the method of the present invention for measuring the hull length on an inclined slipway can measure the hull length under different temperature differences and different seasons, providing accurate data on the deformation of the hull length of various ship types affected by temperature differences and sunlight. Attached Figure Description
[0022] Figure 1 This is a structural diagram of the hull length measurement method in the present invention, which is used to measure the hull length on an inclined slipway. Detailed Implementation
[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the invention is described below with reference to specific examples shown in the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.
[0024] like Figure 1The present invention pertains to a method for measuring the length of a ship's hull on an inclined slipway, and the method specifically includes the following steps:
[0025] The first step is to use a total station to draw the center line 6 of the slipway on the inclined slipway 11, which coincides with the mid-longitudinal section of the hull.
[0026] The second step is to draw the slipway centerline 6 after it is completed, and then use a total station to draw the slipway straight section line 10 on the inclined slipway 11.
[0027] The third step is to set up stern target 7 and bow target 9 on stern target 7 and bow target 9 respectively on stern target 7 and bow target 9 respectively using a total station to adjust the center of the target 7 and the center of the bow target 9 so that the inclination angle of the target center line of the target center of the stern target 7 and the center of the bow target 9 is the same as the inclination angle of the slipway.
[0028] The fourth step is to set up the bow target 9 and the stern target 7 after they are set up. Then, set up the intermediate target 8 on the straight section line 10 of the slipway between the bow target 9 and the stern target 7. Adjust the center of the intermediate target 8 with a total station so that the center of the intermediate target 8 is on the same straight line as the center of the stern target 7 and the center of the bow target 9.
[0029] Fifth step: After the stern target 7, bow target 9 and intermediate target 8 are set up, a stern reflector 1 is set at the stern of the hull and a bow reflector 2 is set at the bow of the hull. The stern length 51 is measured using a total station based on the positions of the stern target 7, intermediate target 8 and stern reflector 1. The bow length 52 is measured using a total station based on the positions of the bow target 9, intermediate target 8 and bow reflector 2.
[0030] The sixth step is to add the measured bow length 52 and stern length 51 to obtain the hull length, thus completing the measurement of the hull length.
[0031] The longitudinal section of the hull in the first step above is the section of the hull midway along the length of the hull.
[0032] In the second step above, the straight section line 10 of the slipway is parallel to the center line 6 of the slipway, and the distance between the straight section line 10 of the slipway and the center line 6 of the slipway is greater than half the width of the hull.
[0033] The specific steps for setting up the stern target 7 and the bow target 9 in the third step above are as follows: The stern target 7 is set up along the hull's straight section line where the stern of the ship is located. A first total station 12 is set up outside the hull's straight section line where the stern of the ship is located. Using the hull's straight section line as a reference line, the first total station 12 is used to measure and adjust the target center of the stern target 7 so that the target center of the stern target 7 coincides with the vertical plane where the hull's straight section line is located, thus completing the setup of the stern target 7; along the hull's straight section line where the bow of the ship is located... The bow target 9 is erected. A second total station 13 is set up outside the straight section line of the hull where the bow is located. Using the straight section line of the hull as a reference line, the second total station 13 is used to measure and adjust the target center of the bow target 9 so that the target center of the bow target 9 coincides with the vertical plane where the straight section line of the hull is located, thus completing the erection of the bow target 9. At the same time, the first total station 12 is used to measure and adjust the target center of the stern target 7 so that the inclination angle of the target center line where the target center of the stern target 7 and the target center of the bow target 9 are located is the same as the inclination angle of the slipway.
[0034] The specific steps for setting up the intermediate target 8 in the fourth step above are as follows: After the stern target 7 and the bow target 9 are set up, the intermediate target 8 is set up on the straight section line of the hull where the middle of the hull is located. The first total station 12 is used to measure and adjust the center of the intermediate target 8 so that the center of the intermediate target 8 coincides with the center line. The stern target 7, the bow target 9 and the intermediate target 8 are on the same straight line.
[0035] The specific steps for measuring the stern length 51 and bow length 52 in the fifth step above are as follows: A first total station 12 is set up outside the straight section line of the hull where the stern is located. The location of the first total station 12 allows for the measurement of the stern reflector 1, stern target 7, and intermediate target 8. The first total station 12 is used to measure the target center line where the center of the intermediate target 8 and the center of the stern target 7 are located. Using the target center line as a reference line and the center of the intermediate target 8 as a reference point, the first total station 12 measures the stern reflector 1 and the intermediate target 8 on the target center line to obtain the projected distance between them, thus obtaining the stern length 51. A second total station 13 is set up outside the straight section line of the hull where the bow is located. The second total station... The instrument 13 is positioned to measure the bow reflector 2, bow target 9, and intermediate target 8. The second total station 13 is used to measure the target center line where the center of the intermediate target 8 and the center of the bow target 9 are located. The second total station 13 uses the target center line as a reference line and the center of the intermediate target 8 as a reference point to measure the bow reflector 2 and obtain the projection distance between the bow reflector 2 and the intermediate target on the target center line, thereby obtaining the bow length 52. By marking the slipway straight section line 10 on the slipway and setting up the stern target 7, bow target 9, and intermediate target 8 on the slipway straight section line 10 to measure the hull length, the error influence of the ship construction cycle and seasonal temperature on the hull length measurement is avoided, and the accuracy of the hull length measurement is improved.
[0036] When measuring the stern length 51 and bow length 52, the first total station 12 and the second total station 13 simultaneously measure the stern length 51 and bow length 52, respectively.
[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.
Claims
1. A method for measuring the length of a ship's hull on an inclined slipway, characterized in that, The method specifically includes the following steps: The first step is to use a total station to draw the center line (6) of the slipway (11) on the inclined slipway, and the center line (6) of the slipway coincides with the mid-longitudinal section of the hull; The second step is to draw the center line (6) of the slipway after the slipway is drawn, and then draw the straight section line (10) of the slipway on the inclined slipway (11) using a total station. The third step is to set up the stern target (7) and the bow target (9) on the straight section line (10) of the slipway after the straight section line (10) is drawn. Then, the center of the stern target (7) and the center of the bow target (9) are adjusted using a total station so that the inclination angle of the line where the center of the stern target (7) and the center of the bow target (9) are located is the same as the inclination angle of the slipway. Fourth step: After the bow target (9) and stern target (7) are set up, the intermediate target (8) is set up on the straight section line (10) of the slipway between the bow target (9) and the stern target (7). The center of the intermediate target (8) is adjusted by the total station so that the center of the intermediate target (8) is on the same straight line as the center of the stern target (7) and the center of the bow target (9). Step 5: After the stern target (7), bow target (9) and intermediate target (8) are set up, a stern reflector (1) is set at the stern of the hull and a bow reflector (2) is set at the bow of the hull. The stern length (51) is measured using a total station based on the positions of the stern target (7), intermediate target (8) and stern reflector (1). The bow length (52) is measured using a total station based on the positions of the bow target (9), intermediate target (8) and bow reflector (2). The sixth step is to add the measured bow length (52) and stern length (51) to obtain the hull length, thus completing the measurement of the hull length.
2. The method for measuring the length of a ship's hull on an inclined slipway according to claim 1, characterized in that, The longitudinal section of the hull in the first step is the section of the hull midway along the length of the hull.
3. The method for measuring the length of a ship's hull on an inclined slipway according to claim 1, characterized in that, In the second step, the straight section line (10) of the slipway is parallel to the center line (6) of the slipway, and the distance between the straight section line (10) of the slipway and the center line (6) of the slipway is greater than half the width of the hull.
4. A method for measuring the length of a ship's hull on an inclined slipway according to claim 1, characterized in that, The specific steps for setting up the stern target (7) and bow target (9) in the third step are as follows: The stern target (7) is set up on the hull's straight section line where the stern of the ship is located. A first total station (12) is set up outside the hull's straight section line where the stern of the ship is located. Using the hull's straight section line as a reference line, the first total station (12) is used to measure and adjust the target center of the stern target (7) so that the target center of the stern target (7) coincides with the vertical plane where the hull's straight section line is located, thus completing the setting up of the stern target (7); The bow target (9) is set up on the hull's straight section line where the bow of the ship is located... For the bow target (9), a second total station (13) is set up outside the straight section line of the hull where the bow is located. Using the straight section line of the hull as a reference line, the second total station (13) is used to measure and adjust the center of the bow target (9) so that the center of the bow target (9) coincides with the vertical plane where the straight section line of the hull is located, thus completing the setting up of the bow target (9). At the same time, the first total station (12) is used to measure and adjust the center of the stern target (7) so that the inclination angle of the line where the center of the stern target (7) and the center of the bow target (9) are located is the same as the inclination angle of the slipway.
5. A method for measuring the length of a ship's hull on an inclined slipway according to claim 1, characterized in that, The specific steps for setting up the intermediate target (8) in the fourth step are as follows: After the stern target (7) and bow target (9) are set up, the intermediate target (8) is set up on the straight section line of the hull where the middle part of the hull is located. The center of the intermediate target (8) is measured and adjusted using the first total station (12) so that the center of the intermediate target (8) coincides with the center line. The stern target (7), bow target (9) and intermediate target (8) are on the same straight line.
6. A method for measuring the length of a ship's hull on an inclined slipway according to claim 1, characterized in that, The specific steps for measuring the stern length (51) and bow length (52) in the fifth step are as follows: A first total station (12) is set up outside the straight section line of the hull where the stern is located. The location of the first total station (12) can measure the stern reflector (1), stern target (7) and intermediate target (8). The first total station (12) is used to measure the target center line where the target center of the intermediate target (8) and the target center of the stern target (7) are located. The first total station (12) uses the target center line as a reference line and the target center of the intermediate target (8) as a reference point to measure the stern reflector to obtain the projection of the stern reflector (1) and the intermediate target (8) on the target center line. The distance is used to obtain the stern length (51); a second total station (13) is set up outside the straight section line of the hull where the bow is located. The location of the second total station (13) can measure the bow reflector (2), the bow target (9) and the intermediate target (8). The second total station (13) is used to measure the target center line where the target center of the intermediate target (8) and the target center of the bow target (9) are located. The second total station (13) uses the target center line as the reference line and the target center of the intermediate target (8) as the reference point to measure the bow reflector (2) to obtain the projection distance between the bow reflector (2) and the intermediate target on the target center line, thereby obtaining the bow length (52).
7. A method for measuring the length of a ship's hull on an inclined slipway according to claim 6, characterized in that, When measuring the stern length (51) and bow length (52), the first total station (12) measures the stern length (51), and the second total station (13) measures the bow length (52).