An automatic optimization control method for adjustable fins of small waterplane area catamarans

Abstract

The invention discloses an automatic optimization control method for adjustable fins of a small waterplane area catamaran, comprising a small waterplane area catamaran, wherein adjustable fins are installed at inner positions of a left hull and a right hull of a submerged body of the small waterplane area catamaran, a first adjustable fin and a third adjustable fin are installed at the bow and stern of the left hull respectively, and a second adjustable fin and a fourth adjustable fin are installed at the bow and stern of the right hull respectively; the control method comprises the following operation process: first, according to theoretical analysis and determination of the ship's longitudinal inclination angle and the ship's sailing speed, and obtaining a corresponding curve map between the actual ship's angle of attack combination, power, longitudinal inclination angle, and sailing speed, performing sailing condition analysis and judgment adjustment according to theoretical calculation, and automatically controlling the ship's sailing attitude by automatically matching the adjustable fin's angle of attack, the ship's speed, the ship's longitudinal inclination angle, and the propulsion power when the small waterplane area catamaran is sailing, thereby resolving the contradiction between the attitude, speed, and energy consumption of the small waterplane area ship type.

Description

Technical Field

[0001] The present invention relates to the technical field of adjustable fin control methods for small waterplane area catamarans, and in particular to an automatic optimization control method for the adjustable fins of a small waterplane area catamaran, which can automatically achieve optimized control of the speed and attitude of the small waterplane area catamaran by controlling the adjustable fins during navigation. Background Art

[0002] A small waterplane area twin-hull vessel (SWATH) is a vessel with a small waterline area and consists of two submersible hulls and an above-water box, connected by two streamlined struts. It is a high-performance vessel with excellent seakeeping. As research on SWATHs deepens, this type of vessel is increasingly being used in specialized vessels such as scientific research vessels, survey vessels, and training vessels.

[0003] Due to the small waterplane area, the unstable moment acting on the submerged body of the small waterplane area catamaran may cause longitudinal motion instability when the small waterplane area catamaran is sailing at high speed, which poses a great threat to the safety of the ship.

[0004] In order to improve the longitudinal motion stability of the small waterplane area catamaran, the most commonly used method is to arrange a pair of adjustable fins at the front and rear inside the inner side of the submerged body. While improving the longitudinal motion stability of the hull, it can also reduce the longitudinal motion response amplitude of the hull and improve the sailing posture.

[0005] Adjustable fins are used as an appendage to the sleek hull of a small waterplane area catamaran. Adjusting the fin's angle of attack adjusts the ship's longitudinal inclination during navigation. However, this adjustment also creates additional resistance, increasing energy consumption and affecting the ship's speed.

[0006] How to optimize the relationship between the adjustable fin attack angle and the longitudinal inclination angle, ship speed and propulsion power while adjusting the longitudinal inclination angle of the ship with the adjustable fin of the small waterplane area catamaran is a key issue that needs to be solved for this high-performance ship type. Summary of the Invention

[0007] In response to the shortcomings of the above-mentioned existing production technology, the applicant provides an automatic optimization control method for the adjustable fins of a small waterplane area catamaran. When the small waterplane area catamaran is sailing, the ship's navigation attitude can be automatically controlled by automatically matching the adjustable fin attack angle, ship speed, ship longitudinal inclination and propulsion power, thereby solving the contradiction between the attitude, speed and energy consumption of the small waterplane area catamaran.

[0008] The technical solutions adopted in the present invention are as follows:

[0009] An automatic optimization control method for adjustable fins of a small waterplane area catamaran includes a small waterplane area catamaran, wherein adjustable fins are installed on the inner sides of the left and right hulls of the submerged body of the small waterplane area catamaran, namely, a first adjustable fin, a second adjustable fin, a third adjustable fin, and a fourth adjustable fin. Specifically, the first adjustable fin and the third adjustable fin are installed on the bow and stern of the left hull, respectively, and the second adjustable fin and the fourth adjustable fin are installed on the bow and stern of the right hull, respectively.

[0010] The control method includes the following operation procedures:

[0011] First, based on theoretical analysis and determination, the ship's trim angle and the ship's sailing speed are determined, and the corresponding curves between the actual ship's angle of attack combination, power, trim angle, and sailing speed are obtained;

[0012] When the ship's trim angle is greater than 0, the ship does not appear to be buried.

[0013] At this time, according to the actual ship test results, the theoretical calculation is corrected to form a corresponding curve map between the actual ship angle of attack combination, power, trim angle, and sailing speed, and any combination of the actual ship angle of attack combination, power, trim angle, and sailing speed is interpolated in the map;

[0014] S1: The ship gives the speed control requirements according to the navigation conditions and mission requirements;

[0015] S2: Based on the corresponding curves of the actual ship's angle of attack combination, power, trim angle, and sailing speed, interpolation is performed to find the most energy-efficient power at the set speed, and the angle of attack combination and trim angle are determined;

[0016] S3: transmits to the propulsion system control unit and gives propulsion power;

[0017] S4: Control the operation of the adjustable fin and adjust the attack angle combination to;

[0018] S5: The ship reaches the trim angle and the set speed;

[0019] S6: Determine whether the set speed is stable;

[0020] S7: If the speed is stable, the ship will continue to sail at a constant speed until the speed changes again;

[0021] S8: If the speed is unstable, the longitudinal inclination of the ship is fed back by the ship attitude indicator to determine whether the ship's attitude has changed due to changes in external sea conditions, causing the speed to be unstable. If the longitudinal inclination of the ship has changed, the latest inclination of the ship is obtained in real time.

[0022] S9: Return to step S2, and interpolate to find the most energy-efficient power required to achieve the set speed under the ship's inclination angle based on the corresponding curves of the actual ship's angle of attack combination, power, trim angle, and sailing speed. Determine the angle of attack combination, and press S2 on the control system until the set speed is reached and stabilized.

[0023] S10: Continuing with step S8, if the speed is unstable, the ship's longitudinal inclination is fed back by the ship's attitude indicator to determine whether the ship's attitude has changed due to changes in external sea conditions, causing the speed to become unstable. If the longitudinal inclination has not changed, an alarm is sent to the monitoring system to alert the crew of the fault.

[0024] S11: At the same time, in order to ensure the safety of the ship, the ship resumes its navigation in a level and floating attitude, and proceeds to S12;

[0025] S12: Following S1, if the crew determines that the ship needs to sail in a level-floating attitude based on the operating conditions and sea conditions, the trim angle of the ship is 0°.

[0026] S13: The crew determines the operating speed based on the operating conditions;

[0027] S14: Ship control is transferred to S1.

[0028] As a further improvement of the above technical solution:

[0029] The ship is in the head-down phenomenon. In this case, the power and angle of attack combination of the ship will not enter the automatic control system.

[0030] The No. 1 and No. 2 adjustable fins at the bow form a pair, which change the angle of attack synchronously.

[0031] The No. 3 and No. 4 adjustable fins at the stern are a pair, which change the angle of attack synchronously.

[0032] The attack angles of the two adjustable fins at the bow and the attack angles of the two adjustable fins at the stern form a fin attack angle combination, and the attack angle combination of the adjustable fins includes multiple groups of fin attack angles.

[0033] The specific methods for theoretical analysis and determination of the ship's trim angle and navigation speed are as follows:

[0034] According to the torque applied to the small waterplane area catamaran during navigation, the relationship between different angles of attack, power, speed, and ship trim angle is determined as follows:

[0035] A1v 2 p[A2(α2-α1)+A3]=A4θ

[0036] Among them, A1, A2, A3, and A4 are constants related to known parameters such as ship displacement and main dimensions;

[0037] v is the sailing speed;

[0038] p is power;

[0039] α1 is the attack angle of the bow adjustable fin, α2 is the attack angle of the stern adjustable fin, and α1 and α2 together constitute the actual ship attack angle combination α;

[0040] θ is the ship's trim angle;

[0041] Through theoretical analysis based on the above formula, the ship's longitudinal inclination angle θ corresponding to each set of fin attack angle combinations under different power p of the small waterplane area catamaran is determined.

[0042] Through theoretical analysis based on the above formula, the ship sailing speed v corresponding to each set of fin attack angles under different power p of the small waterplane area catamaran is determined.

[0043] At the same time, in order to ensure the accuracy of the relationship between the fin attack angle combination and the power, speed, and trim angle, the following tests are carried out during the actual ship navigation phase:

[0044] (a) Determine the trim angle θ of the SWATH ship for the selected representative power combination p and the selected fin attack angle combination.

[0045] (b) Determine the ship's sailing speed v for the SWATH vessel under the selected representative power combination p and the selected fin attack angle combination.

[0046] The results of the actual ship test are corrected by theoretical analysis to determine the ship's trim angle θ for each fin attack angle combination;

[0047] The results of the actual ship test are used to correct the theoretical analysis to determine the ship's sailing speed v under each combination of fin attack angles.

[0048] The beneficial effects of the present invention are as follows:

[0049] The present invention has a compact and reasonable structure and is easy to operate. Through the setting of the adjustable fins, based on theoretical calculation and analysis, when the small waterplane area catamaran is sailing, the ship's sailing attitude can be automatically controlled by automatically matching the adjustable fin attack angle, the ship's speed, the ship's longitudinal inclination angle and the propulsion power, thereby solving the contradiction between the attitude, speed and energy consumption of the small waterplane area catamaran.

[0050] At the same time, the present invention also has the following advantages:

[0051] (1) The present invention can improve the navigation stability of small waterplane area catamarans and improve the seaworthiness of ships.

[0052] (2) The present invention can optimize and adjust the attitude and speed in real time according to the characteristics of the sea conditions in the sea area where the ship is sailing, automatically find the best speed and power matching point under the current sea conditions, and effectively save energy and reduce emissions.

[0053] (3) The present invention automatically controls and provides the crew with a selection of attack angle combinations of the adjustable fins at various speeds that are not conducive to the ship's posture, thereby improving the safety of the ship's navigation. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 The figure is a schematic diagram of the installation of the small waterplane area catamaran of the present invention (stern position).

[0055] Figure 2 This is a schematic diagram of the installation of the left hull of the small waterplane area catamaran of the present invention.

[0056] Figure 3 This is a schematic diagram of the installation of the right hull of the small waterplane area catamaran of the present invention.

[0057] Figure 4 Flowchart of the control method of the present invention.

[0058] Figure 5 The present invention is a flow chart for theoretically analyzing and determining the ship's trim angle and sailing speed.

[0059] Among them: 1. Adjustable fin No. 1; 2. Adjustable fin No. 2; 3. Adjustable fin No. 3; 4. Adjustable fin No. 4; 5. Left body; 6. Right body. DETAILED DESCRIPTION

[0060] The specific embodiments of the present invention will be described below with reference to the accompanying drawings.

[0061] like Figure 1-Figure 5 As shown, an automatic optimization control method for the adjustable fins of a small waterplane area catamaran is provided. The small waterplane area catamaran can sense the ship's attitude at any time through the onboard attitude meter and input it into the control system as a control reference.

[0062] In order to overcome the longitudinal heel moment experienced by the small waterplane area catamaran during navigation, four adjustable fins are installed on the bow and stern of the left hull 5 and the bow and stern of the right hull 6 of the submerged body, respectively. They are adjustable fin No. 1, adjustable fin No. 2, adjustable fin No. 3, and adjustable fin No. 4.

[0063] The bow's adjustable fin No. 1 and adjustable fin No. 2 form a pair and can change the angle of attack synchronously.

[0064] The third adjustable fin 3 and the fourth adjustable fin 4 at the stern are a pair and can change the angle of attack synchronously;

[0065] The attack angles of the two adjustable fins at the bow and the attack angles of the two adjustable fins at the stern form a group of fin attack angle combinations, and the attack angle combination of the adjustable fins is α, which includes multiple groups of fin attack angles.

[0066] According to the torque effect on the small waterplane area catamaran during navigation, the relationship between different angles of attack, power, speed, and ship trim angle is determined as follows:

[0067] A1v 2 p[A2(α2-α1)+A3]=A4θ

[0068] Among them, A1, A2, A3, and A4 are constants related to known parameters such as ship displacement and main dimensions;

[0069] v is the sailing speed;

[0070] p is power;

[0071] α1 is the attack angle of the bow adjustable fin, α2 is the attack angle of the stern adjustable fin, and α1 and α2 together constitute the actual ship attack angle combination α;

[0072] θ is the ship's trim angle;

[0073] Through theoretical analysis based on the above formula, the ship's trim angle θ is determined for the small waterplane area catamaran under different power p and each combination of fin attack angles.

[0074] Through theoretical analysis based on the above formula, the ship's sailing speed v is determined under different power p and each set of fin attack angle combinations.

[0075] At the same time, in order to ensure the accuracy of the relationship between the fin attack angle combination and the power, speed, and trim angle, the following tests are carried out during the actual ship navigation phase:

[0076] (a) Determine the trim angle θ of the SWATH ship for the selected representative power combination p and the selected fin attack angle combination.

[0077] (b) Determine the ship's sailing speed v for the SWATH vessel under the selected representative power combination p and the selected fin attack angle combination.

[0078] The results of the actual ship test are corrected by theoretical analysis to determine the ship's trim angle θ for each fin attack angle combination;

[0079] The results of the actual ship test are used to correct the theoretical analysis to determine the ship's sailing speed v under each combination of fin attack angles.

[0080] Analyze and determine whether the ship's longitudinal inclination angle θ is less than 0, that is, the ship is buried.

[0081] (1) The ship's longitudinal inclination angle θ is greater than 0, and the ship does not appear to be buried.

[0082] At this time, according to the actual ship test results, the theoretical calculation is corrected to form a corresponding curve map between the actual ship angle of attack combination α, power p, trim angle θ, and navigation speed v, and any group of actual ship angle of attack combinations α, power p, trim angle θ, and navigation speed v can be interpolated in the map.

[0083] S1: The ship gives the speed v1 control requirement according to the navigation conditions and mission requirements;

[0084] S2: Based on the corresponding curves of the actual ship's angle of attack combination α, power p, trim angle θ, and sailing speed v, interpolation is performed to find the most energy-efficient power p1 at the set speed v1, and the angle of attack combination α1 and trim angle θ1 are determined;

[0085] S3: transmits to the propulsion system control unit and gives propulsion power;

[0086] S4: Control the operation of the adjustable fin and adjust the attack angle combination to α1;

[0087] S5: The ship reaches the trim angle θ1 and the set speed v1;

[0088] S6: Determine whether the set speed v1 is stable;

[0089] S7: If the speed is stable, the ship will continue to sail at a constant speed until the speed changes again;

[0090] S8: If the speed is unstable, the longitudinal inclination of the ship is fed back by the ship attitude meter to determine whether the ship attitude has changed due to changes in external sea conditions, causing the speed to be unstable. If the longitudinal inclination of the ship has changed, the latest inclination angle θ2 of the ship is obtained in real time;

[0091] S9: Return to step S2, and interpolate to find the most energy-efficient power p2 required to achieve the set speed v1 under the condition of the ship's inclination angle θ2 based on the corresponding curves of the actual ship's angle of attack combination α, power p, trim angle θ, and sailing speed v. Then determine the angle of attack combination α2, and the control system presses S2 until the set speed is reached and stabilized.

[0092] S10: Continuing with step S8, if the speed is unstable, the ship's longitudinal inclination is fed back by the ship's attitude indicator to determine whether the ship's attitude has changed due to changes in external sea conditions, causing the speed to become unstable. If the longitudinal inclination has not changed, an alarm is sent to the monitoring system to alert the crew of the fault.

[0093] S11: At the same time, in order to ensure the safety of the ship, the ship resumes its horizontal floating attitude and goes to step (12);

[0094] S12: Following S1, if the crew determines that the ship needs to sail in a level-floating attitude based on the operating conditions and sea conditions, the trim angle of the ship is 0°.

[0095] S13: The crew determines the operating speed based on the operating conditions;

[0096] S14: Ship control is transferred to S1.

[0097] (2) When the ship's trim angle θ is less than 0 and the ship is in a head-down situation, the power and angle of attack combination of the ship in this case will not be included in the automatic control system, but will be listed as a special item and provided to the crew for reference;

[0098] The present invention can also find the speed points of the ship under different attack angle combinations under the set power, as follows:

[0099] a. Based on the corresponding curves of the actual ship's attack angle combination α, power p, trim angle θ, and sailing speed v, interpolation is performed to find the attack angle combination α3 required for the ship to reach the maximum speed v3 by adjusting the adjustable fin attack angle under the condition of given ship power;

[0100] b. Control the adjustable fin to adjust the attack angle combination to α3;

[0101] c. Monitor whether the ship's operating power is stable;

[0102] d. If the power is stable, the ship will sail at constant power;

[0103] If the ship's attitude and inclination angle change due to changes in external sea conditions, causing power instability, return to S1 of this section and re-find the combination of power, maximum speed point, ship inclination angle, and angle of attack, and determine a new angle of attack until the ship reaches constant power operation.

[0104] The above description is an explanation of the present invention, not a limitation of the present invention. The scope of the present invention is defined in the claims. Any modifications may be made within the scope of protection of the present invention.

Claims

1. An automatic optimization control method for the adjustable fins of a small waterplane area catamaran, comprising a small waterplane area catamaran, characterized in that: Adjustable fins are installed on the inner sides of the left hull (5) and the right hull (6) of the submersible body of the small waterplane area catamaran, which are respectively adjustable fin No. 1 (1), adjustable fin No. 2 (2), adjustable fin No. 3 (3) and adjustable fin No. 4 (4). Specifically, the adjustable fin No. 1 (1) and the adjustable fin No. 3 (3) are installed on the bow and stern of the left hull (5), respectively, and the adjustable fin No. 2 (2) and the adjustable fin No. 4 (4) are installed on the bow and stern of the right hull (6). The control method includes the following operation procedures: First, theoretical analysis and determination of the ship's trim angle and ship speed , and get the actual ship attack angle combination ,power , pitch angle , sailing speed The corresponding curve diagram between them; When the ship's trim angle If it is greater than 0, the ship does not have any head-burying phenomenon. At this time, according to the actual ship test results, the theoretical calculation is corrected to form the actual ship attack angle combination ,power , pitch angle , sailing speed The corresponding curve map between them is used to interpolate any set of real ship attack angle combinations in the map. ,power , pitch angle , sailing speed The combination between; S1: The ship gives the speed of the ship according to the navigation conditions and mission requirements Control demand; S2: Combination based on actual ship attack angle ,power , pitch angle , sailing speed The corresponding curve map between them is used to interpolate and find the set speed. The most energy-efficient power , determine the angle of attack combination , pitch angle ; S3: transmits to the propulsion system control unit and gives propulsion power; S4: Control the operation of the adjustable fin and adjust the angle of attack combination to ; S5: The ship reaches the trim angle , and reach the set speed ; S6: Determine the set speed Is it stable? S7: If the speed is stable, the ship will continue to sail at a constant speed until the speed changes again; S8: If the speed is unstable, the longitudinal tilt of the ship is fed back by the ship attitude meter to determine whether the ship's attitude has changed due to changes in external sea conditions, causing the speed to be unstable. If the longitudinal tilt of the ship changes, the latest tilt of the ship is obtained in real time. ; S9: Return to step S2, and combine the attack angle of the actual ship ,power , pitch angle , sailing speed The corresponding curves between the two are interpolated to find the ship's inclination When the set speed is reached The most energy-efficient power required , determine the angle of attack combination , the control system presses S2 until the set speed is reached and stabilized; S10: Continuing with step S8, if the speed is unstable, the ship's longitudinal inclination is fed back by the ship's attitude indicator to determine whether the ship's attitude has changed due to changes in external sea conditions, causing the speed to become unstable. If the longitudinal inclination has not changed, an alarm is sent to the monitoring system to alert the crew of the fault. S11: At the same time, in order to ensure the safety of the ship, the ship resumes its navigation in a level and floating attitude, and proceeds to S12; S12: Following S1, if the crew determines that the ship needs to sail in a level-floating attitude based on the operating conditions and sea conditions, the trim angle of the ship is 0°. S13: The crew determines the operating speed based on the operating conditions; S14: Ship control transfers to S1; When the ship's trim angle If it is less than 0, the ship will be buried. In this case, the power and attack angle combination of the ship will not enter the automatic control system.

2. The automatic optimization control method for the adjustable fin of a small waterplane area catamaran according to claim 1, characterized in that: The first adjustable fin (1) and the second adjustable fin (2) at the bow are a pair and change the angle of attack synchronously.

3. The automatic optimization control method for the adjustable fins of a small waterplane area catamaran according to claim 1, characterized in that: The third adjustable fin (3) and the fourth adjustable fin (4) at the stern are a pair and change the angle of attack synchronously.

4. The automatic optimization control method for the adjustable fins of a small waterplane area catamaran according to claim 1, characterized in that: The attack angles of the two adjustable fins at the bow and the attack angles of the two adjustable fins at the stern form a set of fin attack angle combinations. The attack angle combination of the adjustable fins is: Contains multiple sets of fin attack angles.

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