Compensation operation simulation method for telescopic active wave compensation trestle

Abstract

The invention discloses a compensation operation simulation method for a telescopic active wave compensation trestle, and the method comprises the steps: taking sea condition parameters as input, combining a wave frequency response factor of a ship, and simulating the six-degree-of-freedom wave frequency motion of the ship; establishing a series coordinate system connected with a compensation mechanism on the telescopic active wave compensation trestle, and constructing a forward motion equation and a reverse solution equation of compensation motion; according to the compensation target position of the tail end of the telescopic active wave compensation trestle, the six-degree-of-freedom motion amplitude of the ship is combined, and the motion stroke of a compensation mechanism is reversely solved; differentiating the motion stroke of the compensation mechanism, calculating the speed and acceleration of the compensation mechanism, and determining the statistical value of the motion time sequence of the compensation mechanism; and finally, judging whether the telescopic active wave compensation trestle can compensate the ship motion caused by the sea condition or not according to the statistical value. Whether the compensation mechanism design of the trestle can compensate the ship motion under the sea condition or not can be judged according to the simulation result.

Description

Technical Field

[0001] The present invention relates to wave compensation technology, and more specifically, to a compensation operation simulation method for a telescopic active wave compensation trestle. Background Art

[0002] With the gradual development of offshore resource development and utilization towards the deep sea, harsher sea conditions will pose greater challenges to engineering operations such as offshore installation, loading and unloading, and operation and maintenance. The ship dynamic positioning system can control the low-frequency motion of the ship in the three degrees of freedom of surge, sway, and yaw in the horizontal plane, but the ship still has short-period wave-frequency motion in the six degrees of freedom (surge, sway, heave, roll, pitch, and yaw). The active wave compensation equipment is the core equipment to ensure the safety, stability, and efficiency of the passage of offshore personnel and the transfer of equipment. The core technology of this type of equipment is the active wave compensation technology, which compensates the impact brought by the ship motion in the reverse direction by precisely controlling the motion of each mechanism of the equipment. The telescopic active wave compensation trestle is a compensation equipment that includes three compensation mechanisms of telescopic, slewing, and luffing. By controlling the motion of the compensation mechanism through the wave compensation algorithm, the purpose of keeping the end of the trestle in stable contact with the target is achieved, ensuring the safety of personnel transfer, passage, and cargo transportation.

[0003] In the design stage of the active wave compensation trestle, it is necessary to design parameters such as the maximum stroke, speed, and acceleration of the compensation mechanism according to the hydrological data of the target wind field, the ship wave frequency response factor, and the installation position of the trestle on the ship. Therefore, the compensation operation simulation of the telescopic active wave compensation trestle is particularly important. At present, the domestic research and development of active wave compensation technology and products are all in the initial stage, and there is no compensation operation simulation technology for the telescopic active wave compensation trestle yet. Summary of the Invention

[0004] Aiming at the defects existing in the prior art, the purpose of the present invention is to provide a compensation operation simulation method for a telescopic active wave compensation trestle, which can evaluate whether the design of the compensation mechanism of the trestle can compensate for the ship motion under this sea condition according to the simulation results.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions:

[0006] A compensation operation simulation method for a telescopic active wave compensation trestle;

[0007] Taking the sea condition parameters as the input, combining with the wave frequency response factor of the ship, simulating the six-degree-of-freedom wave frequency motion of the ship;

[0008] Establishing a series coordinate system connecting the compensation mechanisms on the telescopic active wave compensation trestle, and constructing the forward motion equation and the inverse solution equation of the compensation motion;

[0009] According to the compensation target position at the end of the telescopic active wave compensation trestle, combined with the six-degree-of-freedom motion amplitude of the ship, inversely solve the motion stroke of the compensation mechanism;

[0010] Differentiate the motion stroke of the compensation mechanism, calculate the speed and acceleration of the compensation mechanism, and determine the statistical value of the motion time series of the compensation mechanism;

[0011] Finally, judge whether the telescopic active wave compensation trestle can compensate for the ship motion caused by this sea condition according to the statistical value.

[0012] Preferably, the compensation operation simulation method specifically includes the following steps:

[0013] S1. Establish an inertial coordinate system n based on the environment where the ship is located, establish a hull coordinate system b based on the ship, and establish a series coordinate system based on the telescopic active wave compensation trestle;

[0014] S2. Take the sea condition parameters as input, combine with the wave frequency response factor of the ship, and use the sine signal decomposition method to simulate the time series of the six-degree-of-freedom wave frequency motion of the ship;

[0015] S3. Based on the series coordinate system, establish the forward motion equation of the telescopic active wave compensation trestle, and determine the coordinate value of the end of the trestle in the inertial coordinate system n, that is, the compensation target position;

[0016] S4. Establish the inverse solution equation of the telescopic active wave compensation trestle, and determine the motion stroke of each compensation mechanism based on the compensation target position and the six-degree-of-freedom motion amplitude of the ship;

[0017] S5. Based on the compensation stroke time series of the compensation mechanism, calculate the speed and acceleration of the compensation mechanism, determine the statistical value of the time series of the compensation mechanism, and judge whether the telescopic active wave compensation trestle can compensate for the ship motion caused by this sea condition.

[0018] Preferably, in the step S1, the inertial coordinate system n, the hull coordinate system b, and the series coordinate system are all spatial rectangular coordinate systems.

[0019] Preferably, when establishing the inertial coordinate system n, when the six-degree-of-freedom motion of the ship is zero, the inertial coordinate system n coincides with the hull coordinate system b.

[0020] Preferably, in the hull coordinate system b, the X-axis points to the bow of the ship, the Y-axis points to the starboard of the ship, the Z-axis conforms to the right-hand coordinate system rule, and the coordinate origin is located at the center of gravity of the ship.

[0021] Preferably, establishing the series coordinate system specifically includes:

[0022] Establish a coordinate system 0 at the installation position of the telescopic active wave compensation trestle;

[0023] Establish a corresponding coordinate system q that moves with the compensation mechanism at the motion center of the q-th compensation mechanism of the telescopic active wave compensation trestle, and the selection of the coordinate system q conforms to the DH rule;

[0024] Preferably, the number of the series coordinate systems is m + 2;

[0025] The coordinate system 0 is the base coordinate system, the coordinate systems 1, 2... m correspond to the coordinate systems of each compensation mechanism, and the coordinate system m + 1 is the end coordinate system of the telescopic active wave compensation trestle;

[0026] The number of compensation mechanisms of the telescopic active wave compensation trestle is 3, that is, m = 3.

[0027] Preferably, in the step S2, the sea condition parameters include the significant wave height H s , spectral peak period T p and the main wave direction β0;

[0028] The specific implementation of the sine signal decomposition method includes:

[0029] Select the wave spectrum and direction spectrum of the target wind field sea area. Since irregular waves can be regarded as composed of a finite number of sine waves with different frequencies, the amplitude, frequency, phase angle, and spreading wave direction angle of each sine wave can be calculated through the wave spectrum and direction spectrum. The time series of irregular waves:

[0030]

[0031] where t k is the discrete time series; S(ω i ) is the wave spectrum density function; D(β j - β0) is the direction spectrum density function; ω i is the i-th main frequency; Δω is the frequency interval; N is the number of main frequencies; β j is the j-th spreading wave direction angle; β0 is the main wave direction angle; Δβ is the spreading wave direction angle interval; M is the number of spreading wave direction angles; ε i,j is the phase angle.

[0032] Preferably, in the step S2, the time series of simulating the six-degree-of-freedom wave-frequency motion of the ship specifically includes:

[0033] Determine the six-degree-of-freedom response of the ship under the action of each sine wave according to the wave-frequency response factor of the ship;

[0034] Linearly superpose the motion responses caused by each sine wave to determine the time series of the six-degree-of-freedom motion of the ship:

[0035]

[0036] where RAO l (ω i ,β j ) and phase(RAO l (ω i ,β j )) are respectively the response factor and phase of the l-th degree of freedom of the ship under the action of regular waves with a frequency of ω i and a direction of β j .

[0037] Preferably, the step S3 specifically includes:

[0038] Establish m + 1 coordinate systems according to the DH rule and create a DH coordinate system parameter table;

[0039] According to the DH coordinate system parameter table, establish the homogeneous transformation matrix from coordinate system q to coordinate system q - 1 The homogeneous transformation matrix is a 4D square matrix, and the coordinates of a spatial point also become a 4D vector accordingly. The first three element values are the spatial rectangular coordinate values, and the fourth element value is always 1;

[0040] Finally, according to the outer multiplication of transformation matrices, determine the homogeneous transformation matrix from coordinate system m + 1 to coordinate system 0

[0041] where z q is the current motion stroke of the q-th compensation mechanism;

[0042] When the stroke of the compensation mechanism is given, the forward kinematic equation is used to calculate the coordinate value of the end of the telescopic active wave compensation trestle in the base coordinate system 0:

[0043]

[0044] where is the coordinate value of the end of the telescopic active wave compensation trestle in coordinate system 0;

[0045] Establish the homogeneous transformation matrices from coordinate system 0 to the hull coordinate system b and from the hull coordinate system b to the inertial coordinate system n, and determine the transformation matrix from coordinate system 0 to the inertial coordinate system n

[0046]

[0047] where [InstXb , InstY b , InstZ b is the installation position of the telescopic active wave compensation trestle base, that is, the coordinate value of the origin of coordinate system 0 in coordinate system b;

[0048] According to the coordinate value of the end of the telescopic active wave compensation trestle in coordinate system 0 and the transformation matrix from coordinate system 0 to the inertial coordinate system n Determine the coordinate value of the end of the telescopic active wave compensation trestle in the inertial coordinate system n This coordinate value can be used as the compensation target position:

[0049]

[0050] Preferably, the step S4 specifically includes:

[0051] According to the transformation matrix from coordinate system 0 to the inertial coordinate system n, when the six-degree-of-freedom motion amplitude of the ship and the compensation target position are given, the expected position of the end of the telescopic active wave compensation trestle in coordinate system 0 is:

[0052]

[0053] Based on the expected position of the end of the telescopic active wave compensation trestle, combined with the forward motion equation, reverse solve the motion stroke of each compensation mechanism:

[0054]

[0055] In the formula, is the operation stroke of each compensation mechanism.

[0056] Preferably, the step S5 specifically includes:

[0057] According to the six-degree-of-freedom wave-frequency motion amplitude of the ship at each moment t k determine the motion stroke of the compensation mechanism at this moment to form a time series Taking the first derivative of the motion stroke time series can obtain the velocity time series of the compensation mechanism Taking the second derivative can obtain the acceleration time series of the compensation mechanism as:

[0058]

[0059] Determine the statistical values of the motion stroke, velocity, and acceleration of the compensation mechanism. If 3.7 times the standard deviation exceeds the design value of the compensation mechanism, it is determined that the telescopic active wave compensation trestle cannot compensate for the ship motion caused by this sea condition. Specifically:

[0060]

[0061] In the formula, when InFun(H s , T p , β0) is 1, it means that the active wave compensation trestle can compensate for the ship motion caused by this sea condition; on the contrary, when it is 0, it means that it cannot compensate. Among them, std(·) is the standard deviation of each time series; are the compensation stroke limit, compensation speed limit, and compensation acceleration limit of the qth compensation mechanism.

[0062] A compensation operation simulation method for a telescopic active wave compensation trestle provided by the present invention has the following beneficial effects:

[0063] (1) With significant wave height, spectral peak period, main wave direction, and ship wave frequency response factor and other frequency domain parameters as inputs, the present invention adopts the sine signal decomposition method to quickly simulate the time series of the ship's six-degree-of-freedom wave frequency motion;

[0064] (2) The present invention only needs to take sea condition parameters and ship wave frequency response factors as inputs, and can quickly simulate the time series of the motion stroke, speed, and acceleration of each compensation mechanism of the telescopic active wave compensation trestle, and determine the statistical values of the time series;

[0065] (3) According to the statistical values of the compensation mechanism motion time series, the present invention quickly judges the compensability of the active wave compensation trestle for sea conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 is a schematic flow chart of the compensation operation simulation method of the present invention;

[0067] Figure 2 is a schematic flow chart of step S1 in the compensation operation simulation method of the present invention;

[0068] Figure 3 is a schematic diagram of establishing each coordinate in step S1 of the compensation operation simulation method of the present invention;

[0069] Figure 4 is a schematic flow chart of step S2 in the compensation operation simulation method of the present invention;

[0070] Figure 5 is a corrugation diagram of the maximum stroke, maximum speed, and maximum acceleration allowed by the three compensation mechanisms in the embodiment of the compensation operation simulation method of the present invention. (a) is the maximum stroke, (b) is the maximum speed, and (c) is the maximum acceleration. DETAILED DESCRIPTION OF THE INVENTION

[0071] In order to better understand the above technical solutions of the present invention, the technical solutions of the present invention will be further described below with reference to the drawings and embodiments.

[0072] A compensation operation simulation method for a telescopic active wave compensation trestle provided by the present invention;

[0073] Taking the significant wave height H s , spectral peak period T p and main wave direction β0 and other sea condition parameters as inputs, and combining with the wave frequency response factor of the ship, simulating the six-degree-of-freedom wave frequency motion of the ship;

[0074] Establish a series coordinate system connecting the compensation mechanism on the telescopic active wave compensation trestle, and construct the forward kinematic equation and inverse solution equation of the compensation motion;

[0075] According to the compensation target position at the end of the telescopic active wave compensation trestle, and combining with the six-degree-of-freedom motion amplitude of the ship, inversely solve the motion stroke of the compensation mechanism;

[0076] Differentiate the motion stroke of the compensation mechanism, calculate the speed and acceleration of the compensation mechanism, and determine the statistical value of the motion time series of the compensation mechanism;

[0077] Finally, judge whether the telescopic active wave compensation trestle can compensate for the ship motion caused by this sea condition according to the statistical value.

[0078] Combined with Figure 1 shown, the compensation operation simulation method of the present invention specifically includes the following steps:

[0079] S1. Establish an inertial coordinate system n based on the environment where the ship is located, establish a hull coordinate system b based on the ship, and establish a series coordinate system based on the telescopic active wave compensation trestle; the inertial coordinate system n, the hull coordinate system b and the series coordinate system are all space rectangular coordinate systems;

[0080] S2. Taking the sea condition parameters as inputs, combining with the wave frequency response factor of the ship, and using the sine signal decomposition method, simulate the time series of the six-degree-of-freedom wave frequency motion of the ship;

[0081] S3. Based on the series coordinate system, establish the forward kinematic equation of the telescopic active wave compensation trestle, and determine the coordinate value of the end of the trestle in the inertial coordinate system n, that is, the compensation target position;

[0082] S4. Establish the inverse solution equation of the telescopic active wave compensation trestle, and determine the motion stroke of each compensation mechanism based on the compensation target position and the six-degree-of-freedom motion amplitude of the ship;

[0083] S5. Based on the compensation stroke time series of the compensation mechanism, calculate the speed and acceleration of the compensation mechanism, determine the statistical value of the time series of the compensation mechanism, and judge whether the telescopic active wave compensation trestle can compensate for the ship motion caused by this sea condition.

[0084] Combined with Figure 2 and Figure 3 As shown, in the above step S1, an inertial coordinate system n is established. When the six-degree-of-freedom motion of the ship is zero, the inertial coordinate system n coincides with the hull coordinate system b.

[0085] In the hull coordinate system b, the X-axis points to the bow of the ship, the Y-axis points to the starboard of the ship, the Z-axis conforms to the right-hand coordinate system rule, and the origin of the coordinate system is located at the center of gravity of the ship.

[0086] Establishing a series of coordinate systems specifically includes:

[0087] At the installation position of the telescopic active wave compensation trestle, a coordinate system 0 is established;

[0088] At the motion center of the q-th compensation mechanism of the telescopic active wave compensation trestle, a corresponding coordinate system q that moves with the compensation mechanism is established, and the selection of the coordinate system q conforms to the DH rule;

[0089] The number of the series of coordinate systems is m + 2;

[0090] The coordinate system 0 is the base coordinate system, the coordinate systems 1, 2... m correspond to the coordinate systems of each compensation mechanism, and the coordinate system m + 1 is the end coordinate system of the telescopic active wave compensation trestle;

[0091] The number of compensation mechanisms of the telescopic active wave compensation trestle is 3, that is, m = 3.

[0092] Combined with Figure 4 As shown, in the above step S2, the specific method of using the sine signal decomposition method includes:

[0093] Select the wave spectrum and direction spectrum of the target wind field sea area. According to the fact that irregular waves can be regarded as composed of a finite number of sine waves with different frequencies, the amplitude, frequency, phase angle, and spreading wave direction angle of each sine wave can be calculated through the wave spectrum and direction spectrum. The time series of irregular waves:

[0094]

[0095] where t k is the discrete time series; S(ω i ) is the wave spectrum density function; D(β j -β0) is the direction spectrum density function; ω i is the i-th main frequency; Δω is the frequency interval; N is the number of main frequencies; β j is the j-th spreading wave direction angle; β0 is the main wave direction angle; Δβ is the spreading wave direction angle interval; M is the number of spreading wave direction angles; ε i,j is the phase angle.

[0096] In the above step S2, the time series of the six-degree-of-freedom wave-frequency motion of the simulated ship specifically includes:

[0097] Determine the six-degree-of-freedom response of the ship under the action of each sine wave according to the wave-frequency response factor of the ship;

[0098] Linearly superpose the motion responses caused by each sine wave to determine the time series of the six-degree-of-freedom motion of the ship:

[0099]

[0100] In the formula, RAO l (ω i ,β j ) and phase(RAO l (ω i ,β j )) are respectively the response factor and phase of the l-th degree of freedom of the ship under the action of a regular wave with a frequency of ω i and a direction of β j .

[0101] The above step S3 specifically includes:

[0102] Establish m + 1 coordinate systems according to the DH rule and create a DH coordinate system parameter table;

[0103] According to the DH coordinate system parameter table, establish the homogeneous transformation matrix from coordinate system q to coordinate system q - 1 The homogeneous transformation matrix is a 4-dimensional square matrix, and the coordinates of the space point also become a 4-dimensional vector accordingly. The first three element values are the space rectangular coordinate values, and the fourth element value is always 1;

[0104] Finally, according to the outer multiplication of the transformation matrix, determine the homogeneous transformation matrix from coordinate system m + 1 to coordinate system 0

[0105] In the formula, z q is the current motion stroke of the q-th compensation mechanism;

[0106] When the stroke of the compensation mechanism is given, the forward motion equation is used to calculate the coordinate value of the end of the telescopic active wave compensation trestle in the base coordinate system 0:

[0107]

[0108] In the formula, is the coordinate value of the end of the telescopic active wave compensation trestle in coordinate system 0;

[0109] Establish the homogeneous transformation matrices from coordinate system 0 to hull coordinate system b and from hull coordinate system b to inertial coordinate system n, and determine the transformation matrix from coordinate system 0 to inertial coordinate system n

[0110]

[0111] wherein, [InstX b , InstY b , InsTZ b is the installation position of the base of the telescopic active wave compensation trestle, that is, the coordinate value of the origin of coordinate system 0 in coordinate system b;

[0112] According to the coordinate value of the end of the telescopic active wave compensation trestle in coordinate system 0 and the transformation matrix from coordinate system 0 to inertial coordinate system n determine the coordinate value of the end of the telescopic active wave compensation trestle in inertial coordinate system n This coordinate value can be used as the compensation target position:

[0113]

[0114] The above step S4 specifically includes:

[0115] According to the transformation matrix from coordinate system 0 to inertial coordinate system n, when the six-degree-of-freedom motion amplitudes of the ship and the compensation target position are given, the expected position of the end of the telescopic active wave compensation trestle in coordinate system 0 is:

[0116]

[0117] Based on the expected position of the end of the telescopic active wave compensation trestle, combined with the forward motion equation, inversely solve the motion strokes of each compensation mechanism:

[0118]

[0119] wherein, is the motion stroke of each compensation mechanism.

[0120] The above step S5 specifically includes:

[0121] According to the six-degree-of-freedom wave-frequency motion amplitudes of the ship at each moment t k , determine the motion stroke of the compensation mechanism at this moment to form a time series Differentiate the motion stroke time series once to obtain the velocity time series of the compensation mechanism Differentiate it twice to obtain the acceleration time series of the compensation mechanism as:

[0122]

[0123] Determine the statistical values of the motion stroke, speed, and acceleration of the compensation mechanism. If 3.7 times the standard deviation exceeds the design value of the compensation mechanism, it is determined that the telescopic active wave compensation trestle cannot compensate for the ship motion caused by this sea condition. Specifically:

[0124]

[0125] In the formula, when InFun(H s ,T p ,β0) is 1, it means that the active wave compensation trestle can compensate for the ship motion caused by this sea condition; otherwise, when it is 0, it means that it cannot compensate. Among them, std(·) is the standard deviation of each time series; are the compensation stroke limit, compensation speed limit, and compensation acceleration limit of the qth compensation mechanism.

[0126] Embodiment

[0127] In this embodiment, the wave frequency response factor (RAO) of a wind power operation and maintenance ship is used as the input, the P-M wave spectrum is selected, and the compensation motions of the three-degree-of-freedom active wave compensation trestle under three sea conditions, namely sea condition 1 (significant wave height of 2.5 m, spectral peak period of 8 s, and main wave direction of 50 degrees), sea condition 2 (significant wave height of 3.5 m, spectral peak period of 8 s, and main wave direction of 40 degrees), and sea condition 3 (significant wave height of 3.0 m, spectral peak period of 9 s, and main wave direction of 70 degrees), are simulated.

[0128] Select the P-M wave spectrum. According to the significant wave height and spectral peak period, determine the relationship between the wave spectrum density and frequency as follows:

[0129]

[0130]

[0131] Among them, H s is the significant wave height; T p is the spectral peak period.

[0132] The selection of the directional spectrum is as follows:

[0133]

[0134] Among them, β is the extended wave direction angle; β0 is the main wave direction angle; D(β - β0) is the directional spectrum density function.

[0135] Select 50 main frequencies and 20 direction angles, and the irregular wave time series under this sea condition. Combine with the wave frequency response factor of the ship to determine the six-degree-of-freedom motion time series of the ship under regular waves with each main frequency and direction angle. Linearly sum up the motion responses of each regular wave to calculate the six-degree-of-freedom wave frequency motion time series of the ship under this sea condition, with a time interval of 0.01 s.

[0136] Then combine with Figure 3 As shown, the retractable active wave compensation trestle of this embodiment has 3 compensation mechanisms. The first compensation mechanism is rotation, the second compensation mechanism is luffing, and the third compensation mechanism is telescopic mechanism. The maximum stroke, maximum speed and maximum acceleration allowed by the three compensation mechanisms are as Figure 5 shown.

[0137] Then combine with Figure 3 As shown, the inertial coordinate system n coincides with the hull coordinate system b when the six-degree-of-freedom motion of the ship is zero. The origin of the coordinate system 0 coincides with the installation position of the trestle base. The coordinate system 1 moves with the slewing mechanism, the coordinate system 2 moves with the luffing mechanism, and the coordinate system 3 moves with the telescopic mechanism. The coordinate system 4 has the same direction as the coordinate system 3, but the origin is located at the end of the trestle. According to Figure 3 the series coordinate system shown and the DH coordinate system parameter table shown in Table 1 below, determine the homogeneous transformation matrix from the coordinate system 4 to the coordinate system 0 as:

[0138]

[0139] where, z1 ∈ (-90°, 90°), z2 ∈ (-90°, 90°), z3 ∈ (5, 15).

[0140] Table 1

[0141]

[0142] The forward motion equation is:

[0143]

[0144] The inverse solution equation is:

[0145]

[0146] Taking the coordinate value of the end of the trestle in the inertial coordinate system n when the six-degree-of-freedom motion of the ship is zero and each compensation mechanism of the trestle is in the middle position as the target position, determine the target position coordinates as:

[0147]

[0148] For t kAt a certain moment, based on the six-degree-of-freedom motion response of the ship, the transformation matrix from coordinate system 0 to the inertial coordinate system n is determined, and the expected position of the end of the trestle in coordinate system 0 is solved through matrix inverse operation. It is:

[0149]

[0150] According to the above expected position, t is determined by inversely solving the equation. k The motion strokes of the three compensation mechanisms at the moment:

[0151]

[0152] Differential operations are performed to determine the time series of the motion strokes, speeds, and accelerations of the three compensation mechanisms, as shown in Table 2 below. Statistical analysis is carried out on the time series to determine the standard deviations of the time series of the strokes, speeds, and accelerations of the three compensation mechanisms of slewing, luffing, and telescoping. The 3.7-fold standard deviation is compared with the design value of the telescopic active wave compensation trestle. The specific results are shown in Table 3 below. This active wave compensation trestle can compensate for the ship motion caused by sea state 1, but cannot compensate for the ship motion caused by sea state 2 and sea state 3.

[0153] Table 2

[0154]

[0155] Table 3

[0156] Sea state 1 Sea state 2 Sea state 3 Slewing stroke (degrees) 5.73 7.77 4.89 Luffing stroke (degrees) 6.16 7.97 9.60 Telescoping stroke (meters) 1.40 1.59 2.98 Slewing speed (degrees / second) 5.46 6.93 5.02 Luffing speed (degrees / second) 4.90 6.17 7.63 Telescoping speed (meters / second) 1.02 1.16 2.10 Slewing acceleration (degrees / second / second) 5.52 6.49 5.58 Luffing acceleration (degrees / second / second) 4.08 4.92 6.60 Telescoping acceleration (meters / second / second) 0.79 0.91 1.58 Whether compensation is available Yes No No

[0157] To sum up, the present invention takes the sea state spectrum parameters and the ship wave frequency response factor as inputs, and constructs a compensation operation simulation system for a telescopic active wave compensation trestle based on the multi-body kinematics principle and the DH rule, which can judge whether the design of the compensation mechanism of the trestle can compensate for the ship motion under this sea state according to the simulation results. The system establishes multiple series coordinate systems associated with the compensation mechanism, constructs the homogeneous transformation matrix between the coordinate systems based on the DH rule, and establishes the forward motion equation and the inverse solution equation of the telescopic active wave compensation trestle. The invention simulates the six-degree-of-freedom wave frequency motion time series of the ship through the sine signal decomposition method, based on inputs such as the wave spectrum, direction spectrum, and wave frequency response factor in the frequency domain. Based on the ship motion response, the time series of the motion strokes, speeds, and accelerations of each compensation mechanism are determined by inversely solving the equation. By analyzing the statistical values of the time series and comparing them with the design values of the trestle compensation mechanism, it is judged whether the design values of each compensation mechanism can compensate for the ship motion under the given sea state. The present invention has important guiding significance for the design of the compensation mechanism of the telescopic active wave compensation trestle.

[0158] Those of ordinary skill in the art should recognize that the above embodiments are merely used to illustrate the present invention and are not intended to limit the present invention. As long as it is within the spirit of the present invention, changes and modifications to the above embodiments will fall within the scope of the claims of the present invention.

Claims

1. A compensation operation simulation method for a telescopic active wave compensation trestle, characterized in that: Taking sea condition parameters as input and combining with the wave frequency response factor of the ship, simulating the six-degree-of-freedom wave frequency motion of the ship; Establishing a series coordinate system connecting the compensation mechanism on the telescopic active wave compensation trestle, and constructing the forward kinematic equation and inverse solution equation of the compensation motion; According to the compensation target position at the end of the telescopic active wave compensation trestle and combining with the six-degree-of-freedom motion amplitude of the ship, inversely solving the motion stroke of the compensation mechanism; Differentiating the motion stroke of the compensation mechanism, calculating the speed and acceleration of the compensation mechanism, and determining the statistical value of the motion time series of the compensation mechanism; Finally, judging whether the telescopic active wave compensation trestle can compensate for the ship motion caused by this sea condition according to the statistical value.

2. The compensation operation simulation method for a telescopic active wave compensation trestle according to claim 1, wherein, The compensation operation simulation method specifically includes the following steps: S1, establishing an inertial coordinate system n based on the environment where the ship is located, establishing a hull coordinate system b based on the ship, and establishing a series coordinate system based on the telescopic active wave compensation trestle; S2, taking the sea condition parameters as input, combining with the wave frequency response factor of the ship, and using the sine signal decomposition method to simulate the time series of the six-degree-of-freedom wave frequency motion of the ship; S3, based on the series coordinate system, establishing the forward kinematic equation of the telescopic active wave compensation trestle, and determining the coordinate value of the end of the trestle in the inertial coordinate system n, that is, the compensation target position; S4, establishing the inverse solution equation of the telescopic active wave compensation trestle, and determining the motion stroke of each compensation mechanism based on the compensation target position and the six-degree-of-freedom motion amplitude of the ship; S5, based on the compensation stroke time series of the compensation mechanism, calculating the speed and acceleration of the compensation mechanism, determining the statistical value of the time series of the compensation mechanism, and judging whether the telescopic active wave compensation trestle can compensate for the ship motion caused by this sea condition.

3. The compensation operation simulation method for the retractable active wave compensation trestle according to claim 2, characterized in that: In the step S1, the inertial coordinate system n, the hull coordinate system b and the series coordinate system are all space rectangular coordinate systems.

4. The compensation operation simulation method for a telescopic active wave compensation trestle according to claim 3, wherein: When establishing the inertial coordinate system n, when the six-degree-of-freedom motion of the ship is all zero, the inertial coordinate system n coincides with the hull coordinate system b.

5. The compensation operation simulation method for a telescopic active wave compensation trestle according to claim 3, characterized in that: In the hull coordinate system b, the X-axis points to the bow of the ship, the Y-axis points to the starboard of the ship, the Z-axis conforms to the right-hand coordinate system rule, and the coordinate origin is located at the center of gravity of the ship.

6. The compensation operation simulation method for a telescopic active wave compensation trestle according to claim 3, characterized in that, Establishing the series coordinate system specifically includes: At the installation position of the telescopic active wave compensation trestle, establishing a coordinate system 0; At the motion center of the q-th compensation mechanism of the telescopic active wave compensation trestle, establishing a corresponding coordinate system q that moves with the compensation mechanism, and the selection of the coordinate system q conforms to the DH rule.

7. The compensation operation simulation method for a telescopic active wave compensation trestle according to claim 6, wherein: The number of the series coordinate system is m + 2; The coordinate system 0 is the base coordinate system, the coordinate systems 1, 2... m correspond to the coordinate systems of each compensation mechanism, and the coordinate system m + 1 is the end coordinate system of the telescopic active wave compensation trestle; The number of compensation mechanisms of the telescopic active wave compensation trestle is 3, that is, m = 3.

8. The compensation operation simulation method for the retractable active wave compensation trestle according to claim 2, wherein, In the step S2, the sea state parameters include the significant wave height H s , the spectral peak period T p and the main wave direction β0; The sine signal decomposition method specifically includes: Select the wave spectrum and directional spectrum of the target wind farm sea area. Since irregular waves can be regarded as composed of a finite number of sine waves with different frequencies, the amplitude, frequency, phase angle, and spreading wave direction angle of each sine wave can be calculated through the wave spectrum and directional spectrum. The time series of irregular waves is as follows: where t k is a discrete time series; S(ω i ) is the wave spectral density function; D(β j - β0) is the directional spectral density function; ω i is the i-th main frequency; Δω is the frequency interval; N is the number of main frequencies; β j is the j-th spreading wave direction angle; β0 is the main wave direction angle; Δβ is the spreading wave direction angle interval; M is the number of spreading wave direction angles; ε i,j is the phase angle.

9. The compensation operation simulation method for a telescopic active wave compensation trestle according to claim 2, wherein In step S2, the time series of simulating the six-degree-of-freedom wave-frequency motion of the ship specifically includes: Determine the six-degree-of-freedom response of the ship under the action of each sine wave according to the wave-frequency response factor of the ship; Linearly superimpose the motion responses caused by each sine wave to determine the time series of the six-degree-of-freedom motion of the ship: where, RAO l (ω i , β j ) and phase(RAO l (ω i , β j )) are the response factor and phase of the l-th degree of freedom of the ship under the action of regular waves with frequency ω i and direction β j , respectively.

10. The compensation operation simulation method for a telescopic active wave compensation trestle according to claim 2, characterized in that, Step S3 specifically includes: Establish m + 1 coordinate systems according to the DH rule and create a DH coordinate system parameter table; Establish a homogeneous transformation matrix from coordinate system q to coordinate system q-1 according to the DH coordinate system parameter table The homogeneous transformation matrix is a 4D square matrix, and the coordinates of spatial points also become 4D vectors accordingly. The values of the first three elements are the spatial rectangular coordinate values, and the value of the fourth element is always 1; Finally, according to the outer multiplication of the transformation matrix, the homogeneous transformation matrix from coordinate system m+1 to coordinate system 0 is determined. where z q is the current movement stroke of the q-th compensation mechanism; When the stroke of the compensation mechanism is given, the forward kinematic equation is used to calculate the coordinate value of the end of the telescopic active wave compensation trestle in the base coordinate system 0: In the formula, is the coordinate value of the end of the telescopic active wave compensation trestle in the coordinate system 0; Establish the homogeneous transformation matrices from coordinate system 0 to hull coordinate system b and from hull coordinate system b to inertial coordinate system n, and determine the transformation matrix from coordinate system 0 to inertial coordinate system n where [InstX b , InstY b , InstZ b is the installation position of the telescopic active wave compensation trestle base, that is, the coordinate value of the origin of coordinate system 0 under coordinate system b; According to the coordinate value of the end of the telescopic active wave compensation trestle in coordinate system 0 and the transformation matrix from coordinate system 0 to inertial coordinate system n Determine the coordinate value of the end of the telescopic active wave compensation trestle in inertial coordinate system n This coordinate value can be used as the compensation target position:

11. The compensation operation simulation method for the retractable active wave compensation trestle according to claim 2, characterized in that, Step S4 specifically includes: According to the transformation matrix from coordinate system 0 to the inertial coordinate system n, when the six-degree-of-freedom motion amplitude of the ship and the compensation target position are given, the expected position of the end of the telescopic active wave compensation trestle in coordinate system 0 is as follows: Based on the expected position of the end of the telescopic active wave compensation trestle, combined with the forward kinematic equation, inversely solve the motion strokes of each compensation mechanism: In the formula, is the operating stroke of each compensation mechanism.

12. The compensation operation simulation method for a telescopic active wave compensation trestle according to claim 2, wherein Step S5 specifically includes: According to the wave-frequency motion amplitudes of the six degrees of freedom of the ship at each moment t k determine the motion stroke of the compensation mechanism at this moment to form a time series Differentiating the motion stroke time series once yields the velocity time series of the compensation mechanism Differentiating twice gives the acceleration time series of the compensation mechanism as follows: Determine the statistical values of the motion stroke, speed, and acceleration of the compensation mechanism. If 3.7 times the standard deviation exceeds the design value of the compensation mechanism, it is determined that the telescopic active wave compensation trestle cannot compensate for the ship motion caused by this sea condition. Specifically: Where, InFun(H s , T p , β0) being 1 indicates that the active wave compensation trestle can compensate for the ship motion caused by this sea condition, and being 0 indicates that it cannot compensate; where std(·) is the standard deviation of each time series; are the compensation stroke limit, compensation speed limit, and compensation acceleration limit of the q-th compensation mechanism.

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