Underwater motion simulation device and control method thereof

Abstract

The invention relates to an underwater motion simulation device and a control method thereof.The device comprises a main body frame erected above a pool, a control box is installed on the main body frame, a motor, a winch and a control module are arranged in the control box, the winch is connected with a test sample piece, and the control module controls the working states of the motor and the winch. And adjusting the test sample piece to vertically move in the water according to the set positive and negative acceleration, positive and negative speed or displacement. The method comprises the steps that according to set acceleration, set speed and set displacement working conditions, corresponding acceleration and speed, motor torque and rotating speed and motor control power are calculated in sequence; and a self-tuning fuzzy proportional integral differential control method is adopted to realize self-adaptive control of the rotating speed of the motor. Compared with the prior art, the underwater vertical or horizontal movement can be simulated, different positive and negative acceleration, positive and negative speed or displacement movement modes can be simulated at the same time, and the test requirements of different working conditions can be efficiently and accurately met.

Description

Technical Field

[0001] The present invention relates to the technical field of underwater equipment, and in particular to an underwater motion simulation device and a control method thereof. Background Art

[0002] In recent years, with the rapid development of ocean development and underwater detection technology, various underwater equipment has been continuously used in deep-sea environments. In the field of marine engineering, the dynamic characteristics analysis of the buoy system is crucial to ensure the accuracy and reliability of marine environment monitoring equipment. The vertical or horizontal movement of the buoy in the water, especially when affected by waves, tides and wind, will produce complex vibration behavior. This movement not only affects the stability and performance of the buoy itself, but is also more likely to interfere with the ocean sensors installed on the buoy. Therefore, verifying and simulating the impact of the buoy's movement in the water on the sensor has become an important direction of current research.

[0003] Since underwater motion conditions are relatively complex (different motion directions and different motion speeds, accelerations or displacements), in order to achieve realistic simulation of different motion modes, it is often necessary to design corresponding devices for simulation tests. The construction cost is high, and the operation in actual applications is cumbersome and difficult to adapt to the test requirements of different working conditions, which is not conducive to accurate and efficient completion of the simulation. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and to provide an underwater motion simulation device and a control method thereof, which can simulate underwater vertical or horizontal motion, and at the same time simulate different positive and negative accelerations, positive and negative velocities or displacement motion modes, so as to adapt to the test requirements of different working conditions.

[0005] The objective of the present invention can be achieved through the following technical scheme: an underwater motion simulation device, comprising a main frame erected above a water pool, a distribution box and a control box connected thereto being installed on the main frame, a motor, a winch and a control module being arranged in the control box, the control module being respectively connected to the motor and the winch, the winch being connected to a test sample, the control module being used to control the working state of the motor and the winch to simulate vertical motion or horizontal motion, and to adjust the test sample to undergo vertical motion in the water according to set positive and negative accelerations, positive and negative velocities or displacements.

[0006] Furthermore, the main frame includes two steel platforms, which are symmetrically fixed above the pool, and a fixed bracket is connected between the two steel platforms, and the distribution box and the control box are installed on the fixed bracket.

[0007] Furthermore, the motor is installed beside the winch and connected to the winch through a belt and a coupling, and the output shaft of the motor is aligned with the input shaft of the winch.

[0008] Furthermore, a limiter is installed beside the motor to detect and limit the movement range of the winch.

[0009] Furthermore, the winch is located in the central area of ​​the fixed bracket.

[0010] Furthermore, the control module includes a PLC (Programmable Logic Controller), a touch screen, a servo drive, a switching power supply, a circuit breaker, and a fuse.

[0011] A control method for an underwater motion simulation device comprises the following steps:

[0012] S1. Calculate the corresponding acceleration and speed according to the set acceleration condition, the set speed condition and the set displacement condition;

[0013] S2. Based on the calculated acceleration and speed, further calculate the corresponding motor torque and motor speed, and determine the corresponding motor control power;

[0014] S3. According to the motor control power, the motor rotation is adjusted accordingly, and a self-tuning fuzzy proportional integral derivative (PID) control method is adopted to realize adaptive control of the motor speed.

[0015] Furthermore, the specific process of step S1 is as follows:

[0016] In the working condition with known acceleration, the velocity is obtained by calculating the integral of acceleration over time, and the acceleration and velocity information of continuous time are discretized to obtain the acceleration and velocity within a series of set time intervals δt;

[0017] In the working condition with known speed, the acceleration is obtained by calculating the derivative of speed with respect to time, and the acceleration information of continuous time is discretized to obtain the acceleration within a series of set time intervals δt;

[0018] In the working condition of known displacement, the velocity is obtained by calculating the time derivative of the displacement, and the acceleration is obtained by calculating the time derivative of the velocity. The continuous time acceleration and velocity information is discretized to obtain a series of accelerations and velocities within a set time interval δt.

[0019] Furthermore, the motor torque calculation formula in step S2 is:

[0020] M(g+a)Ri

[0021] The formula for calculating the motor speed is:

[0022]

[0023] The motor control power calculation formula is:

[0024]

[0025] Where i is the transmission ratio, v is the speed of the test specimen, M is the mass of the test specimen, a is the acceleration of the test specimen, g is the acceleration due to gravity, and R is the radius of the winch.

[0026] Furthermore, the adaptive control process of the motor speed in step S3 is specifically as follows:

[0027] The PID parameters are automatically adjusted according to the deviation e and its change rate ec. The PID parameters include the proportional coefficient K P , integral coefficient K i and the differential coefficient K d , determine the quantization factor and the proportional factor according to the formula, and then use the two types of factors to calculate the input value e, ec and the output value ΔK respectively P , ΔK i and ΔK d Fuzzy processing is performed to convert numerical variables into linguistic variables. The linguistic variables are expressed as negative large-negative medium-negative small-zero-positive small-positive medium-positive large. The variable range is set using a discrete domain containing a finite number of integers. For different input and output variables, the membership function is defined:

[0028] (1) |e| is larger, so choose a larger K P In order to respond quickly, take a smaller K i Reduce system overshoot and select a smaller K d Prevent differential overflow;

[0029] (2) |e| is medium, so choose a smaller K P In order to suppress overshoot, choose a medium K i , K d value;

[0030] (3) |e| is small, so take a larger K P , K i In order to weaken the static deviation of the system, take a moderate K d To prevent vibration;

[0031] According to the formula K P =K P0 +ΔK P , K i =K i0 +ΔK i , K d =K d0 +ΔK dComplete the adjustment of the three PID parameters to adapt to dynamic changes, among which K P0 K P The initial value of ΔK P K P The change value of K i0 K i The initial value of ΔK i K i The change value of K d0 K d The initial value of ΔK d K d The change value of .

[0032] Compared with the prior art, the present invention has the following advantages:

[0033] The present invention is designed to erect a main frame above a water pool, and a distribution box and a control box connected thereto are installed on the main frame, wherein a motor, a winch and a control module are arranged in the control box, and the control module is respectively connected to the motor and the winch, and the winch is connected to the test sample, thereby utilizing the control module to control the working states of the motor and the winch to simulate vertical motion or horizontal motion, and adjust the test sample to perform vertical motion in water according to set positive and negative accelerations, positive and negative velocities or displacements. In actual applications, there is no need to frequently replace hardware, and only one set of devices is required to truly simulate underwater vertical motion or horizontal motion, and the test requirements of different working conditions can be adapted at a low cost, and the accuracy of the test can be ensured.

[0034] The present invention installs the motor beside the winch, connects the motor and the winch through a coupling and a belt, and aligns the motor shaft with the winch input shaft, thereby ensuring efficient power transmission.

[0035] The present invention installs a limiter beside the motor to detect and limit the movement range of the winch to prevent excessive operation.

[0036] The present invention arranges the winch at the center of the fixed bracket of the main frame, which facilitates the vertical placement of the test sample into the water pool, so that the test sample can be vertically placed in the water pool below in the middle area of ​​the fixed bracket.

[0037] The present invention first calculates the corresponding acceleration and speed according to the set acceleration working condition, the set speed working condition and the set displacement working condition; then calculates the corresponding motor torque and motor speed in turn, and determines the corresponding motor control power; thereby adjusting the rotation of the motor accordingly according to the motor control power, and adopts a self-tuning fuzzy proportional integral differential control method to realize adaptive control of the motor speed, which can accurately simulate underwater vertical or horizontal movement, and can also simulate three different movement modes of positive and negative acceleration, positive and negative speed or displacement. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic diagram of the structure of the device of the present invention;

[0039] Figure 2 It is a schematic diagram of the side structure of the device of the present invention;

[0040] Figure 3 It is a schematic diagram of the method flow of the present invention;

[0041] Figure 4 It is a schematic diagram of the self-tuning fuzzy proportional integral differential control framework in the present invention;

[0042] Figure 5 A schematic diagram of preset speeds of the simulation device in the embodiment;

[0043] Figure 6 It is a schematic diagram of the actual speed of the simulation device in the embodiment;

[0044] Marking instructions in the figure: 1. Distribution box, 2. Control box, 3. Test sample, 401. Steel platform, 402 Fixed bracket. DETAILED DESCRIPTION

[0045] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0046] Example

[0047] like Figure 1 and Figure 2 As shown, an underwater motion simulation device includes a main frame erected above a water pool, a distribution box 1 and a control box 2 connected thereto are installed on the main frame, a motor, a winch and a control module are arranged in the control box 1, the control module is respectively connected to the motor and the winch, the winch is connected to a test sample 3, the control module includes a PLC, a touch screen, a servo drive, a switching power supply, a circuit breaker, a fuse, etc., the control module is used to control the working state of the motor and the winch to simulate vertical motion or horizontal motion, and adjust the test sample 3 to move vertically in water according to set positive and negative acceleration, positive and negative speed or displacement.

[0048] The main frame includes two steel platforms 401, which are symmetrically fixed above the pool. A fixed bracket 402 is connected between the two steel platforms, and the distribution box and the control box are installed on the fixed bracket 402.

[0049] The motor is installed beside the winch and connected to the winch through a belt and a coupling. The output shaft of the motor is aligned with the input shaft of the winch to ensure efficient power transmission.

[0050] A limiter is installed next to the motor to detect and limit the movement range of the winch to prevent excessive operation;

[0051] The winch is located in the central area of ​​the fixed support 402. Through the lifting of the winch, the test sample 3 is vertically placed from the middle area of ​​the fixed support 402 into the water pool below.

[0052] For the above underwater motion simulation device, its control method is as follows Figure 3 As shown, the following steps are included:

[0053] S1. Calculate the corresponding acceleration and speed according to the set acceleration condition, the set speed condition and the set displacement condition;

[0054] S2. Based on the calculated acceleration and speed, further calculate the corresponding motor torque and motor speed, and determine the corresponding motor control power;

[0055] S3. According to the motor control power, the motor rotation is adjusted accordingly, and a self-tuning fuzzy proportional integral differential control method is used to achieve adaptive control of the motor speed.

[0056] This embodiment applies the above scheme. First, an underwater motion simulation device is built and sensors are installed on the test sample. Then, in a working condition where the acceleration is known, the velocity is obtained by calculating the integral of the acceleration over time, and the acceleration and velocity information of the continuous time is discretized to obtain a series of accelerations and velocities at small time intervals (denoted as δt).

[0057] In the working condition of known speed, the acceleration is obtained by calculating the derivative of speed with respect to time, and the acceleration information of continuous time is discretized to obtain the acceleration of a series of small time intervals (denoted as δt);

[0058] In the working condition of known displacement, the velocity is obtained by calculating the time derivative of displacement, and the acceleration is obtained by calculating the time derivative of velocity. The acceleration and velocity information of continuous time are discretized to obtain the acceleration and velocity of a series of small time intervals (denoted as δt);

[0059] After obtaining the acceleration and speed under the three working conditions, the motor torque and speed corresponding to each δt are calculated; (In the following analysis and control, the resistance of movement in water is not considered. Although it is difficult to calculate the resistance, the traction can be adjusted through feedback to offset the effect of the resistance);

[0060] The motor torque is:

[0061] M(g+a)Ri

[0062] The motor speed is:

[0063]

[0064] Where i is the transmission ratio, v is the speed of the test specimen, M is the mass of the test specimen, a is the acceleration of the test specimen, g is the acceleration due to gravity, and R is the radius of the winch;

[0065] Then, the acceleration and speed corresponding to each δt are simulated by controlling the motor power, and the motor power is controlled as follows:

[0066]

[0067] Power is supplied to the simulation device, the control module starts working, the test sample is connected to the winch through the hook, and is vertically suspended into the water pool, waiting for the test sample to stabilize;

[0068] Then the motor is turned on, and the motor power is input according to the calculated motor power to control the motor rotation, and the self-tuning fuzzy proportional integral differential (PID) control method is used to achieve adaptive control of the motor speed:

[0069] For input e(t) and output u(t), the conventional PID control law is:

[0070]

[0071] Among them, the three coefficients of PID control are proportional coefficient K P , integral coefficient K i and the differential coefficient K d .

[0072] like Figure 4 As shown in the figure, in the self-tuning fuzzy PID control method, the PID parameters are automatically adjusted according to the deviation e and its change rate ec, the quantization factor and the proportional factor are determined according to the formula, and then the input value e, ec and the output value ΔK are adjusted respectively by two types of factors. P , ΔK i and ΔK d Fuzzy processing is performed to convert numerical variables into linguistic variables. The linguistic variables are expressed as negative large-negative medium-negative small-zero-positive small-positive medium-positive large. The variable range is set using a discrete domain containing a finite number of integers. For different input and output variables, the membership function is defined:

[0073] (4) |e| is larger, so choose a larger K P In order to respond quickly, take a smaller K i Reduce system overshoot and select a smaller K d Prevent differential overflow.

[0074] (5) |e| is medium, choose a smaller K P In order to suppress overshoot, choose a medium K i , K d value.

[0075] (6) |e| is small, so take a larger K P , K i In order to weaken the static deviation of the system, take a moderate K d To prevent vibration.

[0076] According to the formula K P =K P0 +ΔK P , K i =K i0 +ΔK i , K d =K d0 +ΔK d Complete the adjustment of the three PID parameters (K P0 K P The initial value of ΔK P K P The change value of K i0 K i The initial value of ΔK i K i The change value of K d0 K d The initial value of ΔK d K d of the changing value) to adapt to dynamic changes.

[0077] In this embodiment, the preset speed to be simulated by the test sample is calculated as follows: Figure 5 As shown in the figure, the actual speed of the test sample collected by the sensor during the simulation test is as follows Figure 6 As shown, by comparison, it can be seen that this scheme can achieve the purpose of accurate and effective simulation.

[0078] In summary, this solution can simulate vertical or horizontal motion underwater, and can also simulate three different motion modes: positive and negative acceleration, positive and negative speed, or displacement. When applied, feedback adjustment is performed through the motor speed adaptive control method. This device is designed as a vertical device. By controlling the relationship between traction and gravity and resistance, it can simulate underwater vertical motion and underwater horizontal motion, and can adapt to different test conditions and research needs. In actual operation, there is no need to frequently replace hardware, and parameter setting can be completed only through software or simple mechanical adjustment, which greatly simplifies the operation process. There is no need to design multiple sets of devices for testing, which greatly reduces the cost of device construction.

Claims

1. An underwater motion simulation device, characterized in that: The invention comprises a main frame erected above a water pool, wherein a distribution box (1) and a control box (2) connected thereto are installed on the main frame, wherein a motor, a hoist and a control module are arranged in the control box (2), wherein the control module is connected to the motor and the hoist respectively, wherein the hoist is connected to a test sample (3), and wherein the control module is used to control the working state of the motor and the hoist to simulate vertical movement or horizontal movement, and to adjust the test sample (3) to move vertically in water according to set positive and negative acceleration, positive and negative speed or displacement.

2. An underwater motion simulation device according to claim 1, characterized in that: The main frame comprises two steel platforms (401), which are symmetrically fixed above the pool. A fixed bracket (402) is connected between the two steel platforms (401), and the distribution box (1) and the control box (2) are installed on the fixed bracket (402).

3. An underwater motion simulation device according to claim 1, characterized in that: The motor is installed beside the winch and connected to the winch through a belt and a coupling. The output shaft of the motor is aligned with the input shaft of the winch.

4. The underwater motion simulation device according to claim 1, characterized in that: A limiter is installed beside the motor to detect and limit the movement range of the winch.

5. The underwater motion simulation device according to claim 2, characterized in that: The hoist is located in the central area of ​​the fixed support (402).

6. The underwater motion simulation device according to claim 1, characterized in that: The control module includes a PLC, a touch screen, a servo driver, a switching power supply, a circuit breaker, and a fuse.

7. A method for controlling an underwater motion simulation device, used for controlling an underwater motion simulation device as claimed in any one of claims 1 to 6, characterized in that: The following steps are involved: S1. Calculate the corresponding acceleration and speed according to the set acceleration condition, the set speed condition and the set displacement condition; S2. Based on the calculated acceleration and speed, further calculate the corresponding motor torque and motor speed, and determine the corresponding motor control power; S3. According to the motor control power, the motor rotation is adjusted accordingly, and a self-tuning fuzzy proportional integral differential control method is used to achieve adaptive control of the motor speed.

8. The control method of the underwater motion simulation device according to claim 7, characterized in that: The specific process of step S1 is as follows: In the working condition with known acceleration, the velocity is obtained by calculating the integral of acceleration over time, and the acceleration and velocity information of continuous time are discretized to obtain the acceleration and velocity within a series of set time intervals δt; In the working condition with known speed, the acceleration is obtained by calculating the derivative of speed with respect to time, and the acceleration information of continuous time is discretized to obtain the acceleration within a series of set time intervals δt; In the working condition of known displacement, the velocity is obtained by calculating the time derivative of the displacement, and the acceleration is obtained by calculating the time derivative of the velocity. The continuous time acceleration and velocity information is discretized to obtain a series of accelerations and velocities within a set time interval δt.

9. The control method of the underwater motion simulation device according to claim 8, characterized in that: The motor torque calculation formula in step S2 is: M(g+a)Ri The formula for calculating the motor speed is: The motor control power calculation formula is: Where i is the transmission ratio, v is the speed of the test specimen, M is the mass of the test specimen, a is the acceleration of the test specimen, g is the acceleration due to gravity, and R is the radius of the winch.

10. The control method of the underwater motion simulation device according to claim 9, characterized in that: The adaptive control process of the motor speed in step S3 is specifically as follows: The PID parameters are automatically adjusted according to the deviation e and its change rate ec. The PID parameters include the proportional coefficient K P , integral coefficient K i and the differential coefficient K d , determine the quantization factor and the proportional factor according to the formula, and then use the two types of factors to calculate the input value e, ec and the output value ΔK respectively P , ΔK i and ΔK d Fuzzy processing is performed to convert numerical variables into linguistic variables. The linguistic variables are expressed as negative large-negative medium-negative small-zero-positive small-positive medium-positive large. The variable range is set using a discrete domain containing a finite number of integers. For different input and output variables, the membership function is defined: (1) |e| is larger, so choose a larger K P In order to respond quickly, take a smaller K i Reduce system overshoot and select a smaller K d Prevent differential overflow; (2) |e| is medium, so choose a smaller K P In order to suppress overshoot, choose a medium K i , K d value; (3) |e| is small, so take a larger K P , K i In order to weaken the static deviation of the system, take a moderate K d To prevent vibration; According to the formula K P =L P0 +ΔL P , L i =L i0 +ΔL i , L d =L d0 +ΔL d Complete the adjustment of the three PID parameters to adapt to dynamic changes, among which L P0 For L P The initial value of ΔK P K P The change value of K i0 K i The initial value of ΔK i For L i The change value of K d0 K d The initial value of ΔL d K d The change value of .

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