Heave compensation electric platform for ship

Abstract

The utility model discloses a marine heave compensation electric platform, which comprises a ship and comprises a motion platform IMU (Inertial Measurement Unit) arranged in the ship and used for generating digital signals; the computer is arranged in the ship, and the computer is connected with the motion platform IMU and is used for sending a digital signal and generating an analog signal; the embedded controller is arranged in the ship, and the embedded controller is connected with the motion platform IMU and the computer, receives and processes the digital signal and the analog signal, and generates a control signal; and the servo driver is arranged in the ship, and the servo driver is connected with the embedded controller, the motion platform IMU and the computer to generate a feedback signal.

Description

Technical Field

[0001] The utility model relates to the technical field of ships, in particular to a ship-used heave compensation electric platform. Background Art

[0002] With the continuous development of science and technology, the safety of ships now needs to be set and calculated in the initial stage of manufacturing, so as to improve the safety factor of ships. With the sudden change of climate, various bad weather may occur at any time. Therefore, ships will face various dangers and new climate challenges at any time during their navigation. When encountering strong winds and waves or severe shaking, the hull will lose balance, posing a great threat to the lives of people on board. Moreover, current ships cannot automatically correct the tilted hull. With the continuous development of the world's shipbuilding industry and the application of various new technologies and new equipment in ships, the research on ship motion control algorithms is particularly important.

[0003] When various existing ships are sailing on the sea with large waves, the balance performance of the ship is affected by external forces such as waves. Usually, due to various reasons such as collision and running aground, the internal cargo is offset, resulting in uneven weight on the ship, which destroys the balance and makes it easy for the ship to tilt or even capsize, causing loss of life and property. Nowadays, there are two types of devices to detect the degree of tilt of the ship: mechanical inclinometer and loading meter, which meet the stability of the ship and ensure the safe navigation of the ship.

[0004] However, mechanical inclinometers and stowage meters need to be regularly inspected on site for reliability and deviation. At the same time, the existing mechanical inclinometers and stowage meters on board may also malfunction during use, resulting in the crew being unable to measure and grasp the degree of ship inclination in a timely manner, posing a hidden danger to navigation safety. How to better prevent the occurrence of such incidents, in addition to the safety design of the ship itself, a marine heave compensation electric platform is needed to improve the safety factor of the ship, thereby ensuring the safety of personnel on board. Utility Model Content

[0005] The present application provides a marine heave compensation electric platform, which is used to solve the technical problems of being unable to eliminate system oscillation and unstable control loop.

[0006] In view of the above problems, the present application provides a ship-based heave compensation electric platform, including a ship, including: a motion platform IMU, the motion platform IMU is arranged inside the ship, and generates a digital signal; a computer, the computer is arranged inside the ship, the computer is connected to the motion platform IMU, sends digital signals and generates analog signals; an embedded controller, the embedded controller is arranged inside the ship, the embedded controller is connected to the motion platform IMU and the computer, receives and processes digital signals and analog signals, and generates control signals; a servo drive, the servo drive is arranged inside the ship, the servo drive is connected to the embedded controller, the motion platform IMU and the computer, and generates a feedback signal.

[0007] One or more technical solutions provided in this application have at least the following technical effects or advantages:

[0008] The embodiment of the present application adopts a feedforward control algorithm with a speed prediction function to compensate for the delay caused by sampling and calculation, eliminate the system oscillation caused by the delay, improve the dynamic characteristics of the system, and at the same time improve the stability of the control loop, eliminate the steady-state error of the system, and make the control effect smoother and more precise. The external AD converter is simulated as an external memory, and the on-chip FSMC interface of the main control chip is used to implement the timing control of the external AD converter and the parallel interface data reading, which improves the parallel port data reading efficiency and reduces the amount of program code and shortens the execution time of the program code. The on-chip external DMA function of the main control chip is used to perform the timing control of the FSMC interface, and the timing control is completed by hardware, which replaces the conventional timing control method in which the CPU runs the software to perform timing control, thereby reducing the CPU time consumption.

[0009] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0011] Figure 1 A side sectional view of a marine heave compensation electric platform provided in this application;

[0012] Figure 2 A schematic diagram of the composition of a six-degree-of-freedom motion platform system of a marine heave compensation electric platform provided in this application;

[0013] Figure 3 A system schematic diagram of a marine heave compensation electric platform provided for this application;

[0014] Figure 4 A schematic diagram of a servo control system for a marine heave compensation electric platform provided in this application;

[0015] Figure 5 A working principle diagram of a control system of a marine heave compensation electric platform provided in this application;

[0016] Figure 6 A servo system structure block diagram of a marine heave compensation electric platform provided in this application;

[0017] Figure 7 A motion principle diagram of a motion control model of a marine heave compensation electric platform provided in this application;

[0018] Figure 8 A simplified block diagram of a control system for a marine heave compensation electric platform provided in this application.

[0019] In the figure: 1. upper platform; 2. upper hinge; 3. electric cylinder; 4. lower platform; 5. motor; 6. lower hinge; 10. ship; 11. motion platform IMU; 12. computer; 13. embedded controller; 14. servo drive. DETAILED DESCRIPTION

[0020] The present application provides a marine heave compensation electric platform, which is used to solve the technical problems of being unable to eliminate system oscillations and unstable control loops.

[0021] In response to the above technical problems, the overall idea of ​​the technical solution provided by this application is as follows:

[0022] In the embodiment of the present application, the motion platform IMU 11 is used to output the motion platform IMU 11 posture information and generate a digital signal. The computer 12 sends the analog posture control command to the analog posture feedback information output by the IMU on the motion platform to generate an analog signal. The embedded controller 13 collects the analog posture command, collects the analog posture feedback information, calculates the posture deviation signal, and reverses the posture information to generate a control signal. The position loop of the six electric cylinders is controlled, and the servo driver 14 controls the motion platform IMU in three ways: position, speed and torque, to achieve high-precision transmission system positioning, generate feedback signals, and adopts a feedforward control algorithm with a speed prediction function to correct the delay caused by sampling and calculation. The compensation is carried out to eliminate the system oscillation caused by the delay, which not only improves the dynamic characteristics of the system, but also improves the stability of the control loop, eliminates the steady-state error of the system, and makes the control effect smoother and more precise. The external AD converter is simulated as an external memory, and the on-chip FSMC interface of the main control chip is used to realize the timing control of the external AD converter and the parallel interface data reading, which improves the parallel port data reading efficiency, reduces the amount of program code, and shortens the execution time of the program code. The on-chip external DMA function of the main control chip is used to perform the timing control of the FSMC interface. The timing control is completed by hardware, which replaces the conventional timing control method in which the CPU runs the software to perform timing control, thereby reducing the CPU time consumption.

[0023] After introducing the basic principles of the present application, the technical solutions in the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments of the present application. It should be understood that the present application is not limited to the example embodiments described here. Based on the embodiments of the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application. It should also be noted that, for the convenience of description, only the parts related to the present application are shown in the accompanying drawings, rather than all of them.

[0024] like Figure 1 and Figure 3As shown, the ship 10 includes: a motion platform IMU 11, which is arranged inside the ship 10 and generates a digital signal; a computer 12, which is arranged inside the ship 10 and connected to the motion platform IMU 11, sends a digital signal and generates an analog signal; an embedded controller 13, which is arranged inside the ship 10 and connected to the motion platform IMU 11 and the computer 12, receives and processes digital signals and analog signals, and generates a control signal; and a servo driver 14, which is arranged inside the ship 10 and connected to the embedded controller 13, the motion platform IMU 11 and the computer 12, and generates a feedback signal.

[0025] During the voyage of the ship, as the attitude of the hull tilts, the attitude information of the motion platform IMU11 is output through the motion platform IMU11, the computer 12 sends the analog attitude control command to the analog attitude feedback information output by the IMU on the motion platform, the embedded controller 13 collects the analog attitude command, collects the analog attitude feedback information, calculates the attitude deviation signal, and reverses the attitude information, the servo driver 14 adjusts the speed loop and current loop of the 6 cylinders, first receives the speed command information, and then compares it with the speed feedback information to obtain the speed deviation, and outputs the current command after speed loop adjustment, filtering and other processing, the current loop processes and adjusts the current command and current feedback information and then outputs the control signal, and outputs the power drive signal after power amplification, drives the motor to rotate, and controls the motion platform IMU11 in three ways: position, speed and torque, to achieve high-precision transmission system positioning, so that when the attitude of the hull tilts, the influence of the hull attitude change on the inertial platform is eliminated, and an inertial platform is established to isolate the mother body movement.

[0026] See also Figure 1 and Figure 2 The motion platform IMU11 includes: an upper platform 1, an upper hinge 2, an electric cylinder 3, a lower platform 4, a motor 5 and a lower hinge 6. The six-degree-of-freedom motion platform is planned to adopt a 6-SPS type motor-driven pure parallel mechanism. The so-called "6-SPS type motor-driven pure parallel mechanism" is actually a Stewart or Gough platform, which is mainly composed of two platforms, one is an upper platform also called a moving platform, and the other is a lower platform also called a base. The two platforms are connected by six retractable or flexural "legs" through a ball hinge. The "legs", that is, the telescopic connecting rods, are driven by an electric cylinder in a closed loop. The Stewart structure has the advantages of simple structure, high rigidity, high precision and high load capacity. The Stewart six-degree-of-freedom motion simulation platform has become an important simulation test device for dynamic reliability research on aircraft, ships, aerospace and vehicle-mounted equipment.

[0027] See also Figure 1 , Figure 7 and Figure 8 , including: motion control model and feedforward control algorithm with speed prediction function. The principle of platform kinematics is to clarify the mathematical relationship between the posture of the upper platform and the length of the cylinder, and then provide a theoretical basis for controlling the cylinder length. In order to study the motion law of the platform, determine the position and posture of the platform, and consider the convenience of calculation, the following two coordinate systems are adopted. The motion coordinate system OXYZ is fixed to the upper platform and moves with the upper platform, referred to as the dynamic system or body coordinate system. The origin O is in the plane where the upper platform hinge is located, located on the vertical line of the center of the upper platform, and the OZ axis is perpendicular to the upper platform and downward is positive; the OX axis is located in the plane where the 6 hinges of the upper platform are located, pointing to the head of the platform as the positive direction; the OY axis is located in the horizontal plane where the OX axis is located. According to the right-hand rule, the OX axis is rotated 90° clockwise. The fixed coordinate system O′X′Y′Z′ is fixed to the earth, referred to as the static system or fixed system. It coincides with the dynamic coordinate system at the initial position. When the platform moves, the static system is stationary relative to the earth.

[0028] Feedforward uses information about the controlled object to improve the command response performance. The command signal is processed before the control law and sent directly to the power converter according to the specified route. Feedforward calculates a best guess that the signal sent to the power converter can produce an ideal response from the controlled object. For the command, this removes the burden of the control loop, because most of the excitation of the power converter can be generated in the feedforward path. The control law only provides correction and responds to disturbances. With feedforward, the command response is almost no longer dependent on the control law gain. After maximizing the control law gain, an aggressive feedforward design can increase the bandwidth of the response command several times. Using feedforward to improve command response is similar to using disturbance decoupling to improve disturbance response performance. Another benefit of using feedforward is that in the presence of a constant command, the steady-state error is eliminated. When the command signal is constant, if the feedforward gain is set to 100%, the steady-state error will be completely eliminated. It may be difficult to accurately predict the feedforward gain, but in some cases, it is very direct.

[0029] The motor adopts a three-loop feedback control method that combines position loop, speed loop and current loop, and adopts compound control PID adjustment to achieve various performance index requirements. First, a closed loop composed of current feedback and encoder feedback; second, a compound control composed of position, speed and acceleration is introduced; third, a feedforward algorithm with speed prediction function is adopted in the control algorithm, which eliminates the phase lag generated in the feedforward channel, improves the dynamic characteristics of the system, eliminates the steady-state error of the system, and makes the control effect smoother and more precise.

[0030] See also Figure 1 and Figure 6The embedded controller 13 includes: an AD acquisition interface, an encoder counting interface and a digital quantity IO interface, wherein the AD acquisition interface is used to receive the posture instructions output by the acquisition computer and the motion platform posture information output by the IMU, the encoder counting interface is used to collect the photoelectric encoder position signal, and the IO interface can be used as an input interface for various protection switch signals of the platform.

[0031] See also Figure 1 and Figure 5 , the servo driver 14 includes: servo drive, servo motor, servo electric cylinder. After the system is powered on, the servo driver 14 software first initializes the system and variables, completes the clock configuration of the system and related peripherals, and initializes the variables. Since we need to use timer interrupts to realize the inverse solution of attitude information and the control of the position loop, and use the encoder interface mode of the timer to collect and process the position information, we need to configure the corresponding functions next, execute timer interrupt initialization, timer encoder mode initialization, and when collecting the attitude instructions sent by the host computer and the attitude feedback information output by the IMU, AD conversion and result reading are required. The FSMC interface and DMA function of STM32F4 are used to realize AD acquisition and conversion, and these functions need to be initialized. It is necessary to use the CAN bus to send speed control instructions to the driver, and the bus interface needs to be initialized. After the initialization is completed, a power-on self-test is performed to detect the basic drive functions of the 6 electric cylinders, and then the motor rotor position is zeroed. Finally, it enters the main loop, receives the attitude command sent by the host computer, parses the communication protocol and judges the command word of the data frame, and executes the corresponding subroutine according to the command word requirements. The corresponding subroutine may include self-test query, zero position calibration, algorithm parameter adjustment, command control quantity calculation, etc.

[0032] Although the present application has been described in conjunction with specific features and embodiments thereof, it is obvious that various modifications and combinations may be made thereto without departing from the spirit and scope of the present application. Accordingly, this specification and the accompanying drawings are merely exemplary illustrations of the present application and are deemed to have covered any and all modifications, variations, combinations or equivalents within the scope of the present application. Obviously, a person skilled in the art may make various modifications and variations to the present application without departing from the scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the present application and its equivalents, the present application is intended to include these modifications and variations.

Claims

1. A marine heave compensation electric platform, comprising a ship (10), characterized in that: include: A motion platform IMU (11), wherein the motion platform IMU (11) is arranged inside the ship (10) and generates a digital signal; A computer (12), wherein the computer (12) is disposed inside the ship (10), and the computer (12) is connected to the motion platform IMU (11), sends digital signals and generates analog signals; An embedded controller (13), the embedded controller (13) being arranged inside the ship (10), the embedded controller (13) being connected to the motion platform IMU (11) and the computer (12), receiving and processing digital signals and analog signals, and generating control signals; A servo driver (14) is arranged inside the ship (10), and the servo driver (14) is connected to the embedded controller (13), the motion platform IMU (11) and the computer (12) to generate a feedback signal.

2. A marine heave compensation electric platform according to claim 1, characterized in that: The motion platform IMU (11) comprises an upper platform, an upper hinge, an electric cylinder, a lower platform, a motor and a lower hinge.

3. The marine heave compensation electric platform according to claim 1, characterized in that: The embedded controller (13) comprises: an AD acquisition interface, an encoder counting interface and a digital quantity IO interface.

4. The marine heave compensation electric platform according to claim 1, characterized in that: The servo driver (14) comprises: a servo drive, a servo motor, and a servo electric cylinder.

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