As a kind of parallel robot, the 6DOF ship motion simulation test bench has developed rapidly and is widely used. The degree of freedom ship motion simulation test bench conducts land tests to verify the reliability of shipborne weapons, equipment or instruments, and reduces the risk and number of sea tests, thereby reducing the test cost and development cycle of weapons, equipment or instruments.
An overview of the research on the ship's six-degree-of-freedom motion platform
Strictly speaking, a ship sailing in rivers, lakes and seas is a six-degree-of-freedom moving body. In order to simplify the analysis, it is often decomposed into horizontal plane motion and vertical plane motion, and the coupling relationship between the two motions is not considered. Most ships have no control means for heave motion and pitch motion in the vertical plane, so only the movement and maneuvering control problems in the horizontal plane are studied for displacement ships. The value of establishing a mathematical model of ship horizontal plane maneuvering is that when designing the overall structure and performance of the ship, the ship maneuverability can be predicted through the mathematical simulation test of maneuvering motion; During the design, the control laws and parameters of the manipulation control equipment are determined through the simulation test.
When the ship sails in wind and wave weather, the course will sway continuously. In high sea conditions, the rudder moment is far from enough to overcome the disturbance moment of the waves. In the automatic mode of the rudder, it will frequently steer but cannot control the swing of the course. In order to eliminate this "ineffective rudder", the introduction of links such as Wiener filter, Kalman filter, asymptotic observation filter, etc. is currently being studied, but this problem has not been well solved so far. Therefore, in the research and simulation of various filtering technologies, it is more practical to establish and adopt the mathematical model of the maneuvering motion of the ship sailing in the wind and waves.
The components of the six-degree-of-freedom ship simulation platform: visual simulation system, manipulation load simulation system, sound effect environment simulation system, computer data processing system, cockpit simulation system and motion simulation simulation platform.
Visual simulation system: It provides the driver with a visual scene outside the cabin. As the "navigation" position and "navigation" status of the simulator change, the corresponding outboard scene is displayed in front of the simulation cabin, including the port, the waves, the sky, the ship's sailing wake, etc. The visual simulation system generally consists of a visual generation computer and a visual display system. The virtual scene completes the interactive display of the virtual scene through scene modeling, scene special effects development, and interactive development. The visual display system is generally realized by a projection display system.
Manipulating the load system: When the driver manipulates the steering wheel, the clock handle and other control mechanisms, the manipulating the load system gives the driver the feeling of manipulating the load force. These load forces change with the changes of parameters such as the stroke size of the control mechanism and the sailing speed. Manipulating the load system usually adopts a force servo system.
Simulated cockpit and sound effect environment simulation system: It is similar to the real ship cockpit, with instruments, indicator lights, switch buttons and joysticks in the cabin. The driver maneuvers the simulator according to instrument indications and exterior displays. The in-cabin instruments can also be developed into virtual instruments as required. The noise simulation system is mainly used to simulate the navigation of the ship simulator, the sound effects of the engine and the external environment, and the voice communication between the crew and the console
Simulation computer data processing system: It is the main component of the driving simulator. The mathematical model of each system of the ship is described by means of programming.
Motion simulation simulation platform: It gives the driver a sense of motion. The motion simulation system generally provides a six-degree-of-freedom motion platform to provide the feeling of the simulator's six angular movements of vertical, horizontal, lateral, pitch, roll and yaw during the "sail" process. The motion base is driven by a high-power servo system, and the driving signal is formed by computer calculation.
Research on the design of the ship's six-degree-of-freedom motion platform:
According to the overall design requirements, performance index requirements and interface requirements of the six-degree-of-freedom ship motion simulation test bench, a scheme of combining the six-degree-of-freedom Stewart platform structure with the lifting platform is used to conduct an overall six-degree-of-freedom ship motion simulation test bench. Design; error modeling and finite element analysis of the mechanical system, selection and calculation of main components such as lifts, electric cylinders, etc.; kinematics, amplitude-frequency characteristics, phase-frequency characteristics analysis of the control system, and use of Visual C++ writes motion control programs, attitude calculation programs and management interface programs. Finally, using Hexagon's three-axis laser measurement system to test the positioning accuracy and repeatability of the six-degree-of-freedom ship motion simulation test bench, the test results meet the performance requirements of the test bench and achieve the expected results.
Nanjing Full Control specializes in the production of three/six degrees of freedom motion platforms, which are safe and reliable. For the six-degree-of-freedom motion platform for ships, our company has a lot of project implementation experience, and its unique finite element analysis and force feedback analysis are accurate for the design scheme. After testing, after meeting the performance indicators, the following picture is produced to ensure that the project is implemented in the fastest and most efficient schedule. Welcome to consult and understand.