The 6DOF platform is very suitable for simulation training. At present, the mainstream simulation training fields basically use 3/6dof platforms to simulate scenes, such as simulating helicopters, airplanes, cars, ships, etc. The human body can be intuitively simulated by riding on the simulator. Feel the simulator acceleration, climbs, descents and bumps. From the point of view of control, the six-degree-of-freedom motion platform control system is an electric servo control system. To carry out the overall design of the control system, it is necessary to clarify the structural characteristics and working principle of the system, and analyze the functional modules that the system should contain. Then, based on its functional requirements, the hardware modules required by the entire system are designed, and the control system composition diagram is drawn. Then the hardware part and the software part are designed and planned separately, so as to complete the overall functional design of the 6dof motion platform control system. In the actual control process, the main control unit needs to frequently perform calculation tasks such as positive and negative solutions, trajectory planning and solution, and the calculation amount of these tasks is relatively large. In addition, a complete control system should also include functions such as human-computer interaction and real-time data storage. Here are some common six-degree-of-freedom motion platform functions:
(1) Position control: The control method used in this paper is mainly position control. When the system issues an instruction, the six electric cylinders of the platform can perform telescopic movement within the limited range of the system according to the instruction, so that the motion platform can realize six free motions in space. degree of target movement.
(2) Limit system: When an electric cylinder of the six-degree-of-freedom motion platform exceeds its range of motion, the limit system must detect this problem, and immediately feed back the limit signal to the upper control system, and the system will send out an alarm. Take appropriate protective measures.
(3) Servo alarm: When the six-degree-of-freedom motion platform has problems such as overload alarm, battery alarm, encoder communication alarm, vibration detection alarm, and heat dissipation system overheat alarm, the system will immediately issue a servo alarm, and the input is prohibited by turning off the servo or command pulse Wait for the action to turn off the servo motor to protect the motion platform in time.
(4) Man-machine interface: the control system needs to provide a user interface, which is easy to operate and easy to control. The interface should include: control scheme selection, parameter initialization, basic command input and output, etc.; the position and posture of the platform and the expansion and contraction of the electric cylinder Synchronous display of feedback parameters such as , speed and their motion curves; the current operating status of the servo control system, etc.
(5) Emergency stop device: When the system issues a serious fault alarm, if the control buttons cannot be used to stop the movement of the platform in time, the emergency stop device can be used to directly cut off the power of the entire system, so that the platform stops immediately to avoid collisions with the moving platform serious accidents such as damage.
(6) Homing and positioning: There must be control buttons on the man-machine interface, which can make the platform automatically return to the zero position, or locate to any position within the limited space.
(7) Automatic detection: After the system is powered on, it immediately starts to detect whether each component module of the servo control system is operating normally, and reports the detection results to the host computer in time.
The above are common six-degree-of-freedom platform functional designs, but six-degree-of-freedom platforms are basically customized products, and we will also customize some specific functional designs according to customer requirements. These need to be designed and tested before production based on customer needs. The production will start only after the force feedback test is correct, so as to ensure that the platform can effectively meet customer needs.