The turntable is a complex modern equipment integrating optical and electromechanical integration. It performs semi-physical simulation and testing in the field of aviation and aerospace, and plays a key role in the development of aircraft. It can simulate various attitude Angle movements of aircraft, reproduce various dynamic characteristics during movement, and repeatedly test the performance of the guidance system, control system and corresponding components of aircraft. Sufficient test data are obtained, and the system is redesigned and improved according to the data to meet the performance index requirements of the overall design of the aircraft.
Classification of turntables
The flight simulation turntable is an indispensable key equipment in the semi-physical flight simulation test system. It can simulate various attitudes of the aircraft in the air under laboratory conditions and reproduce its dynamic characteristics, so as to simulate and test the flight control system or navigation guidance system of the aircraft, and design and improve it accordingly to achieve the ideal performance index.
There are many kinds of classification methods for flight simulation turntable, which are briefly described as follows:
According to the type of servo system energy used by the flight simulation turntable, it can be divided into two categories:
(1) Electric turntable: the servo system of the console body movement is all electrical servo system.
(2) Electric-hydraulic turntable (referred to as hydraulic turntable) : The servo system of the console body movement is an electric-hydraulic servo system.
According to the servo system control signal characteristics of the flight simulation turntable, it can be divided into three categories:
(1) Analog control turntable: The control signal in the turntable servo system is an analog quantity.
(2) Digital control turntable: The control signal in the turntable servo system is a digital quantity.
(3) Multi-mode hybrid control turntable: the control signal in the turntable servo system is both of the above two control signals, that is, both analog and digital quantities.
Degree of freedom
According to the degree of freedom of angular motion reproduced on the flight simulation turntable table, it can be divided into:
(1) One degree of freedom: the table motion has only one degree of freedom, also known as the single-axis turntable, which can only imitate the angular motion of the aircraft in a plane. The body is a desktop automatic single-axis turntable. Surface φ450mm, surface material is stainless steel. There are three adjusting feet below the base, which can be used to adjust the level of the entire platform. As shown in Figure 1:
(2) Two degrees of freedom: the table has two degrees of freedom of angular movement, also known as the two-axis turntable.
(3) Three degrees of freedom: the table movement has three degrees of freedom of angular movement, also known as the three-axis turntable.
Rotation position: The turntable works in the position servo control type, which can adjust the position of each frame according to the given position instruction, and has the required frequency response quality.
Rotation speed: the turntable works in the speed servo control mode, which can adjust the speed of each frame according to the given speed instruction, and has the required frequency response quality.
The Angle position sensor of the Angle measuring system is composed of 360 pole circular induction synchronizer and photoelectric sensor with electric absolute zero position. The system circuit is mainly composed of excitation power amplifier, preamplifier, A/D converter, DSP system, CPLD interface circuit and so on. The Angle measurement system provides a position reference for the whole system, and its accuracy determines the static accuracy of the whole turntable, and directly affects the dynamic characteristics of the system. In order to meet the dynamic and static characteristics of the system, the system Angle measurement scheme adopts our company’s mature technology, which has the characteristics of high precision, high stability, high dynamic characteristics, etc., and can better meet the requirements of this type of turntable Angle positioning accuracy and fast speed.
Turntable limit: there are two kinds of soft limit and hard limit: the soft limit of the turntable is set at any limit value on the controller panel, when the turntable Angle is greater than the soft limit value, the software program handles the limit alarm indication and protection instruction. The hard limit of the turntable is realized by the limit switch installed in the body of the turntable. When the Angle of the turntable is greater than the hard limit value, the limit switch is closed, the protection and alarm circuit of the turntable is switched on, and the turntable is turned into the protection action.
Turntable protection: power amplifier failure, turntable offside, manual emergency, etc. When there is turntable protection, the response action of the turntable controller is: the closed-loop control loop of the turntable position is low gain, the input of the turntable position loop is zero, the servo power supply of the power amplifier is cut off, the turntable servo motor is detached from the power amplifier, and the coil of the turntable servo motor is short-circuited.
Angle display: The turntable controller can provide the numerical display of the turntable Angle, and the general Angle indication resolution is 0.01°.
Microcomputer monitoring: The turntable digital controller adopts microcomputer digital control, and the turntable control has the ability to interface with the upper microcomputer. The turntable controller can accept the instructions of the monitor or the instructions of the upper computer, and the position of the turntable can be transmitted to the upper computer.