A semi-physical simulation high-precision clock synchronization system and method

Abstract

The application discloses a kind of semi-physical simulation high-precision clock synchronization system and method.The system includes simulation platform, equivalent alternative turntable / inertial unit, satellite navigation simulator, GNSS receiver and on-board computer;Satellite navigation simulator is used as the time reference of the whole clock synchronization system, satellite navigation simulator sends time synchronization information to simulation platform, sine frequency standard is converted into square wave frequency standard through voltage comparator, then square wave frequency standard is connected to simulation machine high-precision clock acquisition card of simulation platform after power amplification by power amplifier, then simulation machine time advance carries out time advance according to square wave signal collected by high-precision clock acquisition card, simulation platform calculates and instructs output according to simulation time advance every cycle of rocket movement model;On-board computer uses inertial unit frequency standard interrupt as each cycle time advance.The application realizes time synchronization mechanism of semi-physical simulation system in the form of hardware signal, improves system real-time performance.

Description

Technical Field

[0001] This invention relates to the field of launch vehicle control technology, and in particular to a hardware-in-the-loop simulation high-precision clock synchronization system and method. Background Technology

[0002] The hardware-in-the-loop simulation system for a launch vehicle control system includes various equipment such as onboard equipment, simulation platforms, and ground equivalent devices. When performing hardware closed-loop real-time simulation, all types of equipment need to use the same clock source to advance the simulation. During the synchronization process between the various devices, clock synchronization signals need to be converted and processed to improve the overall simulation time alignment accuracy and ensure the accurate operation of the experiment.

[0003] In a hardware-in-the-loop simulation system with multiple devices participating, a time server is set up for time synchronization between different devices. The time synchronization mechanism is as follows: The external device first generates a Network Time Protocol (NTP) query packet and sends it to the time server over the network; upon receiving the packet, the server generates a NTP time packet based on its local time and sends it to the external device. Both packets contain send and receive timestamps. These four timestamps, T1, T2, T3, and T4, are used to determine the time deviation and network latency between the external device and the time server.

[0004] This solution requires a separate time server and necessitates the use of receiving and sending timestamps from each device during network communication. While it can be generalized on the devices, eliminating the need for a dedicated time synchronization unit, network communication delays exist throughout the experimental system, and the communication timestamp information cannot eliminate clock discrepancies caused by differences in the timing crystals of the devices. Summary of the Invention

[0005] This invention provides a semi-physical simulation high-precision clock synchronization system, comprising: a simulation platform, an equivalent replacement turntable / inertial navigation system, a satellite navigation simulator, a GNSS receiver, and an onboard computer; the simulation platform is connected to the equivalent replacement turntable / inertial navigation system and the satellite navigation simulator via optical fiber; the satellite navigation simulator injects radio frequency into the GNSS receiver; the GNSS receiver is connected to the onboard computer via a bus;

[0006] Using the satellite navigation simulator as the time reference for the entire clock synchronization system, when the satellite navigation simulator sends time synchronization information to the simulation platform, the sinusoidal frequency standard is first converted into a square wave frequency standard by a voltage comparator. Then, the square wave frequency standard is amplified by a power amplifier and connected to the high-precision clock acquisition card of the simulator platform. Subsequently, the simulator advances the time according to the square wave signal acquired by the high-precision clock acquisition card. The simulation platform calculates the rocket motion model and outputs commands according to each cycle of the simulation time advance. The onboard computer uses the inertial navigation system frequency standard interrupt as the time advance for each cycle.

[0007] The aforementioned hardware-in-the-loop simulation high-precision clock synchronization system includes a simulation platform used to implement the kinematics and dynamics equations of the rocket body, perform real-time simulation, and simulate mathematical models of the engine, aerodynamics, and wind field.

[0008] The hardware-in-the-loop high-precision clock synchronization system described above includes an equivalent replacement turntable / inertial navigation system, a rate gyroscope, and a simulated output pulse sampling signal.

[0009] The above-described hardware-in-the-loop high-precision clock synchronization system includes a GNSS receiver that is an equivalent GNSS module that simulates satellite navigation and positioning information, and a GNSS synchronization pulse signal whose falling edge is synchronized with UTC.

[0010] In the hardware-in-the-loop high-precision clock synchronization system described above, the satellite navigation simulator outputs a time synchronization signal to the simulation platform through a 10MHz clock synchronization interface.

[0011] As described above, in a semi-physical simulation high-precision clock synchronization system, the simulation platform outputs position and velocity information to the satellite navigation simulator, and drives the measurement model, actuator model, turntable, satellite signal generator, etc. to operate and output according to the position, velocity, and attitude information of the current cycle, forming a closed loop of data flow for the entire simulation circuit.

[0012] As described above, in a semi-physical simulation high-precision clock synchronization system, the simulation platform synchronizes its clock with an equivalent replacement turntable / inertial navigation system via optical fiber, and the equivalent replacement turntable / inertial navigation system synchronizes its time and frequency standard with an onboard computer.

[0013] This invention also provides a semi-physical simulation method for high-precision clock synchronization, comprising:

[0014] In a hardware-in-the-loop simulation system, the simulation platform is connected to the equivalent replacement turntable / inertial navigation system via optical fiber, and the simulation platform is connected to the satellite navigation simulator via optical fiber.

[0015] The high-precision clock source in the satellite navigation simulator is used as the time reference for the entire hardware-in-the-loop simulation system.

[0016] The satellite navigation simulator sends the time synchronization signal to the simulation platform through a voltage comparator and a power amplifier, converting the sinusoidal frequency standard of the time synchronization signal into a square wave frequency standard;

[0017] The simulation platform calculates the rocket motion model and outputs commands for each cycle according to the square wave frequency standard.

[0018] The simulation platform synchronizes its clock with the equivalent substitute turntable / inertial navigation system via optical fiber. The equivalent substitute turntable / inertial navigation system synchronizes its time and frequency standard with the onboard computer. The onboard computer uses the inertial navigation system frequency standard interruption as the time advance for each cycle.

[0019] The beneficial effects achieved by this invention are as follows:

[0020] 1. The time synchronization mechanism of the hardware-in-the-loop simulation system is implemented using hardware signals, improving system real-time performance. By eliminating network protocol-based time synchronization and adopting hardware frequency standard signal synchronization, the system's real-time performance is greatly improved, reducing system latency from tens of milliseconds to a few nanoseconds.

[0021] 2. By utilizing a voltage comparator + power amplifier approach, the versatility of the frequency signal is greatly improved, allowing the clock synchronization method described in this invention to be used across different devices. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0023] Figure 1 This is a schematic diagram of a semi-physical simulation high-precision clock synchronization system provided in Embodiment 1 of the present invention;

[0024] Figure 2 This is a schematic diagram of signal transmission between the satellite navigation simulator and the simulation platform;

[0025] Figure 3 This is a flowchart of a semi-physical simulation high-precision clock synchronization method provided in Embodiment 2 of the present invention. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Example 1

[0028] like Figure 1 As shown, Embodiment 1 of the present invention provides a semi-physical simulation high-precision clock synchronization system, including: a simulation platform, an equivalent replacement turntable / inertial navigation system, a satellite navigation simulator, a GNSS receiver, and an onboard computer. Wherein:

[0029] The simulation platform is used to realize the kinematics and dynamics equations of the rocket body, perform real-time simulation, and simulate mathematical models of the engine, aerodynamics, wind field, etc. The simulation platform is equivalent to the turntable / inertial navigation system and satellite navigation simulator through fiber optic connection.

[0030] The equivalent replacement turntable / inertial navigation system includes an equivalent replacement laser inertial navigation system and a rate gyroscope, with analog output pulse sampling signals. The synchronization pulse output period of the inertial navigation system is 5ms, the duty cycle is 50%, and it uses RS-422 differential level output, with the falling edge being active.

[0031] The GNSS receiver is an equivalent GNSS module that outputs analog satellite navigation and positioning information. The GNSS receiver is connected to the onboard computer via a bus. The falling edge of the GNSS synchronization pulse signal is synchronized with UTC, the voltage is 5V, the width is ≥10μs, and the output frequency is 10Hz.

[0032] The satellite navigation simulator and the simulation platform are connected via optical fiber, and the satellite navigation simulator injects radio frequency into the GNSS receiver. The satellite navigation simulator is used as the time reference for the entire clock synchronization system, rather than directly using the simulation platform's time system for simulation. The satellite navigation simulator outputs a time synchronization signal to the simulation platform through a 10MHz clock synchronization interface. The time synchronization signal can be a sinusoidal time signal.

[0033] Figure 2This diagram illustrates the signal transmission between the satellite navigation simulator and the simulation platform. When the satellite navigation simulator sends time synchronization information to the simulation platform, the sinusoidal frequency standard is first converted into a square wave frequency standard by a voltage comparator. Then, the square wave frequency standard is amplified by a power amplifier and connected to the high-precision clock acquisition card of the simulator platform. Subsequently, the simulator advances the time according to the square wave signal acquired by the high-precision clock acquisition card. The simulation platform calculates and outputs commands to the rocket motion model for each cycle of the simulation time advance, outputs position and velocity information to the satellite navigation simulator, and drives the measurement model, actuator model, turntable, satellite signal generator, etc. to operate and output according to the position, velocity, and attitude information of the current cycle, forming a closed loop of data flow for the entire simulation circuit.

[0034] The simulation platform synchronizes its clock with the equivalent substitute turntable / inertial navigation system via optical fiber. The equivalent substitute turntable / inertial navigation system synchronizes its time and frequency standard with the onboard computer. The onboard computer uses the inertial navigation system frequency standard interruption as the time advance for each cycle.

[0035] Example 2

[0036] See Figure 3 Embodiment 2 of the present invention provides a semi-physical simulation high-precision clock synchronization method, comprising:

[0037] Step 310: In the hardware-in-the-loop simulation system, connect the simulation platform to the equivalent replacement turntable / inertial navigation system via optical fiber, and connect the simulation platform to the satellite navigation simulator via optical fiber.

[0038] Step 320: Use the high-precision clock source in the satellite navigation simulator as the time reference for the entire hardware-in-the-loop simulation system;

[0039] Step 330: The satellite navigation simulator sends the time synchronization signal to the simulation platform through a voltage comparator and a power amplifier, converting the sinusoidal frequency standard of the time synchronization signal into a square wave frequency standard;

[0040] Step 340: The simulation platform calculates the rocket motion model and outputs commands according to the square wave frequency standard for each cycle;

[0041] Step 350: The simulation platform synchronizes its clock with the equivalent substitute turntable / inertial navigation system via optical fiber. The equivalent substitute turntable / inertial navigation system synchronizes its time and frequency standard with the onboard computer. The onboard computer uses the inertial navigation system frequency standard interruption as the time advance for each cycle.

[0042] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made on the basis of the technical solution of the present invention should be included within the scope of protection of the present invention.

Claims

1. A hardware-in-the-loop high-precision clock synchronization system, characterized in that, include: Simulation platform, equivalent replacement turntable / inertial navigation system, satellite navigation simulator, GNSS receiver and onboard computer; The simulation platform effectively replaces the turntable / inertial navigation system and satellite navigation simulator through fiber optic connections; Satellite navigation simulator with radio frequency injection GNSS receiver; The GNSS receiver is connected to the onboard computer via a bus; Using the satellite navigation simulator as the time reference for the entire clock synchronization system, when the satellite navigation simulator sends time synchronization information to the simulation platform, the sinusoidal frequency standard is first converted into a square wave frequency standard by a voltage comparator. Then, the square wave frequency standard is amplified by a power amplifier and connected to the high-precision clock acquisition card of the simulator platform. Subsequently, the simulator advances the time according to the square wave signal acquired by the high-precision clock acquisition card. The simulation platform calculates and outputs commands to the rocket motion model for each cycle of the simulation time advance; it outputs position and velocity information to the satellite navigation simulator and drives the measurement model, actuator model, turntable, and satellite signal generator to operate and output according to the position, velocity, and attitude information of the current cycle, forming a closed loop of data flow for the entire simulation circuit. The simulation platform synchronizes its clock with the equivalent substitute turntable / inertial navigation system via optical fiber, and the equivalent substitute turntable / inertial navigation system synchronizes its time and frequency standard with the onboard computer; the onboard computer uses the inertial navigation system frequency standard interruption as the time advance for each cycle.

2. The hardware-in-the-loop high-precision clock synchronization system as described in claim 1, characterized in that, The simulation platform is used to realize the kinematics and dynamics equations of the rocket body, perform real-time simulation, and simulate the mathematical models of the engine, aerodynamics, and wind field.

3. The hardware-in-the-loop high-precision clock synchronization system as described in claim 1, characterized in that, The equivalent replacement turntable / inertial navigation system includes an equivalent replacement laser inertial navigation system, a rate gyroscope, and an analog output pulse sampling signal.

4. The hardware-in-the-loop high-precision clock synchronization system as described in claim 1, characterized in that, The GNSS receiver is an equivalent GNSS module that outputs analog satellite navigation and positioning information. The falling edge of the GNSS synchronization pulse signal is synchronized with UTC.

5. A hardware-in-the-loop high-precision clock synchronization system as described in claim 1, characterized in that, The satellite navigation simulator outputs a time synchronization signal to the simulation platform via a 10MHz clock synchronization interface.

6. A semi-physical simulation method for high-precision clock synchronization, characterized in that, include: In a hardware-in-the-loop simulation system, the simulation platform is connected to the equivalent replacement turntable / inertial navigation system via optical fiber, and the simulation platform is connected to the satellite navigation simulator via optical fiber. The high-precision clock source in the satellite navigation simulator is used as the time reference for the entire hardware-in-the-loop simulation system. The satellite navigation simulator sends the time synchronization signal to the simulation platform through a voltage comparator and a power amplifier, converting the sinusoidal frequency standard of the time synchronization signal into a square wave frequency standard; The simulation platform calculates and outputs commands to the rocket motion model for each cycle according to the square wave frequency standard; it outputs position and velocity information to the satellite navigation simulator, and drives the measurement model, actuator model, turntable, satellite signal generator, etc. to operate and output according to the position, velocity, and attitude information of the current cycle, forming a closed loop of data flow for the entire simulation circuit; The simulation platform synchronizes its clock with the equivalent substitute turntable / inertial navigation system via optical fiber. The equivalent substitute turntable / inertial navigation system synchronizes its time and frequency standard with the onboard computer. The onboard computer uses the inertial navigation system frequency standard interruption as the time advance for each cycle.

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