CN-122001510-A - Simulation system clock synchronization method and system based on wireless

CN122001510ACN 122001510 ACN122001510 ACN 122001510ACN-122001510-A

Abstract

The invention provides a wireless-based simulation system clock synchronization method and system, wherein the method comprises the steps of roughly synchronizing S11, obtaining a current time master node period and a current time slave node period, S12, obtaining a difference value between the current time master node period and the current time slave node period, S13, obtaining a phase difference between a transmission signal and a receiving signal, S14, obtaining the transmission time of the next period of a wireless transceiver based on recording a current transmission time timestamp of the wireless transceiver under the condition that the master node synchronously transmits, finely synchronizing S21, taking a residual synchronization error after roughly synchronizing the current synchronization period as an input by a PID controller, obtaining a fine time adjustment quantity, S22, quantifying the fine time adjustment quantity, and S23, and updating the transmission time of the next period of the wireless transceiver. The invention can solve the technical problems of complex hardware, high cost, poor stability and difficult quick realization of synchronization in dynamic or multi-node environments in the prior art based on UWB clock synchronization.

Inventors

TIAN YUZE
GUO ZHUOFENG
HAN JIAN
Su yinke
SHI HANG
ZHAO MINGJIE
WEI ZIHUI

Assignees

北京机电工程研究所

Dates

Publication Date: 20260508
Application Date: 20251230

Claims (10)

1. A wireless-based simulation system clock synchronization method, characterized in that the wireless-based simulation system clock synchronization method comprises: rough synchronization: S11, a master node period and a slave node period at the current moment are obtained by combining the master-slave node initial time sequence; S12, obtaining a difference value between a master node period and a slave node period at the current moment; S13, combining the primary time sequence of the master node and the slave node to acquire the phase difference between the transmitted signal and the received signal; S14, under the condition that the master node synchronously transmits, based on recording the time stamp of the current transmission time of the wireless transceiver, combining the difference value between the period of the master node and the period of the slave node at the current time and the phase difference between the transmission signal and the receiving signal, and acquiring the transmission time of the next period of the wireless transceiver; Fine synchronization: S21, the PID controller takes the residual synchronous error after the rough synchronization of the current synchronous period as input to acquire a fine time adjustment quantity; s22, quantifying a fine time adjustment amount according to the time resolution of DW1000 hardware; S23, combining the rough synchronization and the PID fine adjustment, and updating the transmission time of the next period of the wireless transceiver.
2. The method for synchronizing clocks of a wireless-based simulation system according to claim 1, wherein in S11, the master node period and the slave node period at the current time are obtained according to the following equation: Wherein, T M is the current time master node period, T S is the current time slave node period, T r is the slave node UWB synchronization signal receiving time, T l is the slave node local synchronization signal transmitting time, MAX STC is the maximum value of the wireless transceiver SYSTEM TIME Counter recording time, the subscript n represents the current nth period, and the subscript n+1 represents the n+1th period.
3. The wireless-based simulation system clock synchronization method according to claim 2, wherein in S12, the difference between the master node period and the slave node period at the current time is obtained according to the following equation: ΔT=T M -T S Wherein, deltaT is the difference value between the period of the master node and the period of the slave node at the current moment.
4. The wireless-based simulation system clock synchronization method of claim 3, wherein in S13, a phase difference between the transmission signal and the reception signal is obtained according to: Δθ=t r(n + 1) -t l(n+1) Where Δθ is the phase difference between the transmission signal and the reception signal.
5. The method of claim 4, wherein in S14, the transmission time of the next period of the wireless transceiver is obtained according to the following equation: T NEXT ＝T Local +Δθ+ΔT-T Prop +999,999,996ns wherein, T NEXT is the transmission time of the next period of the wireless transceiver, T Local is the time stamp of recording the current transmission time of the wireless transceiver, and T prop is the signal flight time between the master node and the slave node.
6. The method for synchronizing clocks of a wireless-based simulation system according to claim 5, wherein in S21, a residual error e (k) of a current synchronization period is defined as: Wherein the subscript k represents the current synchronization period, () relative to 1 second represents relative to the second pulse; The fine time adjustment amount u (k) output by the controller is defined as: Wherein K p 、K i and K d are respectively a proportional coefficient, an integral coefficient, and a differential gain coefficient, Δt is a sampling period, and e (i) is a residual error of the i-th synchronization period, i=0, 1.
7. The wireless-based simulation system clock synchronization method of claim 6, wherein the fine time adjustment u (k) is quantized according to the time resolution of DW1000 hardware in S22: Where u quantized (k) is the quantized fine time adjustment amount.
8. The method of claim 7, wherein in S23, the transmission time T NEXT of the next period of the wireless transceiver is updated as follows in combination with the coarse synchronization and the PID fine adjustment: T NEXT ＝T Local +999,999,996ns-T Prop +u quantized (k)。
9. the method of claim 5 or 8, wherein the inter-master-slave signal flight time T prop is calculated according to: The master node broadcasts a time-setting message with a time stamp at a time t 1 , the slave node receives and records a local time stamp at a time t 2 , the slave node transmits a Poll frame to the master node and records a time stamp t 3 after waiting for a period of time in a specified time slot of the slave node, the master node waits for a period of time after receiving the Poll frame of the slave node, unicasts a Response frame to an address of the slave node, wherein the Response frame comprises a time t 4 when the Poll frame is received and a time t 5 when the Response frame is transmitted, and the slave node receives the Response frame and records a time stamp t 6 .
10. A wireless clock distribution system, wherein the wireless clock distribution system implements clock synchronization using the wireless-based simulation system clock synchronization method according to any one of claims 1 to 9; the wireless clock distribution system comprises a GNSS receiving module, a master MCU, a double UWB receiving and transmitting module, a time digital converter and a time synchronization algorithm unit, wherein a master node receives standard second pulse signals through the GNSS receiving module, uses hardware time stamp of one UWB wireless transceiver to record receiving time, uses the other UWB wireless transceiver to send time-giving messages and record sending time, the master MCU reads the recorded receiving time and sending time, calculates difference values and regulates and controls, realizes strict synchronization of the master node signals and GNSS references, receives UWB synchronous signals from the slave node, generates local clock signals synchronous with the master node through the internal double UWB receiving and transmitting module and the time synchronization algorithm unit, and the time digital converter is used for measuring signal flight time.

Description

Simulation system clock synchronization method and system based on wireless Technical Field The invention belongs to the technical field of semi-physical simulation tests, and particularly relates to a wireless-based simulation system clock synchronization method and system. Background The semi-physical simulation high-precision clock synchronization technology is a key bottom layer supporting technology for constructing a semi-physical simulation system, is used for clock synchronization among all devices in the semi-physical simulation system, and has important influence on the reliability and instantaneity of the whole simulation system. Along with the development of the semi-physical simulation test requirements, the equipment among different buildings needs to be combined into a semi-physical simulation system. Although the traditional wired optical fiber network has stable performance, the traditional wired optical fiber network has the problems of high deployment cost, poor flexibility, large expansion difficulty and the like. Semi-physical simulation test scenarios a large number of experimental devices are typically deployed in different buildings, as shown in fig. 4. The clock signal generated by the high-precision clock source in the building A is transmitted to the node in the building B for processing through the optical fiber. And a wireless transmission is used for replacing a wired optical fiber link between the building A and the building B so as to meet the node deployment between newly-added buildings in the future. Currently, the most widely used high-precision clock synchronization approach still relies on the Global Navigation Satellite System (GNSS). GNSS provides standard time reference for the system through pseudo-range measurement or carrier phase analysis, and time service accuracy can reach nanosecond level. However, this type of approach has the following significant limitations: (1) Cannot be used in environments where GNSS signals are limited or denied (e.g., underground spaces, tunnels, mines, indoors, shielded areas, etc.); (2) Although the GNSS pseudolite or the optical fiber timing scheme can solve the problems to a certain extent, the GNSS pseudolite or the optical fiber timing scheme is complex in installation, high in cost, large in engineering quantity and not suitable for flexible deployment; (3) Traditional synchronization schemes such as Network Time Protocol (NTP) or Precision Time Protocol (PTP) are limited by the transport layer delay, and sub-microsecond precision is difficult to achieve. With rapid development of indoor positioning technology, ultra Wideband (UWB) technology is a very promising technology because of its short pulse, multipath resolution, and high accuracy time of arrival (TOA) measurement capability. UWB typically uses extremely short pulses, which makes it possible to accurately determine the arrival time of the received pulses. In an application scenario of indoor positioning, when a target node broadcasts UWB pulses and its transmit time is known, the distance between the target node and the receiving node can be deduced by TOA estimation. Based on these distance information, a high-precision positioning can be achieved. On the other hand, if the time of transmission of the pulse is not available, then positioning can be performed by time difference of arrival (TDOA). The method can realize the positioning accuracy of the decimeter level without additional hardware, and can also be integrated with an inertial sensor and the like to further improve the performance. UWB technology uses very wide spectrum bandwidths (typically greater than 500 MHz) to achieve high data transmission rates, low power consumption, and high resolution time measurement accuracy. Due to the broadband characteristic, the UWB signal has strong penetrating power and multipath interference resistance, the UWB technology provides accurate time stamp information for ultra-wideband wireless signal transmission and reception by measuring signal receiving and transmitting time so as to realize accurate centimeter order ranging and positioning, and compared with the traditional wireless clock synchronization scheme, the synchronization scheme based on the UWB technology has obvious superiority. However, existing UWB-based clock synchronization systems still have the following major problems: (1) The voltage-controlled crystal oscillator (VCXO) or an analog phase-locked loop (PLL) structure is adopted, so that the hardware is complex and the cost is high; (2) PLL loops are sensitive to noise and temperature, and are difficult to operate stably for a long period of time; (3) The system lock time is long, and it is difficult to achieve synchronization quickly in a dynamic or multi-node environment. Disclosure of Invention The present invention aims to solve at least one of the technical problems existing in the prior art. According to an aspect of the present invention, there is