A GPS time information blurring control system, method and vehicle

Abstract

This invention discloses a GPS time information fuzzification control system, method, and vehicle, including a main control module and connected to the main control module, a GNSS and signal processing module, a noise source module, a noise modulation module, an error detection module, and an encryption module. The raw GPS time signal provided by the GNSS and signal processing module is transmitted to the main control module and the noise modulation module. The main control module controls the noise source module to generate an adjustable-amplitude noise signal. The noise signal and the raw GPS time signal are modulated by the noise modulation module to form a mixed-noise GPS time signal. The error detection module compares the mixed-noise GPS time signal with a reference time signal to obtain the time error. The time error is input to the PID unit in the main control module to control the noise source module to adjust the noise amplitude. After adjustment, the encryption module is controlled to encrypt the system status information and the mixed-noise GPS time signal. This invention can protect the location information implicit in the time signal, reducing the risk of privacy leakage.

Description

Technical Field

[0001] This invention belongs to the field of vehicle-to-everything (V2X) and information security technology for new energy vehicle control systems, specifically relating to a GPS time information fuzzification control system, method, and vehicle. Background Technology

[0002] With the development of intelligent connected vehicles, high-precision time synchronization has become a key foundation for V2X communication, collaborative perception, and autonomous driving. Currently, vehicles mainly obtain precise timing signals (such as 1PPS pulses) through GNSS (such as GPS) receivers. However, research shows that high-precision timestamp information itself can be used to infer the vehicle's precise location, trajectory, and even identity, posing a serious risk of privacy breaches.

[0003] Existing solutions to address privacy risks mainly focus on two levels: (1) Privacy protection at the communication and application layers: for example, using pseudonym technology, beacon message content encryption, or transmission frequency control. These methods protect network identity or message content, but do not process or protect the original high-precision time signal itself as a basic physical quantity. Attackers can still obtain the precise time from the device's underlying layer for inference. (2) High-precision time synchronization hardware: The core design goal of existing time synchronization modules is to pursue the ultimate time accuracy and stability, and to optimize the signal through multi-frequency reception, anti-interference algorithms, and other means. Their design philosophy is completely contrary to the proactive introduction of controllable distortion to protect privacy. Therefore, how to proactively and controllably protect the privacy of high-precision time information from the source of data generation (hardware signal level) while ensuring the availability of time synchronization function (maintaining high accuracy) is an urgent problem to be solved. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this application is to provide a GPS time information fuzzification control system, method and vehicle to perform differential privacy protection on the location information hidden in the time signal and reduce the risk of privacy leakage.

[0005] Traditional differential privacy techniques are applied to database queries or location coordinates, but there is currently no solution for applying them to continuous, real-time analog time signals and resolving the dynamic trade-off between accuracy and privacy. This application utilizes differential privacy to achieve fuzzification control of GPS time information. Its core lies in adding controllable noise to the original GPS time signal, thereby preventing the leakage of location privacy and other information.

[0006] In a first aspect, this application provides a GPS time information fuzzification control system, including a main control module, a GNSS and signal processing module, a noise source module, a noise modulation module, an error detection module, and an encryption module. The GNSS and signal processing module is connected to the main control module and the noise modulation module, transmitting the provided and processed raw GPS time signal to the main control module and the noise modulation module. The main control module is connected to the noise source module, controlling the noise source module to generate an amplitude-adjustable noise signal. The noise modulation module is connected to the noise source module and the main control module, acquiring the noise signal and modulating it with the raw GPS time signal to form a mixed-noise GPS time signal. The error detection module is connected to the noise modulation module and the main control module, acquiring the mixed-noise GPS time signal and comparing it with an input reference time signal to obtain a time error. The time error is input to a PID unit in the main control module, which controls the noise source module to adjust the noise amplitude. The encryption module is connected to the noise modulation module and the main control module. After the noise amplitude is adjusted to the appropriate level, the main control module controls the encryption module to encrypt the system status information and the mixed-noise GPS time signal, forming an encrypted data stream.

[0007] The main control module adjusts the noise amplitude output by the noise source module. The noise modulation module superimposes the noise signal onto the original GPS time signal, desensitizing and blurring the high-precision time information, preventing the risk of location tracing due to leakage of the real timestamp. The error detection module compares the mixed-noise GPS time signal with the standard reference time signal to obtain the time error. Relying on the PID unit built into the main control module, a closed-loop feedback is formed to dynamically correct the noise amplitude, stably control the time disturbance range, and ensure controllable blurring effect. The main control module activates the encryption module only after confirming that the noise adjustment meets the standard, synchronously encrypting the mixed-noise GPS time signal (with the noise amplitude meeting the standard) and system status information, preventing the undesensitized original GPS time signal from being transmitted and improving data transmission security.

[0008] Optionally, the noise source module includes a true random number generator, a pseudo random number generator, and a digital potentiometer connected to the main control module and a PID unit in the main control module. The true random number generator is connected to the pseudo random number generator, and the pseudo random number generator is connected to the digital potentiometer. Under the control of the main control module, the true random number generator generates a digital random sequence (i.e., a TRNG seed, an entropy source seed) and inputs it to the pseudo random number generator. Under the control of the main control module, the pseudo random number generator generates a periodic pseudo random digital noise sequence based on the digital random sequence and transmits it to the digital potentiometer. Under the control of the PID unit, the digital potentiometer adjusts the noise amplitude of the pseudo random digital noise sequence by adjusting the DAC output gain and outputs the noise signal.

[0009] Using a high-entropy digital random sequence output by a true random number generator as the seed for a pseudo-random number generator improves noise unpredictability and avoids the drawbacks of a single pseudo-random sequence being too regular and easily reverse-engineered, thus enhancing the security of GPS time ambiguity. The pseudo-random number generator, relying on the entropy source seed, outputs a pseudo-random digital noise sequence, ensuring a continuous and stable supply of noise signal to meet the requirements of long-term time-series scrambling. A digital potentiometer receives control commands from the PID unit and precisely modifies the noise amplitude by adjusting the DAC output gain, matching the closed-loop error adjustment requirements and achieving dynamic controllability of the disturbance intensity.

[0010] Optionally, the main control module can control the true random number generator to adjust the proportion of high and low frequency components in the digital random sequence; the main control module can control the pseudo random number generator to adjust the random number range of the pseudo random number generator.

[0011] The main control module can independently adjust the ratio of high and low frequency components in the digital random sequence output by the true random number generator, flexibly changing the noise spectrum characteristics to adapt to the ambiguity and disturbance requirements of GPS time signals under different security configuration modes, thus improving the diversity of time-series noise interference. The main control module can also adjust the random number output range of the pseudo-random number generator, directly changing the basic noise fluctuation amplitude and quickly switching between different levels of time desensitization intensity to adapt to different security configuration mode requirements.

[0012] Optionally, the noise modulation module includes a DAC converter, an analog multiplier, and a controllable low-pass filter. The DAC converter is connected to the main control module, a digital potentiometer, and the analog multiplier. Under the control of the main control module, the DAC converter acquires the noise signal and converts it into an analog noise signal, which is then transmitted to the analog multiplier. The analog multiplier is connected to the GNSS and signal processing module and the controllable low-pass filter. The analog multiplier nonlinearly superimposes the analog noise signal with the original GPS time signal to obtain a noisy GPS time signal. The controllable low-pass filter performs low-pass filtering on the noisy GPS time signal, removing high-frequency components that exceed the timing bandwidth, and then outputs the mixed-noise GPS time signal.

[0013] The DAC converter converts the (digital) noise signal into an analog noise signal, matching the original GPS time signal format to ensure that both can be synchronously fed into the analog multiplier for superposition. The analog multiplier achieves non-linear coupling and superposition of the noise and the original GPS time signal, forming a perturbed time signal that disrupts the original high-precision timing characteristics, thus achieving desensitization and ambiguity of the time information. A controllable low-pass filter at the back end filters out useless high-frequency noise exceeding the time synchronization bandwidth, avoiding overbandwidth interference introduced by superimposed noise, and ensuring that the output mixed-noise GPS time signal meets the basic time synchronization requirements.

[0014] Optionally, the main control module is connected to the controllable low-pass filter and can adjust the cutoff frequency of the controllable low-pass filter; the main control module can control the error detection module to adjust the detection cycle of the error detection module; the main control module can control the encryption module to adjust the encryption key replacement cycle of the encryption module.

[0015] The main control module dynamically adjusts the cutoff frequency of the controllable low-pass filter to adapt to different noise spectra as needed, flexibly filtering out unnecessary high-frequency interference, and can adapt to time-fuzzy conditions in different security configuration modes. The main control module also adjusts the detection cycle of the error detection module, balancing timing error sampling accuracy with overall computational load, and can adapt to the requirements of different security configuration modes. Furthermore, the main control module changes the key replacement cycle of the encryption module, shortening or extending the key rotation interval to adapt to different security configuration mode requirements.

[0016] Secondly, this application provides a GPS time information fuzzification control method, employing the aforementioned GPS time information fuzzification control system, the method comprising:

[0017] Obtain the user-selected security configuration mode and the original GPS time signal.

[0018] Based on the user-selected security configuration mode, the noise source module, noise modulation module, error detection module, and encryption module are controlled to configure the relevant parameters corresponding to the security configuration mode.

[0019] The noise source module is controlled to generate an amplitude-adjustable noise signal based on the relevant parameters, and the noise modulation module is controlled to modulate the noise signal and the original GPS time signal into a mixed noise GPS time signal based on the relevant parameters.

[0020] The error detection module compares the mixed noise GPS time signal with the input reference time signal based on the relevant parameter configuration to obtain the time error. The PID unit then controls the noise source module to adjust the noise amplitude based on the time error and the original GPS time signal.

[0021] Once the noise amplitude is adjusted to the appropriate level, the encryption module is controlled to encrypt the system status information and the mixed noise GPS time signal based on the relevant parameter configuration, forming an encrypted data stream.

[0022] Based on the user-selected security configuration mode, parameters for noise generation, signal modulation, error detection, and encryption are synchronously matched. Different fuzzing perturbation intensities, filtering characteristics, detection frequencies, and key rotation cycles can be quickly switched to adapt to various security configuration mode requirements. Adjustable amplitude noise is generated according to the configured parameters and modulated and mixed with the original GPS time signal, applying controllable timing perturbation to the high-precision timestamp to achieve time information desensitization and avoid the security risks of reverse positioning based on the original GPS time. The time error is obtained by comparing the mixed timing signal with the reference time signal through the error detection module. The noise amplitude is dynamically corrected using a closed-loop PID unit, stabilizing the time perturbation error within the preset mode range, ensuring accurate and controllable fuzzing effect. The encryption process is initiated only after the noise amplitude is adjusted to the appropriate level, synchronously encrypting the desensitized mixed noise GPS time signal and system status information, thus improving the transmission security level.

[0023] It achieves a standardized processing flow of one-click mode configuration, controllable scrambling, closed-loop correction, and compliance encryption, taking into account the flexibility of timing desensitization, the accuracy of disturbance control, and the security of data transmission, and can be adapted to GPS timing protection scenarios with different security configuration modes.

[0024] Optionally, if the user selects the high-precision security configuration mode, the corresponding parameter configurations are as follows: the proportion of high-frequency components in the digital random sequence is A1, the random number range is a times the full range, the DAC output gain is maintained between k1 and k2, the cutoff frequency of the low-pass filter is f1, and the detection period of the error detection module is t. c1 The encryption key replacement cycle is t. m1 .

[0025] If the user selects the high privacy mode as the security configuration mode, the corresponding parameter configurations are as follows: the proportion of low-frequency components in the digital random sequence is A2, the random number range is the full range, the DAC output gain is maintained between k3 and k4, the cutoff frequency of the low-pass filter is f2, and the detection period of the error detection module is t. c2 The encryption key replacement cycle is t. m2 .

[0026] Where A1 > 60%, A2 > 60%, a ≤ 0.9, k3 > k2, f2 > f1, t c2 <t c1 , t m2 <t m1 .

[0027] In high-precision mode, the proportion of high-frequency components exceeds 60%, the noise random number range is only a times the full range (a≤0.9), the DAC gain range is lower, the cutoff frequency is smaller, the error detection cycle is longer, and the key rotation cycle is longer. Noise disturbance amplitude is limited, high-frequency noise is easily filtered out, and timing disturbance error is smaller. Under the premise of mild desensitization, the basic accuracy of GPS timing is guaranteed, making it suitable for operational scenarios requiring high time accuracy. In high-privacy mode, the proportion of low-frequency components exceeds 60%, noise random numbers are output across the full range, the DAC gain is higher than in high-precision mode, and the noise disturbance amplitude is larger. The cutoff frequency is higher, retaining more disturbance components; the error detection cycle is shorter, the PID closed-loop adjustment response is faster, and it can stably maintain a large noise amplitude; the key replacement cycle is shorter, and the encryption update frequency is higher, significantly increasing the difficulty of reverse-analysis of timestamps, strengthening the device location tracing protection capability, and adapting to high-security and privacy scenarios.

[0028] This solution divides security configurations into two categories: high precision and high privacy. It also matches a complete set of standardized linkage parameters for the two modes, enabling hierarchical control of timing accuracy and timing privacy protection. The protection strategy can be switched with one click according to business needs.

[0029] Optionally, the reference time signal is the real-time time generated by an internal counter at a fixed frequency produced by a stable thermostatic crystal oscillator inside the main control module; or the reference time signal is a high-precision time improved by a satellite atomic clock.

[0030] The main control module employs a built-in temperature-controlled crystal oscillator and an internal counter to generate a local real-time time as a reference time signal. The temperature-controlled crystal oscillator exhibits minimal frequency drift and strong timing stability, eliminating the need for continuous external satellite signal reception. Even in scenarios with GNSS signal obstruction or loss of connectivity, error detection and closed-loop correction can still be performed normally, ensuring uninterrupted operation of the fuzzy control process. A high-precision time output from a satellite atomic clock is selected as the external reference time signal. The atomic clock's timing reference accuracy is extremely high, significantly reducing the error calculation deviation of mixed-noise GPS time signals and improving PID adjustment accuracy, making it suitable for operating conditions with stringent requirements for timing disturbance control.

[0031] Optionally, if the absolute value of the time error of n consecutive connections is less than or equal to a preset first time threshold, the noise amplitude is determined to be adjusted in place; where n is an integer and n≥2.

[0032] The convergence criterion is that the absolute value of the time error in n consecutive (n≥2) samples does not exceed a preset first time threshold. This method abandons the approach of determining compliance based on a single sample, effectively avoiding misjudgments caused by occasional sampling jitter and instantaneous interference, and improving the reliability of noise amplitude adjustment determination. Multiple rounds of continuous error verification confirm the stable convergence of the PID closed-loop adjustment, ensuring that the temporal disturbance of the mixed-noise GPS time signal remains stable within the allowable range over the long term, avoiding repeated fluctuations in noise amplitude, and guaranteeing a consistently consistent GPS time ambiguity effect.

[0033] Thirdly, this application provides a vehicle that includes the aforementioned GPS time information fuzzification control system.

[0034] This application does not make any requirements on the upper-layer communication protocol, but processes the raw time reference signal output by GNSS in real time at the physical layer. By adding dynamically controllable noise, differential privacy protection of the location information hidden in the time signal is achieved. The feedback mechanism can dynamically adjust between high-precision mode and high-privacy mode, thereby achieving the optimal balance between time synchronization accuracy and location privacy strength. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the embodiments of this application will be described below.

[0036] Figure 1 This is a schematic diagram of the vehicle in an embodiment of this application.

[0037] Figure 2 This is a block diagram illustrating the principle of the GPS time information fuzzification control system in this application embodiment.

[0038] Figure 3 This is a flowchart of the GPS time information fuzzification control method in the embodiments of this application. Detailed Implementation

[0039] The embodiments of this application will be described in further detail below with reference to the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to illustrate the principles of this application by way of example, but should not be used to limit the scope of this application, that is, this application is not limited to the described embodiments.

[0040] like Figure 1 As shown, Figure 1This is a schematic diagram of a vehicle in an embodiment of this application. The vehicle may be, but is not limited to, a pure electric vehicle (PEV / BEV), a hybrid electric vehicle (HEV), a range-extended electric vehicle (REEV), a plug-in hybrid electric vehicle (PHEV), or a new energy vehicle.

[0041] like Figure 1 As shown, the vehicle in this embodiment includes the GPS time information fuzzification control system in this embodiment.

[0042] like Figure 2 As shown, the GPS time information fuzzification control system in this embodiment includes a main control module 1, a GNSS and signal processing module 2, a noise source module 3, a noise modulation module 4, an error detection module 5, and an encryption module 6. The GNSS and signal processing module 2 is connected to the main control module 1 and the noise modulation module 4, transmitting the provided and processed original GPS time signal to the main control module 1 and the noise modulation module 4. The main control module 1 is connected to the noise source module 3, controlling it to generate an amplitude-adjustable noise signal. The noise modulation module 4 is connected to the noise source module 3 and the main control module 1, acquiring the noise signal and modulating it with the original GPS time signal to form a mixed-noise GPS time signal. The error detection module 5 is connected to the noise modulation module 4 and the PID unit in the main control module 1, acquiring the mixed-noise GPS time signal and comparing it with the input reference time signal to obtain the time error. This time error is then input to the PID unit in the main control module 1, which controls the noise source module 3 to adjust the noise amplitude. Encryption module 6 is connected to noise modulation module 4 and main control module 1. After the noise amplitude is adjusted to the appropriate level, main control module 1 controls encryption module 6 to encrypt the system status information and the mixed noise GPS time signal, forming an encrypted data stream. PID closed-loop control is used to achieve precise and controllable noise disturbance. First, a controllable timing noise signal is superimposed on the original GPS time signal to complete fuzzy desensitization. Then, the desensitized data is encrypted and output, forming a complete secure link of timing scrambling, error closed-loop correction, and overall encryption. This achieves controlled fuzzification processing of the original GPS time signal, effectively improving the anti-interception and security of time information transmission while maintaining the availability of time synchronization.

[0043] As an example, the GPS time information fuzzification control system in this embodiment is an independent hardware module that can be integrated into a vehicle-mounted T-Box or gateway. The main control module 1 is an MCU module or an FPGA module. The GNSS and signal processing module 2 includes a GNSS module 21 and a filtering and amplification module 22. The GNSS module 21 is connected to the filtering and amplification module 22, which is connected to the main control module 1 and the noise modulation module 4. The GNSS module 21 provides raw GPS time data, which is filtered and amplified by the filtering and amplification module 22 to form the raw GPS time signal, and then transmitted to the main control module 1 and the noise modulation module 4. The error detection module 5 is a time-to-digital converter (TDC).

[0044] In one possible embodiment, the noise source module 3 includes a true random number generator 31 connected to the main control module 1, a pseudo random number generator 32, and a digital potentiometer 33 connected to the PID unit in the main control module 1. The true random number generator 31 is connected to the pseudo random number generator 32, and the pseudo random number generator 32 is connected to the digital potentiometer 33. Under the control of the main control module 1, the true random number generator 31 generates a digital random sequence (i.e., a TRNG seed, an entropy source seed) and inputs it to the pseudo random number generator 32. Under the control of the main control module 1, the pseudo random number generator 32 generates a (periodic) pseudo random digital noise sequence based on the digital random sequence and transmits it to the digital potentiometer 33. Under the control of the PID unit, the digital potentiometer 33 adjusts the noise amplitude of the pseudo random digital noise sequence by adjusting the DAC output gain (corresponding to the resistance value of the digital potentiometer) and outputs a noise signal (a digital signal). The true random number generator first provides a high-security entropy source to ensure the unpredictability of noise. The pseudo-random number generator then generates a noise sequence. Finally, the noise amplitude is adjusted in a closed loop by adjusting a digital potentiometer, which takes into account both the randomness of noise and the controllable precision of disturbance, and effectively balances the security of GPS time desensitization with the stability of timing error control.

[0045] As an example, the true random number generator 31 (TRNG) includes a high-frequency oscillator, a low-frequency sampling clock, and a comparator. The high-frequency oscillator generates an unpredictable random sequence signal. The low-frequency sampling clock then performs steady-state sampling, amplification, and phase jitter on the signal generated by the high-frequency oscillator. The comparator then converts this signal into a digital random sequence, which is input to the pseudo-random number generator 32 (PRNG). The pseudo-random number generator 32 generates a periodic pseudo-random digital noise sequence in the LFSR (32-bit linear shift register) based on the entropy source seed provided by the TRNG, improving randomness and unpredictability, and increasing security.

[0046] In one possible embodiment, the main control module 1 can control the true random number generator 31 to adjust the proportion of high and low frequency components in the digital random sequence. The main control module 1 can also control the pseudo-random number generator 32 to adjust the random number range of the pseudo-random number generator 32. This dual-dimensional adjustable mechanism enables flexible configuration of noise characteristics from the noise spectrum and noise amplitude range, which is beneficial for enriching the perturbation modes of GPS time ambiguity.

[0047] In one possible embodiment, the noise modulation module 4 includes a DAC converter 41, an analog multiplier 42, and a controllable low-pass filter 43. The DAC converter 41 is connected to the main control module 1, the digital potentiometer 33, and the analog multiplier 42. Under the control of the main control module 1, it acquires a noise signal and converts it into an analog noise signal, which is then transmitted to the analog multiplier 42. The analog multiplier 42 is connected to the GNSS and signal processing module 2 and the controllable low-pass filter 43. The analog multiplier 42 nonlinearly superimposes the analog noise signal with the original GPS time signal to obtain a noisy GPS time signal. The controllable low-pass filter 43 performs low-pass filtering on the noisy GPS time signal, removing high-frequency components that exceed the timing bandwidth, and then outputs a mixed-noise GPS time signal. The noise modulation module adopts a cascaded architecture of a DAC converter, an analog multiplier, and a controllable low-pass filter, realizing noise digital-to-analog conversion, nonlinear superposition of timing signals, and clutter filtering in steps, resulting in a clear and reliable modulation process.

[0048] In one possible embodiment, the main control module 1 is connected to the controllable low-pass filter 43 and can adjust the cutoff frequency of the controllable low-pass filter 43; the main control module 1 can control the error detection module 5 to adjust the detection period of the error detection module 5. The main control module 1 can control the encryption module 6 to adjust the encryption key replacement period of the encryption module 6.

[0049] like Figure 3 As shown, the GPS time information fuzzification control method in this embodiment of the application adopts the above-mentioned GPS time information fuzzification control system. The method (the execution process of the main control module 1) includes the following steps:

[0050] S1. Obtain the user-selected security configuration mode and the raw GPS time signal, and then execute S2.

[0051] In one possible embodiment, the system storage has two security configuration modes: high-precision mode and high-privacy mode. Users can manually select either high-precision mode or high-privacy mode according to their actual needs. After the user selects high-precision mode, the main control module 1 will receive a high-precision mode instruction; after the user selects high-privacy mode, the main control module 1 will receive a high-privacy mode instruction.

[0052] S2. Based on the user-selected security configuration mode, control the noise source module 3, noise modulation module 4, error detection module 5, and encryption module 6 to configure the relevant parameters corresponding to the security configuration mode, and then execute S3.

[0053] In one possible embodiment, if the user selects the high-precision security configuration mode, the relevant parameters corresponding to the high-precision mode are configured as follows: the proportion of high-frequency components in the digital random sequence is A1, the random number range is a times the full range, the DAC output gain is maintained between k1 and k2 (corresponding to the amplitude of the noise signal being in the range [A1, A2]), the cutoff frequency of the low-pass filter is f1, and the detection period of the error detection module is t. c1 The encryption key replacement cycle is t. m1 If the user selects the high privacy mode as the security configuration mode, the corresponding parameter configurations are as follows: the proportion of low-frequency components in the digital random sequence is A2, the random number range is the full range, the DAC output gain is maintained between k3 and k4 (the amplitude of the noise signal is in [A3, A4]), the cutoff frequency of the low-pass filter is f2, and the detection period of the error detection module is t. c2 The encryption key replacement cycle is t. m2 Among them, A1 > 60%, A2 > 60%, a ≤ 0.9, k3 > k2, f2 > f1, t c2 <t c1 , t m2 <t m1 .

[0054] As an example, if the user selects the high-precision security configuration mode, then the main control module 1 controls the true random number generator 31 to make the high-frequency component account for 70% of the digital random sequence; the main control module 1 controls the pseudo-random number generator 32 to make the random number range of the pseudo-random number generator 32 0.9 times the full range; the main control module 1 controls the digital potentiometer 33 to keep the DAC output gain between 0.2 and 0.3 (i.e. 0.2 to 0.3); the main control module 1 controls the controllable low-pass filter 43 to make the cutoff frequency of the low-pass filter 20Hz; the main control module 1 controls the error detection module 5 to make the detection period of the error detection module 5 3µs; and the main control module 1 controls the encryption module 6 to make the encryption key replacement period of the encryption module 6 30min.

[0055] As an example, if the user selects the high privacy mode for the security configuration, then the main control module 1 controls the true random number generator 31 to make the low-frequency component account for 65% of the digital random sequence; the main control module 1 controls the pseudo random number generator 32 to make the random number range of the pseudo random number generator 32 the full range; the main control module 1 controls the digital potentiometer 33 to keep the DAC output gain between 0.4 and 0.7 (i.e. 0.4 to 0.7); the main control module 1 controls the controllable low-pass filter 43 to make the cutoff frequency of the low-pass filter 5Hz; the main control module 1 controls the error detection module 5 to make the detection period of the error detection module 5 1µs; and the main control module 1 controls the encryption module 6 to make the encryption key replacement period of the encryption module 6 10min.

[0056] S3. The noise source control module 3 generates an adjustable noise signal based on relevant parameter configuration, and the noise modulation control module 4 modulates the noise signal and the original GPS time signal into a mixed noise GPS time signal based on relevant parameter configuration, and then executes S4.

[0057] As an example, the main control module 1 controls the true random number generator 31 to generate a digital random sequence (i.e., TRNG seed, entropy source seed) which is input to the pseudo random number generator 32. The main control module 1 controls the pseudo random number generator 32 to generate a pseudo random digital noise sequence based on the digital random sequence and transmit it to the digital potentiometer 33. The PID unit controls the digital potentiometer 33 to adjust the noise amplitude of the pseudo random digital noise sequence by adjusting the DAC output gain, and outputs a noise signal. The main control module 1 controls the DAC converter 41 to convert the noise signal into an analog noise signal and transmit it to the analog multiplier 42. The analog multiplier 42 nonlinearly superimposes the analog noise signal with the original GPS time signal to obtain a noisy GPS time signal. The controllable low-pass filter 43 performs low-pass filtering on the noisy GPS time signal to filter out high-frequency components that exceed the timing bandwidth in the noisy GPS time signal, and then outputs a mixed noise GPS time signal.

[0058] S4. The control error detection module 5 compares the mixed noise GPS time signal with the input reference time signal based on the relevant parameter configuration to obtain the time error. The PID unit controls the noise source module 4 to adjust the noise amplitude based on the time error and the original GPS time signal, and then executes S5.

[0059] As an example, the error detection module 5 acquires the mixed noise GPS time signal and compares it with the input reference time signal to obtain the time error. The time error is then input to the PID unit in the main control module 1, which controls the digital potentiometer 33 to adjust the noise amplitude.

[0060] In one possible embodiment, the reference time signal is the real-time time generated by an internal counter through a fixed frequency of a stable thermostatic crystal oscillator inside the main control module 1.

[0061] In one possible embodiment, the reference time signal is a high-precision time enhanced by a satellite atomic clock.

[0062] S5. Determine if the noise amplitude has been adjusted to the correct level. If yes, proceed to S6; otherwise, return to S3.

[0063] In one possible embodiment, the noise amplitude is determined to be adjusted correctly if the absolute value of the time error over n consecutive iterations is less than or equal to a preset first time threshold. Here, n is an integer, and n ≥ 2. As an example, the preset first time threshold is 5 ns, and n = 4.

[0064] S6, the control encryption module 6 encrypts the system status information and mixed noise GPS time signal based on relevant parameter configuration, forming an encrypted data stream, and then ends.

[0065] As an example, the system status information is provided by the main control module 1, including timing error information, noise configuration information, mode selection information, etc.

[0066] Finally, it should be noted that the application of this application is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims. Those skilled in the art can understand and implement all or part of the processes of the above embodiments, and equivalent changes made according to the claims of this application still fall within the scope of this application.

Claims

1. A GPS time information fuzzy control system, characterized in that: The system includes a main control module (1), a GNSS and signal processing module (2), a noise source module (3), a noise modulation module (4), an error detection module (5), and an encryption module (6). The GNSS and signal processing module (2) is connected to the main control module (1) and the noise modulation module (4), and transmits the provided and processed original GPS time signal to the main control module and the noise modulation module. The main control module (1) is connected to the noise source module (3), and controls the noise source module to generate a noise signal with adjustable amplitude. The noise modulation module (4) is connected to the noise source module (3) and the main control module (1), acquires the noise signal, and modulates the noise signal with... The original GPS time signal is modulated into a mixed noise GPS time signal; the error detection module (5) is connected to the noise modulation module (4) and the main control module (1), acquires the mixed noise GPS time signal, compares it with the input reference time signal, obtains the time error, and inputs the time error to the PID unit in the main control module, and controls the noise source module to adjust the noise amplitude through the PID unit; the encryption module (6) is connected to the noise modulation module (4) and the main control module (1), and after the noise amplitude is adjusted to the appropriate level, the main control module controls the encryption module to encrypt the system status information and the mixed noise GPS time signal to form an encrypted data stream.

2. The GPS time information fuzzification control system according to claim 1, characterized in that: The noise source module (3) includes a true random number generator (31), a pseudo random number generator (32), and a digital potentiometer (33) connected to the main control module (1) and a PID unit in the main control module (1). The true random number generator (31) is connected to the pseudo random number generator (32), and the pseudo random number generator (32) is connected to the digital potentiometer (33). Under the control of the main control module (1), the true random number generator (31) generates a digital random sequence and inputs it to the pseudo random number generator (32). Under the control of the main control module (1), the pseudo random number generator (32) generates a pseudo random digital noise sequence based on the digital random sequence and transmits it to the digital potentiometer (33). Under the control of the PID unit, the digital potentiometer (33) adjusts the noise amplitude of the pseudo random digital noise sequence by adjusting the DAC output gain and outputs the noise signal.

3. The GPS time information fuzzification control system according to claim 2, characterized in that: The main control module (1) can control the true random number generator (31) to adjust the proportion of high and low frequency components in the digital random sequence; the main control module (1) can control the pseudo random number generator (32) to adjust its random number range.

4. The GPS time information fuzzification control system according to claim 2, characterized in that: The noise modulation module (4) includes a DAC converter (41), an analog multiplier (42), and a controllable low-pass filter (43). The DAC converter (41) is connected to the main control module (1), the digital potentiometer (33), and the analog multiplier (42). Under the control of the main control module (1), it acquires the noise signal and converts the noise signal into an analog noise signal, which is then transmitted to the analog multiplier (42). The analog multiplier (42) is connected to the GNSS and signal processing module (2) and the controllable low-pass filter (43). The analog multiplier (42) nonlinearly superimposes the analog noise signal with the original GPS time signal to obtain a noisy GPS time signal. The controllable low-pass filter (43) performs low-pass filtering on the noisy GPS time signal and then outputs the mixed noise GPS time signal.

5. The GPS time information fuzzification control system according to claim 4, characterized in that: The main control module (1) is connected to the controllable low-pass filter (43) and can adjust the cutoff frequency of the controllable low-pass filter (43); the main control module (1) can control the error detection module (5) to adjust its detection cycle; the main control module (1) can control the encryption module (6) to adjust its encryption key replacement cycle.

6. A GPS time information fuzzy control method, characterized in that: The GPS time information fuzzification control system as described in any one of claims 1 to 5, wherein the method comprises: Obtain the user-selected security configuration mode and the original GPS time signal; Based on the security configuration mode selected by the user, the noise source module (3), noise modulation module (4), error detection module (5), and encryption module (6) are controlled to configure the relevant parameters corresponding to the security configuration mode; The noise source module (3) is controlled to generate an amplitude-adjustable noise signal based on the relevant parameters, and the noise modulation module (4) is controlled to modulate the noise signal and the original GPS time signal into a mixed noise GPS time signal based on the relevant parameters. The error detection module (5) is controlled to compare the mixed noise GPS time signal with the input reference time signal based on the relevant parameter configuration to obtain the time error. The PID unit controls the noise source module (4) to adjust the noise amplitude based on the time error and the original GPS time signal. Once the noise amplitude is adjusted to the appropriate level, the encryption module (6) is controlled to encrypt the system status information and the mixed noise GPS time signal based on the relevant parameter configuration, forming an encrypted data stream.

7. The GPS time information fuzzification control method according to claim 6, characterized in that: If the user selects the high-precision security configuration mode, the corresponding parameter configurations are as follows: the proportion of high-frequency components in the digital random sequence is A1, the random number range is a times the full range, the DAC output gain is maintained between k1 and k2, the cutoff frequency of the low-pass filter is f1, and the detection period of the error detection module is t. c1 The encryption key replacement cycle is t. m1 ; If the user selects the high privacy mode as the security configuration mode, the corresponding parameter configurations are as follows: the proportion of low-frequency components in the digital random sequence is A2, the random number range is the full range, the DAC output gain is maintained between k3 and k4, the cutoff frequency of the low-pass filter is f2, and the detection period of the error detection module is t. c2 The encryption key replacement cycle is t. m2 ; Where A1 > 60%, A2 > 60%, a ≤ 0.9, k3 > k2, f2 > f1, t c2 <t c1 , t m2 <t m1 .

8. The GPS time information fuzzification control system according to claim 6 or 7, characterized in that: The reference time signal is the real-time time generated by the internal counter through a fixed frequency of the stable isothermal crystal oscillator inside the main control module (1). Alternatively, the reference time signal may be a high-precision time signal provided by a satellite atomic clock.

9. The GPS time information fuzzification control method according to claim 6 or 7, characterized in that: If the absolute value of the time error of n consecutive connections is less than or equal to the preset first time threshold, then the noise amplitude is determined to be adjusted in place; where n is an integer and n≥2.

10. A vehicle, characterized in that: Including the GPS time information fuzzification control system as described in any one of claims 1 to 5.

Images