Test method of vehicle satellite communication system

Abstract

The invention belongs to the technical field of vehicle communication testing, and particularly relates to a testing method of a vehicle satellite communication system, which comprises the following steps of: performing motion-channel joint modeling by applying a vehicle motion equation; performing environment interference dynamic injection; and an automatic closed-loop test step. According to the technical scheme, the test efficiency is improved, and the single test period is shortened from 7 days to 2 hours; the defect detection rate is improved, and the Doppler frequency shift associated fault detection rate is improved; cost is saved, real vehicle road test is avoided, and satellite channel cost is saved.

Description

Technical Field

[0001] This invention belongs to the field of vehicle communication testing technology, and specifically relates to a testing method for a vehicle satellite communication system. Background Technology

[0002] Vehicle satellite communication systems are widely used in fields such as intelligent driving, remote monitoring, and emergency communication. Testing requires verifying communication stability under complex environments such as dynamic multipath fading, Doppler shift, and attitude disturbances. Traditional static laboratory testing cannot reproduce real-world scenarios, leading to problems such as signal interruptions and sharp increases in bit error rate during actual deployment of vehicle-mounted equipment.

[0003] Current testing methods involve vehicle-mounted equipment conducting tests on real roads. GPS tracks are used to record routes, and the vehicle communicates via satellite to make calls to regular numbers and emergency services, with the communication data analyzed in the background. This testing method is extremely costly due to the high expenses associated with satellite communication and long-distance road testing. Furthermore, the testing scenarios are subject to random occurrences of weather and obstructions, making it difficult to reproduce defects. Additionally, data acquisition is delayed, and it cannot inject fault test cases in real time, such as in the event of sudden signal interference. Summary of the Invention

[0004] The purpose of this invention is to provide a testing method for a vehicle satellite communication system, which achieves dynamic coupling simulation of vehicle motion state and satellite channel, programmable simulation of complex environment, and automated closed-loop evaluation of communication indicators with a low-cost and highly reproducible testing scheme.

[0005] To achieve the above objectives, this application employs the following technical solution:

[0006] A test method for a vehicle satellite communication system includes the following steps:

[0007] S1. Apply vehicle motion equations to perform joint motion-channel modeling;

[0008] S2. Perform dynamic injection of environmental interference;

[0009] S3, Automated Closed-Loop Testing.

[0010] Furthermore, the vehicle's motion equations are used to calculate the Doppler frequency shift, as shown in the formula:

[0011] ,in,

[0012] Vehicle speed, in m / s, input via simulation platform or real vehicle data;

[0013] The satellite elevation angle, in radians, is calculated in real time based on satellite orbit data and vehicle position.

[0014] The vehicle's direction of motion angle, in radians, is provided by the inertial measurement unit or simulation platform.

[0015] The wavelength of the satellite signal is measured in meters (m) and is determined by the communication frequency band.

[0016] Furthermore, the specific steps for applying the vehicle motion equations to perform joint motion-channel modeling in step S1 are as follows:

[0017] S11. A six-degree-of-freedom hydraulic platform is adopted to receive real vehicle road spectrum data and generate attitude vibration sequence. The platform adjusts the posture in real time through a PID controller to simulate the dynamic behavior of the vehicle.

[0018] S12. Integrate the motion equations into the embedded system, update the parameters at set intervals, and output... A channel simulator is used to dynamically adjust the carrier frequency offset;

[0019] S13. Synchronize the motion platform pose data and channel parameters through timestamps to ensure that the Doppler frequency shift and attitude vibration phase are consistent.

[0020] Furthermore, in step S2, dynamic injection of environmental disturbances includes occlusion model, multipath model and sudden noise injection;

[0021] The occlusion model uses a ray tracing model and combines it with a 3D digital map to calculate the occlusion rate.

[0022] The multipath model uses an extended SUI model adapted to the environment to calculate multipath components.

[0023] The burst noise injection is calculated using an interference pulse model based on the IEEE 802.11 protocol for power spectral density calculation.

[0024] Furthermore, the formula for calculating the shading rate is:

[0025]

[0026] in:

[0027] This represents the number of sampling points existing in LOS per unit time.

[0028] Total number of sampling points.

[0029] Furthermore, the formula for generating multipath components is:

[0030]

[0031] in:

[0032] Let be the magnitude of the i-th path; Delay, unit: seconds;

[0033] Phase offset, unit: radians.

[0034] Furthermore, the power spectral density formula is:

[0035]

[0036] in:

[0037] Noise power;

[0038] Center frequency;

[0039] :bandwidth.

[0040] Furthermore, in step S3, the automated closed-loop test includes:

[0041] S31. Define scene parameters using a scripting language;

[0042] S32. The test procedure is as follows: motion-channel joint modeling, environmental interference injection, data acquisition and performance analysis.

[0043] S33. Real-time calculation of Doppler frequency shift, 3D occlusion model simulation, multipath information modeling and automated performance evaluation;

[0044] S34. Real-time acquisition of bit error rate and switching latency metrics, evaluation, and generation of test reports.

[0045] The advantages of this invention are:

[0046] This technical solution improves testing efficiency, reducing the single test cycle from 7 days to 2 hours; increases defect detection rate, with a 40% increase in Doppler frequency shift-related fault detection rate; and saves costs by avoiding real-vehicle road testing and reducing satellite channel costs by nearly 85%. Attached Figure Description

[0047] Figure 1 This is a system architecture diagram of the present invention. Detailed Implementation

[0048] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings. The following embodiments are merely exemplary and can only be used to explain and illustrate the technical solution of the present invention, and should not be construed as limiting the technical solution of the present invention.

[0049] like Figure 1As shown, this application provides a test method for a vehicle satellite communication system, which includes the following steps:

[0050] S1. Apply vehicle motion equations to perform joint motion-channel modeling.

[0051] The vehicle motion equations are constructed. In this embodiment, the vehicle motion equations are used to calculate the Doppler frequency shift. The specific formula is as follows:

[0052]

[0053] in:

[0054] Vehicle speed (unit: m / s), input via simulation platform or real vehicle data;

[0055] The satellite elevation angle (in radians) is calculated in real time based on satellite orbit data and vehicle position.

[0056] The vehicle's direction of motion angle (in radians) is provided by an inertial measurement unit (IMU) or simulation platform;

[0057] The wavelength of the satellite signal (unit: m) is determined by the communication frequency band (such as L-band, Ka-band).

[0058] The specific implementation method is as follows:

[0059] S11. Motion Platform Control: A six-degree-of-freedom hydraulic platform is used to receive real-vehicle road spectrum data (such as power spectral density) and generate attitude vibration sequences such as pitch, roll, and yaw. The platform adjusts its posture in real time through a PID controller to simulate dynamic behaviors such as vehicle acceleration, turning, and bumping. The motion platform generates the required motion sequence based on scene parameters and synchronizes with the channel simulator via the CAN bus. The channel simulator dynamically adjusts parameters according to the scene; for example, in tunnel occlusion, it injects -30dB attenuation for 100ms; the Doppler frequency shift is updated in real time according to the motion equation. .

[0060] S12. Real-time Doppler frequency shift calculation: Integrate motion equations into the embedded system, and update parameters every 10ms. , , ), output To the channel simulator, used to dynamically adjust carrier frequency offset.

[0061] S13, Coupling Algorithm: Synchronize the motion platform pose data and channel parameters through timestamps to ensure that the Doppler frequency shift and attitude vibration phase are consistent.

[0062] S2, Dynamic Injection of Environmental Interference:

[0063] In this embodiment, the dynamic injection of environmental interference includes several methods such as occlusion model, multipath model and sudden noise injection.

[0064] The occlusion model employs a "ray tracing model," combined with a 3D digital map (including elevation data for buildings, terrain, tunnels, etc.), specifically:

[0065] 1) Calculate in real time whether the line-of-sight (LOS) between the vehicle and the satellite is obstructed.

[0066] 2) Calculation of shading rate. In this embodiment, the shading rate... Defined as signal power attenuation (dB), the calculation formula is:

[0067]

[0068] in:

[0069] This represents the number of sampling points existing in LOS per unit time.

[0070] This represents the total number of sampling points.

[0071] The occlusion status is dynamically updated every 100ms based on the vehicle's GPS coordinates and 3D map data.

[0072] The multipath model employs the "Extended SUI Model" (Stanford University Interim Model), adapted to environments such as cities and canyons. The specific steps are as follows:

[0073] 1) The reflection coefficient library contains reflection loss and time delay spread parameters for materials such as concrete, glass, and metal.

[0074] 2) Formula for generating multipath components:

[0075]

[0076] in:

[0077] Let be the magnitude of the i-th path; Delay (unit: seconds);

[0078] Phase offset (unit: radians).

[0079] 3) Real-time convolution is implemented using FPGA to simulate multipath channels.

[0080] The sudden noise injection is based on the interference pulse model of the IEEE 802.11 protocol, and the specific scheme is as follows:

[0081] 1) The programmable noise generator injects impulse noise according to the test cases, with a power spectral density (PSD) of:

[0082]

[0083] in:

[0084] Noise power; The center frequency; For bandwidth.

[0085] 2) This technical solution supports custom interference timing, such as periodic pulses or random bursts.

[0086] S3, Automated Closed-Loop Testing, the specific steps are as follows:

[0087] S31. Define scene parameters using a scripting language (such as Python); the core functional modules are as follows:

[0088] VehicleSatComTestSystem is the main test system class, which coordinates the entire test process;

[0089] MotionPlatform is a motion platform control system that simulates vehicle dynamics.

[0090] ChannelSimulator is a channel simulator control that injects environmental interference;

[0091] PerformanceAnalyzer is a performance analyzer used to evaluate communication quality.

[0092] S32. The specific test procedure is as follows:

[0093] 1) Motion-channel joint modeling is performed by calculating Doppler frequency shift in real time and controlling the motion platform.

[0094] 2) Inject environmental interference by configuring occlusion, multipath, or noise models.

[0095] 3) Data is collected by monitoring communication performance indicators in real time.

[0096] 4) Evaluate test results based on thresholds and generate reports for performance analysis.

[0097] The above testing process is achieved through real-time Doppler frequency shift calculation, simulation using a 3D occlusion model, multipath channel modeling, and automated performance evaluation.

[0098] The analysis system in this application evaluates performance by collecting metrics such as bit error rate (BER) and switching latency in real time, using the following formula.

[0099]

[0100]

[0101] Generate a test report, including timing diagrams, statistical analysis, and pass / fail conclusions.

[0102] Example

[0103] Test objective: To verify the satellite locking capability of the vehicle-mounted antenna on bumpy roads.

[0104] Parameter settings: Use the parameters described above.

[0105] Motion platform: sinusoidal vibration (frequency 2Hz, amplitude ±5°).

[0106] Channel model: Add 5 multipath components (maximum delay 2μs).

[0107] Results: Compared with traditional methods, the present invention exposes the antenna stabilizer response delay defect (>200ms).

[0108] Although embodiments of this application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A test method for a vehicle satellite communication system, characterized in that, Includes the following steps: S1. Apply vehicle motion equations to perform joint motion-channel modeling; S2. Perform dynamic injection of environmental interference; S3, Automated Closed-Loop Testing.

2. The test method for the vehicle satellite communication system according to claim 1, characterized in that, The vehicle motion equations are used to calculate the Doppler frequency shift, and the formula is: ,in, Vehicle speed, in m / s, input via simulation platform or real vehicle data; The satellite elevation angle, in radians, is calculated in real time based on satellite orbit data and vehicle position. The vehicle's direction of motion angle, in radians, is provided by the inertial measurement unit or simulation platform. The wavelength of the satellite signal is measured in meters (m) and is determined by the communication frequency band.

3. The test method for the vehicle satellite communication system according to claim 1, characterized in that, The specific steps for applying the vehicle motion equations to perform joint motion-channel modeling in step S1 are as follows: S11. A six-degree-of-freedom hydraulic platform is adopted to receive real vehicle road spectrum data and generate attitude vibration sequence. The platform adjusts the posture in real time through a PID controller to simulate the dynamic behavior of the vehicle. S12. Integrate the motion equations into the embedded system, update the parameters at set intervals, and output... A channel simulator is used to dynamically adjust the carrier frequency offset; S13. Synchronize the motion platform pose data and channel parameters through timestamps to ensure that the Doppler frequency shift and attitude vibration phase are consistent.

4. The test method for the vehicle satellite communication system according to claim 1, characterized in that... In step S2, dynamic environmental interference injection is performed, including occlusion model, multipath model and sudden noise injection. The occlusion model uses a ray tracing model and combines it with a 3D digital map to calculate the occlusion rate. The multipath model uses an extended SUI model adapted to the environment to calculate multipath components. The burst noise injection is calculated using an interference pulse model based on the IEEE 802.11 protocol for power spectral density calculation.

5. The test method for the vehicle satellite communication system according to claim 4, characterized in that, The formula for calculating the shading rate is: in: This represents the number of sampling points existing in LOS per unit time. Total number of sampling points.

6. The test method for the vehicle satellite communication system according to claim 4, characterized in that, The formula for generating multipath components is: in: Let be the magnitude of the i-th path; Delay, unit: seconds; Phase offset, unit: radians.

7. The test method for the vehicle satellite communication system according to claim 4, characterized in that, The formula for power spectral density is: in: Noise power; Center frequency; :bandwidth.

8. The test method for the vehicle satellite communication system according to claim 1, characterized in that, In step S3, the automated closed-loop test includes: S31. Define scene parameters using a scripting language; S32. The test procedure is as follows: motion-channel joint modeling, environmental interference injection, data acquisition and performance analysis. S33. Real-time calculation of Doppler frequency shift, 3D occlusion model simulation, multipath information modeling and automated performance evaluation; S34. Real-time acquisition of bit error rate and switching latency metrics, evaluation, and generation of test reports.

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