Ground penetrating radar emission voltage dynamic adjusting system

Abstract

The invention provides a ground penetrating radar transmitting voltage dynamic adjusting system which adopts a transmitting antenna subsystem and a receiving antenna subsystem which are arranged in a split mode. Through the FPGA chip, the digital potentiometer is adjusted to reduce the level of the high-voltage power supply under the condition that the range of the analog-to-digital converter is full and / or the direct wave is saturated, and the digital potentiometer is adjusted to increase the level of the high-voltage power supply under the condition that the range of the analog-to-digital converter is not full and / or the direct wave is unsaturated, so that the ground penetrating radar can better adapt to different geological conditions. The signal-to-noise ratio of the signal is improved, the detection resolution is further improved, different detection tasks can be quickly responded, and hardware replacement or complex setting does not need to be carried out.

Description

Technical Field

[0001] The invention relates to the technical field of radar equipment, and in particular to a ground penetrating radar transmitting voltage dynamic regulation system. Background Art

[0002] Ground Penetrating Radar (GPR) is a geophysical method that uses high-frequency electromagnetic waves to detect underground structures. With the acceleration of urbanization, the demand for underground space detection continues to grow. GPR is widely used in archaeology, mineral exploration, disaster geological surveys, geotechnical engineering surveys, engineering quality inspections and other fields due to its high precision, high efficiency and non-destructive characteristics.

[0003] The dynamic adjustment of the transmitting voltage has a significant impact on the performance of the ground penetrating radar. The transmitting voltage is proportional to the energy of the radar signal. The GPR signal at a certain distance is proportional to the peak voltage. The increase in the transmitting voltage can improve the penetration of the radar signal, thereby increasing the detection depth. However, the transmitting voltage must also be matched with the system, and the geological conditions need to be considered. Different geological media have different degrees of absorption and scattering of electromagnetic waves. Under certain geological conditions with high conductivity, the signal attenuation is large. Even if the transmitting voltage is increased, the expected detection depth may not be achieved. At the same time, increasing the transmitting voltage, too high a voltage may cause the received signal to contain more noise, which will increase the complexity of data processing and may affect the interpretation and accuracy of the final data. Therefore, there is an urgent need for a ground penetrating radar system that can dynamically adjust the transmitting voltage. Summary of the invention

[0004] In view of this, an embodiment of the present invention provides a ground penetrating radar transmitting voltage dynamic adjustment system to eliminate or improve one or more defects existing in the prior art and solve the problem that the prior art cannot adaptively adjust the transmitting voltage according to the ground penetrating radar signal state, resulting in low detection accuracy.

[0005] One aspect of the present invention provides a ground penetrating radar transmission voltage dynamic adjustment system, the system comprising a transmitting antenna subsystem and a receiving antenna subsystem arranged in a split manner;

[0006] The transmitting antenna subsystem comprises:

[0007] A high voltage module, used for providing high voltage power supply;

[0008] A pulse source module, which outputs a high-voltage pulse signal based on the high-voltage power supply and the trigger pulse;

[0009] A transmitting antenna, used for converting the high-voltage pulse signal into a first electromagnetic wave and radiating it outwards;

[0010] The receiving antenna subsystem comprises:

[0011] A receiving antenna, used for receiving an external second electromagnetic wave, wherein the second electromagnetic wave includes a direct wave and a reflected wave returned in the medium;

[0012] The main control and data acquisition module is used to perform noise suppression, gain adjustment, imaging and image optimization processing on the reflected wave; and to detect the state of the direct wave through an analog-to-digital converter to regulate the high-voltage power supply output by the high-voltage module; wherein the main control and data acquisition module controls the digital potentiometer through an FPGA chip to configure a control resistor for the high-voltage module to adjust the high-voltage power supply; the FPGA chip adjusts the digital potentiometer to reduce the level of the high-voltage power supply when the analog-to-digital converter is full and / or the direct wave is saturated, and adjusts the digital potentiometer to increase the level of the high-voltage power supply when the analog-to-digital converter is not full and / or the direct wave is not saturated.

[0013] In some embodiments, the pulse source module is composed of multiple stages of avalanche diodes, each of which is connected in series in sequence. A parallel resistor and a capacitor are provided at both ends of each avalanche diode for balancing and limiting overcurrent.

[0014] In some embodiments, the high-voltage module adopts a reference voltage division adjustment structure, and the fixed reference voltage of the high-voltage module is divided by setting an external first resistor and a second resistor through the digital potentiometer to adjust the voltage of the high-voltage power supply. The expression is:

[0015]

[0016] Among them, V MAX represents the fixed reference voltage, R1 represents the first resistor, and R2 represents the second resistor.

[0017] In some embodiments, the high-voltage module adopts a feedback voltage-dividing adjustment structure, and the first external resistor and the second external resistor are set by the digital potentiometer to form a feedback voltage-dividing network. The voltage of the high-voltage power supply is adjusted according to the multiple of the reference voltage of the high-voltage module based on the resistance voltage-dividing ratio of the feedback voltage-dividing network. The expression is:

[0018]

[0019] Among them, V ref represents the reference voltage, R1 represents the first resistor, and R2 represents the second resistor.

[0020] In some embodiments the system further comprises:

[0021] A distance adjustment mechanism, used to adjust the distance between the transmitting antenna and the receiving antenna;

[0022] The user interaction module is used to control the distance adjustment mechanism to adjust the distance between the transmitting antenna and the receiving antenna based on the adjustment instruction input by the user.

[0023] In some embodiments, the distance adjustment mechanism comprises:

[0024] Slide rails;

[0025] A first fixed base, fixedly disposed on the slide rail, and used for fixing the transmitting antenna;

[0026] A second fixed base, slidably disposed on the slide rail, for fixing the receiving antenna;

[0027] The driving motor is disposed on the second fixed base and is used to drive the second fixed base to slide on the slide rail.

[0028] In some embodiments, the FPGA chip adjusts the level of the high voltage power supply based on a proportional integral differential feedback control algorithm, including:

[0029] Compare the current level value of the direct wave or reflected wave with the target value, and calculate the error e(t), which is calculated as follows:

[0030] e(t)=V 目标 -V 当前 ;

[0031] Among them, V 目标 represents the target value, V 当前 Indicates the current level value;

[0032] Then the regulation amount u(t) of the high voltage power supply is:

[0033]

[0034] Among them, K p is the proportionality coefficient, K i is the integration coefficient, K d is the differential coefficient.

[0035] In some embodiments, the FPGA chip uses a strategy network pre-trained based on a reinforcement learning model, and takes the level of the high-voltage power supply, the level of the direct wave, the dynamic range of the reflected wave, and the ratio of the dynamic range to the range of the analog-to-digital converter as input, and outputs an adjustment amount for the level of the high-voltage power supply.

[0036] In some embodiments, the pre-training step of the policy network includes:

[0037] Constructing a state space, the state space including the level of the high voltage power supply, the level of the direct wave, the dynamic range of the reflected wave, and the ratio of the dynamic range to the range of the analog-to-digital converter;

[0038] Constructing an action space, wherein the action space is an amount of level adjustment for the high voltage power supply;

[0039] Based on the policy network in reinforcement learning, the level adjustment amount of the high-voltage power supply is outputted with the parameters of the state space as input, and a reward function is constructed by weighted summing the direct wave unsaturation reward, the dynamic range utilization reward and the adjustment amplitude penalty. In multiple iterations, the parameters of the policy network are updated by minimizing the reward function until the reward function converges;

[0040] Among them, the calculation formula of the reward function R is:

[0041] R=ω1R 直达波 +ω2R 动态范围 +ω3R 调整幅度 ;

[0042] Among them, R 直达波 represents the direct wave unsaturated reward, R 动态范围 represents the dynamic range utilization reward, R 调整幅度 represents the adjustment amplitude penalty;

[0043]

[0044] R 动态范围 = -|K-0.95|;

[0045]

[0046] Wherein, K represents the ratio of the dynamic range of the reflected wave to the range of the analog-to-digital converter, and ΔV represents the level adjustment amount of the high voltage power supply.

[0047] In some embodiments, the policy network is composed of a convolutional neural network and a fully connected network.

[0048] The beneficial effects of the present invention are at least:

[0049] The ground penetrating radar transmitting voltage dynamic adjustment system of the present invention adopts a separately arranged transmitting antenna subsystem and receiving antenna subsystem. The receiving antenna subsystem adjusts the digital potentiometer to reduce the level of the high-voltage power supply through the FPGA chip according to the state of the received signal when the analog-to-digital converter is full-scale and / or the direct wave is saturated, and adjusts the digital potentiometer to increase the level of the high-voltage power supply when the analog-to-digital converter is not full-scale and / or the direct wave is not saturated. This enables the ground penetrating radar to better adapt to different geological conditions, helps to improve the signal-to-noise ratio of the signal, and then improves the detection resolution, and can quickly respond to different detection tasks without replacing hardware or performing complex settings.

[0050] Additional advantages, purposes, and features of the present invention will be described in part in the following description, and will become apparent to those skilled in the art after studying the following, or may be learned from the practice of the present invention. The purposes and other advantages of the present invention may be achieved and obtained by the structures specifically indicated in the specification and the accompanying drawings.

[0051] Those skilled in the art will appreciate that the objectives and advantages that can be achieved with the present invention are not limited to the above specific description, and the above and other objectives that can be achieved by the present invention will be more clearly understood from the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] The drawings described herein are used to provide a further understanding of the present invention, constitute a part of the present application, and do not constitute a limitation of the present invention. In the drawings:

[0053] Figure 1 It is a schematic diagram of the structure of a ground penetrating radar transmitting voltage dynamic adjustment system according to an embodiment of the present invention.

[0054] Figure 2 This is a working principle diagram of a pulse source module in a ground penetrating radar transmitting voltage dynamic adjustment system according to another embodiment of the present invention.

[0055] Figure 3 This is a first type of working principle diagram of the high voltage module in the ground penetrating radar transmitting voltage dynamic regulation system according to another embodiment of the present invention.

[0056] Figure 4 This is a second type of working principle diagram of the high voltage module in the ground penetrating radar transmitting voltage dynamic regulation system according to another embodiment of the present invention.

[0057] Figure 5 This is a circuit connection diagram of using an FPGA chip as the control end of a digital potentiometer and a first type of high voltage module.

[0058] Figure 6This is a circuit connection diagram of using an FPGA chip as the control end of a digital potentiometer and a second type of high voltage module.

[0059] Figure 7 For Figure 5 Circuit diagram with resistors added to constrain the high-voltage output range.

[0060] Figure 8 For Figure 6 Circuit diagram with resistors added to constrain the high-voltage output range.

[0061] Fig. 9 The figure is a working logic diagram of the ground penetrating radar transmitting voltage dynamic adjustment system according to an embodiment of the present invention.

[0062] Reference numerals:

[0063] 100: transmitting antenna subsystem; 110: high voltage module; 120: pulse source module;

[0064] 130: transmitting antenna; 200: receiving antenna subsystem; 210: receiving antenna;

[0065] 220: main control and data acquisition module; 221: digital potentiometer; 222: FPGA chip. DETAILED DESCRIPTION

[0066] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments and the accompanying drawings. Here, the illustrative embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention.

[0067] It should also be noted that, in order to avoid obscuring the present invention due to unnecessary details, only structures and / or processing steps closely related to the solutions according to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0068] It should be emphasized that the term “include / comprises” when used herein refers to the presence of features, elements, steps or components, but does not exclude the presence or addition of one or more other features, elements, steps or components.

[0069] It should also be noted that, unless otherwise specified, the term “connection” herein may refer not only to a direct connection but also to an indirect connection with an intermediate.

[0070] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the accompanying drawings, the same reference numerals represent the same or similar components, or the same or similar steps.

[0071] The present invention provides a ground penetrating radar transmitting voltage dynamic adjustment system, which is intended to adjust the transmitting voltage in real time according to different geological conditions to optimize the detection depth and resolution. The function of dynamically adjusting the transmitting voltage is to be able to adjust the transmitting voltage in real time according to different geological conditions and detection targets to optimize the detection depth and resolution. This adjustment capability enables the ground penetrating radar to adapt to various complex underground environments and improve the accuracy and reliability of detection. Through the dynamic adjustment of the transmitting voltage, the best detection effect can be achieved under different geological conditions. By adjusting the transmitting voltage, the detection depth and detection resolution performance of the radar can be maximized.

[0072] Specifically, the present invention provides a ground penetrating radar transmitting voltage dynamic adjustment system, such as Figure 1 and Fig. 9 As shown, the system includes a transmitting antenna 130 subsystem 100 and a receiving antenna subsystem 200 which are arranged in a split manner.

[0073] The transmitting antenna 130 subsystem 100 includes: a high voltage module 110 , a pulse source module 120 and a transmitting antenna 130 .

[0074] The high-voltage module 110 is used to provide a high-voltage power supply and provide the required driving voltage for the pulse source module 120. Its core function is to convert and stabilize the input power supply through the control circuit so that the output voltage can meet the working requirements of the target device. The high-voltage module 110 may include a reference voltage source and a regulating circuit. The reference voltage source provides a stable maximum voltage value for the output voltage, and the regulating circuit uses an external resistor or a digital control device (such as a digital potentiometer 221) to change the voltage division ratio, thereby adjusting the output voltage. The external control method can be divided into resistor division and programmed control; in the resistor division mode, a fixed or variable resistor (such as R1 and R2) is used to adjust the output voltage through the resistance ratio; in the programmed control mode, the control chip (such as FPGA) is connected through the digital potentiometer 221 to achieve automatic and precise adjustment. The high-voltage module 110 may also include a reference voltage source and a regulating circuit. The regulating circuit uses an external resistor or a digital control device (such as a digital potentiometer 221) and uses a fixed or variable resistor (such as R1 and R2) to output a response voltage according to a multiple of the reference voltage through the resistance ratio.

[0075] The pulse source module 120 outputs a high-voltage pulse signal based on a high-voltage power supply and a trigger pulse. In some embodiments, the pulse source module 120 is composed of a multi-stage avalanche diode, each avalanche diode is connected in series in sequence, and a parallel resistor and capacitor are provided at both ends of each avalanche diode for balancing and limiting overcurrent. The parallel resistor ensures that the voltage shared by each diode is consistent to prevent mismatch caused by manufacturing errors. The parallel capacitor increases the circuit response speed and stores energy to enhance the avalanche effect. Each level of avalanche diode is subjected to a portion of the reverse breakdown voltage. When the total voltage reaches the critical value, all avalanche diodes enter the avalanche breakdown state at the same time, releasing the energy in the energy storage capacitor to form a high-speed, high-amplitude voltage pulse.

[0076] The transmitting antenna 130 is used to convert the high-voltage pulse signal into a first electromagnetic wave and radiate it outward. The transmitting antenna 130 can adopt a dipole antenna, a hyperbolic antenna (Bow-Tie Antenna), a horn antenna and a Vivaldi antenna. The dipole antenna has a simple structure and consists of two conductors. It is suitable for narrowband applications, but its performance for broadband detection is limited; the hyperbolic antenna achieves broadband radiation through a hyperbolic-shaped metal plate, which is particularly suitable for efficient transmission and reception of broadband signals and is often used in ground penetrating radars. The horn antenna focuses and radiates electromagnetic waves through a horn-shaped structure. It has the characteristics of strong directivity and high efficiency, but it is large in size and is suitable for scenarios with high requirements for high resolution. The Vivaldi antenna is a gradient slot-type antenna with a light structure and a wide frequency band, which is suitable for the radiation and reception of high-frequency signals.

[0077] The receiving antenna subsystem 200 includes: a receiving antenna 210 and a main control and data acquisition module 220 .

[0078] The receiving antenna 210 is used to receive the external second electromagnetic wave, which includes a direct wave and a reflected wave returned in the medium. The receiving antenna 210 can be a dipole antenna, a hyperbolic antenna (Bow-Tie Antenna), a horn antenna and a Vivaldi antenna. The direct wave is an electromagnetic wave signal directly emitted by the transmitting antenna 130 and received by the receiving antenna 210 in the ground penetrating radar (GPR) system. It is a wave that propagates directly from the transmitting antenna 130 to the receiving antenna 210 without being reflected or scattered by the underground medium. The direct wave is an important component of radar signal propagation and is usually the first signal received in the system because it has the shortest propagation path. The reflected wave is a signal that is partially reflected due to the difference in dielectric constant or conductivity when the electromagnetic wave emitted by the ground penetrating radar (GPR) system encounters a discontinuous interface of the underground medium (such as a boundary of different materials, an underground target or structure) during propagation, and then returns and is received by the receiving antenna 210. The reflected wave carries the characteristic information of the target or medium boundary, and its intensity and delay time are closely related to the material, electromagnetic properties and depth of the underground interface. By analyzing the time, amplitude and phase changes of these reflected waves, the radar system can identify the location, shape, size and composition of underground objects. The reflected wave is the key signal for ground penetrating radar to detect and image underground targets, but in complex media, it may be affected by noise, multiple reflections and scattering, and needs to be interpreted after noise suppression and filtering.

[0079] The main control and data acquisition module 220 is used to perform noise suppression, gain adjustment, imaging and image optimization processing on the reflected wave. Noise suppression removes environmental noise and useless signals through filtering technology (such as low-pass filtering, high-pass filtering or band-pass filtering), and uses multiple superposition averaging to reduce random noise. Gain adjustment compensates for the signal attenuation caused by the increase in propagation distance through dynamic gain control (DGC), so that the deep reflection wave signal is enhanced, thereby achieving the overall signal amplitude equalization. Imaging converts the processed time domain signal into a spatial distribution map (such as a two-dimensional or three-dimensional profile), and often uses a radar beam focusing algorithm or a reverse time migration algorithm to improve the spatial resolution. Finally, image optimization processing uses deconvolution, interpolation, and pseudo-color enhancement techniques to improve the clarity and interpretability of the image, further highlight the target features and suppress background interference. The comprehensive application of these steps enables ground penetrating radar to generate accurate underground target images and provide high-quality data support for geological, archaeological and engineering detection.

[0080] The main control and data acquisition module 220 detects the state of the direct wave through the analog-to-digital converter to regulate the high-voltage power supply output by the high-voltage module 110; wherein, the main control and data acquisition module 220 controls the digital potentiometer 221 through the FPGA chip 222 to configure a control resistor for the high-voltage module 110 to adjust the high-voltage power supply; the FPGA chip 222 adjusts the digital potentiometer 221 to reduce the level of the high-voltage power supply when the analog-to-digital converter is full and / or the direct wave is saturated, and adjusts the digital potentiometer 221 to increase the level of the high-voltage power supply when the analog-to-digital converter is not full and / or the direct wave is not saturated.

[0081] FPGA chip 222 (Field-Programmable Gate Array) is a high-performance programmable logic device, which consists of a large number of configurable logic units, storage units and programmable interconnection matrices. Its functions can be programmed through hardware description language (HDL) according to application requirements. The core feature of FPGA is that its hardware logic can be reconfigured many times, and it can realize various functions from simple logic operations to complex digital signal processing. Compared with ASIC (application-specific integrated circuit), FPGA has the advantages of high flexibility and short development cycle. Digital potentiometer 221 is an electronic device based on the principle of resistor voltage division. Its working principle is to change the voltage division point of the resistor network through digital control to adjust the output voltage or current. It usually consists of a precisely segmented resistor chain and an electronic switch. Each resistor segment is connected by a switch, and the state of the switch is controlled by a digital signal. When a digital value (usually provided by a microcontroller or FPGA) is input, the switch selects the corresponding resistor segment and adjusts the output resistance or voltage division ratio. The digital potentiometer 221 can simulate the functions of a traditional mechanical potentiometer, but has the advantages of small size, high precision, programmability and durability. It is widely used in application scenarios such as gain adjustment, power supply voltage regulation and filter parameter configuration.

[0082] An analog-to-digital converter (ADC) converts analog signals into digital signals and encodes them according to the strength of its input signal. The range of an ADC refers to the range of input voltages that it can effectively measure. If the input signal strength exceeds the maximum measurement range of the ADC (that is, exceeds its maximum input voltage), it will cause full range, also known as "saturation". At this point, the ADC cannot accurately represent the input signal, resulting in signal distortion or loss of details. If the output digital value of the analog-to-digital converter reaches its maximum value (for example, the maximum value of an 8-bit ADC is 255), the ADC can be considered to have reached full range. This means that the input signal has exceeded the measurement range of the ADC.

[0083] Direct wave saturation refers to the situation where the intensity of the direct wave signal received by the receiving antenna 210 is too high, exceeding the dynamic range of the receiving system, resulting in signal saturation. When the signal is saturated, the receiving system cannot accurately measure the signal with higher intensity, which will affect the reception and analysis of the subsequent reflected wave signal. The intensity of the direct wave can be judged by the amplitude of the received signal. If the amplitude of the received direct wave signal is close to or equal to the maximum receiving capacity of the receiving system (i.e., the saturation level of the receiver), it means that the direct wave signal is saturated. At this point, the receiving system may not be able to accurately distinguish between the direct wave and the reflected wave, resulting in system distortion.

[0084] In some embodiments, the high voltage module 110 adopts a reference voltage dividing adjustment structure, and the fixed reference voltage of the high voltage module 110 is divided by setting an external first resistor and a second resistor through a digital potentiometer 221 to adjust the voltage of the high voltage power supply. The expression is:

[0085]

[0086] Among them, V MAX represents a fixed reference voltage, R1 represents a first resistor, and R2 represents a second resistor.

[0087] In some embodiments, the high-voltage module 110 adopts a feedback voltage division adjustment structure, and sets an external first resistor and a second resistor through a digital potentiometer 221 to form a feedback voltage division network. The voltage of the high-voltage power supply is adjusted according to a multiple of the reference voltage of the high-voltage module 110 based on the resistance voltage division ratio of the feedback voltage division network. The expression is:

[0088]

[0089] Among them, V ref represents a reference voltage, R1 represents a first resistor, and R2 represents a second resistor.

[0090] In some embodiments, the system further includes: a distance adjustment mechanism and a user interaction module.

[0091] The distance adjustment mechanism is used to adjust the distance between the transmitting antenna 130 and the receiving antenna 210. The adjustment of the distance can affect the propagation characteristics of the radar wave and the quality of signal reception. Smaller antenna spacing helps to improve the spatial resolution of the system and is suitable for high-precision detection at close range, but it may cause the direct wave signal to be too strong, which may easily cause signal saturation or interference. Larger antenna spacing is conducive to receiving deeper reflected waves, improving the detection depth and anti-interference ability, but may cause signal attenuation and reduced resolution. Therefore, adjusting the antenna spacing can balance the detection depth and resolution according to different detection requirements, avoid excessive saturation of direct waves, and optimize the signal quality and detection accuracy of the system.

[0092] The user interaction module is used to control the distance adjustment mechanism to adjust the distance between the transmitting antenna 130 and the receiving antenna 210 based on the adjustment instruction input by the user. The user interaction module can use a touch screen module with a display function to perform data collection and interaction by setting a corresponding UI interface.

[0093] In some embodiments, the distance adjustment mechanism includes: a slide rail, a first fixed base, a second fixed base and a drive motor.

[0094] The slide rail can be arranged according to the carrier structure. For example, for a handheld ground penetrating radar, the slide rail can be arranged at the front end of the handheld handle and arranged horizontally. For a self-propelled trolley, it can be arranged at the bottom of the trolley platform.

[0095] The first fixed base is fixedly disposed on the slide rail for fixing the transmitting antenna 130 .

[0096] The second fixed base is slidably disposed on the slide rail for fixing the receiving antenna 210 .

[0097] The driving motor is arranged on the second fixed base, and is used to drive the second fixed base to slide on the slide rail. The transmission mode can be gear or belt transmission.

[0098] In some embodiments, the FPGA chip 222 adjusts the level of the high voltage power supply based on a proportional-integral-differential feedback control algorithm, including:

[0099] Compare the current level value of the direct wave or reflected wave with the target value, and calculate the error e(t), which is calculated as follows:

[0100] e(t)=V 目标 -V 当前 ;

[0101] Among them, V 目标 Indicates the target value, V 当前 Indicates the current level value;

[0102] Then the regulation value u(t) of the high voltage power supply is:

[0103]

[0104] Among them, K p is the proportionality coefficient, K i is the integration coefficient, K d is the differential coefficient.

[0105] In some embodiments, the FPGA chip 222 uses the strategy network pre-trained based on the reinforcement learning model as input, the level of the high-voltage power supply, the level of the direct wave, the dynamic range of the reflected wave, and the ratio of the dynamic range to the analog-to-digital converter range, and outputs the level adjustment amount for the high-voltage power supply.

[0106] In some embodiments, the pre-training step of the policy network includes steps S101 to S103:

[0107] Step S101: constructing a state space, where the state space includes the level of the high voltage power supply, the level of the direct wave, the dynamic range of the reflected wave, and the ratio of the dynamic range to the range of the analog-to-digital converter.

[0108] Step S102: constructing an action space, where the action space is the level adjustment amount for the high voltage power supply.

[0109] Step S103: Based on the policy network in reinforcement learning, the level adjustment amount of the output high-voltage power supply is output with the parameters of the state space as input, and the reward function is constructed by weighted summing the direct wave unsaturation reward, the dynamic range utilization reward and the adjustment amplitude penalty. In multiple iterations, the parameters of the policy network are updated by minimizing the reward function until the reward function converges.

[0110] Among them, the calculation formula of the reward function R is:

[0111] R=ω1R 直达波 +ω2R 动态范围 +ω3R 调整幅度 ;

[0112] Among them, R 直达波 represents the direct wave unsaturated reward, R 动态范围 represents the dynamic range utilization reward, R 调整幅度 represents the adjustment amplitude penalty;

[0113]

[0114] R 动态范围 = -|K-0.95|;

[0115]

[0116] Among them, K represents the ratio of the dynamic range of the reflected wave to the range of the analog-to-digital converter, and ΔV represents the level adjustment amount of the high-voltage power supply.

[0117] In some embodiments, the policy network is composed of a convolutional neural network and a fully connected network.

[0118] The present invention is described below in conjunction with a specific embodiment:

[0119] This embodiment provides a transmission voltage dynamic adjustment system for ground penetrating radar, which is intended to adjust the transmission voltage in real time according to different geological conditions to optimize the detection depth and resolution. The system is a split ground penetrating radar system, which includes a transmitting antenna system and a receiving antenna system. The transmitting antenna system includes a transmitting antenna, a pulse source, and a high-voltage module, and the receiving antenna system includes a receiving antenna, a main control and data acquisition module. The transmission voltage adjustment module is integrated in the main control circuit, and dynamically adjusts the transmission voltage according to the input of the geological parameter detection unit.

[0120] Ground penetrating radar uses an antenna to send an instantaneous high-voltage pulse signal to the detection surface, and uses a receiving antenna to receive the echo of the target object, thereby determining the physical information of the target object. Therefore, the transmission power of the pulse source has a huge impact on the performance of the ground penetrating radar. The pulse source is composed of a multi-stage avalanche diode, which inputs a trigger pulse and a high-voltage power supply and outputs a high-voltage pulse signal. The working principle is as follows Figure 2 shown.

[0121] From the working principle of the pulse source, it can be seen that the transmission power of the pulse source is determined by the high-voltage power supply level. Therefore, the control of the pulse source transmission power of the ground penetrating radar is achieved by adjusting the voltage value of the high-voltage power supply.

[0122] High-voltage modules with output voltage regulation function can adjust the output power supply through peripheral resistor configuration, usually in the following two modes.

[0123] The first one is Figure 3 As shown, the high voltage module itself outputs a reference voltage, and the output voltage is adjusted by adjusting the resistance values ​​of R1 and R2, and the adjustment range is between 0 and Vmax.

[0124]

[0125] Among them, V MAX represents a fixed reference voltage, R1 represents a first resistor, and R2 represents a second resistor.

[0126] The second type Figure 4 As shown, the high voltage module generates a reference voltage internally and adjusts the output power value through the proportional relationship of external resistors.

[0127]

[0128] Among them, V ref represents a reference voltage, R1 represents a first resistor, and R2 represents a second resistor.

[0129] The digital potentiometer is used to realize the design of the transmitting voltage adjustment circuit. The digital potentiometer can be used to adjust the resistance value under program control. The FPGA chip is used as the control end of the digital potentiometer to control the resistance value of the potentiometer. In this way, the output voltage of the high-voltage module is controlled, thereby controlling the transmitting power of the pulse source. The connection structure diagram is shown in the figure. Figure 5 and 6 shown.

[0130] The resistance value of the digital potentiometer is not continuously adjustable, but there are 32-position, 64-position, and 128-position options; pay attention to the resistance value of the digital potentiometer when selecting.

[0131] In practical applications, resistors can be configured in the circuit to achieve the purpose of restricting the high voltage output range. Figure 7 shown.

[0132] The function of resistor R2 is to limit the lower limit of the high-voltage module output, and the function of resistor R1 is to limit the upper limit of the high-voltage module output. By reasonably selecting the resistance values ​​of R1, R2 and the digital potentiometer, the output range of the high-voltage module can be limited, effectively controlling the safety of the circuit operation.

[0133] like Figure 8 As shown, the function of resistor R1 is to limit the lower limit of the high-voltage module output. By reasonably selecting the resistance values ​​of resistors R1 and R2 and the digital potentiometer, the output range of the high-voltage module can be limited, and the safety of the circuit operation can be effectively controlled.

[0134] The host computer software is used to autonomously control the transmitting voltage and realize adaptive adjustment of the transmitting voltage. The software collects ground penetrating radar echo data, analyzes the direct wave amplitude in the ground penetrating radar data, and automatically adjusts the transmitting voltage to optimize the detection effect. When the analog-to-digital converter is full and / or the direct wave is saturated, the digital potentiometer is adjusted to reduce the level of the high-voltage power supply. When the analog-to-digital converter is not full and / or the direct wave is not saturated, the digital potentiometer is adjusted to increase the level of the high-voltage power supply. Through real-time feedback and voltage adjustment, the system can quickly respond to changes in underground conditions and provide more accurate detection results. Adaptive adjustment algorithms such as Fig. 9 As shown, until the direct wave amplitude reaches the full-order quantization state.

[0135] Therefore, the voltage is adjusted in this embodiment to improve the detection depth and resolution. By dynamically adjusting the emission voltage, the ground penetrating radar can better adapt to different geological conditions. The increase in emission voltage can provide greater penetration, thereby increasing the detection depth, which is particularly important for the detection of deep geological structures. At the same time, the fine adjustment of the emission voltage also helps to improve the signal-to-noise ratio of the signal, thereby improving the detection resolution. This resolution improvement is crucial for identifying shallow details and complex structures, especially in applications in the fields of archaeology, geology, and environmental science. The adaptability of the system can be enhanced, and the dynamic adjustment of the emission voltage enables the ground penetrating radar system to adapt to various complex underground environments. In strata with high water content, the attenuation of electromagnetic waves is faster. By increasing the emission voltage, this attenuation can be compensated, and the signal strength can be maintained, thereby improving the accuracy and reliability of detection. The operation is simple, the user interface is friendly, and the intuitive operation design allows the operator to easily adjust the emission voltage according to the detection requirements. Dynamically adjusting the emission voltage can provide a wider range of data, which is very helpful for subsequent data processing and interpretation. By adjusting different emission voltages, data of different depths and resolutions can be obtained, which is crucial for the optimization of data processing algorithms and the improvement of imaging quality. It can improve work efficiency. By dynamically adjusting the transmission voltage, the ground penetrating radar system can quickly respond to different detection tasks without changing hardware or making complex settings. This rapid response capability greatly improves work efficiency, especially in situations where quick decision-making is required, such as search and rescue operations and engineering quality inspection.

[0136] In summary, the ground penetrating radar transmitting voltage dynamic adjustment system described in the present invention adopts a split transmitting antenna subsystem and a receiving antenna subsystem. The receiving antenna subsystem adjusts the digital potentiometer to reduce the level of the high-voltage power supply through the FPGA chip according to the state of the received signal when the analog-to-digital converter is full and / or the direct wave is saturated, and adjusts the digital potentiometer to increase the level of the high-voltage power supply when the analog-to-digital converter is not full and / or the direct wave is not saturated. This enables the ground penetrating radar to better adapt to different geological conditions, helps to improve the signal-to-noise ratio of the signal, and then improves the detection resolution, and can quickly respond to different detection tasks without replacing hardware or performing complex settings.

[0137] It should be understood by those skilled in the art that the exemplary components, systems and methods described in conjunction with the embodiments disclosed herein can be implemented in hardware, software or a combination of the two. Whether it is performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention. When implemented in hardware, it can be, for example, an electronic circuit, an application specific integrated circuit (ASIC), appropriate firmware, a plug-in, a function card, etc. When implemented in software, the elements of the present invention are programs or code segments used to perform the required tasks. The program or code segment can be stored in a machine-readable medium, or transmitted on a transmission medium or a communication link via a data signal carried in a carrier.

[0138] It should be clear that the present invention is not limited to the specific configuration and processing described above and shown in the figures. For the sake of simplicity, a detailed description of the known method is omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present invention is not limited to the specific steps described and shown, and those skilled in the art can make various changes, modifications and additions, or change the order between the steps after understanding the spirit of the present invention.

[0139] In the present invention, features described and / or illustrated for one embodiment may be used in the same or similar manner in one or more other embodiments, and / or combined with features of other embodiments or replace features of other embodiments.

[0140] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the embodiments of the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A ground penetrating radar transmitting voltage dynamic adjustment system, characterized in that: The system includes a transmitting antenna subsystem and a receiving antenna subsystem which are arranged in a split manner; The transmitting antenna subsystem comprises: A high voltage module, used for providing high voltage power supply; A pulse source module, which outputs a high-voltage pulse signal based on the high-voltage power supply and the trigger pulse; A transmitting antenna, used for converting the high-voltage pulse signal into a first electromagnetic wave and radiating it outwards; The receiving antenna subsystem comprises: A receiving antenna, used for receiving an external second electromagnetic wave, wherein the second electromagnetic wave includes a direct wave and a reflected wave returned in the medium; The main control and data acquisition module is used to perform noise suppression, gain adjustment, imaging and image optimization processing on the reflected wave; and to detect the state of the direct wave through an analog-to-digital converter to regulate the high-voltage power supply output by the high-voltage module; wherein the main control and data acquisition module controls the digital potentiometer through an FPGA chip to configure a control resistor for the high-voltage module to adjust the high-voltage power supply; the FPGA chip adjusts the digital potentiometer to reduce the level of the high-voltage power supply when the analog-to-digital converter is full and / or the direct wave is saturated, and adjusts the digital potentiometer to increase the level of the high-voltage power supply when the analog-to-digital converter is not full and / or the direct wave is not saturated.

2. The ground penetrating radar transmitting voltage dynamic adjustment system according to claim 1, characterized in that: The pulse source module is composed of multiple stages of avalanche diodes, each of which is connected in series in sequence. A parallel resistor and a capacitor are arranged at both ends of each avalanche diode for balancing and limiting overcurrent.

3. The ground penetrating radar transmitting voltage dynamic adjustment system according to claim 1, characterized in that: The high-voltage module adopts a reference voltage division adjustment structure, and the fixed reference voltage of the high-voltage module is divided by setting an external first resistor and a second resistor through the digital potentiometer to adjust the voltage of the high-voltage power supply. The expression is: Among them, V MAX represents the fixed reference voltage, R1 represents the first resistor, and R2 represents the second resistor.

4. The ground penetrating radar transmitting voltage dynamic adjustment system according to claim 1, characterized in that: The high-voltage module adopts a feedback voltage-dividing adjustment structure. The first resistor and the second resistor are set externally by the digital potentiometer to form a feedback voltage-dividing network. The voltage of the high-voltage power supply is adjusted according to the multiple of the reference voltage of the high-voltage module based on the resistance voltage-dividing ratio of the feedback voltage-dividing network. The expression is: Among them, V ref represents the reference voltage, R1 represents the first resistor, and R2 represents the second resistor.

5. The ground penetrating radar transmitting voltage dynamic adjustment system according to claim 1, characterized in that: The system further comprises: A distance adjustment mechanism, used to adjust the distance between the transmitting antenna and the receiving antenna; The user interaction module is used to control the distance adjustment mechanism to adjust the distance between the transmitting antenna and the receiving antenna based on the adjustment instruction input by the user.

6. The ground penetrating radar transmitting voltage dynamic adjustment system according to claim 5, characterized in that: The distance adjustment mechanism comprises: Slide rails; A first fixed base, fixedly disposed on the slide rail, and used for fixing the transmitting antenna; A second fixed base, slidably disposed on the slide rail, for fixing the receiving antenna; The driving motor is disposed on the second fixed base and is used to drive the second fixed base to slide on the slide rail.

7. The ground penetrating radar transmitting voltage dynamic adjustment system according to claim 1, characterized in that: The FPGA chip adjusts the level of the high voltage power supply based on a proportional integral differential feedback control algorithm, including: Compare the current level value of the direct wave or reflected wave with the target value, and calculate the error e(t), which is calculated as follows: e(t)=V 目标 -V 当前 ; Among them, V 目标 represents the target value, V 当前 Indicates the current level value; Then the regulation amount u(t) of the high voltage power supply is: Among them, K p is the proportionality coefficient, K i is the integration coefficient, K d is the differential coefficient.

8. The ground penetrating radar transmitting voltage dynamic adjustment system according to claim 1, characterized in that: The FPGA chip uses a strategy network pre-trained based on a reinforcement learning model, which takes the level of the high-voltage power supply, the level of the direct wave, the dynamic range of the reflected wave, and the ratio of the dynamic range to the range of the analog-to-digital converter as input, and outputs an adjustment amount for the level of the high-voltage power supply.

9. The ground penetrating radar transmitting voltage dynamic adjustment system according to claim 8, characterized in that: The pre-training steps of the policy network include: Constructing a state space, the state space including the level of the high voltage power supply, the level of the direct wave, the dynamic range of the reflected wave, and the ratio of the dynamic range to the range of the analog-to-digital converter; Constructing an action space, wherein the action space is an amount of level adjustment for the high voltage power supply; Based on the policy network in reinforcement learning, the level adjustment amount of the high-voltage power supply is outputted with the parameters of the state space as input, and a reward function is constructed by weighted summing the direct wave unsaturation reward, the dynamic range utilization reward and the adjustment amplitude penalty. In multiple iterations, the parameters of the policy network are updated by minimizing the reward function until the reward function converges; Among them, the calculation formula of the reward function R is: R=ω1R 直达波 +ω2R 动态范围 +ω3R 调整幅度 ; Among them, R 直达波 represents the unsaturated reward of the direct wave, R 动态范围 represents the dynamic range utilization reward, R 调整幅度 represents the adjustment amplitude penalty; R 动态范围 =-|K-0.95|; Wherein, K represents the ratio of the dynamic range of the reflected wave to the range of the analog-to-digital converter, and ΔV represents the level adjustment amount of the high voltage power supply.

10. The ground penetrating radar transmitting voltage dynamic adjustment system according to claim 9, characterized in that: The policy network is composed of a convolutional neural network and a fully connected network.

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