Time domain multi-component electromagnetic pulse transmitter and control method thereof

Abstract

The present invention provides a time domain multi-component electromagnetic pulse transmitter and a control method thereof. The transmitter comprises: a power module, a MOSFET full-bridge inverter circuit, a digital logic controller, which generates a PWM timing logic control signal and acts on the MOSFET full-bridge inverter circuit to make it output a current pulse; a multi-component output control circuit, which is used to select different component outputs under the action of the multi-component output control signal input by the digital logic controller; a current detection circuit, which is used to detect the output current in real time and feed back the current detection result to the digital logic controller; a multi-level adjustable clamping voltage circuit, which adjusts the passive clamping voltage to clamp the falling edge of the pulse under the control of the clamping voltage control signal obtained according to the current detection result to achieve dynamic multi-level regulation; and a multi-level adaptive damping intervention circuit, which realizes the selection of multi-level damping dynamic intervention time and intervention resistance under the control of the adaptive damping control signal obtained according to the current detection result.

Description

Technical Field

[0001] The present disclosure relates to the technical field of electromagnetic transmitters, and in particular to a time domain multi-component electromagnetic pulse transmitter and a control method thereof. Background Art

[0002] Electromagnetic detection is currently a widely used underground target detection method, which has important guiding significance for urban engineering, mineral resource production, etc. Due to the characteristics of the principle itself, time domain electromagnetic detection can use a shorter instrument to complete long-distance detection that can only be completed by long-size frequency domain detection equipment. Time domain electromagnetic detection mainly consists of three parts: transmitting system, receiving system and acquisition system. The principle is that when a constant current is passed through the transmitting coil, a stable primary field is established around it. At a certain moment, the current in the transmitting coil is turned off, and the primary field around it disappears. At this time, the induced eddy current generated in the underground conductor target will excite the induced electromagnetic field (usually called the secondary field) that changes with time and is received by the receiving system. The induced eddy current size and attenuation rate of abnormal targets with different physical characteristics are different, so the secondary field generated by them reflects the physical characteristic information of the target itself. At present, time domain electromagnetic method has become an important non-contact resource exploration method. This method is considered to be one of the important development directions for future urban engineering and mine resource exploration due to its higher detection efficiency and strong adaptability to the site in some scenarios compared with frequency domain methods, as well as the advantages of instrument manufacturing and service cost control.

[0003] The electromagnetic launch system is the core part of the time domain electromagnetic detection system, which largely determines the detection performance of the system. Underground target detection is different from other geophysical detection. The available space is often extremely narrow, while it is expected to achieve high-power three-dimensional space long-range detection. This requires its launch system to achieve large current pulse emission based on a small device size.

[0004] However, current electromagnetic transmitters find it difficult to achieve high-power transient electromagnetic signal excitation, fast linear shutdown of the falling edge of pulses under complex load conditions, and multi-component transmission load output in a narrow space.

[0005] Public Content

[0006] 1. Technical issues to be resolved

[0007] Based on the above problems, the present disclosure provides a time domain multi-component electromagnetic pulse transmitter and a control method thereof, so as to improve the problem in the prior art that under the condition of limited duty cycle of the pulse waveform of the electromagnetic transmitting system, the falling edge of the transmitting current which directly affects the detection effect cannot achieve multi-level adaptive adjustment of the falling slope / speed to meet rich detection requirements under the premise of good linearity; at the same time, the problem in the prior art that the adaptive damping intervention cannot ensure good suppression effect at the end of the falling edge under the premise of reducing overall power consumption is improved.

[0008] (II) Technical solution

[0009] In one aspect of the present disclosure, a time domain multi-component electromagnetic pulse transmitter is provided, comprising: a power module, a MOSFET full-bridge inverter circuit, a digital logic controller, a multi-component output control circuit, a current detection circuit, a multi-level adjustable clamping voltage circuit, and a multi-level adaptive damping intervention circuit. Among them:

[0010] The power module serves as the overall working power supply of the transmitter;

[0011] An input end of the MOSFET full-bridge inverter circuit is connected to the power module;

[0012] A digital logic controller, connected to the MOSFET full-bridge inverter circuit, for generating a PWM timing logic control signal and acting on the MOSFET full-bridge inverter circuit to make the MOSFET full-bridge inverter circuit output a current pulse;

[0013] The multi-component output control circuit is connected to the MOSFET full-bridge inverter circuit and the digital logic controller respectively, and is used to select different component outputs under the action of the multi-component output control signal input by the digital logic controller;

[0014] The current detection circuit is connected to the multi-component output control circuit, and is used to detect the real-time output current of the multi-component output control circuit, and feed back the current detection result to the digital logic controller;

[0015] A multi-stage adjustable clamping voltage circuit is connected between the MOSFET full-bridge inverter circuit and the digital logic controller, and under the control of the clamping voltage control signal obtained by the digital logic controller according to the current detection result, the passive clamping voltage is adjusted to clamp the falling edge of the pulse to achieve dynamic multi-stage regulation; and

[0016] The multi-level adaptive damping intervention circuit is connected between the MOSFET full-bridge inverter circuit and the multi-component output control circuit, and the selection of the multi-level damping dynamic intervention time and the intervention resistance value is realized under the control of the adaptive damping control signal obtained by the digital logic controller according to the current detection result.

[0017] According to an embodiment of the present disclosure, a multi-stage adjustable clamping voltage circuit includes: a plurality of voltage-stabilizing diodes arranged in series; and a plurality of on-off power switches connected across each of the voltage-stabilizing diodes; the voltage-stabilizing diodes are respectively controlled in real time by controlling the on-off power switches to achieve multi-stage selection of the clamping voltage, so that the falling edge of the current pulse drops rapidly and linearly at a desired slope.

[0018] According to the embodiment of the present disclosure, the current detection circuit detects the real-time output current value of the multi-component output control circuit through a Hall current sensor, and after feeding back the measured value to the digital logic controller, the currently required clamping voltage level is determined by calculating through a preset adaptive clamping voltage algorithm, and then a clamping voltage control signal is sent to the multi-stage adjustable constant voltage clamping circuit to realize multi-stage clamping voltage control of the MOSFET inverter circuit.

[0019] According to the embodiment of the present disclosure, the multi-stage adjustable clamping voltage circuit realizes constant voltage clamping of the device at the falling edge of the current through the reverse voltage regulation characteristic of the Zener diode.

[0020] According to an embodiment of the present disclosure, the multi-stage adaptive damping intervention circuit includes: two MOSFETs, which are arranged in reverse series; a plurality of intervention dampings, which are arranged in series and connected in series with the two MOSFETs; and a plurality of control switches, which are connected to both ends of each of the intervention dampings; the intervention state of each of the intervention dampings is controlled by controlling the on-off of the control switch, thereby realizing multi-stage selection of the damping intervention value.

[0021] According to the embodiment of the present disclosure, the currently required intervention time and damping gear are determined in real time according to the adaptive damping intervention algorithm, and the damping intervention time and intervention resistance value are optimized and adjusted.

[0022] According to an embodiment of the present disclosure, a digital logic controller includes: an FPGA controller, which is used to generate control signals including: a PWM timing logic control signal, which acts on the MOSFET full-bridge inverter circuit to make the MOSFET full-bridge inverter circuit output a current pulse; a clamping voltage control signal, which is used to adjust the passive clamping voltage to clamp the falling edge of the pulse to achieve dynamic multi-stage regulation; an adaptive damping control signal, which acts on the multi-stage adaptive damping intervention circuit to control the damping intervention time and intervention value; and a multi-component output control signal, which acts on the MOSFET full-bridge inverter circuit to make the MOSFET full-bridge inverter circuit output a current pulse.

[0023] According to an embodiment of the present disclosure, the digital logic controller also includes: a MOSFET drive circuit, which is used to convert the PWM timing logic control signal into a MOSFET power switch control function with a strong driving capability, and realize electrical isolation between the FPGA controller and the power switch in the MOSFET inverter circuit; and a multi-component output drive circuit, which is used to convert the multi-component output control signal into a multi-component output terminal switch control function with a strong driving capability, and realize electrical isolation between the FPGA controller and the multi-component output terminal switch.

[0024] Another aspect of the present disclosure provides a control method for a time domain multi-component electromagnetic pulse transmitter, which is used to control the operation of the time domain multi-component electromagnetic pulse transmitter described above. The control method includes: keeping the clamping voltage the same as the power supply voltage Us in a first time period to ensure normal output of the transmitting current pulse; detecting the real-time output current pulse, and accordingly clamping and shaping the pulse falling edge by controlling and adjusting the passive clamping voltage in a second time period to achieve a fast and linear decline of the pulse falling edge; and adaptively adjusting the damping intervention time and intervention value according to the real-time current shutdown waveform using an adaptive damping intervention algorithm to obtain the optimal damping intervention time and intervention value.

[0025] (III) Beneficial effects

[0026] It can be seen from the above technical solutions that the time domain multi-component electromagnetic pulse transmitter and control method thereof disclosed in the present invention have at least one or part of the following beneficial effects:

[0027] (1) Realize the overall rapid linear decline of the falling edge of the current pulse, avoiding the initial spike and the final jitter;

[0028] (2) Precise adaptive control of the current pulse falling slope, achieving multi-level adaptive adjustment of the falling slope to meet various detection requirements;

[0029] (4) Adaptive control of the damping intervention time is achieved, which avoids system power loss and overheating caused by too long an intervention time and waveform fluctuations caused by too late an intervention time;

[0030] (5) Adaptive control of the damping intervention value is realized to achieve a linear and rapid decrease in the final stage of the current decrease, thus avoiding overshoot and agitation at the final stage of the decrease;

[0031] (6) Realize multi-component dynamic control of the transmitting current to meet the detection requirements of the multi-component transmitting end. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 Schematic diagram of the composition architecture of the time domain multi-component electromagnetic pulse transmitter according to an embodiment of the present disclosure.

[0033] Figure 2 The figure is a schematic diagram of the circuit principle of the time domain multi-component electromagnetic pulse transmitter according to an embodiment of the present disclosure.

[0034] Figure 3 It is a schematic diagram of the adaptive passive multi-stage adjustable clamping action in the time domain multi-component electromagnetic pulse transmitter of the embodiment of the present disclosure.

[0035] Figure 4 Schematic diagram of adaptive damping intervention in the time domain multi-component electromagnetic pulse transmitter according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0036] The present invention provides a time domain multi-component electromagnetic pulse transmitter and a control method thereof. Aiming at the demand of transmitting current pulses in time domain electromagnetic detection, a novel adaptive passive multi-stage adjustable clamping technology is proposed to realize multi-stage adaptive adjustment of the slope of the falling edge of the transmitting current under the premise of good linearity of the falling edge of the transmitting current. Compared with the passive single clamping voltage design commonly used in the current traditional small-sized transmitter, its adjustable multi-stage falling edge slope / speed can meet the transmission requirements under more abundant electromagnetic detection needs; in addition, it can realize adaptive damping intervention of precise time and multi-stage resistance value under the premise of reducing overall power consumption, which solves the problem that the precise time and resistance value intervention during the rapid decline period of the current pulse cannot be realized in the current small-sized transmitter that currently selects constant damping intervention because the intervention value and intervention time are fixed; in addition, the present invention can realize multi-component dynamic control of the transmitting output to meet the detection needs of the underground multi-component transmitting end.

[0037] In the process of realizing the present disclosure, the inventor found that the current falling edge shaping method currently commonly used in small-sized transmitters is a passive constant voltage clamping technology, which clamps and shapes the falling edge of the emission current pulse through a single constant clamping voltage brought by a fixed clamping device, thereby improving the attenuation rate of the emission current. However, this clamping method has major shortcomings in actual use: first, this method can only achieve an approximate linear decline in the emission current, and there will still be a relatively slow exponential decline at the end of the decline; second, since the parameters of the clamping device are single and fixed, the clamping voltage is a fixed value, so the falling slope / speed of the emission current falling edge cannot be changed, and when working with different detection targets, it is impossible to achieve multi-stage electromagnetic transmission with adjustable falling slope / speed to meet more complex detection requirements. At present, many small-sized transmitters choose the damping intervention method to achieve overshoot suppression at the end of the rapid current shutdown, but because its intervention time and intervention value are fixed, it is impossible to achieve accurate intervention of the rapid decline period and intervention value of the current pulse, which brings excessive power consumption to the overall system. If an adjustable intervention damping design is adopted, the problem of the time point of the intervention current shutoff cannot be accurately controlled. If the damping intervention time is too early, it will cause problems such as excessive damping power consumption. If the intervention time is too late, it will easily cause the suppression effect to deteriorate, thereby deteriorating the linearity of the electromagnetic pulse emission waveform at the end of the falling edge, which brings many adverse effects to electromagnetic detection.

[0038] In the process of realizing the present disclosure, it is necessary to: (1) design a multi-level adjustable voltage clamp under different emission current falling slope requirements; (2) design a multi-level adjustable damping intervention circuit; (3) accurately control the driving fast-off MOSFET to achieve bridge output; (4) control the output end to achieve multi-component output; (5) accurately detect and feedback the real-time waveform of the emission current; (6) adjust the clamp voltage through adaptive control of the feedback current waveform; (7) accurately control the damping intervention time and intervention value through the feedback current waveform. In view of the above problems, the purpose of the present disclosure is to design adaptive multi-level passive clamp voltage, adaptive damping intervention and multi-component output dynamic control.

[0039] In order to make the objectives, technical solutions and advantages of the present disclosure more clear, the following is a further detailed description in combination with specific embodiments and reference figures.

[0040] The embodiment of the present disclosure provides a time domain multi-component electromagnetic pulse transmitter, which can shape the falling edge of the transmitting current under the premise of optimizing the system power, and combine Figure 1 and Figure 2 As shown, the time domain multi-component electromagnetic pulse transmitter comprises:

[0041] The power module serves as the overall working power supply of the transmitter;

[0042] A MOSFET full-bridge inverter circuit, one input end of which is connected to the power module;

[0043] A digital logic controller, connected to the MOSFET full-bridge inverter circuit, for generating a PWM timing logic control signal and acting on the MOSFET full-bridge inverter circuit to make the MOSFET full-bridge inverter circuit output a current pulse (bipolar DC pulse);

[0044] A multi-component output control circuit, which is connected to the MOSFET full-bridge inverter circuit and the digital logic controller respectively, and is used to select different component outputs under the action of the multi-component output control signal input by the digital logic controller;

[0045] A current detection circuit, connected to the multi-component output control circuit, for detecting the real-time output current of the multi-component output control circuit and feeding back the current detection result to the digital logic controller;

[0046] A multi-stage adjustable clamping voltage circuit is connected between the MOSFET full-bridge inverter circuit and the digital logic controller, and under the control of the clamping voltage control signal obtained by the digital logic controller according to the current detection result, the passive clamping voltage is adjusted to clamp the falling edge of the pulse to achieve dynamic multi-stage regulation; and

[0047] The multi-level adaptive damping intervention circuit is connected between the MOSFET full-bridge inverter circuit and the multi-component output control circuit, and realizes the selection of the multi-level damping dynamic intervention time and the intervention resistance value under the control of the adaptive damping control signal obtained by the digital logic controller according to the current detection result.

[0048] In the embodiments of the present disclosure, Figure 2 As shown, the multi-level adjustable clamping voltage circuit includes:

[0049] A plurality of Zener diodes are arranged in series; and

[0050] A plurality of on-off power switches connected to both ends of each of the voltage stabilizing diodes;

[0051] By controlling the on and off power switches, the voltage zener diodes are respectively controlled in real time to achieve multi-level selection of clamping voltage, so that the falling edge of the current pulse drops rapidly and linearly at a desired slope.

[0052] The multi-stage adjustable clamping voltage circuit realizes the constant voltage clamping of the device at the falling edge of the current through the reverse voltage regulation characteristic of the Zener diode.

[0053] In the disclosed embodiment, the current detection circuit detects the real-time output current value of the multi-component output control circuit through a Hall current sensor, feeds back the measured value to the digital logic controller, and then determines the currently required clamping voltage level through a preset adaptive clamping voltage algorithm, and then sends a clamping voltage control signal to the multi-stage adjustable constant voltage clamping circuit to realize multi-stage clamping voltage control of the MOSFET inverter circuit.

[0054] In the embodiments of the present disclosure, Figure 2 As shown, the multi-stage adaptive damping intervention circuit includes:

[0055] Two MOSFETs, set in reverse series;

[0056] A plurality of intervening dampers are arranged in series and connected in series with the two MOSFETs; and

[0057] A plurality of control switches connected to both ends of each of the intervention dampers;

[0058] The intervention state of each intervention damping is controlled by turning on and off the control switch, thereby realizing multi-level selection of the damping intervention value. The moment and damping gear required for the intervention are determined in real time according to the adaptive damping intervention algorithm, and the damping intervention moment and intervention resistance value are optimized and adjusted.

[0059] In the embodiment of the present disclosure, after the emission current pulse is excited, the real-time emission current value measured by the Hall current sensor is fed back to the controller in real time, and the control signal is transmitted to the corresponding drive circuit after the clamping voltage value and the appropriate damping intervention value and intervention time required for the current measurement are determined by the adaptive algorithm. Figure 2 As shown, switch S D1 -S Dn For low-delay on-off power switch, D Z1 -D Zn There are n voltage regulator diodes, which are controlled by the switch S D1 -S Dn D Z1 -D Zn Real-time control can realize multi-level selection of clamping voltage, so that the falling edge of current pulse can drop quickly and linearly with the expected slope; Q5 and Q6 are a pair of reverse MOSFETs, and their on and off can control the intervention time of damping in real time. Switch S R1 -S Rn It is a low-delay on-off control switch, R1-R n For n intervention damping, by controlling the switch S R1 -S Rn On / off control R1-R nThe intervention state can realize the multi-level selection of the damping intervention value, and realize the linear decline in the late falling edge and the elimination of oscillation in the late stage under the premise of reducing power consumption.

[0060] In the embodiments of the present disclosure, Figure 2 As shown, the digital logic controller comprises:

[0061] FPGA controller, used to generate control signals including:

[0062] A PWM timing logic control signal acts on the MOSFET full-bridge inverter circuit to make the MOSFET full-bridge inverter circuit output a current pulse (bipolar DC pulse);

[0063] Clamp voltage control signal, used to adjust the passive clamp voltage to clamp the pulse falling edge to achieve dynamic multi-level regulation

[0064] an adaptive damping control signal, acting on the multi-stage adaptive damping intervention circuit to control the damping intervention time and intervention value; and

[0065] The multi-component output control signal acts on the MOSFET full-bridge inverter circuit to make the MOSFET full-bridge inverter circuit output current pulses (bipolar DC pulses).

[0066] FPGA controller, used to generate various digital logic signals such as PWM timing logic control signal for controlling the emission current waveform, adaptive clamping voltage, adaptive intervention damping, and multi-component output control;

[0067] The digital logic controller further comprises:

[0068] MOSFET drive circuit, used to convert PWM timing logic control signal into MOSFET power switch control function with strong driving capability, and realize electrical isolation between FPGA controller and power switch in MOSFET inverter circuit; and

[0069] The multi-component output drive circuit is used to convert the multi-component output control signal into a multi-component output terminal switch control function with strong driving capability, and realize electrical isolation between the FPGA controller and the multi-component output terminal switch.

[0070] In general, the MOSFET drive circuit converts the control signal generated by the FPGA controller into a MOSFET power switch control function with strong driving capability, and realizes the electrical isolation between the FPGA controller and the power switch in the MOSFET inverter circuit. The multi-component output drive circuit is used to convert the control signal generated by the FPGA controller into a multi-component output terminal switch control function with strong driving capability, and realizes the electrical isolation between the FPGA controller and the multi-component output terminal switch. Figure 2 As shown, switch S L1 -S Ln There are n relay switches, L1-L n For n transmitting coils of different components, through the control relay S L1 -S Ln Dynamic switching realizes dynamically controllable output of n components to meet the detection requirements of underground multi-component transmitters.

[0071] The present disclosure also provides a control method for a time domain multi-component electromagnetic pulse transmitter, which is used to control the operation of the time domain multi-component electromagnetic pulse transmitter described above. The control method includes:

[0072] In the first time period, the clamping voltage is kept the same as the power supply voltage Us to ensure the normal output of the emission current pulse;

[0073] Detecting the real-time output current pulse, and accordingly clamping and shaping the pulse falling edge by controlling and adjusting the passive clamping voltage in the second time period, so as to achieve a fast and linear fall of the pulse falling edge; and

[0074] According to the real-time current shutdown waveform, the adaptive damping intervention algorithm is used to adaptively adjust the damping intervention time and intervention value to obtain the optimal damping intervention time and intervention value.

[0075] In the embodiments of the present disclosure, Figure 3 As shown, in the first time period (t1-t3 time period), the clamping voltage is kept the same as Us to ensure the normal output of the emission current pulse; in the second time period (t3-t4 time period), the passive clamping voltage is controlled to clamp the pulse falling edge to achieve a fast and linear decline of the pulse falling edge, and the turn-off time / turn-off rate can be flexibly adjusted according to actual needs, that is, by adjusting the switch S D1 -S Dn The clamping diode access position is controlled in real time to achieve multi-level selection of clamping voltage values ​​proportional to the falling slope of the current pulse to meet the emission requirements under more diverse electromagnetic detection needs.

[0076] In the embodiments of the present disclosure, Figure 4As shown in the figure, if the damping intervention time is too late (such as point C), overshoot oscillation will occur at the tail of the current. If the damping intervention time is too early (such as point A), the damping loss will be too large and the shutdown time will be longer. If the intervention damping value is too large, too much power will be consumed. If the intervention value is too small, it will affect the linear optimization effect of the waveform. The falling edge of the current pulse during the shutdown period can actually be divided into two time periods, namely the linear decay section (abbreviated as t1) and the exponential decay section (abbreviated as t2). The mathematical expression is:

[0077]

[0078] Among them, t is the time parameter, t e is the time when the damping circuit intervenes, U C is the clamping voltage, L S is the load equivalent inductance, I0 is the emission current at the initial moment, I e is the emission current when the damping circuit intervenes, R d is the damping resistance value.

[0079] When the constant voltage clamping circuit stops working, the damping circuit intervenes to emit current:

[0080]

[0081] By combining the coil load parameters and clamping voltage parameters with equations 1 and 2, an optimization algorithm for adaptive damping intervention time is established to obtain the damping intervention time and intervention value suitable for different loads and application requirements. According to the current shutdown waveform, this adaptive damping intervention optimization calculation method is used to adaptively adjust the damping intervention time and intervention value to obtain the optimal damping intervention time (such as point B) and intervention value, and then the multi-level damping dynamic intervention time is controlled in real time by the two reverse MOSFETs Q5 and Q6. By controlling the switch SR 1- S Rn Real-time control realizes multi-level gear selection of damping intervention value, and finally achieves tail current shutdown with better linearity while effectively suppressing current overshoot with low power consumption.

[0082] Finally, the multi-component output logic is determined according to the output load requirements to be transmitted, and the relay S L1 -S Ln Dynamic switching realizes dynamically controllable output of n components to meet the detection requirements of underground multi-component transmitters.

[0083] In summary, the power module is a low-voltage DC power module, which serves as the overall working power supply of the transmitter to provide power for the high-power transmitting source and various circuit components; the MOSFET full-bridge inverter circuit generates bipolar DC pulses; the falling edge passive multi-level adjustable clamping voltage circuit realizes intelligent automatic multi-level adjustment of the falling edge clamping voltage through adaptive circuit control; the current detection circuit realizes real-time output current detection; the multi-component output control circuit realizes the selection of different component outputs; the multi-level adaptive damping intervention circuit realizes adaptive intervention of intervention time and intervention resistance through adaptive circuit control; the digital logic controller is connected to the logic circuits of each part to realize the generation of each logic control signal and the calculation and control functions such as real-time adaptive clamping voltage and adaptive damping intervention; the electromagnetic transmitting load is connected to the clamping power supply and emits an electromagnetic field of a specific frequency through alternating current.

[0084] The above definitions of the components and methods are not limited to the various specific structures, shapes or methods mentioned in the embodiments. Those skilled in the art can simply change or replace them; make small changes to the resistance and capacitance values ​​to obtain the current pulses and voltage values ​​required by the scene at that time.

[0085] The embodiments of the present disclosure have been described in detail with reference to the accompanying drawings. It should be noted that in the drawings or the body of the specification, the implementation methods not shown or described are forms known to those skilled in the art and are not described in detail. In addition, the above definitions of the various elements and methods are not limited to the various specific structures, shapes or methods mentioned in the embodiments, and those skilled in the art can simply change or replace them.

[0086] Based on the above description, those skilled in the art can have a basic understanding of the time domain multi-component electromagnetic pulse transmitter and the control method thereof disclosed in the present invention.

[0087] In summary, the present disclosure provides a time domain multi-component electromagnetic pulse transmitter and a control method thereof, and proposes an adaptive passive multi-stage adjustable clamping technology to achieve multi-stage adjustment of the slope of the falling edge of the transmitting current under the premise of good linearity of the falling edge of the transmitting current. Compared with the passive single clamping voltage design commonly used in the current traditional small-size transmitters, its adaptive adjustable multi-stage slope can meet the transmission requirements under more abundant electromagnetic detection needs; it achieves adaptive damping intervention of precise time and resistance value under the premise of reducing overall power consumption, and solves the problem that the small-size transmitters that currently select constant damping intervention cannot achieve precise time and resistance value intervention during the rapid decline period of the current pulse due to the fixed intervention value and intervention time; it achieves multi-component dynamic control of the transmitting output to meet the detection needs of underground multi-component transmitting ends.

[0088] It should also be noted that the directional terms mentioned in the embodiments, such as "upper", "lower", "front", "back", "left", "right", etc., are only reference directions of the drawings and are not intended to limit the scope of protection of the present disclosure. Throughout the drawings, the same elements are represented by the same or similar reference numerals. Conventional structures or configurations will be omitted when they may cause confusion in the understanding of the present disclosure.

[0089] Moreover, the shapes and sizes of the components in the figures do not reflect the real size and proportion, but only illustrate the contents of the embodiments of the present disclosure. In addition, in the claims, any reference symbols between brackets shall not be constructed as limiting the claims.

[0090] Unless otherwise indicated, the numerical parameters in this specification and the appended claims are approximate values ​​and can vary according to the desired properties obtained through the content of the present disclosure. Specifically, all numbers used in the specification and claims to express the content of the composition, reaction conditions, etc., should be understood to be modified by the term "about" in all cases. In general, the meaning of the expression is to include a variation of ±10% in some embodiments, ±5% in some embodiments, ±1% in some embodiments, and ±0.5% in some embodiments by a specific number.

[0091] Furthermore, the word "comprising" does not exclude the presence of elements or steps not listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

[0092] The ordinal numbers used in the specification and claims, such as "first", "second", "third", etc., to modify the corresponding elements, do not themselves mean that the elements have any ordinal numbers, nor do they represent the order of one element and another element, or the order in the manufacturing method. The use of these ordinal numbers is only used to clearly distinguish a component with a certain name from another component with the same name.

[0093] In addition, unless the steps are specifically described or must occur in sequence, the order of the above steps is not limited to the above list, and can be changed or rearranged according to the required design. And the above embodiments can be mixed and matched with each other or with other embodiments based on design and reliability considerations, that is, the technical features in different embodiments can be freely combined to form more embodiments.

[0094] Those skilled in the art can understand and adaptively change the modules in the devices in the embodiment and set them in one or more devices different from the embodiment. The modules or units or components in the embodiment can be combined into one module or unit or component, and in addition, they can be divided into multiple sub-modules or sub-units or sub-components. Except that at least some of such features and / or processes or units are mutually exclusive, all features disclosed in this specification (including the accompanying claims, abstracts and drawings) and all processes or units of any method or device disclosed in this way can be combined in any combination. Unless otherwise explicitly stated, each feature disclosed in this specification (including the accompanying claims, abstracts and drawings) can be replaced by an alternative feature that provides the same, equivalent or similar purpose. In addition, in a unit claim that lists several devices, several of these devices can be embodied by the same hardware item.

[0095] Similarly, it should be understood that in order to streamline the present disclosure and aid in understanding one or more of the various disclosed aspects, in the above description of the exemplary embodiments of the present disclosure, the various features of the present disclosure are sometimes grouped together into a single embodiment, figure, or description thereof. However, this disclosed method should not be interpreted as reflecting the following intention: the claimed disclosure requires more features than the features explicitly recited in each claim. More specifically, as reflected in the claims below, the disclosed aspects are less than all the features of the single embodiment disclosed above. Therefore, the claims that follow the specific embodiment are hereby expressly incorporated into the specific embodiment, with each claim itself serving as a separate embodiment of the present disclosure.

[0096] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present disclosure. It should be understood that the above description is only a specific embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure should be included in the protection scope of the present disclosure.

Claims

1. A time domain multi-component electromagnetic pulse transmitter, comprising: The power module serves as the overall working power supply of the transmitter; A MOSFET full-bridge inverter circuit, one input end of which is connected to the power module; A digital logic controller, connected to the MOSFET full-bridge inverter circuit, for generating a PWM timing logic control signal and acting on the MOSFET full-bridge inverter circuit to make the MOSFET full-bridge inverter circuit output a current pulse; A multi-component output control circuit, which is connected to the MOSFET full-bridge inverter circuit and the digital logic controller respectively, and is used to select different component outputs under the action of the multi-component output control signal input by the digital logic controller; A current detection circuit, connected to the multi-component output control circuit, for detecting the real-time output current of the multi-component output control circuit and feeding back the current detection result to the digital logic controller; A multi-stage adjustable clamping voltage circuit is connected between the MOSFET full-bridge inverter circuit and the digital logic controller, and under the control of the clamping voltage control signal obtained by the digital logic controller according to the current detection result, the passive clamping voltage is adjusted to clamp the falling edge of the pulse to achieve dynamic multi-stage regulation; as well as A multi-level adaptive damping intervention circuit is connected between the MOSFET full-bridge inverter circuit and the multi-component output control circuit, and realizes the selection of multi-level damping dynamic intervention time and intervention resistance value under the control of the adaptive damping control signal obtained by the digital logic controller according to the current detection result; The multi-level adaptive damping intervention circuit includes two MOSFETs, multiple intervention dampers, and multiple control switches; the two MOSFETs are set in reverse series; multiple intervention dampers are set in series and then connected in series with the two MOSFETs; multiple control switches are connected to both ends of each intervention damper; the intervention state of each intervention damper is controlled by turning on and off the control switch, thereby realizing multi-level selection of the damping intervention value; the current required intervention time and damping gear are determined in real time according to the adaptive damping intervention algorithm, and the damping intervention time and intervention resistance value are optimized and adjusted; The digital logic controller includes an FPGA controller, which is used to generate control signals including: PWM timing logic control signal, clamping voltage control signal, adaptive damping control signal, and multi-component output control signal; the PWM timing logic control signal acts on the MOSFET full-bridge inverter circuit to make the MOSFET full-bridge inverter circuit output current pulses; the clamping voltage control signal is used to adjust the passive clamping voltage to clamp the pulse falling edge to achieve dynamic multi-stage regulation; the adaptive damping control signal acts on the multi-stage adaptive damping intervention circuit to control the damping intervention time and intervention value; the multi-component output control signal acts on the MOSFET full-bridge inverter circuit to make the MOSFET full-bridge inverter circuit output current pulses. The digital logic controller also includes a MOSFET drive circuit and a multi-component output drive circuit; the MOSFET drive circuit is used to convert the PWM timing logic control signal into a MOSFET power switch control function with a strong driving capability, and realize the electrical isolation between the FPGA controller and the power switch in the MOSFET inverter circuit; the multi-component output drive circuit is used to convert the multi-component output control signal into a multi-component output terminal switch control function with a strong driving capability, and realize the electrical isolation between the FPGA controller and the multi-component output terminal switch.

2. According to the time domain multi-component electromagnetic pulse transmitter of claim 1, the multi-stage adjustable clamping voltage circuit comprises: Multiple voltage zener diodes are arranged in series; as well as A plurality of on-off power switches connected to both ends of each of the voltage stabilizing diodes; By controlling the on and off power switches, the voltage zener diodes are respectively controlled in real time to achieve multi-level selection of clamping voltage, so that the falling edge of the current pulse drops rapidly and linearly at a desired slope.

3. According to the time domain multi-component electromagnetic pulse transmitter described in claim 1, the current detection circuit detects the real-time output current value of the multi-component output control circuit through a Hall current sensor, and after feeding back the measured value to the digital logic controller, the currently required clamping voltage level is determined by calculating through a preset adaptive clamping voltage algorithm, and then a clamping voltage control signal is sent to the multi-stage adjustable constant voltage clamping circuit to realize multi-stage clamping voltage control of the MOSFET inverter circuit.

4. According to the time domain multi-component electromagnetic pulse transmitter of claim 2, the multi-stage adjustable clamping voltage circuit realizes constant voltage clamping of the device at the falling edge of the current through the reverse voltage regulation characteristics of the Zener diode.

5. A control method for a time domain multi-component electromagnetic pulse transmitter, used to control the operation of the time domain multi-component electromagnetic pulse transmitter according to any one of claims 1 to 4, the control method comprising: In the first time period, the clamping voltage is kept the same as the power supply voltage Us to ensure the normal output of the emission current pulse; The real-time output current pulse is detected, and the passive clamping voltage is controlled and adjusted in the second time period to clamp and shape the pulse falling edge, so as to achieve a fast and linear decline of the pulse falling edge; as well as According to the real-time current shutdown waveform, the adaptive damping intervention algorithm is used to adaptively adjust the damping intervention time and intervention value to obtain the optimal damping intervention time and intervention value.

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