Non-metallic pipeline exploration mini-signal stick

Abstract

The utility model relates to pipeline survey device technical field especially is a kind of non-metal pipeline survey mini signal stick, it includes: bluetooth circuit, control circuit and transmitting circuit;The bluetooth circuit with the control circuit is electrically connected, and the bluetooth circuit is also connected with external device communication;The transmitting circuit includes: four MOSFET drivers, four MOSFET and transmitting coil, four the MOSFET driver is respectively with four the MOSFET electric connection and constitutes H bridge, four the MOSFET all with the transmitting coil electric connection.User can select the most suitable frequency point according to the complex electromagnetic environment of scene, make parameter setting very convenient through the wireless control of bluetooth circuit, change non-metal pipeline into a detectable initiative signal source, fundamentally solve the positioning problem.

Description

Technical Field

[0001] This utility model relates to the technical field of pipeline exploration devices, and in particular to a non-metallic pipeline exploration mini signal stick. Background Technology

[0002] The current difficulties in the surveying of underground non-metallic pipelines mainly stem from their material properties, the complexity of their burial environment, and the limitations of technical means, as specifically manifested as follows:

[0003] Non-metallic pipelines (such as UPVC, concrete pipes, etc.) have poor conductivity and cannot be directly detected by traditional electromagnetic induction methods. Metal pipeline detectors rely on electromagnetic field induction, but non-metallic materials cannot form an effective response, making conventional equipment unsuitable. Utility Model Content

[0004] To address the problems of existing technologies, this utility model provides a mini signal stick for non-metallic pipeline exploration, comprising: a Bluetooth circuit, a control circuit, and a transmitting circuit;

[0005] The Bluetooth circuit is electrically connected to the control circuit, and the Bluetooth circuit is also communicatively connected to external devices;

[0006] The transmitting circuit includes: four MOSFET drivers, four MOSFETs and a transmitting coil. The four MOSFET drivers are electrically connected to the four MOSFETs to form an H-bridge, and the four MOSFETs are all electrically connected to the transmitting coil.

[0007] Furthermore, each of the four MOSFET drivers and the four MOSFETs is electrically connected to a resistor.

[0008] Furthermore, the four MOSFETs include two MOSFET-N and two MOSFET-P.

[0009] Furthermore, the transmitting coil is a 10mH inductor.

[0010] Furthermore, the receiving probe cable of the external device is wrapped with a shielding layer.

[0011] Furthermore, the shielding layer includes an inner electrostatic shielding layer and an outer magnetic shielding layer.

[0012] Furthermore, an isolation amplifier and a low-pass filter are connected between the receiving probe of the external device and the processor.

[0013] The beneficial effects of the technical solution provided by this utility model are: non-metallic pipelines are non-conductive, and the electromagnetic induction method of traditional pipeline detectors is ineffective. This signal rod turns non-metallic pipelines into a detectable active signal source, fundamentally solving the positioning problem.

[0014] Secondly, users can select the most suitable frequency point based on the complex electromagnetic environment on site (such as multiple pipelines and strong interference in the city). The parameter setting is very convenient through Bluetooth circuit control, without the need for digging or direct physical contact with the signal rod.

[0015] In addition, ground equipment uses low-pass filters to remove high-frequency noise and isolation amplifiers to block conducted interference, ultimately restoring useful signals. Attached Figure Description

[0016] Figure 1 This utility model provides a circuit diagram for a mini signal bar for non-metallic pipeline exploration.

[0017] Figure labels: 1-Bluetooth circuit; 2-Control circuit; 3-Transmitting circuit; 4-MOSFET driver; 5-MOSFET; 6-Transmitting coil; 7-Resistor. Detailed Implementation

[0018] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] To make the objectives, technical solutions, and advantages of this utility model clearer, the embodiments of this utility model will be described in further detail below with reference to the accompanying drawings.

[0020] See Figure 1 A non-metallic pipeline exploration mini signal stick, comprising Bluetooth circuit 1, control circuit 2, and transmitting circuit 3.

[0021] Control circuit 2 is a microcontroller, and Bluetooth circuit 1 is a Bluetooth module. Bluetooth circuit 1 is electrically connected to control circuit 2 via a serial port. Bluetooth circuit 1 also communicates with external devices (such as PDAs or handheld devices).

[0022] The transmitting circuit 3 includes: four MOSFET drivers 4, four MOSFETs 5, and a transmitting coil 6; the four MOSFET drivers 4 are of model MCP1402, which can provide up to 2A of peak source current and 2.5A of peak sink current, ensuring that the MOSFETs can be turned on and off quickly, reducing switching losses and improving efficiency.

[0023] The control circuit 2 is electrically connected to four MOSFET drivers 4, which send four PWM signals (PWM1, PWM2N, PWM2, PWM1N) respectively. The first MOSFET driver 4 receives the PWM1 signal, the second MOSFET driver 4 receives the PWM2N signal, the third MOSFET driver 4 receives the PWM2 signal, and the fourth MOSFET driver 4 receives the PWM1N signal.

[0024] The four MOSFETs 5 include two MOSFET-N and two MOSFET-P. MOSFET-N are N-channel MOSFETs and MOSFET-P are P-channel MOSFETs. Each MOSFET driver 4 is connected to the corresponding MOSFET (N-channel or P-channel) through its own resistors 7 (R627, R628, R609, R606), forming two H-bridge drive circuits: MOSF: composed of MOSFET-N connected by resistor R627 and MOSFET-P connected by resistor R628; MOS2: composed of MOSFET-N connected by resistor R609 and MOSFET-P connected by resistor R606.

[0025] In the MOSF, MOSFET-N acts as a pull-down switch, with its source (S) connected to ground (GND). In the MOSF, MOSFET-P acts as a pull-up switch, with its source connected to the positive power supply (VCC). Their drains are connected together and connected to one end of the transmitting coil 6.

[0026] In MOS2, MOSFET-N acts as a pull-down switch with its source grounded, while MOSFET-P in the second path acts as a pull-up switch with its source connected to the power supply. Their drains are connected together and then connected to the other end of the transmitting coil 6.

[0027] Among them, the transmitting coil 6 is an inductor with an inductance of 10 millihenries (mH). 10mH is a relatively large inductance value, which is usually used for low-frequency transmission (such as tens of kHz). The frequency range commonly used for non-metallic pipeline detection is between 1 kHz and 100 kHz. A 10mH inductor, together with a suitable capacitor (such as a few nF to tens of nF), can easily cover this range.

[0028] It should be noted that this non-metallic pipeline survey mini signal stick also includes a plastic tubular outer shell, which can be made of polycarbonate or ABS plastic. The Bluetooth circuit 1, control circuit 2, and transmitting circuit 3 are all housed within the outer shell. The diameter of the shell is smaller than the inner diameter of the pipeline to be measured, with a certain gap to ensure smooth passage. For example, in this embodiment, the diameter of the shell can be 25mm and the length can be 500mm. Additionally, a battery is placed inside the shell and electrically connected to the control circuit.

[0029] In use, the operator implants a mini signal bar into the non-pipeline being surveyed. The ground equipment sets the required operating frequencies (1 ULF frequency, 2 VLF frequencies, and 1 LF frequency). The ground equipment wirelessly sends the frequency setting command to the Bluetooth circuit 1 inside the signal bar via Bluetooth protocol. After receiving the command, the Bluetooth circuit 1 transmits it to the control circuit 2. The control circuit 2 generates 4 PWM signals (PWM1, PWM2N, PWM2, PWM1N) according to the received frequency command. The 4 PWM signals are sent to 4 MOSFET drivers 4 respectively. After receiving the PWM signals, the MOSFET drivers 4 convert them into high current signals that can drive the MOSFETs. The four MOSFET drivers 4 drive the four MOSFETs respectively, forming two H-bridge drive circuits (MOSF and MOS2). The H-bridge drive circuits alternately turn on and off, causing the current to change rapidly in the transmitting coil, thereby generating an alternating electromagnetic field. The alternating electromagnetic field generated by the transmitting circuit 3 penetrates the soil and is transmitted to the ground. Signals of different frequency bands (ULF, VLF, LF) have different penetration and anti-interference capabilities, ensuring that the ground receiving equipment can receive a sufficiently strong and clear signal. The ground receiving device determines the location information of the implanted mini signal bar on the ground and determines the underground trajectory of the non-metallic pipeline of the implanted signal bar through multi-point survey.

[0030] It should be noted that PWM1 / PWM1N and PWM2 / PWM2N are two pairs of complementary signals with dead-time control. These signals are amplified by the MCP1402 driver and control the switching of four MOSFETs (Q11, Q12, Q21, Q22). During one operating cycle, control circuit 2 simultaneously turns on MOSFET-N (Q12) and MOSFET-P (Q21), while turning off MOSFET-N (Q11) and MOSFET-P (Q22), allowing current to flow through the inductor in one direction. In the next operating cycle, control circuit 2 turns on MOSFET-N (Q22) and MOSFET-P (Q11) simultaneously, while turning off MOSFET-N (Q12) and MOSFET-P (Q21), allowing current to flow through the inductor in the opposite direction. This generates an AC square wave voltage across the inductor. By changing the frequency of this switching, the frequency of the output AC signal is changed.

[0031] It should also be noted that one ULF frequency point, two VLF frequency points, and one LF frequency point are superimposed in this non-metallic pipeline exploration mini signal bar. By utilizing the characteristic that different frequency bands correspond to different types of interference, the ultra-low frequency signal (2KHz) can effectively penetrate the medium surrounding the metal body (such as highly conductive soil) because the lower the frequency, the greater the penetration depth, thus reducing the induced interference of the metal body.

[0032] Extremely low frequency (ULF) signals have extremely long wavelengths (e.g., a 2 kHz signal has a wavelength of approximately 150 km). Their electromagnetic radiation is primarily coupled by near-field magnetic fields, giving them strong penetrating power into underground media (soil, rock). This characteristic allows ULF signals to effectively penetrate underground media and transmit to the surface. However, they also face interference from inductive coupling with conductive metals (the metal body induces eddy currents in an alternating magnetic field, forming secondary magnetic field interference) and conducted coupling interference (the metal body acts as a conductor, transmitting noise to the signal loop). Shielding is a key means of resisting interference from conductive metals. Its principle is to block or absorb electromagnetic interference using conductive or magnetically conductive materials.

[0033] Therefore, the receiving probe cable of the external device (the connection line between the ground probe and the host) is wrapped with a shielding layer. The shielding layer includes an inner electrostatic shielding layer and an outer magnetic shielding layer. The electrostatic shielding layer is wrapped with a low-impedance conductive material (such as copper or aluminum) to block the interference of external electric fields on underground signals. The electrostatic shielding layer needs to be grounded at a single point (usually at the receiving end) to avoid the formation of ground loop current (ground loops will cause common-mode interference amplification). The magnetic shielding layer is made of a high-permeability material (such as permalloy or silicon steel sheet) to deal with low-frequency magnetic field interference from conductive metal bodies (such as the magnetic field generated by eddy currents in pipes). The high-permeability material can guide the magnetic lines of force into its own interior (magnetic bypass effect) to reduce the inductive coupling of the metal body to the underground signal.

[0034] In addition, interference from conductive metals typically includes high-frequency noise (such as harmonics from switching power supplies) and conducted interference (such as ground current), which needs to be removed through filtering and isolation measures. Therefore, an isolation amplifier and a low-pass filter are connected between the receiving probe and the processor of the external device. The low-pass filter can filter out high-frequency noise (such as high-frequency eddy currents induced by the metal). For example, an LC low-pass filter can effectively suppress noise above 50 Hz. An isolation amplifier (such as optocoupler isolation or transformer isolation) is used to isolate the underground signal loop from the ground receiving end and block conducted interference (such as ground current).

[0035] It is worth noting that non-metallic pipelines (such as PVC) are non-conductive, rendering the electromagnetic induction method of traditional pipeline detectors ineffective. This signal rod transforms non-metallic pipelines into a detectable active signal source, fundamentally solving the positioning problem.

[0036] Secondly, users can select the most suitable frequency point based on the complex electromagnetic environment on site (such as multiple pipelines and strong interference in the city). The parameter setting is very convenient through Bluetooth circuit control, without the need for digging or direct physical contact with the signal rod.

[0037] In addition, ground equipment uses low-pass filters to remove high-frequency noise and isolation amplifiers to block conducted interference, ultimately restoring useful signals.

[0038] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A mini signal stick for non-metallic pipeline exploration, characterized in that, include: Bluetooth circuit (1), control circuit (2) and transmitting circuit (3); The Bluetooth circuit (1) is electrically connected to the control circuit (2), and the Bluetooth circuit (1) is also connected to an external device for communication. The transmitting circuit (3) includes: four MOSFET drivers (4), four MOSFETs (5) and a transmitting coil (6). The four MOSFET drivers (4) are electrically connected to the four MOSFETs (5) to form an H-bridge, and the four MOSFETs (5) are all electrically connected to the transmitting coil.

2. The mini signal stick for non-metallic pipeline exploration according to claim 1, characterized in that, A resistor (7) is electrically connected between each of the four MOSFET drivers (4) and the four MOSFETs (5).

3. The mini signal stick for non-metallic pipeline exploration according to claim 1, characterized in that, The four MOSFETs (5) include two MOSFET-N and two MOSFET-P.

4. The mini signal stick for non-metallic pipeline exploration according to claim 1, characterized in that, The transmitting coil (6) is a 10mH inductor.

5. The mini signal stick for non-metallic pipeline exploration according to claim 1, characterized in that, The receiving probe cable of the external device is wrapped with a shielding layer.

6. The mini signal stick for non-metallic pipeline exploration according to claim 5, characterized in that, The shielding layer includes an inner electrostatic shielding layer and an outer magnetic shielding layer.

7. The mini signal stick for non-metallic pipeline exploration according to claim 1, characterized in that, An isolation amplifier and a low-pass filter are connected between the receiving probe of the external device and the processor.

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