A handheld Gray busbar detection device and its working method

Abstract

This invention belongs to the field of Gray bus detection technology, and provides a handheld Gray bus detection device and its working method. The device includes a handheld decoder, a miniature antenna box, a vehicle-mounted encoder, a Gray bus, and a terminating resistor board. The handheld decoder includes a main control unit, an AD sampling circuit, and a digital decoding circuit. The AD sampling circuit and the digital decoding circuit receive signals transmitted by the miniature antenna box and are both connected to the main control unit. The vehicle-mounted encoder emits an encoded sinusoidal modulated signal, which, after passing through the Gray bus and the terminating resistor, generates electromagnetic waves proportional to the encoder current around the Gray bus. These waves are received by the miniature antenna box and sent to the handheld decoder for amplitude analysis and digital encoding analysis to determine the position information. This invention provides a convenient installation, rapid and accurate diagnosis, and is an effective means of detecting Gray buses, installation processes, and interference during construction.

Description

Technical Field

[0001] This invention belongs to the field of Gray busbar detection technology, specifically relating to a handheld Gray busbar detection device and its working method, used to check for faults such as broken wires, short circuits, and electromagnetic interference after Gray busbars are laid. Background Technology

[0002] Gray bus ranging technology is used in many distance measurement applications. Gray bus technology uses the simplest electromagnetic induction principle of a single-turn coil for signal transmission. Specifically, the transmitting unit in the Gray bus system amplifies different address information, generates alternating current in the encoding coil, and then generates a corresponding alternating magnetic field. The decoding system in the Gray bus system uses an LC antenna box to couple this alternating frequency, thereby transmitting the address signal contained in the transmitting unit to the induction loop of the Gray bus through electromagnetic coupling. After processing, it is sent to the main control for address decoding.

[0003] The Gray bus uses Gray code for winding, with a minimum coding length of 10cm. To achieve this with long-distance winding, the minimum coding length cannot be increased without maintaining the original length; the only solution is to increase the number of coding lines. The maximum length of the coding cable is calculated as 2n * 10cm. Considering the actual data bit processing and winding convenience, n is chosen to be a maximum of 11. The longest single strand is 204.8m. Each address pair has two lines (positive and negative), plus two pairs for smaller addresses, resulting in a total of 24 lines used for transmitting address information. The reference R lines consist of 6 pairs (12 lines) used to represent different address starting positions. Therefore, the maximum theoretical length of the Gray bus is 204.8m * 6 = 1228.8m, and the Gray bus has 36 lines. The sheer volume of windings inevitably leads to conductor breakage due to excessive stress during fabrication and on-site construction, resulting in open circuits and short circuits between wires. Furthermore, the Gray busbar needs to be fixed parallel to the antenna box over long distances. Interference from on-site frequency converters and other motor-driven equipment, as well as any magnetically conductive or electrically conductive equipment and metal components near the Gray electromagnetic field, can disrupt the magnetic field in the Gray busbar's address area. Discovering these problems after construction is complete and then modifying the construction plan will significantly increase manpower and time costs, negatively impact the customer experience, and may even lead to project losses or project stagnation. Summary of the Invention

[0004] To address the shortcomings of the existing technology, this invention provides a handheld Gray bus detection device and its operating method, which only requires the addition of a handheld decoder and a resonant antenna box. It is easy to install, provides fast and accurate diagnosis, and is an effective means of detecting Gray busbars, installation processes, interference, etc. during construction.

[0005] The objective of this invention is achieved through the following technical measures.

[0006] A handheld Gray bus detection device includes a handheld decoder, a miniature antenna box, a vehicle encoder, a Gray bus, and a terminating resistor board. The handheld decoder includes a LoRa module, a main control unit, an AD sampling circuit, and a digital decoding circuit. The AD sampling circuit and the digital decoding circuit receive signals transmitted by the miniature antenna box. Both the AD sampling circuit and the digital decoding circuit are connected to the main control unit. The vehicle encoder emits an encoded sinusoidal modulated signal, which, after passing through the Gray bus and the terminating resistor, generates electromagnetic waves proportional to the encoder current around the Gray bus. These waves are received by the miniature antenna box and sent to the handheld decoder for amplitude analysis and digital encoding analysis. The AD sampling circuit samples and judges the amplitude of the signal, and the digital decoding circuit digitizes the absolute position information to determine the position information.

[0007] In the above technical solution, the main controller adopts STM32F407.

[0008] In the above technical solution, the handheld decoder is powered by a lithium-ion battery pack, which is connected to the main controller.

[0009] In the above technical solution, the handheld decoder uses LoRa module networking to upload the detection data and results to the host computer wirelessly.

[0010] This invention also provides a method for operating the handheld Gray bus detection device described above. The method involves first simulating the transmission of the same encoded modulation signal to the Gray bus, then using a handheld decoder to inspect along the cable. When discontinuous changes occur in the signal, the main control unit determines the fault type and location. The determination method for different signal lines in the Gray bus is as follows:

[0011] (1) When the reference signal line is disconnected, the reference reference of other address lines disappears, and the address is displayed as 0;

[0012] (2) When other signal lines are disconnected, a jump will occur in the address display, and the address that jumps is the fault line;

[0013] (3) Combined with amplitude judgment, if there is a short circuit in the Gray bus, the amplitude of the corresponding bit signal will increase. The short circuit point can be deduced based on the magnitude of the amplitude and the internal resistance parameter of the Gray bus; if the Gray bus is open, the amplitude of the corresponding bit signal will be 0.

[0014] This invention relates to a handheld Gray busbar inspection device, which is easy to install and provides fast and accurate diagnosis. With the addition of a handheld Gray busbar inspection device, the Gray busbar product can simulate the actual effect before on-site construction, detect problems and make improvements, improve the first-time pass rate of product installation, and basically eliminate the need for rework. This product is an effective device for on-site construction personnel to predict and improve efficiency. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of a handheld Gray busbar detection device according to an embodiment of the present invention.

[0016] In the diagram: 1-Handheld Gray bus decoder, 2-Miniature antenna box, 3-Vehicle encoder, 4-Gray bus, 5-Terminal resistor board.

[0017] Figure 2 This is a schematic diagram of a ground-based Gray bus distance measurement system.

[0018] In the diagram: 1-Ground encoder, 2-Antenna box, 3-Ground encoder, 4-Gray bus, 5-Terminal resistor (encapsulated inside the Gray bus).

[0019] Figure 3 This is a diagram showing the signal output of different signal line encoders in the Gray bus in an embodiment of the present invention.

[0020] Figure 4 This is a schematic diagram of the main control circuit connection in an embodiment of the present invention.

[0021] Figure 5 This is a schematic diagram of the Lora module circuit connection in an embodiment of the present invention.

[0022] Figure 6 This is a schematic diagram of the FPGA circuit connection in an embodiment of the present invention.

[0023] Figure 7 This is a schematic diagram of the EEPROM circuit connection in an embodiment of the present invention.

[0024] In the diagram: RF1 is the antenna, and BT1 is the battery. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0026] like Figure 1As shown, this embodiment of the invention provides a handheld Gray bus detection device, including a handheld Gray bus decoder 1, a miniature antenna box 2, a vehicle inspection encoder 3, a Gray bus 4, a terminal resistor board 5, etc.

[0027] For the vehicle inspection system, the vehicle inspection encoder 3 emits an encoded sinusoidal modulated signal, which, after passing through the Gray bus 4 and the terminating resistor 5, generates an electromagnetic wave around the Gray bus 4 that is proportional to the encoder current (I=V / R). This wave is then received by the miniature antenna box 2 (the antenna box has a thin plate-like structure, making it easy for on-site personnel to carry and move it for inspection) and sent to the handheld Gray bus decoder 1.

[0028] The handheld decoder 1 includes a LoRa module, a main control unit, an AD sampling circuit, and a digital decoding circuit. The AD sampling circuit and the digital decoding circuit receive signals transmitted by a miniature antenna box. Both the AD sampling circuit and the digital decoding circuit are connected to the main control unit. The vehicle encoder emits an encoded sinusoidal modulated signal, which, after passing through the Gray bus and the terminating resistor, generates electromagnetic waves proportional to the encoder current around the Gray bus. These waves are received by the miniature antenna box and sent to the handheld decoder for amplitude analysis and digital encoding analysis. The AD sampling circuit samples and judges the amplitude of the signal, and the digital decoding circuit digitizes the absolute position information to determine the position information.

[0029] In the above embodiment, the main controller is an STM32F407, and its circuit connection diagram is shown below. Figure 4 As shown.

[0030] In the above embodiments, the handheld decoder is powered by a lithium-ion battery pack, which is connected to the main controller.

[0031] In the above embodiment, the handheld decoder uses a Lora module network to wirelessly upload detection data and results to a host computer. This allows for convenient detection of the entire Gray busbar operating conditions in situations where manual operation is inconvenient, by using a mechanical means to move the detection device. A circuit connection diagram of the Lora module is shown below. Figure 5 As shown.

[0032] In addition, the handheld decoder can transmit data to the host computer system via the LoRa local area network, and can also collect addresses via a serial port debugging assistant.

[0033] Figure 6 This is a schematic diagram of the FPGA circuit connection. The FPGA is used to decode digital signals.

[0034] Figure 7 This is a schematic diagram of the EEPROM circuit connection. The EEPROM is used to store fault signals.

[0035] In practical use, Gray busbars may be subject to external interference, such as encountering large metal planes, magnetic field coupling caused by parallel high-current or high-voltage cables. Such faults will inevitably cause interference to every signal line of the Gray busbar. Therefore, if such a fault alarm is encountered during the detection process, the above situations should be checked nearby. After eliminating the above external interference, further Gray busbar detection can be carried out using this handheld Gray busbar detection device.

[0036] For different signal lines in the Gray busbar, the vehicle inspection encoder 3 sends signals as follows: Figure 3 As shown, S1-S4, SR5, and SR6 are reference signals, and S5-S16 are position signals. Only one reference signal is displayed per segment of the Gray bus, representing different address starting positions, such as S1 position marking 0-204.8m, S2 position marking 204.8-409.6m, etc. When the reference signal line is disconnected, the reference for other address lines disappears, and the address will display 0. When other signals are disconnected, a jump will first appear in the address display, and the address that jumps is the fault line. Figure 3 As shown in Table 1, a break in S5 will inevitably cause a loss of low potential in the corresponding bit timing T0. Combined with amplitude judgment, a short circuit in the Gray bus will inevitably cause an increase in the amplitude of the corresponding bit signal, while a break will cause the amplitude of the corresponding bit signal to be 0. Furthermore, the short circuit point can be deduced based on the magnitude of the amplitude and the internal resistance parameters of the Gray bus.

[0037] Table 1

[0038]

[0039] For both vehicle inspection systems and ground inspection systems, the Gray busbar essentially transmits signals through the principle of electromagnetic induction. In a vehicle inspection system, signal generation consists of an encoder, the Gray busbar, and a terminating resistor board; the antenna box acts as the receiving device, and the Gray busbar acts as the transmitting device. In a ground inspection system, signal generation consists of an encoder and a resonant antenna box; the Gray busbar serves as the signal receiving end, and the terminating resistor is typically sealed inside the Gray busbar.

[0040] like Figure 2 As shown, for the ground inspection system, encoder 1 transmits a fixed-frequency sinusoidal signal through the coil in the resonant antenna box 2 to emit electromagnetic waves. Gray bus 4 is connected to ground inspection decoder 3, and terminating resistor 5 is generally encapsulated in Gray bus 4. Both vehicle inspection and ground inspection systems determine the condition of the Gray bus, so normalization can be achieved. The difference is that in the ground inspection system, a vehicle inspection encoder 3 is required as the oscillation unit, and then the handheld Gray bus detection device of this invention can be used to perform the Gray bus inspection operation.

[0041] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0042] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A handheld Gray busbar detection device, characterized in that: The system includes a handheld decoder, a miniature antenna box, a vehicle encoder, a Gray bus, and a terminating resistor board. The handheld decoder includes a LoRa module, a main control unit, an AD sampling circuit, and a digital decoding circuit. The AD sampling circuit and the digital decoding circuit receive signals transmitted by the miniature antenna box. The LoRa module, AD sampling circuit, and digital decoding circuit are all connected to the main control unit. The vehicle encoder emits an encoded sinusoidal modulated signal, which, after passing through the Gray bus and the terminating resistor, generates electromagnetic waves proportional to the encoder current around the Gray bus. These waves are received by the miniature antenna box and sent to the handheld decoder for amplitude analysis and digital encoding analysis. The AD sampling circuit samples and judges the amplitude of the signal, and the digital decoding circuit digitizes the absolute position information to determine the position information.

2. The handheld Gray busbar detection device according to claim 1, characterized in that: The main controller is an STM32F407.

3. The handheld Gray busbar detection device according to claim 1, characterized in that: The handheld decoder is powered by a lithium-ion battery pack, which is connected to the main controller.

4. The handheld Gray busbar detection device according to claim 1, characterized in that: The handheld decoder uses LoRa modules for networking, and uploads the detection data and results to the host computer wirelessly.

5. A method of operating the handheld Gray busbar detection device as described in claim 1, characterized in that: First, the same coded and modulated signal is simulated and sent to the Gray bus. Then, a handheld decoder is used to inspect the cable. When the signal shows discontinuous changes, the main control unit determines the fault type and location. The judgment method for different signal lines in the Gray bus is as follows: (1) When the reference signal line is disconnected, the reference reference of other address lines disappears, and the address is displayed as 0; (2) When other signal lines are disconnected, a jump will occur in the address display, and the address that jumps is the fault line; (3) Combined with amplitude judgment, if there is a short circuit in the Gray bus, the amplitude of the corresponding bit signal will increase. The short circuit point can be deduced based on the magnitude of the amplitude and the internal resistance parameter of the Gray bus; if the Gray bus is open, the amplitude of the corresponding bit signal will be 0.

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