A position recognition system based on photoelectric coding

Abstract

The application discloses a position recognition system based on photoelectric coding, and belongs to the field of industrial automation. The system comprises a light shielding baffle arranged on a track, wherein the light shielding baffle is provided with long teeth and short teeth, the long teeth are used for triggering position reading, and the short teeth are used for identifying different positions in a BCD coding mode; and a control board arranged on an RGV trolley, wherein the control board comprises: a photoelectric switch array comprising a photoelectric switch 0 and photoelectric switches 1-N, the photoelectric switch 0 is matched with the long teeth, and the photoelectric switches 1-N are matched with the short teeth; an inverter connected with the photoelectric switch array and used for shaping and filtering the output signals of the photoelectric switches; a latch connected with the inverter and used for latching the shielding conditions of the photoelectric switches 1-N by using the rising edge of the output of the photoelectric switch 0; and an MCU connected with the latch and the photoelectric switch 0, wherein the rising edge of the output of the photoelectric switch 0 is used as an interrupt trigger signal of the MCU, and the MCU reads the data kept in the latch in an interrupt response function and converts the data into position information.

Description

Technical Field

[0001] This application relates to the field of industrial automation, and more specifically, to a position recognition system based on photoelectric coding. Background Technology

[0002] In industrial scenarios such as automated logistics, smart warehousing, and flexible production lines, accurate location identification of mobile devices (such as RGV carts, AGVs, and stacker cranes) is crucial for ensuring the efficient and reliable operation of the system. Traditional location detection technologies, such as RFID, barcode recognition, and laser ranging, while offering high accuracy, also suffer from drawbacks such as high cost, susceptibility to contamination, complex installation, and slow response times. For example, RFID requires deploying tags and installing readers at each location, and the system cost increases significantly with the number of locations; optical barcodes are easily rendered ineffective by dust and oil.

[0003] Therefore, the market urgently needs a positioning solution that is low-cost, simple in structure, strong in anti-interference capability, and can meet the detection needs of most discrete points. While mechanical limit switches are low-cost, they suffer from poor accuracy and are prone to wear; single photoelectric switches can only detect "present / absent" points and cannot provide a unique identification code. Based on these industry pain points, a photoelectric coding position recognition system combining mechanical structure and digital coding technology has emerged. This system, through an innovative "long-tooth-short-tooth" mechanical structure and BCD coding principle, achieves rapid and reliable identification of multiple discrete positions during movement. Summary of the Invention

[0004] The summary section of this application is intended to provide a brief overview of the concepts, which will be described in detail in the detailed description section below. This summary section is not intended to identify key or essential features of the claimed technical solutions, nor is it intended to limit the scope of the claimed technical solutions.

[0005] To address the technical problems mentioned in the background section, some embodiments of this application provide a position recognition system based on photoelectric coding, comprising: a light-shielding plate deployed on a track, the light-shielding plate having long teeth and short teeth, the long teeth being used to trigger position reading, and the short teeth being used to identify different positions using BCD encoding; a control board deployed on an RGV trolley, the control board comprising: a photoelectric switch array, including photoelectric switch 0 and photoelectric switches 1-N, photoelectric switch 0 cooperating with the long teeth, and photoelectric switches 1-N cooperating with the short teeth; an inverter connected to the photoelectric switch array, used to shape and filter the output signals of the photoelectric switches; a latch connected to the inverter, used to latch the occlusion status of photoelectric switches 1-N using the rising edge of the output of photoelectric switch 0; and an MCU connected to the latch and photoelectric switch 0, the rising edge of the output of photoelectric switch 0 serving as an interrupt trigger signal for the MCU, the MCU reading the data held in the latch and converting it into position information in the interrupt response function.

[0006] Furthermore, the number of short teeth of the light-shielding plate is N, which can represent 2 to the power of N positions.

[0007] Furthermore, the inverter is used to make the signal edge steeper while filtering out narrow pulse interference.

[0008] Furthermore, the latch signal of the latch is triggered by the rising edge of the output of photoelectric switch 0.

[0009] Furthermore, the MCU reads the high and low states of the data pins, converts them into position information, and reports it to the host computer system.

[0010] Furthermore, the photoelectric switch 0 is triggered to read the current position whenever the long toothed piece passes through.

[0011] Furthermore, the light-shielding baffles at each position have different teeth.

[0012] Furthermore, the short tooth is encoded using BCD encoding. All four digits of the dental radiograph indicate position 15#, encoded as "1111"; the second and third digits are not present, indicating position 5#, encoded as "1001".

[0013] Furthermore, the latch is used to ensure that the MCU can read the correct data. The rising edge of the output of photoelectric switch 0 is used as the latch signal of the latch to freeze the blocking status of photoelectric switches 1-N at the current moment.

[0014] Furthermore, the MCU immediately enters the interrupt function, reads the high and low status of the data pins, converts them into position information, and reports it to the host computer system.

[0015] The beneficial effects of this application are: high reliability and strong anti-interference capability: the system uses a Schmitt trigger to shape the signal, which can effectively filter out narrow pulse interference caused by vibration, dust, etc. The introduction of the latch ensures that the position encoding data can be captured and latched instantly when the mobile device passes by at high speed, avoiding data misreading caused by signal jitter or untimely MCU response.

[0016] Low cost and high performance: The core components are conventional photoelectric switches and general-purpose digital chips (inverters, latches), eliminating the need for expensive dedicated sensors or recognition modules. The light-shielding baffle can be made of wear-resistant engineering plastics or stainless steel, which is simple to process and extremely low in cost, making it particularly suitable for applications requiring a large number of deployment points.

[0017] Simple structure, easy to deploy and maintain: Only passive physical light-shielding plates need to be installed on the track side, which are sturdy, durable and not easily damaged. The control board is integrated into the mobile equipment, and the modular design makes installation, commissioning and subsequent maintenance very simple.

[0018] Fast recognition speed and good real-time performance: The trigger signal of the first photoelectric switch serves as an external interrupt for the MCU, enabling the system to respond immediately and read location data with almost no delay, thus meeting the real-time positioning requirements of mobile devices operating at high speeds.

[0019] Flexible scalability: The system's encoding capacity is determined by the number of short teeth (N short teeth can represent 2^N positions). Users can flexibly design the encoding scheme of the light-shielding baffle according to the actual required positioning accuracy and number of points, resulting in strong scalability.

[0020] High environmental adaptability: The photoelectric switch can be selected as either through-beam or reflective, and the most suitable sensor type can be selected according to the specific installation environment of the track (such as space size and cleanliness), which enhances the applicability of the system. Attached Figure Description

[0021] The accompanying drawings, which form part of this application, are used to provide a further understanding of the application and to make other features, objects, and advantages of the application more apparent. The illustrative embodiments and descriptions of this application are used to explain the application and do not constitute an undue limitation of the application.

[0022] Furthermore, throughout the accompanying drawings, the same or similar reference numerals denote the same or similar elements. It should be understood that the drawings are schematic, and the elements are not necessarily drawn to scale.

[0023] In the attached diagram:

[0024] Figure 1 It is based on the hardware block diagram;

[0025] Figure 2This is a structural diagram of a part of an embodiment, mainly showing the software flowchart;

[0026] Figure 3 This is an example image of a light-blocking shield. Detailed Implementation

[0027] Embodiments of this disclosure will now be described in more detail with reference to the accompanying drawings. While some embodiments of this disclosure are shown in the drawings, it should be understood that this disclosure can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this disclosure. It should be understood that the accompanying drawings and embodiments of this disclosure are for illustrative purposes only and are not intended to limit the scope of protection of this disclosure.

[0028] It should also be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings. Unless otherwise specified, the embodiments and features described in this disclosure can be combined with each other.

[0029] It should be noted that the concepts of "first" and "second" mentioned in this disclosure are used only to distinguish different devices, modules or units, and are not used to limit the order of functions performed by these devices, modules or units or their interdependencies.

[0030] It should be noted that the terms "a" and "a plurality of" used in this disclosure are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0031] The following will describe the process in detail with reference to the accompanying drawings and embodiments.

[0032] Reference Figure 1-3 , A position recognition system based on photoelectric coding includes a light-shielding plate and a control board. The light-shielding plate is fixedly deployed on a track and is made of a wear-resistant material such as stainless steel or engineering plastic. The light-shielding plate has long teeth and multiple short teeth, with the long teeth being longer than the short teeth to ensure that the first photoelectric switch is triggered preferentially when a mobile device passes by. The short teeth are arranged in a BCD coding pattern; for example, 4 short teeth can represent 16 positions (0000 to 1111), and N short teeth can represent 2^N positions.

[0033] A position recognition system based on photoelectric coding includes a light-shielding plate and a control board. The light-shielding plate is fixedly deployed on a track and is made of a wear-resistant material such as stainless steel or engineering plastic. The light-shielding plate has long teeth and multiple short teeth, with the long teeth being longer than the short teeth to ensure that the first photoelectric switch is triggered preferentially when a mobile device passes by. The short teeth are arranged in a BCD coding pattern; for example, 4 short teeth can represent 16 positions (0000 to 1111), and N short teeth can represent 2^N positions.

[0034] The control board is deployed on a mobile device, such as an RGV (Remotely Receiving Vehicle), which moves along a track. The control board includes an array of photoelectric switches, an inverter, a latch, and an MCU (Microcontroller Unit). The photoelectric switch array includes a first photoelectric switch and multiple second photoelectric switches; the first photoelectric switch engages with a long-toothed sensor, and the second photoelectric switches engage with a short-toothed sensor. The photoelectric switch array can use either through-beam or reflective sensors, selected depending on the installation environment.

[0035] An inverter connects to the output of an optoelectronic switch array and is used to shape and filter signals. The inverter may include a Schmitt trigger to filter out narrow pulse interference and steepen the signal edge, improving noise immunity.

[0036] The latch is connected to the output of the inverter, and its latching signal is triggered by the rising edge of the first photoelectric switch. When the long tooth passes through the first photoelectric switch, a rising edge signal is generated, and the latch immediately latches the current state of the second photoelectric switch, ensuring that data is stably captured during the movement of the mobile device.

[0037] The MCU24 connects to a latch and the first photoelectric switch. The trigger signal of the first photoelectric switch is input to the MCU24 as an interrupt signal, and the MCU24 reads the data from the latch in the interrupt response function. The MCU24 has a built-in decoding program that converts the state of the second photoelectric switch into a position code through a lookup table or algorithm, and reports it to the host computer system through a communication interface (such as UART, CAN, or Ethernet).

[0038] The control board also includes a power management module to supply power to the entire system and ensure stable operation.

[0039] In practical applications, light-blocking baffles are deployed along the track at each location requiring positioning, with each location having a unique short-tooth code. When a mobile device passes by, the long tooth triggers the first photoelectric switch, the latch stores the occlusion state of the short tooth, and the MCU24 decodes and reports the location. This system achieves low-cost, high-reliability location identification and is suitable for scenarios such as automated warehouses and production lines.

[0040] The location identification process of this system is a rapid response process that combines hardware and software. Its core principle can be divided into the following steps:

[0041] Encoding Deployment: At each location along the track requiring identification, a light-shielding plate with a unique BCD code is fixedly installed. The longer teeth on the plate generate a synchronization trigger signal, their length ensuring they trigger the first photoelectric switch before the shorter teeth. The "present / absent" combinations of multiple shorter teeth constitute the unique binary code for that location.

[0042] Signal triggering and acquisition:

[0043] As the mobile device moves along the track, the photoelectric switch array on its control panel passes through the light-shielding plate.

[0044] The tooth first passes through the first photoelectric switch, changing its state from "blocked" to "unblocked", generating a rising edge signal.

[0045] Meanwhile, multiple short teeth pass through the corresponding second photoelectric switch array. Each switch outputs a high or low level depending on whether it is blocked by a short tooth, together forming a set of parallel position coding signals.

[0046] Signal processing and latching:

[0047] The original output signal of all photoelectric switches is first sent to an inverter (containing a Schmitt trigger) for shaping, eliminating glitches and interference, and generating a digital signal with steep edges.

[0048] The shaped second photoelectric switch signal (i.e., position code) is sent to the data input terminal of the latch.

[0049] The rising edge signal generated by the first photoelectric switch is connected to the latch as a latch trigger signal. At the instant the rising edge arrives, the latch instantly latches and holds the current state of all the second photoelectric switches.

[0050] Data Decoding and Reporting:

[0051] The rising edge signal of the first photoelectric switch is simultaneously input to the MCU as an interrupt signal.

[0052] Upon receiving an interrupt, the MCU immediately executes the interrupt service routine to reliably read the latched position code data from the latch.

[0053] The MCU runs a decoding program that uses a lookup table or decoding algorithm to convert the read binary code into a corresponding unique position number.

[0054] Finally, the MCU reports the identified location information to the host computer control system in real time through communication interfaces such as UART, CAN, or Ethernet, completing a full location identification task.

[0055] The above description is merely a selection of preferred embodiments of this disclosure and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in the embodiments of this disclosure is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions disclosed in the embodiments of this disclosure.

Claims

1. A location recognition system based on photoelectric coding, characterized in that, include: A light-shielding plate is deployed on the track. The light-shielding plate has long teeth and short teeth. The long teeth are used to trigger position reading, and the short teeth are used to identify different positions using BCD encoding. A control board, deployed on the RGV vehicle, includes: A photoelectric switch array includes photoelectric switch 0 and photoelectric switches 1-N, wherein photoelectric switch 0 engages with the long tooth and photoelectric switches 1-N engage with the short tooth; An inverter, connected to the photoelectric switch array, is used to shape and filter the output signal of the photoelectric switches; A latch, connected to the inverter, is used to latch the blocking status of photoelectric switches 1-N using the rising edge of the output of photoelectric switch 0. The MCU connects the latch and photoelectric switch 0. The rising edge of the output of the photoelectric switch 0 serves as the interrupt trigger signal for the MCU. In the interrupt response function, the MCU reads the data held in the latch and converts it into position information.

2. The location identification system according to claim 1, characterized in that: The number of short teeth in the light-shielding plate is N, which can represent 2 to the power of N positions.

3. The location identification system according to claim 2, characterized in that: The inverter is used to make the signal edge steeper while filtering out narrow pulse interference.

4. The location identification system according to claim 3, characterized in that: The latch signal of the latch is triggered by the rising edge of the output of photoelectric switch 0.

5. The location identification system according to claim 4, characterized in that: The MCU reads the high and low status of the data pins, converts them into position information, and reports it to the host computer system.

6. The location identification system according to claim 5, characterized in that: The photoelectric switch 0 is triggered to read the current position whenever the long tooth plate passes through it.

7. The location identification system according to claim 6, characterized in that: The light-shielding baffles have different teeth at each position.

8. The location identification system according to claim 7, characterized in that: The short teeth are encoded using BCD encoding. If all four digits of the dental radiograph are present, it indicates position 15#, encoded as "1111". If the second and third digits are absent, it indicates position 5#, encoded as "1001".

9. The location identification system according to claim 8, characterized in that: The latch is used to ensure that the MCU can read the correct data. The rising edge of the output of photoelectric switch 0 is used as the latch signal of the latch to freeze the blocking status of photoelectric switches 1-N at the current moment.

10. The location identification system according to claim 9, characterized in that: The MCU immediately enters the interrupt function, reads the high and low status of the data pins, converts them into position information, and reports it to the host computer system.

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