Industrial automation control system and method based on VLC and optical power supply

Abstract

The invention relates to the technical field of industrial electronics, and provides an industrial automation control system based on VLC and optical power supply, a VLC modem completes modulation and demodulation tasks of a control side, and a VLC lamp group is used for converting an electric signal output by the VLC modem into an optical signal for emission, receiving an optical signal emitted by a field side and converting the optical signal into an electric signal at the same time. Visible light communication is established between equipment on the field side and the control side, meanwhile, field light power supply is achieved, the field side VLC actuator executes corresponding actions according to control instructions sent by the PLC, the field side VLC collector collects signals and uploads the signals to the PLC, and the field side VLC communicator is used for achieving indirect communication between the PLC and other modules on the field side. Compared with a traditional automatic control system, the system provided by the invention fundamentally overcomes the defects of high deployment difficulty, high material cost, poor signal stability and high maintenance difficulty caused by large-scale wiring.

Description

Technical Field

[0001] The present invention belongs to the technical field of industrial electronics, and in particular relates to an industrial automation control system and method based on VLC and optical power supply. Background Art

[0002] Industrial automation refers to the measurement, manipulation, information processing and process control of the production process according to the predetermined goals through various machines, equipment or systems without direct human intervention. Automation technology is a highly comprehensive technology, covering multiple technical fields such as machinery, microelectronics, computers, machine vision, etc., and is widely used in modern manufacturing. As one of the most critical supporting technologies in the manufacturing industry in the 21st century, industrial automation control technology combines control theory, instrumentation, computers and information technology to achieve detection, control, optimization, scheduling, management and decision-making of industrial production processes, and ultimately achieves the purpose of increasing output, improving quality, reducing energy consumption and ensuring safety. Whether it is an enterprise pursuing high-speed batch manufacturing or a small-scale manufacturing unit that prefers flexible customization, they are increasingly relying on industrial automation systems to achieve their production goals.

[0003] Traditional industrial automation control systems usually use Figure 1 The topology shown in the figure consists of programmable logic controllers (PLCs), communication devices (such as distributed digital input / output modules, distributed analog input modules, etc.), actuators, data collectors and other units. In terms of the connection between components, the system mainly uses a large number of digital output (DO), digital input (DI), analog input (AI) and other cables, as well as a small number of communication bus connection cables to achieve information interaction and control logic execution, and power supply cables also need to be laid. Although this structure is relatively mature and stable in terms of control function realization, with the increasing complexity of the industrial production environment and the continuous expansion of the system scale, this type of traditional control system has gradually exposed a series of problems caused by the large number of connection cables.

[0004] Specifically, the deployment of a large number of connecting cables in traditional control systems brings significant construction workload and high material costs; in addition, long-distance wiring is prone to electromagnetic compatibility and electromagnetic interference (EMI) problems, and may cause voltage drops, which may cause terminal equipment to misjudge signals. In harsh industrial environments, cables that are exposed for a long time also face the risk of reduced reliability. Once a fault occurs, the troubleshooting and repair process is time-consuming and labor-intensive. In serious cases, the system will be shut down for a long time, affecting the efficiency and safety of enterprise operations.

[0005] To overcome the above problems, some industrial automation equipment manufacturers and research teams have tried to use wireless communication to replace traditional long-distance wired connections to reduce cable deployment and improve system flexibility. However, this solution has also posed a new round of technical challenges. In large-scale industrial control systems, if star, tree, or mesh topologies are used for electromagnetic wireless communication, a large number of data exchange links or channels are required, making signal crosstalk extremely likely to occur, affecting system stability, and thus posing higher requirements for communication coding and decoding algorithms and the anti-crosstalk ability of hardware, further driving up the overall cost of system design, manufacturing, and deployment. If a ring network topology is used, although channel interference can be reduced, since data transmission needs to pass through multiple nodes, it is difficult to guarantee the system response time and real-time performance. Even if a bus network structure is selected, there are also problems such as the increased number of nodes causing pressure on the data distribution and arbitration mechanisms, thus affecting the timeliness and reliability of the system.

[0006] To further avoid the above deficiencies brought by radio communication, some researchers have tried to introduce spread-spectrum communication technology. However, with the increasingly tight radio spectrum resources, large-scale deployment of spread-spectrum communication will undoubtedly exacerbate the problems of frequency band conflict and interference, and the chip processes and channel characteristics relied on by high-frequency communication are still difficult to make breakthroughs in the short term, further restricting the engineering application feasibility of such technologies. Therefore, to fundamentally solve the problem of excessive connecting cables in current industrial automation control systems, it is necessary to break through the traditional electromagnetic wireless communication ideas and find a new signal access and transmission method by taking a different approach.

[0007] In recent years, visible light communication (VLC) has gradually become an important research direction in the communication field due to its advantages such as rich spectrum resources, low cost, low power consumption, high speed, and high confidentiality. This technology uses ordinary LED lighting devices as signal transmitters, modulates the rapid flashing of LED lights (imperceptible to the human eye), and uses optical signals as communication media for data transmission; at the receiving end, a photodiode or other photosensitive elements are used to receive the optical signal and restore the original data. Thanks to the wide use of LED lighting devices in industrial scenarios, visible light communication has a good deployment foundation and is gradually regarded by the academic and industrial circles as a potential technology to replace cables and electromagnetic wireless communication. Currently, domestic and foreign scholars have developed a variety of visible light communication systems based on different frequency points, bandwidths, and modulation methods, with good test results and the basis for popularizing and applying them to industrial automation systems.

[0008] However, the application of existing visible light communication technology in industrial automation control still faces many practical obstacles. For example, the combination of optical fiber and radio frequency module is used to realize wireless communication between the master PLC and field devices. Although it can reduce some cables, the stability of optical fiber deployment on devices with mechanical vibration is poor and it is easily damaged. In addition, it is still difficult to avoid electromagnetic interference problems in large-scale deployment of electromagnetic wireless communication, which affects the system stability. Moreover, the existing methods have problems such as high system integration complexity, high maintenance cost, and insufficient environmental adaptability.

[0009] In summary, although radio communication and visible light communication have alleviated the disadvantages brought by excessive connection cables in traditional industrial automation systems to a certain extent, they still face challenges in terms of stability, real-time performance, system complexity, and communication reliability. Therefore, there is an urgent need to propose a new solution that can achieve efficient, stable, and scalable data communication methods in complex industrial environments, so as to completely solve the common technical problems in existing industrial automation control systems. Summary of the Invention

[0010] The present invention provides an industrial automation control system and method based on VLC and optical power supply to solve the problems of poor stability, complex deployment, and insufficient environmental adaptability in the prior art. In order to solve the above technical problems, the embodiments of the present invention disclose the following technical solutions: One aspect of the present invention provides an industrial automation control system based on VLC and optical power supply, including a PLC controller, a VLC modem, and a VLC lamp group arranged on the control side, and a VLC actuator, a VLC collector, and a VLC communicator arranged on the field side and powered by light energy, wherein: The PLC controller is communicatively connected to the VLC modem, and is used for generating and processing electrical signals, and sending and receiving electrical signals through the VLC modulation regulator; The VLC modem is communicatively connected to the VLC lamp group, and is used for processing the conversion operation between electrical signals and modulation signals, and sending and receiving modulation signals through the VLC lamp group; The VLC lamp group is composed of LED lamps with visible light communication functions, and is used for processing the conversion operation between modulation signals and visible light signals, and emitting and receiving visible light signals through free optical paths; The VLC actuator is communicatively connected to multiple field devices, and is used for receiving visible light signals through free optical paths, and parsing them into control instructions and sending them to the field devices; The VLC collector is communicatively connected to multiple field sensors, and is used for converting the status data collected by the field sensors into visible light signals, and emitting them to the VLC lamp group through free optical paths; The VLC communicator is communicatively connected to multiple external devices, and is used to convert visible light signals into communication data and send it to the external devices, and to convert the communication data transmitted by the external devices into visible light signals and emit them to the VLC lamp group through a free optical path.

[0011] Optionally, the VLC actuator, the VLC collector, and the VLC communicator all have a photovoltaic module, which is used to convert the light energy generated by the VLC lamp group into electrical energy to supply power to themselves.

[0012] Optionally, the PLC controller includes a control signal module and a communication signal module, where the control signal module is used to generate a baseband control signal according to a preset control logic and send it to the VLC modem; the communication signal module is used to generate a master station baseband signal according to a preset communication logic and send it to the VLC modem.

[0013] Optionally, the VLC modem includes an encoding and modulation module, which is used to encode and modulate the baseband control signal to obtain a modulated control signal and send it to the VLC lamp group, and to encode and modulate the master station baseband signal to obtain a master station modulated signal and send it to the VLC lamp group.

[0014] Optionally, the VLC lamp group includes an optical signal conversion module, which is used to convert the modulated control signal into an optical control signal and emit it to the VLC actuator through a free optical path, and to convert the master station modulated signal into a master station optical signal and emit it to the VLC communicator through a free optical path.

[0015] Optionally, the VLC actuator is communicatively connected to multiple field devices, and is used to restore the optical control signal to a modulated control signal, and to restore the modulated control signal to a baseband control signal and send it to the control unit of the corresponding field device.

[0016] Optionally, the VLC collector is communicatively connected to multiple field sensors, and is used to encode and modulate the status data collected by the field sensors to obtain a modulated acquisition signal, and to perform an optoelectronic conversion operation on the modulated acquisition signal to obtain an optical acquisition signal and emit it to the VLC lamp group through a free optical path.

[0017] Optionally, the VLC communicator is communicatively connected to multiple external devices, including an external transmission module and a feedback transmission module, where the external transmission module is used to perform optoelectronic conversion on the master station optical signal to restore the master station modulated signal, and to decode and demodulate the master station modulated signal to restore the master station baseband signal and send it to the corresponding external device; The feedback transmission module is used to encode and modulate the substation baseband signal transmitted by the external device to obtain the substation modulated signal, and, after performing optoelectronic conversion on the substation modulated signal, obtain the substation optical signal, and transmit it to the VLC lamp group through a free optical path.

[0018] Optionally, the VLC lamp group further includes a modulation signal conversion module, which is used to convert the optical acquisition signal into a modulation acquisition signal and then send it to the VLC modem, and, convert the substation optical signal into a substation modulated signal and then send it to the VLC modem.

[0019] Optionally, the VLC modem further includes a decoding and demodulation module, which is used to decode and demodulate the modulation acquisition signal to obtain the baseband acquisition signal and send it to the PLC controller, and, decode and demodulate the substation modulated signal to obtain the substation baseband signal and send it to the PLC controller.

[0020] Optionally, the VLC lamp group includes a lamp group controller, which is used to dynamically adjust the output DC voltage to adapt to the operating voltage of the LED lamps used in the VLC lamp group.

[0021] Another aspect of the present invention provides an industrial automation control method based on VLC and optical power supply, which is applied to the industrial automation control system based on VLC and optical power supply provided in the foregoing aspect.

[0022] An industrial automation control system and method based on VLC and optical power supply disclosed by the present invention use visible light wireless communication technology to replace a large number of wired signal transmissions from the control side to the field side in the prior art, saving a large number of signal transmission cables, thereby greatly reducing the deployment cost, deployment difficulty, and maintenance difficulty of the cable part in the industrial automation control system. It also saves the cost pressure of PLC selection caused by the use requirements of a large number of DI / DO points of PLC in the traditional industrial automation control system.

[0023] In addition, the system and method disclosed by the present invention use on-site optical power supply technology to supply power to the on-site VLC actuators, VLC collectors, and VLC communicators, which not only simplifies a large number of power supply cables on the site side, but also reduces the deployment cost of the cable part on the site side and the energy consumption on the site side.

[0024] Due to the simplification of a large number of signal transmission cables and power supply cables, the signal crosstalk problem between cables in the industrial field is greatly improved, as well as the problem of misjudgment of signals by terminal devices caused by excessive voltage drop on the line during long-distance wiring.

[0025] The system and method disclosed by the present invention only need to add a VLC modem based on the PLC controller on the control side, and slightly modify the original lighting devices. On the field side, only the original actuators, collectors, and communication devices need to be replaced with VLC actuators, VLC collectors, and VLC communicators, without any additional operations. The deployment difficulty and electrical connection complexity are extremely low, and it is very easy to maintain.

[0026] Since there are some field-side devices that are inconvenient to access through visible light communication in practical applications, therefore, in the present invention, the VLC communicator provides a wired bus communication interface, which provides extremely strong scalability for the system and has field universality.

[0027] At the same time, the visible light wireless communication technology adopted by the present invention, compared with the traditional radio communication technology, has rich free spectrum resources, hardly generates electromagnetic interference, supports ultra-high-speed data transmission, is extremely suitable for high-density indoor networking, and has extremely high stability.

[0028] The description of the invention content is provided to introduce the selection of concepts in a simplified form, which will be further described in the specific implementation manners below. The invention content is not intended to identify the important features or essential features of the present disclosure, nor is it intended to limit the scope of the present disclosure. Brief Description of the Drawings

[0029] By describing the exemplary embodiments of the present disclosure in more detail in conjunction with the drawings, the above and other objects, features, and advantages of the present disclosure will become more obvious. Among them, in the exemplary embodiments of the present disclosure, the same reference numerals generally represent the same components.

[0030] Figure 1 It is a schematic structural diagram of a traditional industrial automation control system provided by an embodiment of the present invention; Figure 2 It is a schematic structural diagram of an industrial automation control system based on VLC and optical power supply provided by an embodiment of the present invention; Figure 3 It is a schematic structural diagram of a traditional LED lamp group provided by an embodiment of the present invention; Figure 4 It is a schematic structural diagram of a VLC lamp group provided by an embodiment of the present invention; Figure 5 It is a schematic structural diagram of an original fully automated motor painting production line provided by an embodiment of the present invention; Figure 6 It is a schematic structural diagram of a transformed fully automated motor painting production line provided by an embodiment of the present invention. Detailed Description of the Invention

[0031] Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure will be more thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art.

[0032] As used herein, the term "comprising" and variations thereof mean open inclusion, i.e., "including but not limited to". Unless otherwise specified, the term "or" means "and / or". The term "based on" means "at least partially based on". The terms "an example embodiment" and "an embodiment" mean "at least one example embodiment". The term "another embodiment" means "at least one additional embodiment". The terms "first", "second", etc. may refer to different or the same objects. Other explicit and implicit definitions may also be included below.

[0033] Figure 2 A schematic structural diagram of an industrial automation control system based on VLC and optical power supply provided for an embodiment of the present invention is as Figure 2 shown. The system includes a PLC controller 1, a VLC modem 2, and a VLC lamp group 3 disposed on the control side, and a VLC actuator 4, a VLC collector 5, and a VLC communicator 6 disposed on the field side.

[0034] In an embodiment disclosed by the present invention, the VLC actuator 4, the VLC collector 5, and the VLC communicator 6 all have photovoltaic modules for efficiently converting the light energy from the VLC lamp group 3 into electrical energy to power their own electronic circuits and functional modules. The photovoltaic module includes a highly sensitive photoelectric conversion unit that can perform energy harvesting while receiving the VLC optical signal, realizing the coordinated operation of communication and power supply, avoiding the access of external power supplies, and improving the flexibility of the layout of on-site devices and the overall simplification degree of the system.

[0035] The system disclosed in the embodiments of the present invention covers various signal transmission links and processing processes during operation. For example, a control signal link, a status acquisition link, and a bus communication link. Each component of the system will be specifically described below: (I) PLC controller (acting on the downlink paths of the control signal link and the master station communication link) The PLC controller 1 can generate and process electrical signals, and send or receive electrical signals through the VLC modulation regulator 2.

[0036] First, the downlink path of the PLC controller 1 will be described. The downlink path covers the control signal link and the master station communication link.

[0037] The PLC controller 1, as the control unit, undertakes the core tasks of global system scheduling, decision-making, and data processing. The PLC controller 1 can judge and perform arithmetic processing on control commands according to the pre-set control logic, so as to generate corresponding control outputs; at the same time, the PLC controller 1 can also organize and generate corresponding data according to the communication logic for the communication protocols and data interaction requirements between various nodes in the system, so as to ensure the orderly circulation of data in the system.

[0038] In an embodiment disclosed by the present invention, the PLC controller 1 includes a control signal module and a communication signal module. Among them, the control signal module is used to generate a baseband control signal according to the pre-set control logic and send it to the VLC modem 2; the communication signal module is used to generate a master station baseband signal according to the pre-set communication logic and send it to the VLC modem 2.

[0039] The signals output by the PLC controller 1 include two categories: baseband control signals and master station baseband signals. Among them, the baseband control signal is an original digital control instruction generated by the PLC controller 1 under the action of the internal control logic and used to drive the VLC actuator 4 to perform on-site actions, and has not been modulated or encoded. The master station baseband signal is an original data signal generated by the PLC controller 1 as the bus master for communication purposes under the action of the bus communication logic, and is mainly used for master-slave communication with external devices (such as sensor arrays, smart terminals) connected to the VLC communicator 6.

[0040] These baseband signals will be transmitted to the VLC modem 2, and the latter will complete the modulation and encoding operations, so as to be converted into modulation signals suitable for optical channel transmission, and then transmitted to the free optical path through the VLC lamp group 3 to realize the wireless optical communication control function.

[0041] (2) VLC Modem (acting on the downstream path of the control signal link and the master station communication link) The VLC modem 2 is used to process the conversion operation between electrical signals and modulation signals, and send or receive modulation signals through the VLC lamp group 3.

[0042] First, the downstream path of the VLC modem 2 will be described. This downstream path covers the control signal link and the master station communication link.

[0043] In an embodiment disclosed by the present invention, the VLC modem 2 includes an encoding and modulation module, which is used to perform encoding and modulation processing on the baseband control signal to obtain a modulation control signal and send it to the VLC lamp group 3, and perform encoding and modulation processing on the master station baseband signal to obtain a master station modulation signal and send it to the VLC lamp group 3.

[0044] The VLC modem 2 receives two different types of baseband signals from the PLC controller 1, namely the baseband control signal and the master station baseband signal. After these two types of baseband signals enter the VLC modem 2, first, they are subjected to encoding processing by the encoding and modulation module. The encoding processing can include error detection encoding (such as CRC), channel encoding (such as Manchester encoding, 4B / 5B encoding), etc., to enhance the anti-interference ability and recognizability of the signals during transmission. Then, the encoded signals will enter the modulation processing stage. The modulation processing can convert the digital encoded signals into analog or quasi-analog modulation signals suitable for LED modulation. For example, modulation methods applicable to VLC such as on-off keying modulation (OOK), pulse width modulation (PWM), and quadrature amplitude modulation (QAM) can be used.

[0045] Finally, the modulation control signal and the master station modulation signal output by the encoding and modulation module respectively represent the instructions for on-site action control and bus communication in the system. These modulation signals will be sent to the VLC lamp group 3. After completing the optoelectronic conversion operation in the lamp group, they will be emitted in the form of visible light through the free optical path.

[0046] (III) VLC Lamp Group (Acting on the Downlink Paths of the Control Signal Link and the Master Station Communication Link) The VLC lamp group 3 is used to handle the conversion operation between modulation signals and visible light signals, and transmit or receive visible light signals through the free optical path. For the structure of the VLC lamp group 3 in this application, reference can be made to Figure 3 For the structure of the traditional LED lamp group, reference can be made to Figure 4 Based on the traditional LED lamp group, the VLC lamp group 3 disclosed in this application can be obtained by making modifications.

[0047] First, the downlink path of the VLC lamp group 3 will be described. This downlink path covers the control signal link and the master station communication link.

[0048] In an embodiment disclosed in the present invention, the VLC lamp group 3 includes an optical signal conversion module, which is used to convert the modulation control signal into an optical control signal and transmit it to the VLC actuator 4 through the free optical path, and convert the master station modulation signal into a master station optical signal and transmit it to the VLC communicator 6.

[0049] The optical signal conversion module is closely integrated with the LED light source, receives the modulation control signal sent by the VLC modem 2, and controls the on-off state or brightness change of the LED lamp core in real time according to the modulation method (such as OOK, PWM, etc.), thereby generating the corresponding optical control signal in the free optical path. This optical control signal carries control instruction information, propagates along the free optical path, and is finally received by the VLC actuator 4 to drive the on-site equipment to perform corresponding actions.

[0050] On the other hand, the optical signal conversion module also receives the master station modulation signal transmitted from the VLC modem 2, which represents the communication data interaction content between the control side and the external device. This module also converts the master station modulation signal into a master station optical signal by modulating and controlling the light-emitting state of the LED lamp, and transmits it to the VLC communicator 6 on the field side through the free optical path. The master station optical signal can be received by the VLC communicator 6, restored to the master station baseband signal, and further transmitted to the connected external device.

[0051] (4) VLC actuator (acting on the downstream path of the control signal link) The VLC actuator 4 is used to receive the visible light signal through the free optical path and parse it into a control instruction to be sent to the field device. The following describes the downstream path of the VLC actuator 4, which covers the control signal link.

[0052] In an embodiment disclosed by the present invention, the VLC actuator 4 is communicatively connected to a variety of field devices, and is used to restore the optical control signal to a modulation control signal, and further restore the modulation control signal to a baseband control signal and send it to the control unit of the corresponding field device.

[0053] The VLC actuator 4 receives the optical control signal transmitted by the VLC lamp group 3 through the free optical path through its integrated optical receiving component (such as a high-sensitivity photodiode or a photodetector), and this optical control signal carries the control instruction information of the control side.

[0054] After receiving the optical signal, the photoelectric conversion module inside the VLC actuator 4 first converts it into a corresponding modulation control electrical signal. Subsequently, the decoding and demodulation module inside the VLC actuator 4 performs restoration processing on the modulation signal, including modulation mode identification (such as OOK, PWM, FSK, etc.), carrier removal, symbol identification, and protocol decoding, etc., and finally obtains the original, unmodulated baseband control signal.

[0055] The baseband control signal contains specific control instructions for the field device, such as "start the motor", "adjust the valve opening to 70%", or "turn off the relay K1", etc. The VLC actuator 4 can send the baseband control signal to the control units of various field devices communicatively connected to it (such as PLC sub-modules, embedded microcontrollers, actuator drive boards, etc.) according to the system configuration. The communication connection methods can include industrial common interfaces such as SPI, I²C, RS-485, CAN, etc., and indirect control can also be achieved through intermediate relay or electrical control modules.

[0056] (5) VLC collector (acting on the upstream path of the status acquisition link) The VLC collector 5 is used to convert the status data collected by on-site sensors into visible light signals and transmit them to the VLC lamp group 3 through a free optical path. The following describes the upstream path of the VLC collector 5, which covers the status collection link.

[0057] In an embodiment disclosed by the present invention, the VLC collector 5 is communicatively connected to multiple on-site sensors, and is used to encode and modulate the status data collected by the on-site sensors to obtain a modulated collection signal, and, after performing an optoelectronic conversion operation on the modulated collection signal, obtain an optical collection signal and transmit it to the VLC lamp group 3 through a free optical path.

[0058] The VLC collector 5 establishes a data connection with various types of on-site sensors through its communication interface. The connected sensors include but are not limited to: temperature sensors, pressure sensors, liquid level sensors, vibration sensors, current / voltage sensors, infrared or optoelectronic switches, etc.

[0059] After the sensors collect the status data of the environment or equipment, the VLC collector 5 first formats these original measurement data or discrete status information, and converts them into digital information uniformly recognized by the system according to a preset communication protocol to form a baseband collection signal. The baseband collection signal is an unmodulated digital electrical signal that carries complete on-site status information for analysis by the control side.

[0060] After that, the encoding and modulation module inside the VLC collector 5 encodes (such as NRZ, Manchester encoding) and modulates (such as OOK, FSK, etc.) the baseband collection signal to generate a modulated collection signal.

[0061] After modulation, the VLC collector 5 converts the modulated collection signal into an optical collection signal through its optical emission module (such as a high-brightness LED or a laser diode), and this optical signal is transmitted to the VLC lamp group 3 through a free optical path.

[0062] The optical collection signal carries the equipment status and environmental information sensed by the on-site sensors. After receiving this signal, the VLC lamp group 3 restores it to an electrical signal and transmits it back to the control side PLC controller 1 through the VLC modem 2, realizing remote, non-contact real-time sensing and analysis of the on-site status.

[0063] (VI) VLC communicator (acting on the upstream path and downstream path of the bus communication link) The VLC communicator 6 is used to convert visible light signals into communication data and send them to external devices, and, convert the communication data transmitted by external devices into visible light signals and transmit them to the VLC lamp group 3 through a free optical path.

[0064] The VLC communicator 6 is deployed on the field side of the industrial automation system and serves as a bridging module between the control side and external devices. Through its built-in optoelectronic conversion and signal processing capabilities, the VLC communicator 6 enables two-way, non-contact optical communication between the control side and various external devices.

[0065] In an embodiment disclosed by the present invention, the VLC communicator 6 includes an external transmission module and a feedback transmission module, and the two cooperate to complete the parsing, transmission, restoration, and multiplexing of bus data.

[0066] The following describes the downlink path (external transmission module) of the VLC communicator 6, which covers the bus communication link.

[0067] The external transmission module is used to restore the master station optical signal to the master station modulation signal by means of optoelectronic conversion operation, and, after decoding and demodulating the master station modulation signal, restore the master station baseband signal and send it to the corresponding external device.

[0068] The external transmission module is used to process the master station optical signal transmitted from the control side through the free optical path. This module first performs optoelectronic conversion operation on the master station optical signal through an optoelectronic receiver (such as a PIN photodiode) to generate the master station modulation signal. Then, this module further restores the master station modulation signal to the master station baseband signal through the internal decoding unit and modulation and demodulation unit, that is, a digital electrical signal stream with clear logical meaning (such as control commands, configuration parameters, etc.). Finally, the master station baseband signal is output through a standard industrial interface and sent to the external device.

[0069] The following describes the uplink path (feedback transmission module) of the VLC communicator 6, which covers the bus communication link.

[0070] The feedback transmission module is used to perform encoding and modulation operations on the slave station baseband signal transmitted by the external device to obtain the slave station modulation signal, and, after performing optoelectronic conversion on the slave station modulation signal to obtain the slave station optical signal, transmit it through the free optical path to the VLC lamp group 3.

[0071] The feedback transmission module is mainly responsible for accessing the slave station baseband signal returned by the external device (such as a bus slave station or a sensor gateway) to the VLC communication system. This module first performs encoding and modulation processing on the slave station baseband signal to generate a slave station modulation signal suitable for visible light communication, and the modulation method can be technologies such as OOK (On-Off Keying), PWM (Pulse Width Modulation), VPPM (Variable Pulse Width Pulse), etc. Subsequently, the optical transmitter (such as an LED or an LD) in the module converts the modulation signal into a slave station optical signal and transmits it through the free optical path to the VLC lamp group 3, which is then relayed and uploaded to the control side PLC controller 1 to realize the status feedback and data upload of the external device.

[0072] The VLC communicator 6 has the ability to be compatible with various industrial protocol devices, and is particularly suitable for typical industrial bus types such as ProfiNet, EtherCAT, CANopen, Modbus RTU / TCP, EtherNet / IP, etc. By integrating the corresponding protocol stack or physical interface conversion module inside the VLC communicator 6, the system can flexibly adapt to the communication requirements under various control protocols, achieving true "seamless fusion of optical and electrical protocols".

[0073] (VII) VLC lamp group (acting on the upstream paths of the status acquisition link and the bus communication link) The following describes the upstream path of the VLC lamp group 3, which covers the status acquisition link and the bus communication link.

[0074] In an embodiment disclosed in the present invention, in addition to the function of transmitting optical control signals and master station optical signals outward, the VLC lamp group 3 is further integrated with a modulation signal conversion module to achieve the reverse reception and processing of signals from the field side, thereby completing the two-way communication closed-loop at the system level. As the signal reception and processing unit in the lamp group, the main function of the modulation signal conversion module is: to convert the upstream optical signals received from the free optical path (including optical acquisition signals and sub-station optical signals) into modulation signals recognizable by the system (modulation acquisition signals and sub-station modulation signals), and transmit these electrical signals to the VLC modem 2 for subsequent processing.

[0075] Specifically, the modulation signal conversion module includes the following two main functional paths: Optical acquisition signal processing path: When the VLC lamp group 3 receives the optical acquisition signal emitted by the VLC collector 5, the modulation signal conversion module first converts the optical signal into the corresponding modulation acquisition signal through an optoelectronic conversion device. Then, the modulation acquisition signal is sent to the VLC modem 2 connected to the VLC lamp group 3 for demodulation and decoding processing, and finally restored to the baseband acquisition signal and reported to the control-side PLC controller 1.

[0076] Sub-station optical signal processing path: When the sub-station optical signal from the VLC communicator 6 arrives at the VLC lamp group 3 through the free optical path, the module also first performs optoelectronic conversion operations to restore it to the sub-station modulation signal. The sub-station modulation signal represents the response data or status feedback of the field-side bus communication device, and is then transmitted to the VLC modem 2, which completes demodulation and parsing and uploads it to the PLC controller 1 for data integration or further control logic processing.

[0077] With the introduction of the modulation signal conversion module, the VLC lamp group 3 not only assumes the role of the "optical transmitter" in the traditional sense of the VLC communication system, but also has the function of the "optical receiving relay station", making the VLC lamp group 3 a true two-way signal collection and distribution hub between the control side and the field side.

[0078] (VIII) VLC Modem (acting on the upstream paths of the status acquisition link and the bus communication link) The following describes the upstream paths of the VLC modem 2, which cover the status acquisition link and the bus communication link.

[0079] In an embodiment disclosed by the present invention, the VLC modem 2 further includes a decoding and demodulation module, which is used to decode and demodulate the modulated acquisition signal and the substation modulation signal forwarded from the VLC lamp group 3, respectively restore them to the baseband acquisition signal and the substation baseband signal, and send the restored signals to the PLC controller 1 for unified management and logical processing.

[0080] Among them, the processing flow for the modulated acquisition signal is as follows: after the VLC modem 2 receives the modulated acquisition signal transmitted by the VLC lamp group 3, the decoding and demodulation module first identifies the modulation method adopted by it (such as pulse position modulation, amplitude shift keying, etc.), and performs corresponding demodulation operations accordingly to restore the analog or digital modulation signal to the original baseband electrical signal. Subsequently, the demodulated electrical signal is parsed by the decoding and demodulation module to obtain specific status information data (such as sensor values, voltage, current, displacement, temperature and humidity, etc.), and finally a structured baseband acquisition signal is formed and transmitted to the PLC controller 1 for logical judgment, trend analysis or alarm response.

[0081] The processing flow for the substation modulation signal is as follows: when the VLC modem 2 receives the substation modulation signal transmitted by the VLC lamp group 3, the decoding and demodulation module calls the corresponding demodulation and decoding algorithms according to its communication protocol type (such as EtherCAT, ProfiNet, CANopen, etc.) to restore it to the substation baseband signal that conforms to the bus communication format. This signal represents the response information, status feedback or data upload content of external devices. After decoding, it is also transmitted to the PLC controller 1 in a timely manner, and the main station logic module performs response matching, loop verification or further instruction issuance.

[0082] The above is the description of each part of the system disclosed by the present invention.

[0083] In an embodiment disclosed by the present invention, as Figure 3 shown, the VLC lamp group 3 includes a lamp group controller, which is used to dynamically adjust the output DC voltage to adapt to the operating voltage of the LED lamps used in the VLC lamp group 3.

[0084] The lamp group controller in the VLC lamp group 3 not only undertakes the core task of controlling the LED light emission behavior, but also has the ability of dynamic voltage regulation, which is used to intelligently adjust the output DC voltage according to the characteristics of the LED lamp core to adapt to the stable operation requirements of different types of LEDs in the visible light communication (VLC) working mode.

[0085] Specifically, the LED lamp cores used in the VLC system may have different driving voltage requirements. For example, high-brightness white LEDs may require relatively high voltages (such as 12V, 24V), while some low-power indicator LEDs may operate within the voltage range of 3.3V or 5V. To achieve compatibility with different LED lamp cores, the lamp group controller uses the built-in constant voltage adjustment circuit or PWM control module to monitor the LED working status in real time and output an accurate DC voltage according to the system-set or automatically recognized LED parameters, so as to avoid problems such as LED heating, light decay, or communication distortion caused by overvoltage or undervoltage.

[0086] In addition, when performing VLC signal modulation, the lamp group controller also needs to ensure that the voltage adjustment does not affect the integrity of the modulation waveform and communication synchronization. Therefore, the lamp group controller is usually equipped with a high-speed response voltage stabilization control algorithm to balance dimming modulation and voltage stabilization, ensure that the amplitude, frequency, or duty cycle of the modulation signal is accurately transmitted in the optical domain, and avoid error codes or distortion.

[0087] To facilitate understanding of the data transmission process between various parts of the system disclosed in the embodiments of the present invention, the above content is summarized as follows: I. Control signal link (from PLC controller to VLC actuator) 1. PLC Generate baseband control signals.

[0088] 2. VLC modem Encode and modulate the baseband control signal → obtain the modulated control signal → send it to the VLC lamp group.

[0089] 3. VLC lamp group Convert the modulated control signal from electricity to light → obtain the optical control signal → send it to the VLC actuator.

[0090] 4. VLC actuator Receive the optical control signal → convert it from light to electricity → obtain the modulated control signal → decode and demodulate it → obtain the baseband control signal → send it to the field device.

[0091] II. Status acquisition link (from VLC collector to PLC controller) 1. VLC collector Collect on-site status → Generate baseband acquisition signal → Encode and modulate → Obtain modulated acquisition signal → Electrical-to-optical conversion → Obtain optical acquisition signal → Transmit to VLC lamp group.

[0092] 2. VLC lamp group Receive optical acquisition signal → Optical-to-electrical conversion → Obtain modulated acquisition signal → Transmit to VLC modem.

[0093] 3. VLC modem Receive modulated acquisition signal → Decode and demodulate → Obtain baseband acquisition signal → Transmit to PLC controller.

[0094] 4. PLC controller Process the baseband acquisition signal.

[0095] III. Bus communication link (I) Downlink path (from PLC controller to external device) 1. PLC controller Generate master station baseband signal → Transmit to VLC modem.

[0096] 2. VLC modem Master station baseband signal → Encode and modulate → Obtain master station modulated signal → Transmit to VLC lamp group.

[0097] 3. VLC lamp group Receive master station modulated signal → Electrical-to-optical conversion → Obtain master station optical signal → Transmit to VLC communicator.

[0098] 4. VLC communicator Receive master station optical signal → Optical-to-electrical conversion → Obtain master station modulated signal → Decode and demodulate → Obtain master station baseband signal → Transmit to external device.

[0099] (II) Uplink path (from external device to PLC controller) 1. External device Generate slave station baseband signal → Transmit to VLC communicator.

[0100] 2. VLC communicator Receive slave station baseband signal → Encode and modulate → Obtain slave station modulated signal → Electrical-to-optical conversion → Obtain slave station optical signal → Transmit to VLC lamp group.

[0101] 3. VLC lamp group Receive slave station optical signal → Optical-to-electrical conversion → Obtain slave station modulated signal → Transmit to VLC modem.

[0102] 4. VLC modem Received sub-station modulation signal → Demodulation and decoding → Obtained sub-station baseband signal → Sent to the PLC controller.

[0103] 5. PLC controller Receives the sub-station baseband signal and processes it.

[0104] In modern industrial automation systems, the communication between PLC controllers and peripheral devices depends on various industrial communication bus protocols. Different manufacturers or different automation systems often adopt one or several of them as the main communication protocols during device selection.

[0105] To enable the system to be flexibly deployed in various industrial field environments, in the embodiments disclosed in the present invention, the VLC modem 2 is designed to support multiple types of communication bus protocols, specifically the following four models: VLC modem (EtherCAT): Suitable for EtherCAT industrial networks characterized by high-speed synchronization, and adapted to mainstream devices such as BECKHOFF and Siemens; VLC modem (ProfiNet): Oriented to the ProfiNet network widely used in manufacturing, and compatible with systems such as Siemens S7 series PLCs; VLC modem (CanOpen): Commonly used in embedded devices and small control networks, suitable for modular device control scenarios; VLC modem (EtherNet / IP): Adapted to control systems such as AB (Rockwell), and supports industrial data communication based on Ethernet.

[0106] By providing model selections on the VLC modem side that are compatible with the PLC controller interface, the system can be directly connected to the existing control system during deployment without replacing the PLC controller or modifying the communication logic, thus effectively reducing the engineering transformation cost and system integration complexity.

[0107] The VLC lamp group 3 can be connected to the VLC modem 2 using a radio frequency cable and can be transformed from a traditional LED lamp group. The traditional LED lamp group consists of LED lamp cores and an LED lamp group controller. The controller is responsible for converting the external lighting power supply from AC to DC and step-down processing, and supplying power to the LED lamp cores. When transforming the traditional LED lamp group into the VLC lamp group 3, only the original LED lamp group controller needs to be removed and replaced with a lamp group controller with VLC function, and at the same time, a radio frequency cable is led out and connected to the VLC modem 2. This transformation method is simple and efficient, avoiding the replacement of the entire lamp group, reducing the engineering cost and complexity, and facilitating the rapid deployment of the VLC system in the existing industrial field.

[0108] Considering that there may be differences in the supply voltages of LED lamp cores in different industrial sites, the controller of the VLC lamp group 3 has the function of dynamically adjusting the DC output voltage, and can adjust according to the actual working voltage requirements of the lamp cores to ensure the normal operation of the LED lamp cores. This voltage adjustment function enhances the versatility and adaptability of the lamp group controller, enabling it to be compatible with various types and specifications of LED lamp cores, and improving the universality and stability of the system on-site.

[0109] Through the above transformation, the VLC lamp group 3 not only retains the lighting function of traditional LED lamps, but also realizes optical signal communication with the VLC modem 2, supporting the optical communication requirements in industrial automation control systems.

[0110] In addition, the controller of the VLC lamp group 3 also supports the on-site optical power supply function, that is, by receiving the light energy from the on-site light source, converting the light energy into electrical energy to supply power to other modules. This optical power supply method avoids the complexity of traditional power wiring, reduces the on-site wiring cost and maintenance difficulty, and is especially suitable for complex or dangerous industrial environments. Through optical power supply, the VLC lamp group 3 realizes a high degree of integration of communication and power supply, further improving the installation flexibility and on-site adaptability of the system.

[0111] In the embodiments disclosed in the present invention, the VLC actuator 4 can be divided into five main models according to different types of its output signals to meet the diverse control requirements in industrial automation sites. Specifically, they include: VLC actuator (relay), VLC actuator (transistor), VLC actuator (voltage), VLC actuator (current), and VLC actuator (pulse). Among them, the VLC actuator (relay) is suitable for relay-type digital output (DO) signals and can achieve switch control through mechanical contacts, and can be applied to occasions that require isolation and high-power switching; the VLC actuator (transistor) is suitable for transistor-type digital output signals, with advantages such as fast response speed and no mechanical wear, and is suitable for fast switch control; the VLC actuator (voltage) can output an analog voltage signal of 0 to 10V and is suitable for driving analog control devices such as dimmers and valves; the VLC actuator (current) outputs an analog current signal of 0 to 20mA and has the characteristic of strong anti-interference ability; the VLC actuator (pulse) can output high-speed pulse signals to meet the control requirements of high-frequency signals such as encoders and counters.

[0112] In addition, for control tasks of different scales and complexities, the VLC actuators are further divided into three models, namely single-channel, four-channel, and eight-channel models, according to the number of output channels. The single-channel actuator is suitable for controlling a single device or control point, with a simple structure and low cost; the four-channel actuator can control up to four outputs simultaneously, suitable for medium and small-scale control systems, improving the device integration and usage efficiency; the eight-channel actuator supports larger-scale multi-point control requirements, suitable for complex industrial automation sites, which can effectively save the number of devices and wiring work, and enhance the system's expansion ability and flexibility.

[0113] Through the above diverse model divisions and channel designs, the VLC actuator 4 can flexibly adapt to different industrial automation application scenarios, meet the diverse requirements of users for the type and scale of control signals, and improve the overall performance of the system and the universality of on-site applications.

[0114] In the embodiments disclosed in the present invention, the VLC collector 5 can be further divided into five models according to the type of the collected signal to meet the diverse signal collection requirements in the industrial field. Specifically, they include: VLC collector (relay), VLC collector (transistor), VLC collector (voltage), VLC collector (current), and VLC collector (pulse). Among them, the VLC collector (relay) is specifically used for collecting relay-type digital output (DO) signals, capable of accurately detecting the relay switch state, and is applied to the monitoring of the on-off state of on-site equipment; the VLC collector (transistor) is suitable for collecting transistor-type digital output signals, with the characteristics of fast response and high reliability, and can be applied to the monitoring of high-frequency switch signals; the VLC collector (voltage) is used to collect analog voltage signals from 0 to 10V, suitable for collecting analog signals output by devices such as sensors and transmitters, and supports multiple industrial sensing signal standards; the VLC collector (current) can collect analog current signals from 0 to 20mA, with strong anti-interference ability and transmission stability; while the VLC collector (pulse) is for collecting high-speed pulse signals, suitable for scenarios such as encoders and counters that require high-speed counting or frequency measurement.

[0115] In addition, for different on-site collection requirements, the VLC collector 5 can be further divided according to the number of collection channels, mainly including single-channel, four-channel, and eight-channel models. The single-channel collector is suitable for collecting a single path of signal, with a simple structure and low cost, and is suitable for point-to-point signal collection; the four-channel collector can collect up to four signals simultaneously, suitable for medium-scale on-site monitoring tasks, improving the collection efficiency and device utilization rate; the eight-channel collector supports larger-scale multi-point collection, meets the real-time monitoring requirements of a large number of signals in complex industrial sites, effectively reduces the number of devices and wiring complexity, and improves the system's expandability and integration.

[0116] Through the above design of multiple models and multiple channels, the VLC collector 5 can flexibly adapt to the signal acquisition requirements of various industrial sites, be compatible with various signal types and acquisition scales, improve the adaptability and reliability of the overall system, and meet the requirements of modern industrial automation control systems for efficient and accurate data acquisition.

[0117] In the embodiments disclosed in the present invention, the VLC communicator 6 can be subdivided into nine models according to the different types of supported wired bus communication interfaces, namely: VLC communicator (Profibus), VLC communicator (EtherCAT), VLC communicator (ProfiNet), VLC communicator (CanOpen), VLC communicator (EtherNet / IP), VLC communicator (ModBus), VLC communicator (RS-232), VLC communicator (IO-Link), and VLC communicator (CC-Link). Each model is designed for the communication bus protocols widely used in the corresponding industrial sites, and can provide a standardized wired bus communication interface for communication devices of the corresponding protocol, ensuring the compatibility and interconnection between systems. For example, the VLC communicator (Profibus) supports the access of Profibus protocol devices and meets the high real-time and reliability requirements of this protocol in the field of automation control; the VLC communicator (EtherCAT) supports the EtherCAT protocol and is suitable for high-performance industrial Ethernet applications; the VLC communicator (ProfiNet) supports the ProfiNet protocol and can be applied to factory automation; the VLC communicator (CanOpen) and the VLC communicator (ModBus) support classic field bus protocols and are compatible with traditional industrial equipment; while the VLC communicator (RS-232) supports point-to-point serial communication and is suitable for the access of simple devices; the VLC communicator (IO-Link) supports the communication of intelligent sensors and actuators, improving the intelligence level of on-site devices; the VLC communicator (CC-Link) is suitable for high-speed industrial network environments. These diverse interface types enable the VLC communicator to flexibly adapt to the needs of different industrial automation systems, improving the convenience and reliability of system integration.

[0118] In addition, the VLC communicator 6 is also classified according to the number of supported bus channels, mainly divided into single-channel, four-channel, and eight-channel models. The single-channel VLC communicator 6 is suitable for simple or point-to-point bus communication requirements. It has a compact structure, low cost, and is convenient for integration in small-scale or single-device scenarios. The four-channel model can manage up to four bus channels simultaneously, making it suitable for medium-scale industrial sites, enhancing the system's communication capabilities and management efficiency, and reducing wiring complexity. The eight-channel model further enhances the system's parallel communication capabilities and is applicable to large-scale industrial automation systems or complex communication environments with multiple devices and nodes, greatly improving the concurrency of data transmission and the flexible scalability of the overall system. Through the flexible configuration of the number of channels, the VLC communicator 6 can meet the diverse industrial field communication requirements from simple to complex, and from small-scale to large-scale, ensuring that the system has strong scalability and stability.

[0119] When the disclosed embodiments of the present invention are actually applied, visible light wireless communication technology is used to replace the wired signal connection from the control side to the field side in traditional industrial automation control systems.

[0120] On the field side, traditional actuators, collectors, and communication devices are integrated with full-duplex visible light communication and on-site optical power supply (power receiving) functions, and are improved to VLC actuators, VLC collectors, and VLC communicators, etc.

[0121] At the same time, on the control side, the original LED lighting fixtures in the factory building are transformed into transmitting / receiving antennas for full-duplex visible light communication, enabling the control side to have full-duplex visible light communication and on-site optical power supply (power supply) functions, and connecting to the PLC through a VLC modem.

[0122] During operation, the PLC on the control side generates a baseband control signal according to the control logic and sends it to the VLC modem. The VLC modem encodes and modulates the baseband control signal to obtain a modulated control signal, which is then transmitted to the VLC lamp group. It is coupled with the DC power supply that drives the VLC lamp group, enabling the VLC lamp group to emit a light control signal while realizing the lighting function. The light control signal is transmitted through the free optical path to the field side, received by the VLC actuator and restored to the modulated control signal, and then further restored to the baseband control signal through demodulation and decoding. The corresponding VLC actuator directly or indirectly responds to the corresponding control operation.

[0123] The VLC collector on the field side directly or indirectly collects status information to generate a baseband collection signal. At the same time, the baseband collection signal is encoded and modulated to obtain a modulated collection signal, which is then converted into an optical collection signal and transmitted. The optical collection signal is transmitted through the free optical path to the control side, received by the VLC lamp group and restored to the modulated collection signal, and then further restored to the baseband collection signal through demodulation and decoding by the VLC modem. The PLC reads the baseband collection signal to identify the field status.

[0124] In addition, the PLC on the control side generates a bus master station transmission signal according to the communication logic and sends it to the VLC modem. After the VLC modem encodes and modulates the bus master station baseband signal to obtain a bus master station modulated signal, it is transmitted to the VLC lamp group of the transmission device, which is coupled to the DC power supply driving the VLC lamp group, enabling the VLC lamp group to emit the bus master station optical signal while realizing the lighting function. The bus master station optical signal is transmitted through the free optical path to the field side, received by the VLC actuator and restored to the bus master station modulated signal, and then further restored to the bus master station baseband signal through demodulation and decoding for the external bus communication device connected to the VLC communicator by wire to read; the VLC communicator receives the bus slave station baseband signal sent by the external communication device connected by wire, and at the same time modulates the bus slave station baseband signal to obtain a bus slave station modulated signal, and emits it after converting it into a bus slave station optical signal. The bus slave station optical signal is transmitted through the free optical path to the control side, received by the VLC lamp group and restored to the bus slave station modulated signal, and then further restored to the bus slave baseband transmission signal through demodulation and decoding by the VLC modem for the PLC to read.

[0125] The following uses an actual application case to illustrate the technical effects that can be achieved by the embodiments of the present invention: Such as Figure 5 As shown, a certain deceleration motor manufacturing factory currently has a fully automated motor painting production line. The field side structure includes a loading area, an operation area, and an unloading area. Workpieces are transported through three transmission chains and lifting cables, and multiple transmission motors, clutches, rolling shutters, nozzles, sensors, RFID readers and other equipment are used for collaborative operation. The control side is centrally controlled by a PLC, and each device is directly connected to the power supply distribution box and various ports of the PLC by wire to achieve power supply and signal acquisition and control.

[0126] The main problems existing in its existing system are: 1. Cable disconnection fault: The control signal, acquisition signal, and communication cable are broken due to natural aging or mechanical stress, affecting the system stability. 2. Signal crosstalk: Signal crosstalk between cables causes misjudgment of terminal equipment, resulting in abnormal control. 3. Voltage drop caused by long-distance cable routing: The line is long, the voltage drop is too high, the signal quality deteriorates, and the accuracy of acquisition and control is affected. 4. Overvoltage problem of the low-voltage power supply system: Frequent relay switching causes overvoltage of the power supply rail, damaging the on-site low-voltage power supply equipment.

[0127] According to the system provided in the embodiments of the present invention, it is transformed, as Figure 6 shown, specifically: 1. New equipment added on the control side Add a VLC modem (EtherCAT) in the original PLC control cabinet and connect it through the EtherCAT port of the PLC.

[0128] 2. On-site equipment transformation Four groups of LED lights on the factory building ceiling are transformed into four VLC light groups (the first to the fourth VLC light groups) for emitting optical control signals.

[0129] 3. On-site installation An eight-channel VLC actuator (relay) controls the first clutch, the second clutch, the first rolling shutter, the second rolling shutter, the first nozzle, and the second nozzle.

[0130] A four-channel VLC actuator (current) controls three drive motors and an air heating dryer.

[0131] An eight-channel VLC collector (transistor) collects signals from five position sensors.

[0132] A single-channel VLC communicator (IO-Link) realizes the IO-Link bus communication between the PLC and the RFID reader.

[0133] 4. Power supply method The VLC on-site equipment is powered by the lighting, eliminating the need for complex on-site cable power supply wiring.

[0134] 5. Communication and control method The PLC drives the VLC light group to emit optical signals, and the on-site VLC actuators and collectors receive the optical signals to realize the wireless optical transmission of control signals; the collector returns the on-site collected signals to the PLC through optical signals; the VLC communicator realizes the interaction of the bus data of the RFID reader through optical signals.

[0135] After the transformation, the following technical effects can be achieved: 1. Significantly reduce the length and quantity of cables: Save nearly three thousand meters of cables and several intermediate relays, reducing the wiring cost and maintenance difficulty.

[0136] 2. Improve the stability and reliability of the system: Use optical communication to eliminate electrical signal crosstalk and voltage drop problems, and avoid damage to equipment caused by overshoot of low-voltage power supplies.

[0137] 3. The trial operation results are good: Achieve a cumulative operation of about 792 hours in 3 months (12 hours / day × 22 days / month × 3 months), with no obvious faults, and the operation efficiency and production capacity are significantly improved.

[0138] It can be seen that the embodiments of the present invention can achieve very ideal effects in practical applications.

[0139] Another embodiment of the present invention provides an industrial automation control method based on VLC and optical power supply. This method applies the industrial automation control system based on VLC and optical power supply provided in the foregoing embodiments. For the specific steps, reference can be made to the above description of the control system, which will not be elaborated here.

[0140] The embodiments of the present disclosure have been described above. The above description is exemplary and not exhaustive, and is also not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The choice of terms used herein is intended to best explain the principles of the embodiments, the practical application, or the technical improvements to the technology in the market, or to enable other ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. An industrial automation control system based on VLC and optical power supply, characterized in that, It includes a PLC controller, a VLC modem, and a VLC lamp set arranged on the control side, as well as a VLC actuator, a VLC collector, and a VLC communicator arranged on the field side and powered by light energy, where: The PLC controller is communicatively connected to the VLC modem, and is used to generate and process electrical signals, and send and receive electrical signals through the VLC modulation regulator; The VLC modem is communicatively connected to the VLC lamp set, and is used to process the conversion operation between electrical signals and modulation signals, and send and receive modulation signals through the VLC lamp set; The VLC lamp set is composed of LED lamps with visible light communication function, and is used to process the conversion operation between modulation signals and visible light signals, and emit and receive visible light signals through the free optical path; The VLC actuator is communicatively connected to multiple field devices, and is used to receive visible light signals through the free optical path, and parse them into control instructions and send them to the field devices; The VLC collector is communicatively connected to multiple field sensors, and is used to convert the status data collected by the field sensors into visible light signals, and emit them to the VLC lamp set through the free optical path; The VLC communicator is communicatively connected to multiple external devices, and is used to convert visible light signals into communication data and send them to external devices, and convert the communication data transmitted by external devices into visible light signals and emit them to the VLC lamp set through the free optical path.

2. The control system according to claim 1, wherein The VLC actuator, the VLC collector, and the VLC communicator all have photovoltaic modules, which are used to convert the light energy generated by the VLC lamp set into electrical energy to supply power for themselves.

3. The control system according to claim 1, wherein The PLC controller includes a control signal module and a communication signal module, where, The control signal module is used to generate a baseband control signal according to a preset control logic and send it to the VLC modem; The communication signal module is used to generate a master station baseband signal according to a preset communication logic and send it to the VLC modem.

4. The control system according to claim 3, characterized in that The VLC modem includes an encoding and modulation module, which is used to encode and modulate the baseband control signal to obtain a modulated control signal and send it to the VLC lamp set, and encode and modulate the master station baseband signal to obtain a master station modulated signal and send it to the VLC lamp set.

5. The control system according to claim 4, wherein The VLC lamp set includes an optical signal conversion module, which is used to convert the modulated control signal into an optical control signal and emit it to the VLC actuator through the free optical path, and convert the master station modulated signal into a master station optical signal and emit it to the VLC communicator through the free optical path.

6. The control system according to claim 5, wherein, The VLC actuator is communicatively connected to multiple field devices, and is used to restore the optical control signal to a modulated control signal, and restore the modulated control signal to a baseband control signal and send it to the control unit of the corresponding field device.

7. The control system according to claim 6, wherein The VLC collector is communicatively connected to multiple field sensors, and is used to encode and modulate the status data collected by the field sensors to obtain a modulated acquisition signal, and perform an optoelectronic conversion operation on the modulated acquisition signal to obtain an optical acquisition signal and emit it to the VLC lamp set through the free optical path.

8. The control system according to claim 7, wherein The VLC communicator is communicatively connected to multiple external devices, including an external transmission module and a feedback transmission module, where, The external transmission module is used to perform optoelectronic conversion on the master station optical signal and then restore it to the master station modulation signal, and, decode and demodulate the master station modulation signal to restore it to the master station baseband signal and send it to the corresponding external device; The feedback transmission module is used to encode and modulate the slave station baseband signal transmitted by the external device to obtain the slave station modulation signal, and, perform optoelectronic conversion on the slave station modulation signal to obtain the slave station optical signal, and transmit it to the VLC lamp group through a free optical path.

9. The control system according to claim 8, wherein The VLC lamp group further includes a modulation signal conversion module, which is used to convert the optical acquisition signal into a modulation acquisition signal and then send it to the VLC modem, and, convert the slave station optical signal into the slave station modulation signal and then send it to the VLC modem.

10. The control system according to claim 9, wherein The VLC modem further includes a decoding and demodulation module, which is used to decode and demodulate the modulation acquisition signal to obtain the baseband acquisition signal and send it to the PLC controller, and, decode and demodulate the slave station modulation signal to obtain the slave station baseband signal and send it to the PLC controller.

11. The control system according to claim 1, characterized in that, The VLC lamp group includes a lamp group controller, which is used to dynamically adjust the output DC voltage to adapt to the operating voltage of the LED lamp used in the VLC lamp group.

12. An industrial automation control method based on VLC and optical power supply, characterized in that, The method is applied to the industrial automation control system based on VLC and optical power supply according to any one of claims 1 to 11.

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