High-precision linear motor position detection and high-speed low-latency wireless optical transmission system

Abstract

The application provides a high-precision linear motor position detection and high-speed low-latency wireless optical transmission system, which comprises an encoder fixedly installed on a linear motor stator and used for generating an encoding signal; a position sensor module installed on a linear motor mover, wherein a plurality of inductive proximity sensors are integrated in the module; the encoder and the position sensor module jointly generate a position signal, that is, when the mover moves, the encoding teeth on the encoder enter the detection areas of the sensors in the position sensor module in sequence to generate corresponding encoding signals, so that position information feedback is realized; and a signal transmission unit is used for wirelessly transmitting the position information to an external control system to realize closed-loop control of the linear motor. The application has the characteristics of low cost, high position detection precision, high data transmission rate and low latency, strong anti-interference capability and high reliability.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of linear motor position detection, and particularly relates to a high-precision linear motor position detection system. BACKGROUND

[0002] In a high-speed linear motor driving system, positioning and speed measurement technology is a key link to ensure stable operation of the system, which requires high reliability and high precision of position detection technology to feed back the position of the mover in real time and accurately. The existing technology usually adopts an inductive proximity switch as a position sensor, forms a sensor array by arranging a large number of sensors on the stator of the linear motor, and installs an encoder on the mover. When the mover moves, the signals output by the encoder interact with the sensors distributed on the stator, the sensor array respectively collects mutually orthogonal position signals, and the actual position of the mover is calculated by the controller processing. Although this scheme can adapt to high-speed motion in a complex electromagnetic environment, it has the following disadvantages:

[0003] 1. High system cost and installation complexity

[0004] Due to the need to arrange a large number of position sensors on a long linear motor track, the construction, calibration and maintenance cost of the sensor array is high, and the installation and wiring are complex, which is easily affected by changes in the field environment.

[0005] 2. Limited by the limitations of the stator arrangement

[0006] The existing scheme mainly relies on the sensor array on the stator, which is limited to a fixed position and is difficult to flexibly respond to dynamic changes and disturbances generated by moving parts during high-speed operation.

[0007] In order to reduce system cost, simplify installation complexity and improve overall real-time performance and reliability, a new scheme proposes to arrange position sensors on the mover, and the position signals collected by the sensors on the mover are transmitted to the ground control system in real time for closed-loop control. This scheme can greatly reduce the number of sensors and the difficulty of arrangement, but at the same time faces the following technical challenges:

[0008] 1. High-speed, low-latency data transmission requirements

[0009] When the mover moves at high speed, the position signals collected by the sensors must be transmitted to the ground control system in real time and accurately, requiring high data transmission rate (such as 100 Mbps) and low end-to-end latency (such as less than 50 μs).

[0010] 2. Complex electromagnetic environment and transmission anti-interference

[0011] In environments with complex electromagnetic interference and limited space, ensuring the stability and reliability of wireless transmission links becomes a critical issue. Wireless optical communication is considered to have good applicability due to its high bandwidth and strong resistance to electromagnetic interference, but traditional wireless optical communication systems still have shortcomings in interference suppression and transmission stability. Summary of the Invention

[0012] The purpose of this invention is to overcome the shortcomings of the aforementioned background technology and provide a high-precision linear motor position detection system, which features low cost, high position detection accuracy, high data transmission rate and low latency, strong anti-interference ability and high reliability.

[0013] The technical solution adopted in this invention is: a high-precision linear motor position detection system, comprising:

[0014] An encoder is fixedly mounted on the stator of a linear motor and is used to generate encoded signals;

[0015] The position sensor module is mounted on the linear motor actuator and integrates multiple inductive proximity sensors.

[0016] The encoder and the position sensor module work together to generate position signals. That is, when the mover moves, the coding teeth on the encoder enter the detection areas of each sensor in the position sensor module in sequence, generating corresponding coding signals, thereby realizing position information feedback.

[0017] A signal transmission unit is used to wirelessly transmit the location information to an external control system.

[0018] In the above technical solution, the signal transmission unit includes:

[0019] Two sets of wireless optical communication components are redundant to each other and use different frequencies of light for wireless transmission.

[0020] The data acquisition module is installed on the linear motor drive load and is used to acquire the position signal generated by the position sensor module and transmit the position signal to the data receiving module through the wireless optical communication component.

[0021] The data receiving module, located outside the linear motor, is used to receive position signals via a wireless optical communication component and transmit the position information to an external control system to achieve closed-loop control of the linear motor.

[0022] In the above technical solution, the encoder teeth are evenly distributed with equal spacing, and the tooth pitch matches the detection range of the inductive proximity sensor to ensure that each encoder tooth generates a stable encoded signal with a target duty cycle when it passes through.

[0023] In the above technical solution, the encoder and the position sensor module are structurally matched to make the encoded signals collected by each inductive proximity sensor present a predetermined phase difference, thereby subdividing the individual encoder teeth and achieving a position resolution that meets or exceeds the set requirements.

[0024] In the above technical solution, the parameter design process for the encoder and the inductive proximity sensor includes:

[0025] Based on the target duty cycle, determine the matching relationship between the detection range of the inductive proximity sensor and the tooth width and tooth pitch of the coding tooth plate, so that the sensor output high level and low level meet the required duty cycle within one cycle;

[0026] Based on the coded tooth pitch and the predetermined detection accuracy, a predetermined phase difference is determined between the output signals of equivalent adjacent inductive proximity sensors, which is used to subdivide the coded tooth pitch period into several equal parts, thereby achieving the target position resolution.

[0027] Based on the detection accuracy and coded tooth pitch, the number of inductive proximity sensors is selected to generate discrete phase states within one tooth pitch cycle, thereby meeting the resolution requirements.

[0028] The inductive proximity sensors are numbered sequentially according to their arrangement, and a 90° phase difference is set between the output signals of two inductive proximity sensors with a number difference of k; where k is a positive integer and half the number of sensors, thus forming k sets of orthogonal signals in one cycle.

[0029] Based on the aforementioned phase difference requirements, the specific installation spacing of the inductive proximity sensor is derived and determined so that the sensor output simultaneously satisfies the duty cycle, subdivision number, and quadrature signal targets within one cycle.

[0030] In the above technical solution, two sets of parallel redundant wireless optical communication components transmit data simultaneously on two independent communication links.

[0031] In the above technical solution, each wireless optical communication component consists of a moving end component and a ground end component, and the moving end component and the ground end component respectively include a transmitter and a receiver, which are used to realize full-duplex communication between the moving end component and the ground end component; the moving end component is set on the moving part load of the linear motor and moves back and forth linearly with it at high speed, and the ground end component is set outside the linear motor.

[0032] In the above technical solution, the transmitting end consists of a signal modulation circuit, a driving circuit, an LD light source, and an optical antenna, which is used to convert electrical signals into optical signals and transmit them through the optical antenna;

[0033] The receiver consists of a filter, a photoelectric sensor, a signal demodulation circuit, and an amplification processing circuit, and is used to receive and demodulate optical signals.

[0034] In the above technical solution, the transmitting light sources of the two moving end components adopt different wavelength light sources, and the receiving ends of the corresponding two ground end components are equipped with filters that match the selected transmission wavelength of their corresponding transmitting ends.

[0035] The transmitters of the two ground-end components use light sources of different wavelengths, and the receivers of the two corresponding moving-end components are equipped with filters that match the selected emission wavelength of their respective transmitters.

[0036] In the above technical solution, the communication between the data acquisition module, the wireless optical communication component and the data receiving module adopts the UDP protocol, with a transmission rate of 100Mbps and a latency of less than 50μs, which meets the requirements of real-time control of linear motors.

[0037] The beneficial effects of this invention are as follows: This invention consists of an encoder fixedly mounted on the stator, a position sensor module mounted on the mover, and a module for data acquisition and transmission. The encoder and sensor module interact left and right to achieve position signal feedback. This invention simplifies the complex installation method of traditionally deploying a large number of sensors on the stator, integrating some sensors on the mover, significantly reducing system cost and installation difficulty, while providing real-time feedback of mover position information, providing accurate data for closed-loop control. The system cost of this invention is low; this position detection system can use only one position sensor module and one encoder. The position sensor module is mounted on the linear motor mover, and the encoder is fixedly mounted on the linear motor stator, reducing the number of position sensor modules and lowering system complexity.

[0038] Furthermore, through structural matching design, the present invention enables the digital signals acquired by each sensor to present a predetermined phase difference. By utilizing the predetermined phase difference, a single encoder signal is subdivided into multiple detection units, which significantly improves the system position resolution and enables the detection accuracy to reach or exceed the set requirements (e.g., 1mm level), thus meeting the needs of high-precision position detection.

[0039] Furthermore, the present invention employs an encoder with uniformly distributed coding teeth at equal intervals, and matches the tooth pitch with the detection range of the inductive proximity sensor to ensure that each coding tooth generates a stable digital signal with a target duty cycle when it passes by. This provides a stable and reliable signal foundation for subsequent signal subdivision and data processing, and reduces measurement errors caused by signal fluctuations.

[0040] Furthermore, this invention introduces a high-precision position design method to accurately calculate and determine the matching parameters between the encoder and the sensor, achieving sufficient subdivision within one encoder cycle. This allows for the generation of multiple sets of mutually orthogonal position signals, ensuring that the system achieves the required high-resolution position detection effect. This improves the overall detection accuracy and repeatability, enabling high-precision position detection.

[0041] Furthermore, the position signal transmission of this invention adopts a wireless optical transmission method and integrates a full-duplex transceiver module. Wireless optical transmission features high bandwidth and low latency. The full-duplex design allows for simultaneous transmission and reception of data, enabling the system to achieve a high-speed transmission rate of 100Mbps and a single-trip transmission latency of less than 50μs, meeting the requirements of real-time control. The position signal can be reliably transmitted in a directional manner in the complex electromagnetic environment of a linear motor, and it has strong anti-electromagnetic interference capabilities.

[0042] Furthermore, the present invention employs a redundant design in location signal transmission, that is, it utilizes multiple communication links to transmit data simultaneously, thereby improving the reliability of location signal transmission.

[0043] Furthermore, this invention employs light of different frequencies (wavelengths) for wireless transmission in each communication path. By using frequency division to avoid co-channel interference, the transmission of each path is made independent, thereby further improving the stability and anti-interference capability of data transmission and ensuring reliable operation in complex electromagnetic environments.

[0044] Furthermore, this invention combines two sets of ODCs with parallel redundancy, cross-configuration, and full-duplex communication. For applications involving high-speed linear motor movement and space constraints, it presents an effective anti-interference and high-reliability optical transmission scheme. By employing different wavelength light sources at the ODC transmitter and selectively receiving corresponding filters at the receiver, the wavelengths of each path do not overlap, avoiding co-channel interference. Combined with redundant design and full-duplex mode, the system achieves significant improvements in high-speed, high-bandwidth data transmission. Compared to traditional single-wavelength, half-duplex, or non-redundant wireless optical communication, this scheme demonstrates significant progress in interference suppression, reliability, and real-time performance, possessing outstanding practical value and inventiveness.

[0045] Furthermore, the communication between the data acquisition module, the wireless optical communication component, and the data receiving module of this invention all adopt the UDP protocol with high real-time performance, achieving a transmission rate of 100Mbps and an end-to-end latency of less than 50μs, which greatly satisfies the requirements of real-time control of linear motors for data transmission latency and rate. Attached Figure Description

[0046] Figure 1 This is a schematic diagram of the principle of the system of the present invention;

[0047] Figure 2This is a schematic diagram of the encoder and position sensor module structure of the system of the present invention;

[0048] Figure 3 This is a schematic diagram of the equivalent working characteristics of the position sensor module of the system of the present invention;

[0049] Figure 4 This is a functional block diagram of the wireless optical communication component of the system of the present invention. Detailed Implementation

[0050] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments to facilitate a clear understanding of the present invention, but these descriptions do not constitute a limitation on the present invention.

[0051] like Figure 1 As shown, the present invention provides a high-precision linear motor position detection and high-speed, low-latency wireless optical transmission system, including an encoder, a position sensor module, a data acquisition module, two sets of wireless optical communication components, and a data receiving module.

[0052] An encoder is fixedly mounted on the stator of a linear motor and is used to generate encoded signals;

[0053] The position sensor module is mounted on the linear motor actuator. This module integrates multiple inductive proximity sensors, including S1, S2, ..., SN, for a total of N sensors.

[0054] The encoder and the position sensor module interact to form a position signal. That is, when the mover moves, the encoder teeth on the encoder enter the detection area of ​​each sensor in the position sensor module in sequence, generating corresponding digital signals, thereby realizing position information feedback.

[0055] The data acquisition module is installed on the moving load and is responsible for acquiring the position signal sensed by the position sensor module.

[0056] Two sets of wireless optical communication components (ODCs) are redundant with each other. The first ODC includes ODC1A and ODC1B, forming a full-duplex transmission path; the second ODC includes ODC2A and ODC2B, forming a full-duplex transmission path. ODC1A and ODC2A are installed on the moving load, receive the position signal of the data acquisition module, and transmit it to the corresponding ODC1B and ODC2B through wireless optical communication, respectively. ODC1B and ODC2B are fixed to the ground.

[0057] The data receiving module is installed and fixed on the ground to receive position signals for closed-loop control of the linear motor.

[0058] This specific embodiment, based on the application scenario of high-speed linear motor position detection, proposes a high-precision linear motor position detection and high-speed, low-latency wireless optical transmission system. This system can achieve real-time wireless data transmission with a position detection accuracy of up to 1mm, a communication rate of up to 100Mbps, and a latency of less than 50µs. The position detection method of this invention uses fewer position sensors, resulting in lower system complexity and effectively saving system costs. Furthermore, the wireless optical transmission system of this invention employs redundant communication and anti-optical coupling interference design, improving the reliability of system data transmission and providing strong resistance to optical co-frequency interference.

[0059] Specifically, the encoder teeth are evenly distributed with equal spacing, and the tooth pitch matches the detection range of the inductive proximity sensor to ensure that each encoder tooth generates a stable digital signal with a target duty cycle when it passes. The encoder and position sensor module are structurally matched so that the digital signals collected by each inductive proximity sensor exhibit a predetermined phase difference in time, thereby subdividing a single encoder tooth into multiple detection units and achieving a position resolution that meets or exceeds the set requirements.

[0060] Specifically, the parameter design process for encoders and inductive proximity sensors includes:

[0061] Based on the target duty cycle, determine the matching relationship between the detection range of the inductive proximity sensor and the tooth width and tooth pitch of the coding tooth plate, so that the sensor output high level and low level meet the required duty cycle within one cycle;

[0062] Based on the coded tooth pitch and the predetermined detection accuracy, a predetermined phase difference is determined between the output signals of equivalent adjacent inductive proximity sensors, which is used to subdivide the coded tooth pitch period into several equal parts, thereby achieving the target position resolution.

[0063] Based on the detection accuracy and coded tooth pitch, the number of inductive proximity sensors is selected to generate discrete phase states within one tooth pitch cycle, thereby meeting the resolution requirements.

[0064] The inductive proximity sensors are numbered sequentially according to their arrangement, and a 90° phase difference is set between the output signals of two inductive proximity sensors with a number difference of k; where k is a positive integer and is half of the total number of sensors, thus forming k sets of orthogonal signals in one cycle.

[0065] Based on the aforementioned phase difference requirements, the specific installation spacing of the inductive proximity sensor is derived and determined so that the sensor output simultaneously satisfies the duty cycle, subdivision number, and quadrature signal targets within one cycle.

[0066] In this embodiment, to obtain an ideal high-low level ratio (i.e., duty cycle, for example, 50%), it is typically required that the high-level and low-level times each account for half of the sensor's time when the encoder teeth pass by. The encoder tooth width is w, the encoder tooth pitch is D, and the sensor detection range is Ds. Ds is related to the encoder tooth width w and the characteristics of the high-speed proximity switch sensor itself. Therefore, the duty cycle of the sensor's output signal is Ds / D.

[0067] Different models of inductive proximity switches have different detection characteristics, which are also affected by the metal material, shape, and mounting clearance. It is necessary to select a suitable detection range based on the actual mechanical dimensions, tooth plate material (non-metallic substrate + metal teeth), and high-speed motion requirements to ensure reliable detection and no loss of position signals. The sensor detection range is generally slightly larger than the tooth width (e.g., 13mm tooth width, 20mm detection range) to ensure a 50% duty cycle for the position signal output. That is, after determining the detection range of the inductive proximity switch sensor based on the encoder tooth width and the sensor's own characteristics, the encoder tooth spacing is determined based on the duty cycle.

[0068] In this embodiment, as Figure 1 and 2 As shown, a position sensor box is mounted on the mover. The position sensor box contains multiple high-speed proximity switch sensors, which are arranged at equal intervals L along the direction of the mover's movement within the position sensor box. An encoder is mounted on the stator of the linear motor. The encoder consists of a non-metallic substrate and a certain number of encoder teeth. The encoder teeth are distributed at equal intervals D along the length direction of the encoder (i.e., the direction of the mover's movement) on the non-metallic substrate. The width of each encoder tooth is w, and the tooth spacing is D (referred to as tooth pitch). The detection range of a single encoder tooth for the high-speed proximity switch sensor is Ds, which can be selected according to actual conditions. In this embodiment, the detection range Ds of the high-speed proximity switch sensor is selected as 20mm. Ds is related to the encoder tooth width w and the characteristics of the high-speed proximity switch sensor itself; the encoder tooth width w is 13mm.

[0069] When the encoder teeth enter the detection range of the high-speed proximity switch sensor, the sensor outputs a high-level signal; when the encoder teeth leave the detection range, the sensor outputs a low-level signal. Therefore, the duty cycle of the output signal is Ds / D. To achieve an ideal 50% duty cycle, the encoder tooth spacing D should be twice the detection range Ds of the high-speed proximity switch sensor, i.e., D = 40 mm.

[0070] like Figure 2 As shown, in order to obtain higher detection accuracy within one tooth pitch cycle (40mm), this embodiment installs 20 high-speed proximity switch sensors on the mover, numbered 1, 2, ..., 20 in sequence.

[0071] Based on this, we define two sensors whose number difference is half the total number of sensors (i.e., N and N+k, where k is 10 in this embodiment) have an output difference of 90° to form k sets of orthogonal signals. This allows us to determine direction within the same period and achieve higher resolution by cooperating with adjacent subdivisions.

[0072] To subdivide a 40mm tooth pitch into 40 parts (i.e., 1mm accuracy), the phase difference between the output signals of equivalent adjacent sensors needs to be 360 / 40 = 9 degrees. Thus, every 1mm movement (1 / 40 of 40mm) will increase the equivalent phase of the output signal by 9°, thereby ensuring a 1mm resolution.

[0073] To physically achieve an equivalent phase difference of 9° between adjacent sensors and a phase difference of 90° between sensor pairs,

[0074] Two sensors with a number difference equal to half the total number of sensors (i.e., N and N+10) output a 90° difference; this can be expressed as: the physical distance L0 between (N, N+10) is L0 = (n + 0.25) × D.

[0075] The physical distance between adjacent sensors (N, N+1) is L = (0.1n + 0.025) × D

[0076] Where n is a positive integer to be selected, and D is the tooth pitch of 40mm.

[0077] When n=14, L0=10×L (10 is the value of k), which meets the orthogonality requirement of 90° phase difference. Therefore, the 20 sensors can be divided into 10 groups of orthogonal signals.

[0078] Finally, n=14 was selected:

[0079] Physical spacing between adjacent sensors:

[0080] L=(0.1×14+0.025)×40mm=1.425×40mm=57mm.

[0081] Sensors with a number difference of 10 have a phase difference of approximately 90°; equivalent adjacent sensors have a phase difference of approximately 9°.

[0082] This allows the output signal to be subdivided into 40 discrete steps (each 1mm→9°) within a 40mm cycle, forming 10 sets of orthogonal signals. The equivalent operating characteristics of the position sensor module are illustrated below. Figure 3 As shown.

[0083] In this embodiment, as Figure 1 and Figure 2As shown, the data acquisition module, wireless optical communication component, and data receiving module realize the function of acquiring and wirelessly transmitting position signals. The position signals can be reliably transmitted in a directional manner in the complex electromagnetic environment of the linear motor, with strong anti-electromagnetic interference capability. In addition, the wireless optical transmission has the characteristics of high bandwidth and low latency. It adopts a full-duplex design, which can achieve a transmission rate of 100Mbps and a single-pass transmission delay of less than 50μs, meeting the needs of real-time control of linear motors.

[0084] Preferably, the wireless optical communication component employs a redundant design, transmitting data simultaneously on different communication paths. The different communication paths of the wireless optical communication component use light of different frequencies for wireless transmission.

[0085] Specifically, each of the two sets of parallel redundant wireless optical communication components consists of a moving end component and a ground end component, and the moving end component and the ground end component respectively include a transmitter and a receiver, used to realize full-duplex communication, wherein:

[0086] The transmitter consists of a signal modulation circuit, a driving circuit, an LD light source, and an optical antenna, and is used to convert electrical signals into optical signals and transmit them through the optical antenna.

[0087] The receiver consists of a filter, a photoelectric sensor, a signal demodulation circuit, and an amplification processing circuit, and is used to receive and demodulate optical signals.

[0088] The transmitters of the two moving end components use light sources of different wavelengths, and the receivers of the two corresponding ground end components are equipped with filters that match the selected emission wavelength of their respective transmitters.

[0089] The transmitters of the two ground-end components use light sources of different wavelengths, and the receivers of the two corresponding moving-end components are equipped with filters that match the selected emission wavelength of their respective transmitters.

[0090] Preferably, such as Figure 4 As shown, this invention employs two sets of ODCs for parallel communication transmission, which are redundant to each other. Each ODC's ODCA and ODCB contain a transmitter and a receiver, enabling full-duplex communication. The transmitter of the ODC consists of a signal modulation circuit, a driving circuit, an LD light source, and an optical antenna, etc. The receiver of the ODC consists of a filter, a photoelectric sensor, a signal demodulation circuit, and an amplification processing circuit, etc.

[0091] The system employs two completely independent ODCs (ODC1 and ODC2), each consisting of a transmitter (ODC1A, ODC2A) and a ground terminal (ODC1B, ODC2B). Each ODC has a complete transmitter and receiver, forming a full-duplex transmission link. Parallel redundancy means that the two links can operate simultaneously and serve as backups for each other. If one link experiences optical path obstruction, failure, or channel interference, the other link can still maintain normal data transmission, ensuring continuous feedback of location information and reducing the risk of system downtime. In industrial scenarios, redundancy design can significantly reduce the impact of single-point failures on production and control systems, improving the overall system availability and security.

[0092] The transmitting light sources of ODC1A and ODC2A use red and infrared light respectively, while the receiving ends of ODC1B and ODC2B use corresponding filters. Similarly, the transmitting light sources of ODC1B and ODC2B use infrared and red light respectively, while the receiving ends of ODC1A and ODC2A use corresponding filters. This scheme effectively avoids co-channel interference in optical transmission, improving transmission reliability. Through this cross-configuration, bidirectional optical transmission can be achieved simultaneously without interference between the two bands. In full-duplex mode, the mover and ground ends can transmit and receive data in parallel, significantly reducing latency and meeting the real-time control requirements of high-speed linear motors. The distinct spectral bandwidths of red and infrared light, combined with matching filters, avoid mutual interference within the same band, ensuring communication reliability and signal-to-noise ratio. Due to wavelength cross-comparison and filter filtering, high-bandwidth, low-latency data transmission can still be achieved in confined spaces and complex industrial environments.

[0093] The transmitting end includes a signal modulation circuit, a driving circuit, an LD light source, and an optical antenna; the receiving end includes a filter, a photoelectric sensor, a signal demodulation circuit, and an amplification processing circuit.

[0094] The transmitting end is responsible for converting digital signals into light pulses of corresponding wavelengths and transmitting them outwards; the receiving end selectively receives light signals of corresponding wavelengths through filters, and then performs photoelectric conversion and demodulation.

[0095] Using LD (laser diode) or high-performance LED light sources can provide high output power over a wide bandwidth; the matching design of filters and photoelectric sensors can further improve receiving sensitivity. Direct hardware connection reduces intermediate conversion steps, enabling data rates of hundreds of megabits per second (100 Mbps) and latency in the nanosecond range, meeting the real-time signal requirements of high-speed motion control.

[0096] ODC1A / ODC1B and ODC2A / ODC2B operate at different wavelengths (such as red and infrared light), and the receiver uses a filter that matches the transmitted wavelength. This ensures that in scenarios with limited space and potential channel overlap, the two channels do not interfere with each other, minimizing the possibility of superposition or crosstalk between signals at the same frequency, avoiding multipath interference at a single wavelength, and reducing the impact of background light and ambient light on communication. The two non-overlapping communication links can operate simultaneously in parallel or provide redundancy when necessary, further reducing the risk of data loss and communication interruption.

[0097] The moving-end ODC (ODCA) moves back and forth at high speed with a linear motor, while the ground-end ODC (ODCB) is fixed to the ground. Through the cross-configuration of red light, infrared light, and filter selection, stable communication can be maintained even under rapid changes in distance or angle. The parallel redundancy mode can abandon a link and automatically switch to another link when one link experiences temporary fading. This meets the harsh conditions of industrial environments, where high-speed movement is often accompanied by interference from vibration, dust, and stray light; the cross-configuration improves signal recognition and alignment accuracy, and reduces bit errors. In space-constrained environments, the division of labor through different wavelengths and filters ensures that devices do not interfere with each other, enhancing the overall maintainability of the system.

[0098] Specifically, the location signal transmission process adopts a high-speed communication protocol. In this embodiment, the UDP protocol with high real-time performance is used. Data encoding, modulation, demodulation and decoding are directly implemented in hardware such as FPGA in a parallel pipeline manner, thereby ensuring a high data transmission rate and low end-to-end processing latency.

[0099] This embodiment uses dual channels (different optical wavelengths) for wireless optical transmission to avoid co-channel interference. It also adopts a full-duplex, redundant adaptive switching mode to achieve highly reliable data transmission in harsh and space-constrained environments. The end-to-end transmission delay of the position signal is less than 50μs, and the transmission rate is as high as 100Mbps, which meets the requirements of closed-loop control of high-speed linear motors.

[0100] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

Claims

1. A high-precision linear motor position detection and high-speed, low-latency wireless optical transmission system, characterized in that, include: An encoder is fixedly mounted on the stator of a linear motor and is used to generate encoded signals; The position sensor module is mounted on the linear motor actuator and integrates multiple inductive proximity sensors. The encoder and the position sensor module work together to generate position signals. That is, when the mover moves, the coding teeth on the encoder enter the detection areas of each sensor in the position sensor module in sequence, generating corresponding coding signals, thereby realizing position information feedback. A signal transmission unit is used to wirelessly transmit the location information to an external control system. The parameter design process for encoders and inductive proximity sensors includes: Based on the target duty cycle, determine the matching relationship between the detection range of the inductive proximity sensor and the tooth width and tooth pitch of the coding tooth plate, so that the sensor output high level and low level meet the required duty cycle within one cycle; Based on the coded tooth pitch and the predetermined detection accuracy, a predetermined phase difference is determined between the output signals of equivalent adjacent inductive proximity sensors, which is used to subdivide the coded tooth pitch period into several equal parts, thereby achieving the target position resolution. Based on the detection accuracy and coded tooth pitch, the number of inductive proximity sensors is selected to generate discrete phase states within one tooth pitch cycle, thereby meeting the resolution requirements. The inductive proximity sensors are numbered sequentially according to their arrangement, and a 90° phase difference is set between the output signals of two inductive proximity sensors with a number difference of k; where k is a positive integer and half the number of sensors, thus forming k sets of orthogonal signals in one cycle. Based on the aforementioned phase difference requirements, the specific installation spacing of the inductive proximity sensor is derived and determined so that the sensor output simultaneously satisfies the duty cycle, subdivision number, and quadrature signal targets within one cycle.

2. The system according to claim 1, characterized in that: The signal transmission unit includes: Two sets of wireless optical communication components are redundant to each other and use different frequencies of light for wireless transmission. The data acquisition module is installed on the linear motor drive load and is used to acquire the position signal generated by the position sensor module and transmit the position signal to the data receiving module through the wireless optical communication component. The data receiving module, located outside the linear motor, is used to receive position signals via a wireless optical communication component and transmit the position information to an external control system to achieve closed-loop control of the linear motor.

3. The system according to claim 1, characterized in that, The encoder teeth are evenly distributed with equal spacing, and the tooth pitch matches the detection range of the inductive proximity sensor to ensure that each encoder tooth generates a stable encoded signal with the target duty cycle when it passes through.

4. The system according to claim 2, characterized in that: Two sets of parallel redundant wireless optical communication components transmit data simultaneously on two independent communication links.

5. The system according to claim 2, characterized in that, Each wireless optical communication component consists of a moving end component and a ground end component, and the moving end component and the ground end component respectively include a transmitter and a receiver, which are used to realize full-duplex communication between the moving end component and the ground end component; the moving end component is set on the moving part load of the linear motor and moves back and forth linearly with it at high speed, and the ground end component is set outside the linear motor.

6. The system according to claim 5, characterized in that: The transmitter consists of a signal modulation circuit, a driving circuit, an LD light source, and an optical antenna, and is used to convert electrical signals into optical signals and transmit them through the optical antenna. The receiver consists of a filter, a photoelectric sensor, a signal demodulation circuit, and an amplification processing circuit, and is used to receive and demodulate optical signals.

7. The system according to claim 5, characterized in that: The transmitters of the two moving end components use light sources of different wavelengths, and the receivers of the two corresponding ground end components are equipped with filters that match the selected emission wavelength of their respective transmitters. The transmitters of the two ground-end components use light sources of different wavelengths, and the receivers of the two corresponding moving-end components are equipped with filters that match the selected emission wavelength of their respective transmitters.

8. The system according to claim 2, characterized in that, The communication between the data acquisition module, the wireless optical communication component, and the data receiving module adopts the UDP protocol, with a transmission rate of 100Mbps and a latency of less than 50μs, which meets the requirements of real-time control of linear motors.

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