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

Abstract

The invention provides a high-precision linear motor position detection and high-speed low-delay wireless optical transmission system, and the system comprises an encoder which is fixedly disposed on a stator of a linear motor, and is used for generating an encoding signal; the position sensor module is mounted on the linear motor rotor, and a plurality of inductance type proximity sensors are integrated in the position sensor module; the encoder and the position sensor module jointly act to generate a position signal, that is, when the rotor moves, encoding teeth on the encoder sequentially enter detection areas of sensors in the position sensor module to generate corresponding encoding signals, so that position information feedback is realized; and the signal transmission unit is used for wirelessly and optically transmitting the position information to an external control system to realize closed-loop control of the linear motor. The method has the characteristics of low cost, high position detection precision, high data transmission rate, low time delay, strong anti-interference capability, high reliability and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of linear motor position detection, and in particular relates to a high-precision linear motor position detection system. Background Art

[0002] In high-speed linear motor drive systems, positioning and speed measurement technology is a key link to ensure the stable operation of the system. It requires position detection technology with high reliability and high precision to provide real-time and accurate feedback on the position of the mover. Existing technologies usually use inductive proximity switches as position sensors. A large number of sensors are arranged in sections on the stator of the linear motor to form a sensor array, and the encoder is installed on the mover. When the mover moves, the signal output by the encoder interacts with the sensors distributed on the stator. The sensor array collects mutually orthogonal position signals, and then processes and calculates the actual position of the mover through the controller. Although this solution can adapt to high-speed movement in complex electromagnetic environments, its disadvantages are: 1. High system cost and installation complexity Since a large number of position sensors need to be deployed on the long linear motor track, the construction, calibration and maintenance costs of the sensor array are high. At the same time, the installation and wiring are complex and easily affected by changes in the on-site environment.

[0003] 2. Limited by the limitations of stator layout Existing solutions mainly rely on sensor arrays on the stator, which are limited to fixed positions and cannot flexibly respond to dynamic changes and interference caused by moving parts during high-speed operation.

[0004] To reduce system costs, simplify installation complexity, and improve overall real-time performance and reliability, a new solution proposes placing position sensors on the movers. These sensors collect position signals in real time and transmit them wirelessly to the ground control system for closed-loop control. This solution significantly reduces the number of sensors and the difficulty of deployment, but it also faces the following technical challenges: 1. High-speed, low-latency data transmission requirements When the mover moves in a straight line at high speed, the position signal collected by the sensor must be transmitted to the ground control system in real time and accurately, requiring a high data transmission rate (such as 100Mbps) and low end-to-end delay (such as less than 50μs).

[0005] 2. Complex electromagnetic environment and transmission anti-interference Ensuring the stability and reliability of wireless transmission links in environments with complex electromagnetic interference and limited space becomes a key issue. Optical wireless communications are considered highly applicable due to their high bandwidth and strong resistance to electromagnetic interference, but traditional optical wireless communication systems still have shortcomings in interference suppression and transmission stability. Summary of the Invention

[0006] The purpose of the present invention is to solve the shortcomings of the above-mentioned background technology and provide a high-precision linear motor position detection system with the characteristics of low cost, high position detection accuracy, high data transmission rate and low delay, strong anti-interference ability and high reliability.

[0007] The technical solution adopted by the present invention is: a high-precision linear motor position detection system, comprising: The encoder is fixedly mounted on the stator of the linear motor and is used to generate encoding signals; The position sensor module is installed on the linear motor mover and integrates multiple inductive proximity sensors; The encoder and position sensor module work together to generate position signals. That is, when the mover moves, the coding teeth on the encoder sequentially enter the detection area of each sensor in the position sensor module, generating corresponding coding signals, thereby realizing position information feedback; The signal transmission unit is used to transmit the position information wirelessly to an external control system.

[0008] In the above technical solution, the signal transmission unit includes: Two sets of wireless optical communication components, which are redundant and use different frequencies of light for wireless transmission; The data acquisition module is provided on the linear motor mover load and is used to collect 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 is arranged outside the linear motor and is used to receive the position signal through the wireless optical communication component; and transmit the position information to the external control system to realize closed-loop control of the linear motor.

[0009] In the above technical solution, the encoding teeth of the encoder are evenly distributed at equal intervals, and the tooth pitch matches the detection range of the inductive proximity sensor to ensure that a stable encoding signal with a target duty cycle is generated when each encoding tooth passes.

[0010] In the above technical solution, the encoder and position sensor module are designed with structural matching so that the encoding signals collected by each inductive proximity sensor present a predetermined phase difference, thereby subdividing a single encoding tooth to achieve a position resolution that meets or exceeds the set requirements.

[0011] In the above technical solution, the parameter design process of the encoder and inductive proximity sensor includes: According to the target duty cycle, determining the matching relationship between the detection range of the inductive proximity sensor and the tooth width and tooth pitch of the encoding gear plate so that the sensor outputs high and low levels to meet the required duty cycle within one cycle; Determining a predetermined phase difference between output signals of equivalent adjacent inductive proximity sensors based on the encoding pitch and a predetermined detection accuracy, for subdividing the encoding pitch period into a number of equal parts, thereby achieving a target position resolution; According to the detection accuracy and the encoding pitch, the number of inductive proximity sensors is selected so that discrete phase states are generated within one pitch period to meet the resolution requirement; The inductive proximity sensors are numbered in the order of arrangement, and a 90° phase difference is set for the output signals of two inductive proximity sensors with a number difference of k, where k is a positive integer and is half the number of sensors, thereby forming k sets of orthogonal signals within one cycle; Based on the above phase difference requirements, the specific installation spacing of the inductive proximity sensor is derived and determined so that the sensor output can simultaneously meet the duty cycle, subdivision number and orthogonal signal targets within one cycle.

[0012] In the above technical solution, two sets of parallel redundant wireless optical communication components transmit data simultaneously on two independent communication links.

[0013] In the above technical solution, each set of wireless optical communication components is composed of a mover-end component and a ground-end component, and the mover-end component and the ground-end component respectively include a transmitting end and a receiving end, which are used to realize full-duplex communication between the mover-end component and the ground-end component; the mover-end component is arranged on the mover load of the linear motor and moves back and forth in a straight line at high speed, and the ground-end component is arranged outside the linear motor.

[0014] In the above technical solution, the transmitting end is composed of a signal modulation circuit, a driving circuit, an LD light source and an optical antenna, and is used to convert the electrical signal into an optical signal and transmit it through the optical antenna; The receiving end 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.

[0015] In the above technical solution, the transmitting light sources of the two moving end components respectively use light sources of different wavelength bands, and the receiving ends of the corresponding two ground end components are respectively equipped with filters that match the emission wavelengths selected by their corresponding transmitting ends; The transmitting end light sources of the two ground-end components respectively use light sources of different wavelength bands, and the receiving ends of the corresponding two movable end components are respectively equipped with filters that match the emission wavelengths selected by their corresponding transmitting ends.

[0016] 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 delay of less than 50μs, which meets the requirements of real-time control of the linear motor.

[0017] The beneficial effects of the present invention are as follows: the present invention is composed 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 the sensor module interact with each other to realize position signal feedback. The present invention simplifies the traditional complex installation method of arranging a large number of sensors on the stator, integrates some sensors on the mover, greatly reduces the system cost and installation difficulty, and can also provide real-time feedback on the mover position information to provide accurate data for closed-loop control. The system cost of the present invention is low, and the position detection system can only use one position sensor module and a set of encoders, wherein the position sensor module is installed on the mover of the linear motor, and the encoder is fixedly installed on the stator of the linear motor, which reduces the number of position sensor modules and reduces the complexity of the system.

[0018] Furthermore, the present invention adopts structural matching design so that the digital signals collected by each sensor present a predetermined phase difference, and uses the predetermined phase difference to subdivide a single encoder signal into multiple detection units, thereby significantly improving the system position resolution and making the detection accuracy reach or exceed the set requirements (for example, 1mm level), meeting the needs of high-precision position detection.

[0019] Furthermore, the present invention adopts an encoder with evenly spaced encoding teeth and matches its tooth pitch with the detection range of the inductive proximity sensor, ensuring that each encoding tooth can generate a stable digital signal with a target duty cycle when passing by, providing a stable and reliable signal basis for subsequent signal segmentation and data processing, and reducing measurement errors caused by signal fluctuations.

[0020] Furthermore, the present invention introduces a high-precision position design method to accurately calculate and determine the matching parameters of the encoder and the sensor, achieve sufficient subdivision within one encoder cycle, and obtain multiple sets of mutually orthogonal position signals, thereby ensuring that the system achieves the required high-resolution position detection effect, improving the accuracy and repeatability of the overall detection, and realizing high-precision position detection.

[0021] Furthermore, the present invention utilizes wireless optical transmission for position signal transmission and integrates a full-duplex transceiver module. Wireless optical transmission offers high bandwidth and low latency. The full-duplex design allows for simultaneous data transmission and reception, enabling the system to achieve a high-speed transmission rate of 100Mbps and a strict one-way transmission latency of less than 50μs, meeting the stringent requirements of real-time control. Position signals can be transmitted reliably and directionally in the complex electromagnetic environment of the linear motor, demonstrating strong resistance to electromagnetic interference.

[0022] Furthermore, the present invention adopts a redundant design in the position signal transmission, that is, using multiple communication links to transmit data simultaneously, thereby improving the reliability of the position signal transmission.

[0023] Furthermore, the present invention uses light of different frequencies (wavelengths) for wireless transmission within each communication channel. Frequency division avoids co-frequency interference, ensuring that transmissions from each channel do not interfere with each other. This further improves the stability and anti-interference performance of data transmission, ensuring reliable operation in complex electromagnetic environments.

[0024] Furthermore, the present invention requires combining two sets of ODC parallel redundancy, cross configuration and full-duplex communication, and provides an effective anti-interference, high-reliability optical transmission solution for application scenarios of high-speed motion of linear motors and limited space. By using light sources of different wavelengths at the ODC transmitting end and selective reception of corresponding filters at the receiving end, the wavelengths of each channel do not overlap, avoiding co-frequency interference; coupled with redundant design and full-duplex mode, the system has achieved significant improvements in high-speed, high-bandwidth data transmission. Compared with traditional single-wavelength, half-duplex or lack-of-redundancy wireless optical communications, this solution has made significant progress in interference suppression, reliability and real-time performance, and has outstanding practical value and creativity.

[0025] Furthermore, the communication between the data acquisition module, wireless optical communication component and data receiving module of the present invention all adopts the UDP protocol with higher real-time performance, with a transmission rate of 100Mbps and an end-to-end delay of less than 50μs, which greatly meets the requirements of linear motor real-time control for data transmission delay and rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the principle of the system of the present invention; Figure 2 It is a schematic diagram of the structure of the encoder and position sensor module of the system of the present invention; Figure 3 is a schematic diagram of equivalent working characteristics of the position sensor module of the system of the present invention; Figure 4 It is a functional block diagram of the wireless optical communication components of the system of the present invention. DETAILED DESCRIPTION

[0027] 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 they do not constitute a limitation to the present invention.

[0028] 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 a set of encoders, a position sensor module, a data acquisition module, two sets of wireless optical communication components and a data receiving module.

[0029] The encoder is fixedly mounted on the stator of the linear motor and is used to generate encoding signals; The position sensor module is installed on the linear motor mover and integrates multiple inductive proximity sensors, including S1, S2, ..., SN, a total of N sensors; 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 sequentially enter the detection area of each sensor in the position sensor module, generating corresponding digital signals, thereby realizing position information feedback. The data acquisition module is installed on the mover load and is responsible for collecting the position signal sensed by the position sensor module; Two sets of wireless optical communication components (ODCs) are redundant. The first set of ODCs includes ODC1A and ODC1B, forming a full-duplex transmission path. The second set of ODCs includes ODC2A and ODC2B, forming a full-duplex transmission path. ODC1A and ODC2A are installed on the mover load, receive position signals from the data acquisition module, and transmit them to the corresponding ODC1B and ODC2B via wireless optical communication. ODC1B and ODC2B are installed and fixed to the ground. The data receiving module is installed and fixed on the ground to receive position signals for closed-loop control of the linear motor.

[0030] 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, which can achieve real-time wireless data transmission with a position detection accuracy of up to 1mm, a communication rate of 100Mbps, and a delay of less than 50us. The position detection method of the present invention uses a small number of position sensors and has low system complexity, which can effectively save system costs. In addition, the wireless optical transmission system of the present invention adopts redundant communication and anti-optical coupling interference design to improve the reliability of system data transmission and has strong resistance to optical co-frequency interference.

[0031] Specifically, the encoder's coding teeth are evenly spaced, with their pitch matching the detection range of the inductive proximity sensor. This ensures that each coding tooth generates a stable digital signal with the target duty cycle. The encoder and position sensor modules are structurally matched, ensuring that the digital signals collected by each inductive proximity sensor exhibit a predetermined phase difference in time. This subdivides a single coding tooth into multiple detection units, achieving a position resolution that meets or exceeds the specified requirements.

[0032] Specifically, the parameter design process for the encoder and inductive proximity sensor includes: According to the target duty cycle, determining the matching relationship between the detection range of the inductive proximity sensor and the tooth width and tooth pitch of the encoding gear plate so that the sensor outputs high and low levels to meet the required duty cycle within one cycle; Determining a predetermined phase difference between output signals of equivalent adjacent inductive proximity sensors based on the encoding pitch and a predetermined detection accuracy, for subdividing the encoding pitch period into a number of equal parts, thereby achieving a target position resolution; According to the detection accuracy and the encoding pitch, the number of inductive proximity sensors is selected so that discrete phase states are generated within one pitch period to meet the resolution requirement; The inductive proximity sensors are numbered in sequence according to the arrangement order, and a 90° phase difference is set for the output signals of two inductive proximity sensors with a number difference of k; where k is a positive integer equal to half the total number of sensors, thereby forming k groups of orthogonal signals in one cycle; Based on the above phase difference requirements, the specific installation spacing of the inductive proximity sensor is derived and determined so that the sensor output can simultaneously meet the duty cycle, subdivision number and orthogonal signal targets within one cycle.

[0033] In this embodiment, to achieve an ideal high-to-low level ratio (i.e., a 50% duty cycle), the sensor is typically required to spend half of its high and half of its low level time when the encoder tooth passes. Given the encoder tooth width w, the encoder tooth pitch D, and the sensor's detection range Ds, which is related to the encoder tooth width w and the characteristics of the high-speed proximity switch, the duty cycle of the sensor's output signal is Ds / D.

[0034] Different inductive proximity switches have different detection characteristics, which are also affected by the metal material, shape, and installation clearance. The appropriate detection range must be selected based on the actual machine dimensions, the tooth plate material (non-metallic base + metal teeth), and high-speed motion requirements to ensure reliable position signal detection and prevent loss. The sensor's detection range is generally slightly larger than the tooth width (for example, a 13mm tooth width and a 20mm detection range) to ensure a 50% duty cycle for the position signal output. This means that after determining the inductive proximity switch's detection range based on the encoder tooth width and the sensor's characteristics, the encoder tooth pitch is determined based on the duty cycle.

[0035] In this embodiment, Figure 1 and 2As shown, a position sensor box is mounted on the mover and contains multiple high-speed proximity switch sensors, which are arranged within the box at equal intervals L along the mover's direction of motion. An encoder is mounted on the linear motor's stator. The encoder consists of a non-metallic substrate and a number of encoder teeth, which are spaced at equal intervals D along the encoder's length (i.e., the mover's direction of motion). The encoder teeth have a width w and a pitch D (referred to as the tooth pitch). The high-speed proximity switch sensor has a detection range Ds for a single encoder tooth, which can be selected based on actual conditions. In this embodiment, the detection range Ds is 20 mm. 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 13 mm.

[0036] When the encoder teeth enter the high-speed proximity switch's detection range, the sensor outputs a high-level signal. When the encoder teeth leave the high-speed proximity switch's detection range, the sensor outputs a low-level signal. Therefore, the output signal's duty cycle is Ds / D. To achieve an ideal 50% duty cycle, the encoder teeth spacing D should be twice the high-speed proximity switch's detection range Ds, or 40mm.

[0037] like Figure 2 As shown, in order to obtain higher detection accuracy within one pitch period (40 mm), this embodiment installs 20 high-speed proximity switch sensors on the mover, numbered 1, 2, ..., 20 in sequence.

[0038] On this basis, it is defined that the outputs of two sensors with a number difference equal to half the total number of sensors (i.e., N and N+k, where k is 10 in this embodiment) differ by 90° to form k groups of orthogonal signals. This allows both direction determination and higher resolution to be achieved in conjunction with adjacent subdivisions within the same cycle.

[0039] To subdivide a 40mm pitch into 40 parts (i.e., 1mm accuracy), the phase difference between the output signals of equivalent adjacent sensors must be 360 / 40 = 9 degrees. Thus, every 1mm of movement (1 / 40 of 40mm) causes the output signal's equivalent phase to increase by 9°, thus ensuring 1mm resolution.

[0040] In order to physically achieve an equivalent phase difference of 9° between adjacent sensors and 90° between sensor pairs, The outputs of two sensors with a number difference of half the total number of sensors (i.e. N and N+10) differ by 90°; in terms of formula, it can be written as: the physical distance L0 of (N, N+10) = (n+0.25) × D, The physical distance between adjacent sensors (N, N+1) is L=(0.1n+0.025)×D Among them, n is a positive integer to be selected, and D is the tooth pitch of 40 mm.

[0041] When n = 14, L0 = 10 × L (10 is the value of k), which satisfies the orthogonal requirement of 90° phase difference. Therefore, the 20 sensors can be divided into 10 groups of orthogonal signals.

[0042] Finally, n=14 was selected: Physical distance between adjacent sensors: L=(0.1×14+0.025)×40mm=1.425×40mm=57mm. Sensor pairs with a number difference of 10 satisfy a phase difference of approximately 90°; equivalent adjacent sensors satisfy a phase difference of approximately 9°.

[0043] Therefore, the output signal can be subdivided into 40 discrete steps (every 1mm→9°) within a 40mm cycle, and 10 groups of orthogonal signals are formed. The equivalent working characteristics of the position sensor module are shown as follows: Figure 3 shown.

[0044] In this embodiment, Figure 1 and Figure 2 As shown in the figure, the data acquisition module, wireless optical communication component and data receiving module realize the function of collecting and wirelessly transmitting position signals. The position signals can be transmitted directionally and reliably in the complex electromagnetic environment of the linear motor and have strong anti-electromagnetic interference capability. In addition, 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 one-way transmission delay of less than 50μs, meeting the needs of real-time control of the linear motor.

[0045] Preferably, the wireless optical communication component adopts a redundant design to transmit data simultaneously on different communication paths. The different communication paths of the wireless optical communication component respectively use light of different frequencies for wireless transmission.

[0046] Specifically, the two sets of parallel redundant wireless optical communication components, each set of wireless optical communication components is composed of a mover end component and a ground end component, and the mover end component and the ground end component respectively include a transmitting end and a receiving end, for realizing full-duplex communication, wherein: The transmitting end is composed 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 receiving end 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; The transmitting end light sources of the two moving end components respectively use light sources of different wavelength bands, and the receiving ends of the corresponding two ground end components are respectively equipped with filters that match the emission wavelengths selected by their corresponding transmitting ends; The transmitting end light sources of the two ground-end components respectively use light sources of different wavelength bands, and the receiving ends of the corresponding two movable end components are respectively equipped with filters that match the emission wavelengths selected by their corresponding transmitting ends.

[0047] Preferably, if Figure 4 As shown, the present invention adopts two sets of ODCs for parallel communication transmission, which are redundant to each other; the ODCA and ODCB of each set of ODCs include a transmitter and a receiver, which can perform full-duplex communication; the ODC transmitter consists of a signal modulation circuit, a drive circuit, an LD light source and an optical antenna; the ODC receiver consists of a filter, a photoelectric sensor, a signal demodulation circuit and an amplification processing circuit.

[0048] The system is equipped with two completely independent ODCs (ODC1 and ODC2), consisting of a mover end (ODC1A, ODC2A) and a ground end (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 back up 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 position information and reducing the risk of system downtime. In industrial scenarios, redundant design can significantly reduce the impact of single-point failures on production and control systems, improving the availability and safety of the overall system.

[0049] The ODC1A and ODC2A transmitters use red and infrared light, respectively, while the ODC1B and ODC2B receivers utilize corresponding filters. Similarly, the ODC1B and ODC2B transmitters use infrared and red light, respectively, while the ODC1A and ODC2A receivers utilize corresponding filters. This solution effectively avoids co-channel interference in optical transmission and improves transmission reliability. This cross-band configuration enables simultaneous bidirectional optical transmission without interference between the two wavelength bands. In full-duplex mode, the actuator and ground terminals can transmit and receive data concurrently, significantly reducing latency and meeting the real-time control requirements of high-speed linear motors. The distinct spectral bandwidth separation between red and infrared light, combined with matched filters, prevents interference within the same wavelength band, ensuring communication reliability and signal-to-noise ratio. The wavelength cross-banding and filter filtering enable high-bandwidth, low-latency data transmission even in confined spaces and complex environments.

[0050] 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.

[0051] The transmitting end is responsible for converting the digital signal into light pulses of corresponding wavelengths and transmitting them outward; the receiving end selectively receives the light signals of corresponding wavelengths through filters, and then performs photoelectric conversion and demodulation.

[0052] Using LD (laser diode) or high-performance LED light sources provides high output power across a wide bandwidth; matching filters with photoelectric sensors further enhances receiver sensitivity. Direct hardware connection reduces intermediate conversion steps, enabling 100Mbps data rates and nanosecond latency, meeting the real-time signal requirements of high-speed motion control.

[0053] ODC1A / ODC1B and ODC2A / ODC2B operate at different wavelengths (such as red and infrared), respectively, and the receiving end uses filters that match the transmitting wavelength. This ensures that the two channels do not interfere with each other in scenarios where spatial range is limited and channels may overlap. This minimizes the possibility of overlapping or crosstalking optical signals at the same frequency, avoids multipath interference at a single wavelength, and reduces the impact of background and ambient light on communications. The two communication links, with their non-overlapping wavelengths, can operate simultaneously or provide redundant backup when necessary, further reducing the risk of data loss and communication interruptions.

[0054] The mover-side ODC (ODCA) moves back and forth at high speed with the linear motor, while the ground-side ODC (ODCB) is fixed to the ground. A cross-configuration of red and infrared light and filter selection ensures stable communication even under rapid changes in distance or angle. Parallel redundancy mode automatically switches to another link if one link experiences a temporary drop. To meet the demanding conditions of industrial sites, where high-speed motion is often accompanied by interference from vibration, dust, and stray light, the cross-configuration improves signal recognition and alignment accuracy, reducing bit errors. In spatially constrained environments, the use of different wavelengths and filters prevents interference between devices, enhancing overall system maintainability.

[0055] Specifically, the position signal transmission process adopts a high-speed communication protocol. This embodiment adopts the UDP protocol with higher real-time performance, and directly implements data encoding, modulation, demodulation and decoding in a parallel pipeline manner in hardware such as FPGA, thereby ensuring a higher data transmission rate and lower end-to-end processing delay.

[0056] This embodiment uses dual channels (different optical wavelengths) for wireless optical transmission to avoid co-frequency interference, and adopts full-duplex, redundant adaptive switching to achieve high-reliability 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, meeting the requirements of closed-loop control of high-speed linear motors.

[0057] The contents not described in detail in this specification belong to the prior art 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: The encoder is fixedly mounted on the stator of the linear motor and is used to generate encoding signals; The position sensor module is installed on the linear motor mover and integrates multiple inductive proximity sensors; The encoder and position sensor module work together to generate position signals. That is, when the mover moves, the coding teeth on the encoder sequentially enter the detection area of each sensor in the position sensor module, generating corresponding coding signals, thereby realizing position information feedback; The signal transmission unit is used to transmit the position information wirelessly to an external control system.

2. The system according to claim 1, wherein: The signal transmission unit includes: Two sets of wireless optical communication components, which are redundant and use different frequencies of light for wireless transmission; The data acquisition module is provided on the linear motor mover load and is used to collect 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 is arranged outside the linear motor and is used to receive the position signal through the wireless optical communication component; and transmit the position information to the external control system to realize closed-loop control of the linear motor.

3. The system according to claim 1, wherein: The encoding teeth of the encoder are evenly distributed at equal intervals, and the tooth pitch matches the detection range of the inductive proximity sensor to ensure that a stable encoding signal with a target duty cycle is generated when each encoding tooth passes.

4. The system according to claim 1, wherein: The encoder and position sensor module are designed with structural matching so that the encoding signals collected by each inductive proximity sensor present a predetermined phase difference, thereby subdividing a single encoding tooth to achieve a position resolution that meets or exceeds the set requirements.

5. The system according to claim 4, characterized in that The parameter design process for encoders and inductive proximity sensors includes: According to the target duty cycle, determining the matching relationship between the detection range of the inductive proximity sensor and the tooth width and tooth pitch of the encoding gear plate so that the sensor outputs high and low levels to meet the required duty cycle within one cycle; Determining a predetermined phase difference between output signals of equivalent adjacent inductive proximity sensors based on the encoding pitch and a predetermined detection accuracy, for subdividing the encoding pitch period into a number of equal parts, thereby achieving a target position resolution; According to the detection accuracy and the encoding pitch, the number of inductive proximity sensors is selected so that discrete phase states are generated within one pitch period to meet the resolution requirement; The inductive proximity sensors are numbered in sequence according to the arrangement order, and a 90° phase difference is set for the output signals of two inductive proximity sensors with a number difference of k, where k is a positive integer and is half the number of sensors, thereby forming k sets of orthogonal signals in one cycle; Based on the above phase difference requirements, the specific installation spacing of the inductive proximity sensor is derived and determined so that the sensor output can simultaneously meet the duty cycle, subdivision number and orthogonal signal targets within one cycle.

6. 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.

7. The system according to claim 2, characterized in that: Each set of wireless optical communication components consists of a mover-end component and a ground-end component, and the mover-end component and the ground-end component respectively include a transmitting end and a receiving end, which are used to realize full-duplex communication between the mover-end component and the ground-end component; the mover-end component is arranged on the mover load of the linear motor and moves back and forth in a straight line at high speed, and the ground-end component is arranged outside the linear motor.

8. The system according to claim 7, characterized in that: The transmitting end is composed 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 receiving end 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.

9. The system according to claim 7, characterized in that: The transmitting end light sources of the two moving end components respectively use light sources of different wavelength bands, and the receiving ends of the corresponding two ground end components are respectively equipped with filters that match the emission wavelengths selected by their corresponding transmitting ends; The transmitting end light sources of the two ground-end components respectively use light sources of different wavelength bands, and the receiving ends of the corresponding two movable end components are respectively equipped with filters that match the emission wavelengths selected by their corresponding transmitting ends.

10. The system according to claim 2, wherein: The communication between the data acquisition module, wireless optical communication component and data receiving module adopts the UDP protocol, with a transmission rate of 100Mbps and a delay of less than 50μs, which meets the requirements of real-time control of the linear motor.

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