High-integration intelligent precise displacement sensor

Abstract

The utility model discloses a kind of high-integration intelligent accurate displacement sensors, belong to displacement measurement technical field.The utility model aims at solving the technical problems of low measurement accuracy and poor environmental adaptability caused by the existing LVDT sensor due to signal remote transmission being susceptible to interference, and temperature, environmental magnetic field and mechanical movement Compound interference cannot be compensated.The sensor includes sensor shell, LVDT coil and internal control circuit board;The control circuit board is integrated with signal processing unit for source digitization of LVDT coil signal, and high-precision temperature sensor, high-sensitivity magnetic sensor and 6-axis motion sensor for real-time compensation;After displacement signal is comprehensively compensated and corrected according to each sensor data by processor, high-precision digital displacement signal is directly output through digital bus interface.The utility model improves the measurement accuracy and environmental adaptability of sensor significantly by integrated design and multidimensional intelligent compensation, and simplifies system integration.

Description

Technical Field

[0001] This utility model belongs to the field of displacement measurement technology, specifically relating to a highly integrated intelligent precision displacement sensor. Background Technology

[0002] Linear variable differential transformers (LVDTs), as highly reliable electromechanical conversion components, are widely used in various industrial and scientific research fields requiring high-precision linear displacement measurement. Traditional LVDT sensor systems typically employ a split structure, consisting of a sensor probe containing only the LVDT coil and a movable iron core, and a separate external signal conditioning circuit box. In operation, the sensor probe senses the displacement of the measured object and outputs a weak differential analog voltage signal. This signal must be transmitted over a long distance via a specially shielded cable to the external signal conditioning circuit for amplification, filtering, demodulation, and analog-to-digital conversion before finally outputting a displacement reading that can be recognized by the control system.

[0003] However, the aforementioned traditional split-type LVDT sensor solutions have revealed inherent shortcomings in practical applications. First, the millivolt-level analog signal output from the probe is highly susceptible to electromagnetic interference (EMI) and radio frequency interference (RFI) generated by motors, frequency converters, and other equipment in industrial environments during long-distance cable transmission, leading to severe signal distortion and reduced measurement accuracy and stability. Second, traditional temperature compensation schemes typically place temperature sensors outside or near the probe. The physical distance and thermal delay between the measurement point and the core heating area of ​​the coil prevent the sensor from accurately reflecting the coil's true operating temperature in real time, significantly diminishing the effectiveness of temperature compensation. More importantly, existing LVDT sensors are "passively" adapted to complex industrial environments. They cannot actively sense and respond to unknown strong magnetic field interference, nor can they compensate for measurement errors introduced by equipment vibration or dynamic movement. These unknown interference factors can lead to severe deviations or even data failure in measurement. Therefore, fundamentally improving the measurement accuracy, anti-interference capability, and environmental adaptability of LVDT sensors in complex industrial environments is a pressing technical problem that needs to be solved in this field. Utility Model Content

[0004] The purpose of this invention is to address the deficiencies mentioned in the background art by proposing a highly integrated intelligent and precise displacement sensor.

[0005] The technical solution adopted in this utility model is as follows:

[0006] This utility model provides a highly integrated intelligent precision displacement sensor, comprising:

[0007] Sensor housing;

[0008] An LVDT coil is installed inside the sensor housing;

[0009] A movable iron core that can move within the LVDT coil in response to displacement; and

[0010] The control circuit board is located inside the sensor housing;

[0011] The control circuit board integrates:

[0012] A signal processing unit electrically connected to the LVDT coil for digitizing the analog displacement signal it generates;

[0013] A high-precision temperature sensor used to monitor the operating temperature of the LVDT coil;

[0014] A high-sensitivity magnetic sensor used to monitor the magnetic field of the environment in which the sensor housing is located;

[0015] A 6-axis motion sensor used to monitor the motion state of the sensor housing itself;

[0016] A custom processor is electrically connected to the signal processing unit, the high-precision temperature sensor, the high-sensitivity magnetic sensor, and the 6-axis motion sensor, respectively. The custom processor is configured to: compensate and correct the digital displacement signal output by the signal processing unit based on data collected by the high-precision temperature sensor, the high-sensitivity magnetic sensor, and the 6-axis motion sensor, to generate final displacement data; and

[0017] A digital bus interface electrically connected to the custom processor for outputting the final displacement data to external devices.

[0018] As a preferred technical solution of this utility model, the customized processor is configured to: call a preset temperature compensation model and use the real-time temperature value collected by the high-precision temperature sensor to perform temperature drift compensation on the digital displacement signal.

[0019] As a preferred embodiment of this invention, the high-precision temperature sensor is mounted on the control circuit board in a surface mount manner, close to the LVDT coil.

[0020] As a preferred technical solution of this utility model, the customized processor is configured to: when the environmental magnetic field data collected by the high-sensitivity magnetic sensor exceeds a preset threshold, perform at least one of the following operations on the final displacement data: alarm, correction, or locking.

[0021] As a preferred technical solution of this utility model, the high-sensitivity magnetic sensor is a triaxial magnetic sensor used to monitor the magnetic field strength in the X, Y, and Z directions.

[0022] As a preferred embodiment of this utility model, the customized processor is configured to: perform vibration or dynamic motion compensation on the digital displacement signal based on the acceleration or angular velocity data collected by the 6-axis motion sensor through filtering or dynamic calibration algorithms.

[0023] As a preferred embodiment of this invention, the 6-axis motion sensor includes a three-axis accelerometer and a three-axis gyroscope.

[0024] As a preferred embodiment of this utility model, the digital bus interface is an RS-485 interface or a USB interface.

[0025] This invention integrates a signal processing unit, a multi-physical quantity compensation sensor, a digital communication interface, and an LVDT coil into a single sensor housing, achieving significant advantages over existing technologies.

[0026] First, this invention places the signal processing unit close to the LVDT coil, completing the analog-to-digital conversion at the source of the signal output. This physically eliminates the risk of weak analog signals being contaminated by external electromagnetic noise during long-distance transmission, greatly improving the original accuracy and anti-interference capability of the measurement.

[0027] Secondly, this invention, through its built-in high-precision temperature sensor, high-sensitivity magnetic sensor, and 6-axis motion sensor, endows the sensor with the ability to actively sense temperature changes, environmental magnetic field interference, and its own vibration and motion states. The processor utilizes this real-time acquired multi-dimensional data to perform internal closed-loop, comprehensive compensation and correction of the displacement signal, accurately eliminating measurement errors introduced by temperature drift, magnetic field interference, and mechanical motion. This allows the sensor to provide highly stable and reliable measurement results even under harsh or dynamic operating conditions where traditional solutions are inadequate, greatly enhancing the product's environmental adaptability.

[0028] Finally, this invention directly outputs standard digital bus signals, achieving "plug-and-play" compatibility with modern PLCs, PCs, and other digital control systems, eliminating the need for users to configure expensive signal conditioning modules and complex shielded cables. This significantly simplifies system integration and wiring for users, while also reducing overall system construction and maintenance costs. Attached Figure Description

[0029] Figure 1 This is an exploded view of the structure of this utility model;

[0030] Figure 2 This is a block diagram of the module of this utility model.

[0031] Explanation of reference numerals in the attached diagram: 1. Sensor housing; 2. LVDT coil; 3. Movable iron core; 4. Control circuit board; 5. Signal processing unit; 6. High-precision temperature sensor; 7. High-sensitivity magnetic sensor; 8. Processor; 9. Digital bus interface; 10. 6-axis motion sensor. Detailed Implementation

[0032] It should be noted that, unless otherwise specified, the embodiments and features described in this embodiment can be combined with each other. The technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0033] Please see Figure 1 , 2 This utility model provides a highly integrated intelligent precision displacement sensor, which aims to integrate sensing, signal processing, multi-dimensional intelligent compensation and digital communication functions into a single compact structure, fundamentally solving the problems of signal susceptibility to interference, inaccurate temperature compensation, inability to resist unknown magnetic fields and motion interference, and complex system integration of the existing split-type LVDT (linear variable differential transformer) sensors.

[0034] In one specific embodiment, the sensor of this invention includes a sensor housing 1, an LVDT coil 2 disposed inside the sensor housing 1, a movable iron core 3 that can move linearly within the coil 2 to reflect the displacement of the measured object, and a control circuit board 4 also integrated inside the sensor housing 1. The core innovation of this invention lies in integrating the signal conditioning circuit, which is traditionally placed externally, and the newly added intelligent compensation unit onto the control circuit board 4, placing it adjacent to the LVDT coil 2, which serves as the signal source.

[0035] Specifically, the control circuit board 4 integrates a signal processing unit 5, a high-precision temperature sensor 6, a high-sensitivity magnetic sensor 7, a 6-axis motion sensor 10, a processor 8, and a digital bus interface 9. These electronic components are electrically connected to each other via printed circuit traces on the control circuit board 4 and are powered by an onboard power management module. This highly integrated physical layout is the foundation for achieving high-performance measurement. The raw differential analog voltage signal generated by the LVDT coil 2 is directly input to the signal processing unit 5 on the adjacent control circuit board 4 without any long leads. Specifically, the excitation output terminal of the signal processing unit 5 is electrically connected to the primary coil of the LVDT coil 2 to provide it with an excitation signal; the secondary coil output terminal of the LVDT coil 2 is electrically connected to the differential signal input terminal of the signal processing unit 5. The signal processing unit 5 is responsible for providing a stable excitation signal to the LVDT coil 2 and amplifying, filtering, and demodulating the weak analog signal output by the coil 2, ultimately converting it into a digitized raw displacement signal through a high-precision analog-to-digital converter (A / D) circuit. After analog-to-digital conversion, the data output terminal of signal processing unit 5 is connected to the data input terminal of processor 8 to transmit the digitized original displacement signal. This design, which digitizes the signal at its source, physically isolates the signal from electromagnetic interference (EMI) and radio frequency interference (RFI) during long cable transmission, greatly ensuring signal fidelity and signal-to-noise ratio.

[0036] To eliminate the impact of temperature changes on measurement accuracy, this invention incorporates a high-precision temperature sensor 6 mounted on the control circuit board 4, particularly close to the core heating area of ​​the LVDT coil 2. This high-precision temperature sensor 6 can monitor the actual operating temperature of the LVDT coil 2 in real time and accurately, continuously transmitting this temperature data to the processor 8. In terms of circuit connection, the data output terminal of the high-precision temperature sensor 6 is connected to the corresponding interface of the processor 8 via a digital communication bus (e.g., I2C or SPI bus). The processor 8's internal memory pre-stores a temperature compensation model for the sensor. This model can be obtained through experimental calibration and exists in the form of a lookup table or a polynomial fitting function. Upon receiving the original displacement signal, the processor 8 invokes this temperature compensation model, using the real-time temperature value acquired by the high-precision temperature sensor 6 to perform dynamic, closed-loop compensation calculations on the original displacement signal, thereby accurately eliminating measurement errors introduced by temperature drift.

[0037] To cope with the complex electromagnetic environment of industrial sites, this invention also integrates a high-sensitivity magnetic sensor 7 on the control circuit board 4. This high-sensitivity magnetic sensor 7 is preferably a triaxial magnetic sensor, capable of continuously monitoring the static and alternating magnetic field strengths in the X, Y, and Z orthogonal directions of the space where the sensor is located, and sending this multi-dimensional magnetic field environment data to the processor 8. Its data output terminal is also electrically connected to the processor 8 via a digital communication bus (such as I2C or SPI bus). The processor 8 analyzes this data and compares it with preset safety thresholds. When the magnetic field strength in any direction exceeds a preset threshold, the processor 8 can execute one or more predetermined strategies: First, it can send an alarm status bit to the main system (such as a host computer / PLC / PC 11) through the digital bus interface 9 to indicate that the current measurement data may be affected by magnetic field interference; second, when the interference field strength is within a specific range, the processor 8 can call a preset magnetic field influence correction model to compensate and correct the displacement data to reduce the impact of interference; finally, if the interference field strength is detected to be too large, which may cause serious distortion of the measurement value, the processor 8 can lock the output value as the last valid measurement value and continuously issue alarms to prevent erroneous control commands from being executed.

[0038] To address the interference of equipment vibration or dynamic motion on measurement accuracy, this invention further integrates a 6-axis motion sensor 10 on the control circuit board 4. This 6-axis motion sensor 10 typically includes a three-axis accelerometer and a three-axis gyroscope, capable of real-time monitoring of the sensor's linear acceleration in the X, Y, and Z directions and its angular velocity around these three axes, and sending complete motion attitude data to the processor 8. The data output terminal of the 6-axis motion sensor 10 is electrically connected to the processor 8 via a digital communication bus (e.g., I2C or SPI bus). By analyzing this motion data, the processor 8 can identify measurement noise introduced by high-frequency vibration of the equipment, or measurement offset introduced by low-frequency acceleration, deceleration, tilting, or other dynamic motions of the equipment. For high-frequency vibration, the processor 8 can use digital filtering algorithms (e.g., high-pass filtering or adaptive filtering algorithms) to process the displacement signal, effectively filtering out vibration noise; for low-frequency dynamic motion, the processor 8 can perform real-time dynamic calibration of the displacement data based on a preset motion compensation model, eliminating measurement deviations caused by changes in sensor attitude or overall motion. Similarly, when the 6-axis motion sensor 10 detects severe vibration or impact exceeding the safety threshold, the processor 8 can also issue an alarm through the digital bus interface 9 and selectively lock the output value.

[0039] Processor 8 is the core of the entire intelligent sensor's computation and control. It is responsible for aggregating the raw displacement data from signal processing unit 5, as well as environmental and motion state data from high-precision temperature sensor 6, high-sensitivity magnetic sensor 7, and 6-axis motion sensor 10. After performing the aforementioned series of precise compensation and correction calculations on the raw displacement signal, processor 8 outputs the final high-precision displacement data directly through digital bus interface 9. Specifically, the serial communication interface (such as UART) or parallel data bus of processor 8 is connected to the data input terminal of digital bus interface 9. Digital bus interface 9 then converts the logic level signals transmitted by the processor into corresponding bus physical layer signals (such as RS-485 differential signals or USB D+ / D- signals) and outputs them.

[0040] The digital bus interface 9 provides a standardized interface for the sensor to communicate with external devices (such as a host computer / PLC / PC 11). In one embodiment, the digital bus interface 9 can be an RS-485 interface, which uses differential signal transmission, has strong anti-common-mode interference capability, supports long-distance communication up to 1200 meters and multi-point networking, and is compatible with standard industrial protocols such as Modbus. In another embodiment, the digital bus interface 9 can also be a USB interface, providing plug-and-play convenience, allowing users to quickly configure parameters, diagnose status, and acquire data from the sensor via a personal computer or portable device. This direct output of standard digital signals completely replaces traditional analog outputs (such as 4-20mA current or voltage), eliminating the need for users to configure expensive signal conditioning modules and dedicated cables, greatly simplifying system integration, reducing total cost of ownership, and potential points of failure.

[0041] Of course, this utility model is not limited to the above-described embodiments. In other alternative solutions, the digital bus interface 9 can be replaced with other mainstream industrial fieldbus interfaces, such as CANopen, EtherCAT, Profinet, or IO-Link, depending on the specific industrial application scenario, to achieve seamless integration with different control systems. Furthermore, to adapt to more diverse application needs, other types of sensors, such as pressure sensors or humidity sensors, can be integrated on the control circuit board 4 as needed to achieve comprehensive sensing of more environmental parameters. For situations where wiring is inconvenient or mobile measurement is required, the digital bus interface 9 can also be replaced with a wireless communication module, such as a LoRa, Wi-Fi, Bluetooth, or Zigbee module, to achieve wireless transmission of displacement data.

[0042] In summary, this invention highly integrates the LVDT coil 2, high-performance signal processing circuit, microcontroller, and multiple physical quantity sensors (temperature, magnetic field, motion, etc.) into a single housing 1, achieving source-level digitalization of signals and intelligent compensation within a closed loop, while directly providing standard digital bus output. This not only fundamentally improves the accuracy, stability, and anti-interference capability of displacement measurement but also endows the sensor with unprecedented environmental and motion self-sensing and adaptive capabilities, significantly simplifying system integration and providing a high-performance, high-reliability, and highly intelligent precision displacement measurement solution for modern industrial automation.

[0043] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0044] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A highly integrated intelligent precision displacement sensor, characterized in that, include: Sensor housing (1); LVDT coil (2) is installed inside the sensor housing (1); A movable iron core (3) that can move within the LVDT coil (2) in response to displacement; and The control circuit board (4) is disposed inside the sensor housing (1); The control circuit board (4) integrates: A signal processing unit (5) electrically connected to the LVDT coil (2) for digitizing the analog displacement signal generated by it; A high-precision temperature sensor (6) is used to monitor the operating temperature of the LVDT coil (2). A high-sensitivity magnetic sensor (7) is used to monitor the magnetic field of the environment in which the sensor housing (1) is located. A 6-axis motion sensor (10) for monitoring the motion state of the sensor housing (1) itself. A processor (8) is electrically connected to the signal processing unit (5), the high-precision temperature sensor (6), the high-sensitivity magnetic sensor (7), and the 6-axis motion sensor (10), respectively; the processor (8) is configured to: compensate and correct the digital displacement signal output by the signal processing unit (5) based on the data collected by the high-precision temperature sensor (6), the high-sensitivity magnetic sensor (7), and the 6-axis motion sensor (10) to generate final displacement data; as well as A digital bus interface (9) electrically connected to the processor (8) for outputting the final displacement data to an external device.

2. The sensor according to claim 1, characterized in that, The processor (8) is configured to: call a preset temperature compensation model and use the real-time temperature value collected by the high-precision temperature sensor (6) to perform temperature drift compensation on the digital displacement signal.

3. The sensor according to claim 2, characterized in that, The high-precision temperature sensor (6) is mounted on the control circuit board (4) close to the LVDT coil (2).

4. The sensor according to claim 1, characterized in that, The processor (8) is configured to: when the environmental magnetic field data collected by the high-sensitivity magnetic sensor (7) exceeds a preset threshold, perform at least one of the following operations: alarm, correction or locking of the final displacement data.

5. The sensor according to claim 4, characterized in that, The high-sensitivity magnetic sensor (7) is a triaxial magnetic sensor used to monitor the magnetic field strength in the X, Y, and Z directions.

6. The sensor according to claim 1, characterized in that, The processor (8) is configured to: based on the acceleration or angular velocity data collected by the 6-axis motion sensor (10), perform vibration or dynamic motion compensation on the digital displacement signal through filtering or dynamic calibration algorithms.

7. The sensor according to claim 6, characterized in that, The 6-axis motion sensor (10) includes a three-axis accelerometer and a three-axis gyroscope.

8. The sensor according to claim 1, characterized in that, The digital bus interface (9) is an RS-485 interface or a USB interface.

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