PCB type inductosyn with high-precision anti-interference capability
Through the integrated design of PCB winding module, excitation module, calculation module and software algorithm, the anti-interference problem of traditional PCB synchronizers in complex electromagnetic environment is solved, and high-precision and high-reliability measurement is achieved. It has strong adaptability and maintains the advantages of low cost and easy mass production of PCB process.
Patent Information
- Application Number
- CN202511724341.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-23
- Publication Date
- 2026-02-27
AI Technical Summary
Traditional PCB wire-wound synchronizers have insufficient anti-interference capability in complex electromagnetic environments, low accuracy, poor consistency, and lack of effective software compensation mechanisms, resulting in insufficient measurement stability and accuracy.
By employing PCB winding modules, excitation modules, calculation modules, and software algorithms, and through local electromagnetic cancellation circuits, fine-channel winding design, low-drift components, and adaptive amplitude modulation phase adjustment algorithms, a full-chain anti-interference system is formed to improve the signal-to-noise ratio and measurement accuracy.
It achieves high-precision and high-reliability measurement in complex industrial environments, is highly adaptable, maintains the advantages of low cost and easy mass production of PCB technology, and significantly improves anti-interference capabilities.
Smart Images
Figure CN121584952A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of precision measurement, in particular to an inductive synchro with printed circuit board winding and comprehensive anti-interference design in structure, circuit and software, and more particularly to a PCB inductive synchro with high precision anti-interference capability. BACKGROUND
[0002] The inductive synchro is a key sensor for precision angle or linear displacement measurement. The traditional wire-wound synchro has the problems of low precision, poor consistency and easy interference. Although the PCB winding improves the consistency, it does not fundamentally solve the anti-interference problem in complex electromagnetic environment. The existing PCB synchro lacks consideration of the suppression of space electromagnetic interference in structure, winding design; the temperature drift and zero drift of the analog signal processing link have significant influence in circuit; and there is a lack of software compensation mechanism matching the hardware characteristics at the system level. This leads to challenges in measurement stability and precision in high-end industrial applications. Therefore, it is of great significance to design a PCB winding inductive synchro with high precision anti-interference capability. SUMMARY
[0003] In order to overcome the defects of the prior art, the present application provides the following technical scheme: a PCB inductive synchro with high precision anti-interference capability, comprising a winding module, an excitation module, a solving module and a software algorithm, the winding module is composed of a PCB winding, a metal substrate, a coupling coil and a wire harness, and is used for outputting an inductive signal corresponding to an angle; the excitation module is used for generating an excitation signal with a frequency of 10 kHz; the solving module is used for amplifying, filtering and AD converting the sine and cosine signals output by the PCB winding, and outputting a digital angle position signal of the shaft system angle position information; and the software algorithm performs amplitude compensation and phase compensation operations on the digital angle position signal of the shaft system angle position information.
[0004] Preferably, the PCB winding has a precision channel winding structure of 90 pairs of poles, 180 pairs of poles, 360 pairs of poles or 720 pairs of poles.
[0005] Preferably, the PCB winding adopts single-phase continuous winding excitation or segmented winding excitation, and performs amplitude detection through single-phase output or dual-phase output.
[0006] Preferably, in the PCB wiring, a dedicated backflow ground wire is arranged in parallel with each key signal lead, and the backflow ground wire and the signal lead have constant spacing and consistent direction, forming a local electromagnetic cancellation loop.
[0007] Preferably, the PCB winding increases the radial effective length of the precision channel continuous winding to improve the electromagnetic coupling area, thereby improving the amplitude of the induced electromotive force.
[0008] Preferably, the OPA1612 low noise operational amplifier, the 4700pF capacitor of North Yuan and the thin film resistor with tolerance less than 0.1% and temperature drift less than 5ppm / °C are used in the solving module.
[0009] Preferably, the software algorithm includes an amplitude automatic zeroing algorithm for controlling the amplitude difference of the sine and cosine two-phase signals output by the PCB winding within 10mV.
[0010] Preferably, the software algorithm includes a phase automatic zeroing algorithm for iterative correction of the phase difference of the sine and cosine two-phase signals.
[0011] Preferably, mechanical positioning marks are arranged on the PCB winding, and the mechanical positioning marks are matched with the positioning pins of the mounting base plate to ensure the coaxiality of the stator PCB and the rotor PCB.
[0012] Preferably, the excitation module outputs a voltage of 10Vp to improve the signal-to-noise ratio of the induced electromotive force of the PCB winding and enhance the common mode rejection capability.
[0013] Compared with the prior art, the present application has the following beneficial effects: (1) Systematic improvement of anti-interference capability: a full-chain, multi-level anti-interference system is formed from "near-field shielding (backflow line) - signal enhancement (large winding) - circuit purification (low drift circuit) - digital filtering (software)", which improves the working stability in complex industrial environments; (2) Higher precision and reliability: the compensation design and installation positioning marks on the structure improve the original precision and consistency of the sensor; the selection of electrical components ensures the quality of the analog signal; the software and hardware collaborative compensation eliminates the slow varying error of the system. Combined with the three, high precision and high reliability are achieved; (3) Stronger environmental adaptability: the use of low drift components and the automatic compensation algorithm of the software makes the present application not sensitive to environmental factors such as temperature change and power fluctuation, and the applicable temperature range is wider; (4) Maintaining the advantages of PCB technology: while achieving high performance, it inherits the advantages of high consistency, low cost and easy batch production brought by PCB technology; (5) Providing adaptive amplitude modulation and phase adjustment algorithms, the amplitude difference of the SIN and COS two-phase signals is reduced and controlled within 10mV, which improves the system decoding precision. BRIEF DESCRIPTION OF DRAWINGS
[0014] Figure 1 The electrical system block diagram of the present application.
[0015] Figure 2This is a schematic diagram of the traces and vias on the PCB stator winding board of the present invention.
[0016] Figure 3 This is a schematic diagram of the wiring and vias of the PCB rotor winding board of the present invention.
[0017] Figure 4 This is a block diagram of the signal conditioning circuit of the present invention.
[0018] Figure 5 This is a schematic diagram of the bandpass filter principle of the present invention.
[0019] Figure 6 This is a block diagram of the excitation circuit of the present invention.
[0020] Figure 7 The flowchart shows the automatic amplitude adjustment algorithm.
[0021] Figure 8 This is a block diagram of the automatic phase adjustment algorithm. Detailed Implementation
[0022] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.
[0023] This invention provides a PCB-type inductive synchro with high-precision anti-interference capability. Through triple optimization design of structure, electrical system, and software, the anti-interference capability, temperature stability, and final measurement accuracy of the product are systematically improved. The PCB-type inductive synchro with high-precision anti-interference capability includes a winding module, an excitation module, a calculation module, and a software algorithm. The winding module consists of a PCB winding, a corresponding metal substrate, a coupling coil, and a wire harness, outputting an induced angle signal. The excitation module generates a 10kHz excitation signal. The calculation module amplifies, filters, and performs AD conversion on the PCB output signal, outputting a digital signal of the shaft angle position information. The software algorithm performs calculations on the shaft angle signal. During PCB winding routing, a dedicated return ground wire is arranged in parallel with the critical signal leads. This return ground wire has a constant spacing and consistent direction with the signal conductors, forming a local loop. By increasing the radial effective length of the fine-channel excitation continuous winding, the coupling area with the stator winding is increased under the same excitation conditions. High-precision mechanical positioning marks are set on the PCB winding board, which cooperate with positioning pins on the mounting substrate. The excitation module increases the output signal amplitude to 10Vp. This high-level excitation signal is used to counteract interference from noise in the PCB windings on the electromagnetic induction signal. The signal rectification and filtering circuit in the calculation module uses a low-noise, low-distortion OPA1612 chip, with matching capacitors being 4700pF capacitors from Beiyuan Liu, and precision thin-film resistors (tolerance less than 0.1%, temperature drift less than 5ppm / °C). Adaptive amplitude modulation and phase adjustment algorithms can reduce the amplitude difference between the SIN and COS phase signals and control the difference within 10mV.
[0024] As Figure 1 shown, including winding module, excitation module, solving module and software algorithm, excitation module generates 10 kHz excitation signal; excitation signal input to winding module, by electromagnetic induction law generates angle signal corresponding to angle movement; solving module to PCB output signal amplification, filtering and AD conversion output shaft angle position information digital signal; software algorithm to shaft angle signal operation and output to the customer.
[0025] As Figure 2 and Figure 3 shown, PCB winding in wiring, for the key signal lead parallel arrangement of a dedicated backflow ground, the requirement of backflow ground and signal wire spacing as small as possible, the backflow ground and signal wire spacing constant, consistent with the trend, constitute a local loop, thereby effectively offset the lead in space induced common-mode error electromotive force; by increasing the precision channel excitation continuous winding radial effective length, under the same excitation conditions, increased the coupling area with the stator winding, thereby enhancing the amplitude of induced electromotive force, improve the signal-to-noise ratio of the system; on the PCB winding board, there is a high precision mechanical positioning mark, the positioning mark and the positioning pin on the installation base plate cooperate, ensure the coaxiality of the stator and rotor PCB in the installation to the mechanical base, from the source to reduce the electrical error caused by mechanical installation deviation.
[0026] As Figure 4 and Figure 5 shown, the signal rectifier filter circuit in the solving module is selected from low noise, low distortion OPA1612 chip, and the supporting capacitor C1 and C2 are selected from Beiyuan six 4700 pF capacitor, and the amplification resistor is selected from precision thin film resistor for impedance matching, and the resistance tolerance is required to be less than 0.1%, and the temperature drift is required to be less than 5 ppm / °C, so that the temperature drift and zero drift of the shaft angle signal can be improved.
[0027] As Figure 6 shown, the excitation circuit is composed of three parts: Waveform generation: waveform generation module is responsible for generating a frequency, phase and amplitude initial controllable sine baseband signal. Oscillation / generator unit: generate a reference sine wave close to 10 kHz (or higher precision digital synthesis after digital to analog conversion), the key performance indicators are frequency stability, low phase noise and low harmonic distortion. The unit output is a small amplitude, impedance matching for high resistance reference signal, which is convenient for subsequent filtering and amplification processing. Amplitude adjustment / detection interface: here, the amplitude adjustment point (for example, through the adjustable amplifier or digital to analog control) is reserved, so that the software and hardware cooperate to complete the amplitude automatic zero adjustment / gain calibration. Functionally, the waveform generator not only outputs sine wave, but also provides corresponding monitoring point and synchronous trigger (for ADC sampling clock, amplitude / phase detection reference, etc.), for Figure 7The automatic amplitude / phase algorithm provides a reference timing; Band-pass filtering: After the waveform generator, the signal must enter the band-pass filter unit to remove the high harmonics and sideband noise, ensuring the purity of the fundamental wave before reaching the power amplifier. The band-pass filter includes: center frequency: set to 10 kHz, bandwidth designed according to the frequency offset and phase error tolerated by the system (usually the bandwidth needs to be narrow enough to suppress noise, and wide enough to allow slight frequency drift and temperature change). Order and Q value: higher order can obtain steep out-of-band attenuation, but may bring phase nonlinearity; therefore, second or fourth order filter combination is often used, considering amplitude and phase characteristics. Phase characteristics of the filter: the filter unit should try to ensure phase linearity to avoid introducing unpredictable phase distortion in subsequent differential sampling and phase calculation. Band-pass filtering also serves as a system spurious suppression threshold, reducing the impact of narrowband interference in the electromagnetic environment on the excitation carrier, thereby improving the signal-to-noise ratio (SNR) of the entire measurement link; Power amplification: after band-pass filtering, the signal enters the power amplification unit, which mainly functions to amplify the small amplitude reference sine wave to the voltage and current level required to drive the PCB winding (10Vp as the target amplitude). Output power and load adaptation: the amplifier needs to have sufficient output current to overcome the impedance of the winding and coupling coil, and be able to stably drive the capacitive / inductive load of the PCB winding. Distortion control: the amplification link should use low-distortion, low-noise linear power amplifiers to avoid generating harmonics into the measured signal. Impedance matching and isolation: the output end and the winding should achieve good impedance matching and necessary isolation (to avoid coupling of internal noise of the amplifier back to the signal path through the ground loop). Amplitude adjustment and protection mechanism: the amplifier reserves amplitude adjustment interfaces and overcurrent / overvoltage protection, facilitating safe adjustment of excitation amplitude by software during calibration and protection of hardware.
[0028] Finally, a standard sine wave with an excitation frequency of 10 kHz is generated. Increasing the excitation signal can effectively reduce the signal-to-noise ratio, and for differential transmission of sine and cosine signals, increasing the signal amplitude can also improve the common-mode rejection ratio. Reason for choosing 10 kHz (based on system trade-offs): 10 kHz is chosen as the excitation frequency to balance size, coupling efficiency, and filter realizability: it can ensure that the PCB winding obtains sufficient induced voltage under reasonable size, and it can use a compact band-pass circuit to achieve high spectral purity. Increasing the signal amplitude can also improve the common-mode rejection ratio. Increasing the excitation amplitude can increase the induced signal amplitude, making the differential amplification and ADC in the back end work above the inherent noise, thereby relatively improving the effective signal-to-noise ratio, and the ability of differential processing and high-amplitude signals to combat common-mode noise is also enhanced.
[0029] As Figure 7As shown, the software collects and calculates the amplitude of SIN and COS signals of each axis of the turntable in real time, calculates the peak value, calculates the difference coefficient P through the difference of the two-phase peak value, and gets the stable and reasonable P value through multiple iteration calculation and average processing. The software can reduce the difference of the amplitude of SIN and COS signals through the P value and control the difference within 10 mV.
[0030] As shown in Figure 8 The data D is automatically added by 1 in each sampling period, and the AD sampling value is saved. The software calculates the maximum value (peak value) of the AD sampling value in real time and records the D value at this time. The software can obtain a stable and reliable D value through multiple repeated operations.
Claims
1. A PCB inductive resolver with high precision anti-interference capability, comprising a winding module, an excitation module, a resolving module and a software algorithm, characterized in that: the winding module is composed of a PCB winding, a metal substrate, a coupling coil and a wire harness, and is used for outputting an inductive signal corresponding to an angle; the excitation module is used for generating an excitation signal with a frequency of 10 kHz; the resolving module is used for amplifying, filtering and AD converting the sine and cosine signals output by the PCB winding, and is used for outputting a digital angle position signal of shaft system angle position information; and the software algorithm is used for performing amplitude compensation and phase compensation operations on the digital angle position signal of shaft system angle position information. The PCB winding has a precision channel winding structure with 90 pairs of poles, 180 pairs of poles, 360 pairs of poles or 720 pairs of poles. The PCB winding adopts single-phase continuous winding excitation or segmented winding excitation, and performs amplitude detection through single-phase output or dual-phase output. In the PCB wiring, a dedicated backflow ground wire is arranged in parallel with each key signal lead, and the backflow ground wire and the signal lead have constant spacing and consistent direction, forming a local electromagnetic cancellation loop. The PCB winding increases the radial effective length of the precision channel continuous winding to increase the electromagnetic coupling area, thereby improving the amplitude of the induced electromotive force.
2. The PCB inductive synchronizer with high precision and anti-interference capability according to claim 1, characterized in that: In the resolving module, an OPA1612 low-noise operational amplifier, a Beiyuan 4700pF capacitor and a thin-film resistor with a tolerance of less than 0.1% and a temperature drift of less than 5ppm / °C are used.
3. The PCB inductive synchronizer with high precision and anti-interference capability according to claim 1, characterized in that: The software algorithm includes an amplitude automatic zero adjustment algorithm, which is used for controlling the amplitude difference of the sine and cosine signals output by the PCB winding to be within 10mV.
4. The PCB inductive synchronizer with high precision and anti-interference capability according to claim 1, characterized in that: The software algorithm includes a phase automatic zero adjustment algorithm, which is used for iterative correction of the phase difference of the sine and cosine signals.
5. The PCB inductive synchronizer with high precision and anti-interference capability according to claim 1, characterized in that: A mechanical positioning mark is arranged on the PCB winding, and the mechanical positioning mark cooperates with a positioning pin of a mounting substrate to ensure the coaxiality of the stator PCB and the rotor PCB.
6. The PCB inductive synchronizer with high precision and anti-interference capability according to claim 1, characterized in that: The excitation module outputs a voltage of 10Vp to improve the signal-to-noise ratio of the induced electromotive force of the PCB winding and improve the common-mode rejection capability.
7. The PCB inductive synchronizer with high precision and anti-interference capability according to claim 6, characterized in that: 8. The PCB inductive synchronizer with high precision and anti-interference capability according to claim 7, characterized in that: 9. The PCB inductive synchronizer with high precision and anti-interference capability according to claim 8, characterized in that: 10. The PCB inductive synchronizer with high precision and anti-interference capability according to claim 9, characterized in that: