Frequency division multiplexing transmitter crosstalk compensation method

Abstract

The invention relates to a crosstalk compensation method for a frequency division multiplexing transmitter. The crosstalk compensation method comprises the following steps: transmitting coils of excitation circuits in the frequency division multiplexing transmitter generate radiation signals with different frequencies and phases under the excitation of coil excitation signals; collecting a current signal in each transmitting coil; after the collected current signals are processed, the frequency, the phase and the amplitude of each crosstalk current signal contained in the current signals are extracted; generating a corresponding crosstalk current signal compensation current signal according to the frequency, the phase and the amplitude of each path of crosstalk current signal extracted from each transmitting coil; and generating a compensation current signal corresponding to the crosstalk current signal, outputting the excitation signal of the coil and the corresponding compensation current signal to the excited transmitting coil, and eliminating the crosstalk between the coils while outputting the radiation signal. According to the invention, interference signals in the transmitting coils can be monitored in real time, and crosstalk between the transmitting coils is eliminated.

Description

Technical Field

[0001] The present invention relates to the technical field of frequency division multiplexing transmission, and particularly relates to a method for compensating crosstalk of a frequency division multiplexing transmitter. Background Art

[0002] A frequency division multiplexing transmitter can provide continuous excitation signals for multiple coils. The receiving coil receives the excitation signal, and after the main control unit collects the signal of the receiving coil, it calculates the pose of the receiving coil, so as to realize the electromagnetic positioning function. However, since frequency division multiplexing requires multiple coils to generate excitation signals of different frequencies simultaneously, there will be mutual interference between the transmitting coils, resulting in distortion of the excitation signal, and ultimately leading to a large error in the positioning result, which limits the application of the frequency division multiplexing transmitter in electromagnetic positioning. Summary of the Invention

[0003] In view of the above analysis, the present invention aims to disclose a method for compensating crosstalk of a frequency division multiplexing transmitter; it can monitor the interference signal in the transmitting coil in real time and compensate the excitation signal; and solves the crosstalk problem between the transmitting coils.

[0004] On the one hand, the present invention discloses a method for compensating crosstalk of a frequency division multiplexing transmitter, including:

[0005] Step S1: The transmitting coils of each excitation circuit in the frequency division multiplexing transmitter generate radiation signals of different frequencies and phases under the excitation of the coil excitation signal;

[0006] Step S2: Collect the current signals in each transmitting coil; the current signal collected by each transmitting coil includes the excitation current of this coil and multiple crosstalk current signals generated due to crosstalk from other coils;

[0007] Step S3: After processing the collected current signals, extract the frequency, phase, and amplitude of each crosstalk current signal contained therein;

[0008] Step S4: Generate corresponding crosstalk current signal compensation current signals according to the frequency, phase, and amplitude of each crosstalk current signal extracted from each transmitting coil;

[0009] Step S5: Generate compensation current signals corresponding to the crosstalk current signals, and output the excitation signal of the coil and the corresponding compensation current signal to the excited transmitting coil together, so as to eliminate the crosstalk between the coils while outputting the radiation signal.

[0010] Further, the current signals in each coil are collected by connecting a sampling resistor in series on each coil.

[0011] Further, after performing current-to-voltage conversion processing on the collected current signal, the collected voltage signal is obtained. The collected voltage signal includes the excitation voltage signal of the present coil and the crosstalk voltage signal of other coils to the present coil;

[0012] The crosstalk voltage signal of the excitation circuit m in the excitation circuit n after processing the collected current signal is:

[0013]

[0014] In the formula,

[0015] is the frequency of the crosstalk current signal of the excitation circuit m in the excitation circuit n;

[0016] is the angular frequency of the crosstalk current signal of the excitation circuit m in the excitation circuit n;

[0017] is the initial phase of the crosstalk current signal of the excitation circuit m in the excitation circuit n;

[0018] is the current sampling gain of the excitation circuit n;

[0019] is the crosstalk voltage amplitude of the mth excitation circuit in the nth excitation circuit obtained by conversion;

[0020] The frequency of the crosstalk current signal of the excitation circuit m in the excitation circuit n is the excitation signal frequency f of the excitation circuit m m ;

[0021] The angular frequency of the crosstalk current signal of the excitation circuit m in the excitation circuit n is the excitation signal angular frequency ω of the excitation circuit m m ;

[0022] The initial phase of the crosstalk signal

[0023] In the formula, θ n is the initial phase of the excitation signal in the excitation circuit n; is the phase difference between the crosstalk signal of the excitation circuit m in the excitation circuit n and the excitation signal of the excitation circuit n.

[0024] Further, in step S4, the process of generating the compensation current signal includes:

[0025] 1) Determine the initial phase of the compensation current signal for compensating each crosstalk current signal in each excitation circuit;

[0026] 2) Calculate the reactance value in the series resonance circuit when compensating for the crosstalk current in each excitation circuit;

[0027] 3) Calculate the current phase angle at both ends of the resonance circuit in each excitation circuit;

[0028] 4) Calculate the initial phase of the compensation voltage signal working at both ends of the series resonance circuit in each excitation circuit;

[0029] 5) Calculate the voltage amplitude for compensating each crosstalk signal in each excitation circuit;

[0030] 6) Obtain the compensation voltage signal based on the calculated voltage, frequency, and initial phase of the compensation voltage signal, and then combine it with the reactance of the series resonance circuit to obtain a compensation current signal with the same amplitude as the crosstalk signal.

[0031] Furthermore, during the generation of the compensation current signal, when compensating for the crosstalk current in excitation circuit n caused by excitation circuit m, the determined initial phase of the compensation current is the initial phase of the crosstalk current in excitation circuit n caused by excitation circuit m.

[0032] Furthermore, during the generation of the compensation current signal, when compensating for the crosstalk current in excitation circuit n caused by excitation circuit m, the calculated reactance of the series resonance circuit in excitation circuit n combined with the crosstalk of excitation circuit m is:

[0033]

[0034] In the formula,

[0035] is the angular frequency of the crosstalk signal of excitation circuit m compensated in excitation circuit n;

[0036] L n is the coil inductance value of excitation circuit n;

[0037] C n is the coil resonance capacitance value of excitation circuit n;

[0038] R n is the coil resistance value of excitation circuit n;

[0039] Among them,

[0040] Furthermore, during the generation of the compensation current signal, when the series resonance circuit in excitation circuit n operates at frequency, the calculated current phase angle is:

[0041]

[0042] Further, during the generation of the compensation current signal, when the series resonance circuit in the excitation circuit n operates at a frequency, the initial phase of the compensation voltage signal calculated across the series resonance circuit is:

[0043]

[0044] Further, during the generation of the compensation current signal, when compensating for the crosstalk current in the excitation circuit n caused by the excitation circuit m, the calculated compensation voltage amplitude is:

[0045]

[0046] Further, during the generation of the compensation current signal, when compensating for the crosstalk current in the excitation circuit n caused by the excitation circuit m, the calculated compensation current signal is:

[0047]

[0048] One of the beneficial effects that can be achieved by the present invention is as follows:

[0049] The crosstalk compensation method for a frequency division multiplexing transmitter disclosed by the present invention can monitor the interference signals in the transmitting coil in real time and compensate the excitation signal through the compensation current signal, thereby solving the crosstalk problem between the transmitting coils; when applied to the field of electromagnetic positioning, the electromagnetic positioning accuracy can be improved. Description of the Drawings

[0050] The drawings are only for the purpose of showing specific embodiments and are not considered as a limitation to the present invention. Throughout the drawings, the same reference signs denote the same components.

[0051] Figure 1 It is a flowchart of the crosstalk compensation method for a frequency division multiplexing transmitter in an embodiment of the present invention. Detailed Embodiments

[0052] The following will specifically describe the preferred embodiments of the present invention with reference to the drawings, wherein the drawings form a part of this application and are used together with the embodiments of the present invention to explain the principle of the present invention.

[0053] An embodiment of the present invention discloses a crosstalk compensation method for a frequency division multiplexing transmitter, as Figure 1 shown, including the following steps:

[0054] Step S1: The transmitting coils of each excitation circuit in the frequency division multiplexing transmitter generate radiation signals with different frequencies and phases under the excitation of the coil excitation signals;

[0055] Step S2: Collect the current signals in each transmitting coil; the current signals collected by each transmitting coil include the excitation current of this coil and multiple crosstalk current signals generated due to crosstalk from other coils.

[0056] Step S3: After processing the collected current signals, extract the frequency, phase, and amplitude of each crosstalk current signal contained therein.

[0057] Step S4: Generate corresponding crosstalk current signal compensation current signals according to the frequency, phase, and amplitude of each crosstalk current signal extracted from each transmitting coil.

[0058] Step S5: Generate compensation current signals corresponding to the crosstalk current signals, and output the excitation signal of the coil and the corresponding compensation current signals to the excited transmitting coil together, so as to eliminate the crosstalk between the coils while outputting the radiation signal.

[0059] Specifically, the frequency-division multiplexing transmitter can provide different and continuous excitation signals with different frequencies for the transmitting coils of each excitation circuit. The driving signal of the m-th excitation circuit is:

[0060] S m =cos(2×π×f m ×t + θ m ) = cos(ω m ×t + θ m );

[0061] In the formula,

[0062] f m is the driving signal frequency of the m-th excitation circuit;

[0063] ω m is the angular frequency of the driving signal of the m-th excitation circuit;

[0064] θ m is the initial phase of the driving signal of the m-th excitation circuit;

[0065] During electromagnetic positioning, the transmitting coils of each excitation circuit in the frequency-division multiplexing transmitter are installed in a close-range manner; when each coil radiates signals at its own transmitting frequency and phase at the same time; due to the coil electrical parameters between different coils and the relative position and pose relationship between the coils during installation, crosstalk signals will be generated between different coils; thus, they will interfere with each other, resulting in distortion of the excitation signal and ultimately a large error in the positioning result.

[0066] Specifically, in step S2, the current signals in each coil are collected by connecting sampling resistors in series on each coil.

[0067] Specifically, in step S3, after performing current-to-voltage conversion processing on the collected current signal, the collected voltage signal is obtained. The collected voltage signal includes the excitation voltage signal of the present coil and the crosstalk voltage signal of other coils to the present coil;

[0068] Optionally, by performing FFT transformation on the collected voltage signal, the frequency, phase, and amplitude of the crosstalk signal contained therein are extracted.

[0069] The crosstalk voltage signal of the excitation circuit m in the excitation circuit n obtained after processing the collected current signal is:

[0070]

[0071] In the formula,

[0072] is the frequency of the crosstalk current signal of the excitation circuit m in the excitation circuit n;

[0073] is the angular frequency of the crosstalk current signal of the excitation circuit m in the excitation circuit n;

[0074] is the initial phase of the crosstalk current signal of the excitation circuit m in the excitation circuit n;

[0075] is the current sampling gain of the excitation circuit n;

[0076] is the crosstalk voltage amplitude of the excitation circuit m in the excitation circuit n obtained by conversion;

[0077] The frequency of the crosstalk current signal of the excitation circuit m in the excitation circuit n is the excitation signal frequency f of the excitation circuit m m ;

[0078] The angular frequency of the crosstalk current signal of the excitation circuit m in the excitation circuit n is the excitation signal angular frequency ω of the excitation circuit m m ;

[0079] The initial phase of the crosstalk signal

[0080] In the formula, θ n is the initial phase of the excitation signal in the excitation circuit n; is the phase difference between the crosstalk signal of the excitation circuit m in the excitation circuit n and the excitation signal of the excitation circuit n.

[0081] Specifically, in step S4, the process of generating the compensation current signal includes:

[0082] 1) Determine the initial phase of the compensation current signal for compensating each crosstalk current signal in each excitation circuit;

[0083] In this embodiment, since the purpose of generating the compensation current signal is to cancel the crosstalk signal, the generated compensation current signal is in antiphase with the crosstalk current signal for signal cancellation.

[0084] That is, when compensating for the crosstalk current in excitation circuit n caused by excitation circuit m, the determined initial phase of the compensation current is the initial phase of the crosstalk current in excitation circuit n caused by excitation circuit m.

[0085] 2) Calculate the reactance value in the series resonance circuit when compensating for the crosstalk current in each excitation circuit;

[0086] Since the resonance points of the series resonance circuits in excitation circuit m and excitation circuit n are different. Therefore, when compensating for the crosstalk current in excitation circuit n caused by excitation circuit m, the calculated reactance of the series resonance circuit in excitation circuit n combined with the crosstalk of excitation circuit m is:

[0087]

[0088] In the formula,

[0089] is the angular frequency of the crosstalk signal of excitation circuit m compensated in excitation circuit n;

[0090] L n is the coil inductance value of excitation circuit n;

[0091] C n is the resonant capacitance value of the coil of excitation circuit n;

[0092] R n is the coil resistance value of excitation circuit n;

[0093] Among them,

[0094] 3) Calculate the current phase angle at both ends of the resonance circuit in each excitation circuit;

[0095] Among them, when the series resonance circuit in excitation circuit n operates at frequency, the calculated current phase angle is:

[0096]

[0097] 4) Calculate the initial phase of the compensation voltage signal working at both ends of the series resonance circuit in each excitation circuit;

[0098] When the series resonance circuit in the excitation circuit n operates at a frequency, the initial phase of the compensated voltage signal calculated across the series resonance circuit is:

[0099]

[0100] 5) Calculate the voltage amplitude for compensating each crosstalk signal in each excitation circuit;

[0101] When compensating for the crosstalk current in the excitation circuit n caused by the excitation circuit m, the reactance modulus of the series resonance circuit in the excitation circuit n is |Z n |. To obtain a compensated current signal with the same amplitude, the calculated compensated voltage amplitude is:

[0102]

[0103] 6) Obtain the compensated voltage signal based on the voltage, frequency, and initial phase of the calculated compensated voltage signal, and then combine it with the reactance of the series resonance circuit to obtain a compensated current signal with the same amplitude as the crosstalk signal.

[0104] When compensating for the crosstalk current in the excitation circuit n caused by the excitation circuit m, the calculated compensated current signal is:

[0105]

[0106] After generating the compensated current signal corresponding to the crosstalk current signal, output the excitation signal of the coil and the corresponding compensated current signal to the excited coil together, eliminating the crosstalk between the coils while outputting the radiation signal.

[0107] In summary, the crosstalk compensation method for the frequency-division multiplexing transmitter disclosed in the embodiments of the present invention can monitor the interference signals in the transmitting coil in real time, compensate the excitation signal through the compensated current signal, and solve the crosstalk problem between the transmitting coils; when applied to the electromagnetic positioning field, the electromagnetic positioning accuracy is improved.

[0108] Taking the crosstalk compensation test of two mutually crosstalking transmitting coils as an example, the excitation circuit n and the excitation circuit m respectively apply signal excitations with frequencies of 3.75 KHz and 5.00 KHz to their respective transmitting coils.

[0109] When crosstalk compensation is not adopted, the amplitude difference between the excitation current and the crosstalk signal in the 3.75 KHz LC resonance circuit is approximately 31.331 dB (about 2.7%), and the amplitude difference between the excitation current and the crosstalk signal in the 5.00 KHz LC resonance circuit is approximately 34.619 dB (about 1.9%).

[0110] After compensation according to the method of this embodiment, the compensation parameters of the 3.75KHz and 5.00KHz LC resonant circuits are respectively obtained as shown in the following table.

[0111] Compensation Phase Compensation Amplitude 3.75KHz LC 263.9828 0.0065 5.00KHz LC 261.8376 0.0089

[0112] After crosstalk compensation, the amplitude difference between the excitation current and the crosstalk signal in the 3.75KHz LC resonant circuit is about 73.595dB (about 0.209‰), and the amplitude difference between the excitation current and the crosstalk signal in the 5.00KHz LC resonant circuit is about 68.431dB (about 0.379‰).

[0113] It can be seen from the crosstalk compensation test that the frequency division multiplexing transmitter crosstalk compensation method of this embodiment has a significant suppressive effect on the crosstalk between transmitting coils.

[0114] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for crosstalk compensation of a frequency division multiplexing transmitter, characterized in that, Including: Step S1: The transmitting coils of each excitation circuit in the frequency division multiplexing transmitter generate radiation signals with different frequencies and phases under the excitation of the coil excitation signals; Step S2: Collect the current signals in each transmitting coil; The current signal collected by each transmitting coil includes the excitation current of this coil and the multiplex crosstalk current signals generated due to the crosstalk of other coils; Step S3: After processing the collected current signals, extract the frequency, phase and amplitude of each crosstalk current signal contained therein; Step S4: Generate corresponding crosstalk current signal compensation current signals according to the frequency, phase and amplitude of each crosstalk current signal extracted from each transmitting coil; Step S5: Generate compensation current signals corresponding to the crosstalk current signals, and output the excitation signal of the coil and the corresponding compensation current signal to the excited transmitting coil together to eliminate the crosstalk between the coils while outputting the radiation signal.

2. The method for crosstalk compensation of a frequency division multiplexing transmitter according to claim 1, characterized in that, Collect the current signals in each coil by connecting a sampling resistor in series on each coil.

3. The method for crosstalk compensation of a frequency division multiplexing transmitter according to claim 2, characterized in that, After performing current-to-voltage conversion processing on the collected current signals, the collected voltage signals are obtained. The collected voltage signals include the excitation voltage signal of the collected coil itself and the crosstalk voltage signals of other coils to this coil; The crosstalk voltage signal of excitation circuit m in excitation circuit n after processing the collected current signals is: In the formula, The frequency of the current signal for crosstalk between the excitation circuit m and the excitation circuit n in the excitation circuit n; The angular frequency of the current signal for crosstalk of the excitation circuit m in the excitation circuit n; is the initial phase of the current signal for crosstalk of the excitation circuit m in the excitation circuit n; is the current sampling gain of the excitation circuit n; is the crosstalk voltage amplitude of the m-th excitation circuit obtained by conversion in the n-th excitation circuit; The current signal frequency of crosstalk between the excitation circuit m and the excitation circuit n is the excitation signal frequency f of the excitation circuit m m ; The angular frequency of the current signal of the crosstalk of excitation circuit m in excitation circuit n is the angular frequency ω of the excitation signal of excitation circuit m m ; Initial phase of crosstalk signal where θ n is the initial phase of the excitation signal in the excitation circuit n; is the phase difference between the crosstalk signal of the excitation circuit m and the excitation signal of the excitation circuit n in the excitation circuit n.

4. The method for crosstalk compensation of a frequency division multiplexing transmitter according to claim 3, characterized in that, In step S4, the process of generating the compensation current signal includes: 1) Determine the initial phase of the compensation current signal for compensating each crosstalk current signal in each excitation circuit; 2) Calculate the reactance value in the series resonance circuit when compensating the crosstalk current in each excitation circuit; 3) Calculate the current phase angle at both ends of the resonance circuit in each excitation circuit; 4) Calculate the initial phase of the compensation voltage signal working at both ends of the series resonance circuit in each excitation circuit; 5) Calculate the voltage amplitude for compensating each crosstalk signal in each excitation circuit; 6) Obtain the compensation voltage signal according to the voltage, frequency and initial phase of the calculated compensation voltage signal, and then combine it with the reactance of the series resonance circuit to obtain a compensation current signal with the same amplitude as the crosstalk signal.

5. The method for crosstalk compensation of a frequency division multiplexing transmitter according to claim 4, characterized in that, During the generation of the compensation current signal, when compensating for the crosstalk current in excitation circuit n caused by excitation circuit m, the initial phase of the determined compensation current is the initial phase of the crosstalk current in excitation circuit n caused by excitation circuit m.

6. The method for compensating crosstalk of a frequency division multiplexing transmitter according to claim 5, wherein, During the process of generating the compensation current signal, when compensating the crosstalk current caused by excitation circuit m in excitation circuit n, the calculated reactance of the series resonance circuit in excitation circuit n combined with the crosstalk of excitation circuit m is: In the formula, To stimulate the crosstalk signal angular frequency of the compensation excitation circuit m in the excitation circuit n; L n is the inductance value of the n coil of the excitation circuit; C n is the resonant capacitance value of the excitation circuit n coil; R n is the coil resistance value of the excitation circuit n; Among them, 7. The method for compensating crosstalk of a frequency division multiplexing transmitter according to claim 6, wherein, During the generation of the compensation current signal, when the series resonance circuit in the excitation circuit n operates at frequency, the calculated current phase angle is:

8. The method for compensating crosstalk of a frequency division multiplexing transmitter according to claim 7, wherein, During the generation of the compensation current signal, when the series resonance circuit in the excitation circuit n operates at a frequency, the initial phase of the calculated compensation voltage signal across the series resonance circuit is:

9. The method for compensating crosstalk of a frequency division multiplexing transmitter according to claim 8, wherein, During the process of generating the compensation current signal, when compensating the crosstalk current caused by excitation circuit m in excitation circuit n, the calculated compensation voltage amplitude is:

10. The method for compensating crosstalk of a frequency division multiplexing transmitter according to claim 9, wherein, During the process of generating the compensation current signal, when compensating the crosstalk current caused by excitation circuit m in excitation circuit n, the calculated compensation current signal is:

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