CN102590732B

CN102590732B - Multi-channel circuit asymmetry calibration method

Info

Publication number: CN102590732B
Application number: CN201210044556.1A
Authority: CN
Inventors: 易星; 冷用斌
Original assignee: Shanghai Institute of Applied Physics of CAS
Current assignee: Shanghai Institute of Applied Physics of CAS
Priority date: 2012-02-24
Filing date: 2012-02-24
Publication date: 2014-07-23
Anticipated expiration: 2032-02-24
Also published as: CN102590732A

Abstract

The present invention relates to a method for calibrating the asymmetry of a multi-channel circuit, which comprises the following steps: Step S1, establishing the input-output response mathematical model f(f, x, n) of the multi-channel circuit; Step S2, fitting to obtain The coefficient factor (a _ijn , b _ijn ) of the mathematical model f (f, x, n); step S3, using the peripheral actual multi-channel signal as the actual input signal of the multi-channel circuit, and collecting the actual multi-channel circuit output value, select the corresponding coefficient factor (a _ijn , b _ijn ) according to the amplitude and frequency of the actual multi-channel signal, and according to the selected coefficient factor (a _ijn , b _ijn ), the actual output value and the expression Formula (1), the amplitude of the calibration input signal is calculated to correct the amplitude of the actual input signal and calibrate the asymmetry of the multi-channel circuit. The invention has high precision and good flexibility, can effectively correct the asymmetry of the multi-channel circuit, and does not affect the data bandwidth and noise level of the original signal.

Description

A method for calibrating the asymmetry of multi-channel circuits

技术领域 technical field

本发明涉及一种用于多通道电路不对称的自动校准方法，尤其涉及一种用于加速器领域中数字束流位置监测处理器(DBPM)的多通道电路不对称性的校准方法。The invention relates to an automatic calibration method for multi-channel circuit asymmetry, in particular to a multi-channel circuit asymmetry calibration method for a digital beam position monitoring processor (DBPM) in the accelerator field.

背景技术 Background technique

束流位置测量系统中位置探头输出为多通道信号，因此，相对应的需要在位置探头的输出端连接多通道射频前端处理电路。由于每一通道前端处理电路中的同型号的元器件的性能存在差异和非线性，如功率放大器、滤波器和模数转换芯片，因此，容易造成每个单一电路通道的输入输出响应不对称；而多通道的不对称性则会影响DBPM处理器的高精度测量性能，因此，需要对这种多通道电路不对称性进行有效的校准。The output of the position probe in the beam position measurement system is a multi-channel signal, therefore, correspondingly, a multi-channel RF front-end processing circuit needs to be connected to the output end of the position probe. Due to the performance difference and nonlinearity of the same type of components in the front-end processing circuit of each channel, such as power amplifiers, filters and analog-to-digital conversion chips, it is easy to cause asymmetric input and output responses of each single circuit channel; The multi-channel asymmetry will affect the high-precision measurement performance of the DBPM processor. Therefore, it is necessary to effectively calibrate the multi-channel circuit asymmetry.

目前多通道电路不对称性修正方法为基于射频开关的多路平衡方法，主要内容为通过射频开关的实时切换，周期性的使用每个通道来处理信号，通过平均的方式来修正通道不对称性。由于该方法中使用了周期性切换的开关，因此由切换开关引入的周期性噪声将会影响处理器的噪声水平和数据带宽。为此，现在需要对这种多通道电路不对称性的修正方法进行改进。At present, the multi-channel circuit asymmetry correction method is a multi-channel balancing method based on radio frequency switches. The main content is to use the real-time switching of radio frequency switches to process signals periodically using each channel, and to correct the channel asymmetry by averaging. . Since a periodically switched switch is used in this method, the periodic noise introduced by switching the switch will affect the processor's noise level and data bandwidth. For this reason, it is necessary to improve the method of correcting the asymmetry of this multi-channel circuit.

发明内容 Contents of the invention

为了解决上述现有技术存在的问题，本发明旨在提供一种精度高、灵活性好的多通道电路不对称性的校准方法，以有效修正多通道电路的不对称性，且不影响原始信号的数据带宽和噪声水平。In order to solve the above-mentioned problems in the prior art, the present invention aims to provide a method for calibrating the asymmetry of multi-channel circuits with high precision and good flexibility, so as to effectively correct the asymmetry of multi-channel circuits without affecting the original signal data bandwidth and noise level.

本发明所述的一种多通道电路不对称性的校准方法，它包括以下步骤：A method for calibrating multi-channel circuit asymmetry of the present invention, it comprises the following steps:

步骤S1，建立所述多通道电路的输入输出响应数学模型f(f，x，n)，该步骤S1包括：根据不同的输入频率范围和幅值范围将所述多通道电路的输入输出响应函数划分为多个一阶线性函数，所述多个一阶线性函数的表达式为：Step S1, establishing the input and output response mathematical model f(f, x, n) of the multi-channel circuit, this step S1 includes: according to the input and output response function of the multi-channel circuit according to different input frequency ranges and amplitude ranges Divided into multiple first-order linear functions, the expressions of the multiple first-order linear functions are:

$f f ((f f,, x x,, n no)) = = \{\begin{matrix} {a a}_{1111 n no} \cdot \cdot x x + + {b b}_{1111 n no},, & {X x}_{00} \leq \leq x x \leq \leq {X x}_{11} \\ {a a}_{1212 n no} \cdot \cdot x x + + {b b}_{1212 n no},, & {X x}_{11} \leq \leq x x \leq \leq {X x}_{22} \\ {a a}_{1313 n no} \cdot \cdot x x + + {b b}_{1313 n no},, & {X x}_{22} \leq \leq x x \leq \leq {X x}_{33} \\ . . . . . .,, & . . . . . . \\ {a a}_{11 jn jn} \cdot \cdot x x + + {b b}_{11 jn jn},, & {X x}_{j j - - 11} \leq \leq x x \leq \leq {X x}_{j j} \end{matrix}\},, {F f}_{00} \leq \leq f f \leq \leq {F f}_{11}$

$f f ((f f,, x x,, n no)) = = \{\begin{matrix} {a a}_{21 twenty one n no} \cdot &Center Dot; x x + + {b b}_{21 twenty one n no},, & {X x}_{00} \leq \leq x x \leq \leq {X x}_{11} \\ {a a}_{22 twenty two n no} \cdot \cdot x x + + {b b}_{22 twenty two n no},, & {X x}_{11} \leq \leq x x \leq \leq {X x}_{22} \\ {a a}_{23 twenty three n no} \cdot \cdot x x + + {b b}_{23 twenty three n no},, & {X x}_{22} \leq \leq x x \leq \leq {X x}_{33} \\ . . . . . .,, & . . . . . . \\ {a a}_{22 jn jn} \cdot \cdot x x + + {b b}_{22 jn jn},, & {X x}_{j j - - 11} \leq \leq x x \leq \leq {X x}_{j j} \end{matrix}\},, {F f}_{11} \leq \leq f f \leq \leq {F f}_{22}$

… (1)… (1)

$f f ((f f,, x x,, n no)) = = \{\begin{matrix} {a a}_{((i i - - 11)) 11 n no} \cdot &Center Dot; x x + + {b b}_{((i i - - 11)) 11 n no},, & {X x}_{00} \leq \leq x x \leq \leq {X x}_{11} \\ {a a}_{((i i - - 11)) 22 n no} \cdot &Center Dot; x x + + {b b}_{((i i - - 11)) 22 n no},, & {X x}_{11} \leq \leq x x \leq \leq {X x}_{22} \\ {a a}_{((i i - - 11)) 33 n no} \cdot \cdot x x + + {b b}_{((i i - - 11)) 33 n no},, & {X x}_{22} \leq \leq x x \leq \leq {X x}_{33} \\ . . . . . .,, & . . . . . . \\ {a a}_{((i i - - 11)) j j n no} \cdot \cdot x x + + {b b}_{((i i - - 11)) j j n no},, & {X x}_{j j - - 11} \leq \leq x x \leq \leq {X x}_{j j} \end{matrix}\},, {F f}_{i i - - 22} \leq \leq f f \leq \leq {F f}_{i i - - 11}$

$f f ((f f,, x x,, n no)) = = \{\begin{matrix} {a a}_{i i 11 n no} \cdot &Center Dot; x x + + {b b}_{i i 11 n no},, & {X x}_{00} \leq \leq x x \leq \leq {X x}_{11} \\ {a a}_{i i 22 n no} \cdot \cdot x x + + {b b}_{i i 22 n no},, & {X x}_{11} \leq \leq x x \leq \leq {X x}_{22} \\ {a a}_{i i 33 n no} \cdot \cdot x x + + {b b}_{i i 33 n no},, & {X x}_{22} \leq \leq x x \leq \leq {X x}_{33} \\ . . . . . .,, & . . . . . . \\ {a a}_{ijn ijn} \cdot \cdot x x + + {b b}_{ijn ijn},, & {X x}_{j j - - 11} \leq \leq x x \leq \leq {X x}_{j j} \end{matrix}\},, {F f}_{i i - - 11} \leq \leq f f \leq \leq {F f}_{i i}$

其中，f为频率变量，x为幅值变量，n为通道数，且n≥1，F₀，F₁，…，F_i为频率界定点，i为频率划分的区间数，且i≥1，X₀，X₁，…，X_j为幅值界定点，j为幅值划分的区间数，且j≥1，(a_ijn，b_ijn)为系数因子；Among them, f is the frequency variable, x is the amplitude variable, n is the number of channels, and n≥1, F ₀ , F ₁ ,..., F _i is the frequency limit point, i is the number of intervals divided by frequency, and i≥1 , X ₀ , X ₁ ,..., X _j is the amplitude limit point, j is the number of intervals divided by the amplitude, and j≥1, (a _ijn , b _ijn ) is the coefficient factor;

步骤S2，拟合得到所述数学模型f(f，x，n)的系数因子(a_ijn，b_ijn)，该步骤S2包括：Step S2, fitting to obtain the coefficient factor (a _ijn , b _ijn ) of the mathematical model f (f, x, n), this step S2 includes:

步骤S21，将一标准信号源输出的n路信号作为所述多通道电路的n个通道的输入信号，且每个通道的输入信号的频率f_i相等，并定义每个通道的输入信号的幅值X_ij1＝X_ij2＝…＝X_ijn，所述n个通道的输出值分别为Y_ij1，Y_ij2，…，Y_ijn；Step S21, taking the n-channel signals output by a standard signal source as the input signals of n channels of the multi-channel circuit, and the frequency _fi of the input signals of each channel is equal, and defining the amplitude of the input signal of each channel Value X _ij1 =X _ij2 =...=X _ijn , the output values of the n channels are respectively Y _ij1 , Y _ij2 ,...,Y _ijn ;

步骤S22，控制所述多通道电路的n个通道的输入信号的初始幅值X₁₀₁＝X₁₀₂＝…＝X_10n＝A₀初始频率f₁＝B₁，采集n个通道的初始输出值Y₁₀₁，Y₁₀₂，…，Y_10n；Step S22, controlling the initial amplitude X ₁₀₁ =X ₁₀₂ =...=X _10n =A ₀ initial frequency f ₁ =B ₁ of the input signal of the n channels of the multi-channel circuit, and collecting the initial output value Y of the n channels ₁₀₁ , Y ₁₀₂ , ..., Y _10n ;

步骤S23，控制所述多通道电路的n个通道的输入信号的频率不变，改变该输入信号的幅值，使X_1jn＝X_1(j-1)n+A_j，其中，n分别取为1、2、…、n，分别采集在频率为f₁的不同幅值的输入信号下的n个通道的输出值Y_1j1，Y_1j2，…，Y_1jn，其中，A_j为信号源幅度的递增值，j≥1；Step S23, controlling the frequency of the input signal of the n channels of the multi-channel circuit to remain unchanged, changing the amplitude of the input signal so that X _1jn =X _1(j-1)n +A _j , where n is respectively are 1, 2, ..., n, respectively collect the output values Y _1j1 , Y _1j2 , ..., Y _1jn of n channels under the input signals of different amplitudes with frequency f ₁ , where A _j is the amplitude of the signal source The incremental value of j≥1;

步骤S24，将数据组(X_1(j-1)n，Y_1(j-1)n)和(X_1jn，Y_1jn)代入表达式(1)中，计算得到系数因子 $a_{1 jn} = \frac{Y_{1 jn} - Y_{1 (j - 1) n}}{X_{1 jn} - X_{1 (j - 1) n}},$ $b_{1 jn} = \frac{Y_{1 jn} \cdot X_{1 (j - 1) n} - Y_{1 (j - 1) n} \cdot X_{1 jn}}{X_{1 (j - 1) n} - X_{1 jn}},$ 其中，j≥1，n分别取为1、2、…、n；Step S24, substituting the data group (X _1(j-1)n , Y _1(j-1)n ) and (X _1jn , Y _1jn ) into expression (1), and calculating the coefficient factor $a_{1 jn} = \frac{Y_{1 jn} - Y_{1 (j - 1) no}}{x_{1 jn} - x_{1 (j - 1) no}},$ $b_{1 jn} = \frac{Y_{1 jn} &Center Dot; x_{1 (j - 1) no} - Y_{1 (j - 1) no} &Center Dot; x_{1 jn}}{x_{1 (j - 1) no} - x_{1 jn}},$ Wherein, j≥1, n is taken as 1, 2, ..., n respectively;

步骤S25，改变所述多通道电路的n个通道的输入信号的频率，使f_i＝f_i-1+B_i，初始化当前输入信号的幅值，使X_i01＝X_i02＝…＝X_i0n＝A₀，采集当前n个通道的初始输出值Y_i01，Y_i02，…，Y_i0n，其中，B_i为信号源频率的递增值，i≥2；Step S25, changing the frequency of the input signal of the n channels of the multi-channel circuit, so that f _i =f _i-1 +B _i , initializing the amplitude of the current input signal, making X _i01 =X _i02 =...=X _i0n =A ₀ , collect the initial output values Y _i01 , Y _i02 , ..., Y _i0n of the current n channels, where B _i is the incremental value of the signal source frequency, i≥2;

步骤S26，重复步骤S23，得到在频率为f_i的不同幅值的输入信号下的n个通道的输出值Y_ij1，Y_ij2，…，Y_ijn，其中，i≥2，j≥1；Step S26, repeating step S23, to obtain the output values Y _ij1 , Y _ij2 , ..., Y _ijn of n channels under the input signals of different amplitudes with frequency f _i , wherein, i≥2, j≥1;

步骤S27，重复步骤S24，得到系数因子其中，i≥2，j≥1，n分别取为1、2、…、n；Step S27, repeat step S24 to obtain the coefficient factor Among them, i≥2, j≥1, and n are respectively taken as 1, 2, ..., n;

步骤S3，将外围实际多路信号作为所述多通道电路的实际输入信号，采集该多通道电路的实际输出值，根据所述实际多路信号的幅值和频率选取相应的系数因子(a_ijn，b_ijn)，并根据该选取的系数因子(a_ijn，b_ijn)、所述实际输出值以及表达式(1)，计算得到校准输入信号的幅值，以修正所述实际输入信号的幅值，校准所述多通道电路的不对称性。Step S3, using the peripheral actual multi-channel signal as the actual input signal of the multi-channel circuit, collecting the actual output value of the multi-channel circuit, and selecting the corresponding coefficient factor (a _ijn , b _ijn ), and according to the selected coefficient factor (a _ijn , b _ijn ), the actual output value and the expression (1), the amplitude of the calibration input signal is calculated to correct the amplitude of the actual input signal value, to calibrate the asymmetry of the multichannel circuit.

在上述的多通道电路不对称性的校准方法中，所述各个信号源幅度的递增值A_j均相同，其中，j≥1。In the above method for calibrating the asymmetry of a multi-channel circuit, the incremental values A _j of the amplitudes of the respective signal sources are all the same, where j≥1.

在上述的多通道电路不对称性的校准方法中，所述各个信号源幅度的递增值A_j均不相同，其中，j≥1。In the above method for calibrating the asymmetry of the multi-channel circuit, the incremental values A _j of the amplitudes of the respective signal sources are different, where j≥1.

在上述的多通道电路不对称性的校准方法中，所述各个信号源频率的递增值B_i均相同，i≥2。In the above method for calibrating the asymmetry of multi-channel circuits, the incremental values B _i of the frequency of each signal source are the same, i≥2.

在上述的多通道电路不对称性的校准方法中，所述各个信号源频率的递增值B_i均不相同，i≥2。In the above method for calibrating the asymmetry of the multi-channel circuit, the incremental values B _i of the frequencies of the respective signal sources are different, i≥2.

在上述的多通道电路不对称性的校准方法中，所述标准信号源输出的n路信号均为单频率正弦信号。In the above method for calibrating the asymmetry of multi-channel circuits, the n-channel signals output by the standard signal source are all single-frequency sinusoidal signals.

在上述的多通道电路不对称性的校准方法中，所述步骤S2还包括：步骤S28，存储所述系数因子(a_ijn，b_ijn)，其中，i≥1，j≥1。In the above method for calibrating the asymmetry of multi-channel circuits, the step S2 further includes: step S28, storing the coefficient factors (a _ijn , b _ijn ), where i≥1, j≥1.

在上述的多通道电路不对称性的校准方法中，所述方法通过连接在所述多通道电路的输出端的FPGA、嵌入式控制器或计算机实现。In the above method for calibrating the asymmetry of the multi-channel circuit, the method is realized by an FPGA, an embedded controller or a computer connected to the output end of the multi-channel circuit.

由于采用了上述的技术解决方案，本发明通过建立待校准的多通道电路的输入输出响应数学模型，并使用标准信号源测定构建的数学模型的系数因子，最后在信号处理阶段时利用拟合得到的系数因子修正多个通道的不一致性。由于本发明的方法不需要实时切换射频开关，只需利用FPGA(现场可编程逻辑阵列)、嵌入式控制器或计算机实现即可，从而可以避免影响原始输入信号的数据带宽和噪声水平。Owing to having adopted above-mentioned technical solution, the present invention is by setting up the input and output response mathematical model of the multi-channel circuit to be calibrated, and uses the standard signal source to measure the coefficient factor of the mathematical model that builds, utilizes fitting to obtain in the signal processing stage at last The coefficient factor corrects for inconsistencies across multiple channels. Since the method of the present invention does not need to switch radio frequency switches in real time, it only needs to be realized by FPGA (field programmable logic array), embedded controller or computer, thereby avoiding affecting the data bandwidth and noise level of the original input signal.

附图说明 Description of drawings

图1是实现本发明一种多通道电路不对称性的校准方法的电路原理图。Fig. 1 is a schematic circuit diagram for realizing a method for calibrating multi-channel circuit asymmetry of the present invention.

具体实施方式 Detailed ways

下面结合附图，给出本发明的较佳实施例，并予以详细描述。Below in conjunction with the drawings, preferred embodiments of the present invention are given and described in detail.

如图1所示，在本实施例中，本发明，即一种多通道电路不对称性的校准方法，以连接在待校准的多通道电路1的输出端的FPGA 2作为实现平台，多通道电路1为应用于加速器测量的4通道前端处理电路。As shown in Figure 1, in the present embodiment, the present invention, namely a kind of calibration method of the asymmetry of multi-channel circuit, uses FPGA 2 connected at the output end of multi-channel circuit 1 to be calibrated as realization platform, multi-channel circuit 1 is a 4-channel front-end processing circuit applied to accelerator measurement.

本发明的方法包括以下步骤：Method of the present invention comprises the following steps:

步骤S1，建立多通道电路1的输入输出响应数学模型f(f，x，n)，该步骤S1包括：根据不同的输入频率范围和幅值范围将多通道电路1的输入输出响应函数划分为多个一阶线性函数，该多个一阶线性函数的表达式为：Step S1, establishing the input-output response mathematical model f(f, x, n) of the multi-channel circuit 1, the step S1 includes: dividing the input-output response function of the multi-channel circuit 1 according to different input frequency ranges and amplitude ranges into A plurality of first-order linear functions, the expressions of the plurality of first-order linear functions are:

$f f ((f f,, x x,, n no)) = = \{\begin{matrix} {a a}_{1111 n no} \cdot &Center Dot; x x + + {b b}_{1111 n no},, & {X x}_{00} \leq \leq x x \leq \leq {X x}_{11} \\ {a a}_{1212 n no} \cdot &Center Dot; x x + + {b b}_{1212 n no},, & {X x}_{11} \leq \leq x x \leq \leq {X x}_{22} \\ {a a}_{1313 n no} \cdot \cdot x x + + {b b}_{1313 n no},, & {X x}_{22} \leq \leq x x \leq \leq {X x}_{33} \\ . . . . . .,, & . . . . . . \\ {a a}_{11 jn jn} \cdot &Center Dot; x x + + {b b}_{11 jn jn},, & {X x}_{j j - - 11} \leq \leq x x \leq \leq {X x}_{j j} \end{matrix}\},, {F f}_{00} \leq \leq f f \leq \leq {F f}_{11}$

$f f ((f f,, x x,, n no)) = = \{\begin{matrix} {a a}_{21 twenty one n no} \cdot &Center Dot; x x + + {b b}_{21 twenty one n no},, & {X x}_{00} \leq \leq x x \leq \leq {X x}_{11} \\ {a a}_{22 twenty two n no} \cdot &Center Dot; x x + + {b b}_{22 twenty two n no},, & {X x}_{11} \leq \leq x x \leq \leq {X x}_{22} \\ {a a}_{23 twenty three n no} \cdot \cdot x x + + {b b}_{23 twenty three n no},, & {X x}_{22} \leq \leq x x \leq \leq {X x}_{33} \\ . . . . . .,, & . . . . . . \\ {a a}_{22 jn jn} \cdot &Center Dot; x x + + {b b}_{22 jn jn},, & {X x}_{j j - - 11} \leq \leq x x \leq \leq {X x}_{j j} \end{matrix}\},, {F f}_{11} \leq \leq f f \leq \leq {F f}_{22}$

… (1)… (1)

$f f ((f f,, x x,, n no)) = = \{\begin{matrix} {a a}_{((i i - - 11)) 11 n no} \cdot \cdot x x + + {b b}_{((i i - - 11)) 11 n no},, & {X x}_{00} \leq \leq x x \leq \leq {X x}_{11} \\ {a a}_{((i i - - 11)) 22 n no} \cdot \cdot x x + + {b b}_{((i i - - 11)) 22 n no},, & {X x}_{11} \leq \leq x x \leq \leq {X x}_{22} \\ {a a}_{((i i - - 11)) 33 n no} \cdot &Center Dot; x x + + {b b}_{((i i - - 11)) 33 n no},, & {X x}_{22} \leq \leq x x \leq \leq {X x}_{33} \\ . . . . . .,, & . . . . . . \\ {a a}_{((i i - - 11)) j j n no} \cdot &Center Dot; x x + + {b b}_{((i i - - 11)) j j n no},, & {X x}_{j j - - 11} \leq \leq x x \leq \leq {X x}_{j j} \end{matrix}\},, {F f}_{i i - - 22} \leq \leq f f \leq \leq {F f}_{i i - - 11}$

$f f ((f f,, x x,, n no)) = = \{\begin{matrix} {a a}_{i i 11 n no} \cdot \cdot x x + + {b b}_{i i 11 n no},, & {X x}_{00} \leq \leq x x \leq \leq {X x}_{11} \\ {a a}_{i i 22 n no} \cdot \cdot x x + + {b b}_{i i 22 n no},, & {X x}_{11} \leq \leq x x \leq \leq {X x}_{22} \\ {a a}_{i i 33 n no} \cdot \cdot x x + + {b b}_{i i 33 n no},, & {X x}_{22} \leq \leq x x \leq \leq {X x}_{33} \\ . . . . . .,, & . . . . . . \\ {a a}_{ijn ijn} \cdot \cdot x x + + {b b}_{ijn ijn},, & {X x}_{j j - - 11} \leq \leq x x \leq \leq {X x}_{j j} \end{matrix}\},, {F f}_{i i - - 11} \leq \leq f f \leq \leq {F f}_{i i}$

在本实施例中，n分别取为1、2、3和4，i＝10(即，将频率划分为10个区间)，j＝50(即，将幅值划分为50个区间)；In this embodiment, n is taken as 1, 2, 3 and 4 respectively, i=10 (that is, the frequency is divided into 10 intervals), j=50 (that is, the amplitude is divided into 50 intervals);

步骤S2，拟合得到数学模型f(f，x，n)的系数因子(a_ijn，b_ijn)；该步骤S2包括：Step S2, fitting to obtain the coefficient factor (a _ijn , b _ijn ) of the mathematical model f (f, x, n); this step S2 includes:

步骤S21，通过切换射频开关4将一标准信号源3输出的4路信号作为多通道电路1的4个通道的输入信号，且每个通道的输入信号的频率f_i相等，并定义每个通道的输入信号的幅值X_ij1＝X_ij2＝X_ij3＝X_ij4，所述n个通道的输出值分别为Y_ij1，Y_ij2，Y_ij3和Y_ij4；Step S21, by switching the radio frequency switch 4, the 4-way signal output by a standard signal source 3 is used as the input signal of the 4 channels of the multi-channel circuit 1, and the frequency _fi of the input signal of each channel is equal, and each channel is defined The amplitude of the input signal X _ij1 =X _ij2 =X _ij3 =X _ij4 , the output values of the n channels are respectively Y _ij1 , Y _ij2 , Y _ij3 and Y _ij4 ;

步骤S22，FPGA 2控制多通道电路1的4个通道的输入信号的初始幅值X₁₀₁＝X₁₀₂＝X₁₀₃＝X₁₀₄＝A₀，初始频率f₁＝B₁，采集n个通道的初始输出值Y₁₀₁，Y₁₀₂，Y₁₀₃，Y₁₀₄；Step S22, FPGA 2 controls the initial amplitude X ₁₀₁ =X ₁₀₂ =X ₁₀₃ =X ₁₀₄ =A ₀ of the input signals of the 4 channels of the multi-channel circuit 1, the initial frequency f ₁ =B ₁ , and collects the initial Output values Y ₁₀₁ , Y ₁₀₂ , Y ₁₀₃ , Y ₁₀₄ ;

步骤S23，FPGA2控制多通道电路1的4个通道的输入信号的频率不变，改变该输入信号的幅值，使X_1jn＝X_1(j-1)n+A_j，其中，n分别取为1、2、3和4，分别采集在频率为f₁的不同幅值的输入信号下的4个通道的输出值Y_1j1，Y_1j2，Y_1j3，Y_1j4，其中，A_j为信号源幅度的递增值，1≤j≤50；根据实际应用可选择各个信号源幅度的递增值A_j均相同，即A₁＝A₂＝…＝A_j，也可以选择各不相同的A_j，即A₁≠A₂…≠A_j，在本实施例中，采用相同的幅度递增值A_j；Step S23, FPGA2 controls the frequency of the input signals of the 4 channels of the multi-channel circuit 1 to be constant, and changes the amplitude of the input signal so that X _1jn =X _1(j-1)n +A _j , where n is respectively are 1, 2, 3 and 4, respectively collect the output values Y _1j1 , Y _1j2 , Y _1j3 , Y _1j4 of the four channels under the input signals of different amplitudes with frequency f ₁ , where A _j is the signal source The incremental value of the amplitude, 1≤j≤50; according to the actual application, the incremental value A _j of the amplitude of each signal source can be selected to be the same, that is, A ₁ =A ₂ =...=A _j , or a different A _j can be selected, That is, A ₁ ≠A ₂ ...≠A _j , in this embodiment, the same amplitude increment value A _j is used;

步骤S24，通过FPGA 2将数据组(X_1(j-1)n，Y_1(j-1)n)和(X_1jn，Y_1jn)代入表达式(1)中，计算得到系数因子 $a_{1 jn} = \frac{Y_{1 jn} - Y_{1 (j - 1) n}}{X_{1 jn} - X_{1 (j - 1) n}},$ $b_{1 jn} = \frac{Y_{1 jn} \cdot X_{1 (j - 1) n} - Y_{1 (j - 1) n} \cdot X_{1 jn}}{X_{1 (j - 1) n} - X_{1 jn}},$ 其中，1≤j≤50，n分别取为1、2、3和4；Step S24, substitute the data group (X _1(j-1)n , Y _1(j-1)n ) and (X _1jn , Y _1jn ) into expression (1) through FPGA 2, and calculate the coefficient factor $a_{1 jn} = \frac{Y_{1 jn} - Y_{1 (j - 1) no}}{x_{1 jn} - x_{1 (j - 1) no}},$ $b_{1 jn} = \frac{Y_{1 jn} \cdot x_{1 (j - 1) no} - Y_{1 (j - 1) no} &Center Dot; x_{1 jn}}{x_{1 (j - 1) no} - x_{1 jn}},$ Wherein, 1≤j≤50, n is taken as 1, 2, 3 and 4 respectively;

例如，当j＝1时，系数因子为：For example, when j=1, the coefficient factor is:

${a a}_{111111} = = \frac{{Y Y}_{111111} - - {Y Y}_{101101}}{{X x}_{111111} - - {X x}_{101101}},,$ ${b b}_{111111} = = \frac{{Y Y}_{111111} \cdot \cdot {X x}_{101101} - - {Y Y}_{101101} \cdot \cdot {X x}_{111111}}{{X x}_{101101} - - {X x}_{111111}}$

${a a}_{112112} = = \frac{{Y Y}_{112112} - - {Y Y}_{102102}}{{X x}_{112112} - - {X x}_{102102}},,$ ${b b}_{112112} = = \frac{{Y Y}_{112112} \cdot \cdot {X x}_{102102} - - {Y Y}_{102102} \cdot \cdot {X x}_{112112}}{{X x}_{102102} - - {X x}_{112112}}$

${a a}_{113113} = = \frac{{Y Y}_{113113} - - {Y Y}_{103103}}{{X x}_{113113} - - {X x}_{103103}},,$ ${b b}_{111111} = = \frac{{Y Y}_{113113} \cdot \cdot {X x}_{103103} - - {Y Y}_{103103} \cdot \cdot {X x}_{113113}}{{X x}_{103103} - - {X x}_{113113}}$

${a a}_{114114} = = \frac{{Y Y}_{114114} - - {Y Y}_{104104}}{{X x}_{114114} - - {X x}_{104104}},,$ ${b b}_{111111} = = \frac{{Y Y}_{114114} \cdot \cdot {X x}_{104104} - - {Y Y}_{104104} \cdot \cdot {X x}_{114114}}{{X x}_{104104} - - {X x}_{114114}}$

步骤S25，FPGA 2改变多通道电路的4个通道的输入信号的频率，使f_i＝f_i-1+B_i，初始化当前输入信号的幅值，使X_i01＝X_i02＝X_i03＝X_i04＝A₀，采集当前4个通道的初始输出值Y_i01，Y_i02，Y_i03，Y_i04，其中，B_i为信号源频率的递增值，2≤i≤10；根据实际应用可选择各个信号源频率的递增值B_i均相同，即B₁＝B₂＝…＝B_i，也可以选择各不相同的B_i，即B₁≠B₂…≠B_i；Step S25, FPGA 2 changes the frequency of the input signals of the 4 channels of the multi-channel circuit, so that f _i =f _i-1 +B _i , and initializes the amplitude of the current input signal, so that X _i01 =X _i02 =X _i03 =X _i04 ＝A ₀ , collect the initial output values Y _i01 , Y _i02 , Y _i03 , Y _i04 of the current 4 channels, where B _i is the incremental value of the signal source frequency, 2≤i≤10; each can be selected according to the actual application The incremental values B _i of the signal source frequency are all the same, that is, B ₁ =B ₂ =...=B _i , or different B _i can be selected, that is, B ₁ ≠B ₂ ...≠B _i ;

步骤S26，重复步骤S23，得到在频率为f_i的不同幅值的输入信号下的4个通道的输出值Y_ij1，Y_ij2，Y_ij3，Y_ij4，其中，2≤i≤10，1≤j≤50；Step S26, repeat step S23 to obtain the output values Y _ij1 , Y _ij2 , Y _ij3 , Y _ij4 of the four channels under the input signals of different amplitudes with frequency _fi , where 2≤i≤10, 1≤ j≤50;

步骤S27，重复步骤S24，得到系数因子其中，2≤i≤10，1≤j≤50，n分别取为1、2、3和4；Step S27, repeat step S24 to obtain the coefficient factor Among them, 2≤i≤10, 1≤j≤50, n is taken as 1, 2, 3 and 4 respectively;

步骤S28，将系数因子(a_ijn，b_ijn)存储在FPGA 2的存储器21中，其中，1≤i≤10，1≤j≤50，n分别取为1、2、3和4Step S28, store the coefficient factors (a _ijn , b _ijn ) in the memory 21 of FPGA 2, wherein, 1≤i≤10, 1≤j≤50, n is taken as 1, 2, 3 and 4 respectively

步骤S3，通过切换射频开关4将将外围实际多路信号(在本实施例中为探头信号)作为多通道电路1的实际输入信号，采集该多通道电路1的实际输出值，根据实际多路信号的幅值和频率在存储器21中选取相应的系数因子(a_ijn，b_ijn)，并根据该选取的系数因子(a_ijn，b_ijn)、实际输出值以及表达式(1)，计算得到校准输入信号的幅值，以修正实际输入信号的幅值，校准多通道电路1的不对称性。Step S3, by switching the radio frequency switch 4, the actual multi-channel signal of the periphery (in this embodiment, the probe signal) is used as the actual input signal of the multi-channel circuit 1, and the actual output value of the multi-channel circuit 1 is collected, according to the actual multi-channel signal. Select the corresponding coefficient factor (a _ijn , b _ijn ) in the memory 21 for the amplitude and frequency of the signal, and calculate according to the selected coefficient factor (a _ijn , b _ijn ), the actual output value and the expression (1). The amplitude of the input signal is calibrated to correct the amplitude of the actual input signal, and the asymmetry of the multi-channel circuit 1 is calibrated.

在本实施例中，标准信号源采用的是基于锁相环的电路，其输出的4路信号均为单频率正弦信号，且信号的输出功率和频率均由FPGA 2控制。本发明的方法还可以通过连接在所述多通道电路的输出端的嵌入式控制器或计算机实现；多通道电路1还可以为应用于加速器测量的8通道或16通道的前端处理电路。In this embodiment, the standard signal source adopts a circuit based on a phase-locked loop, and the 4 signals output by it are all single-frequency sinusoidal signals, and the output power and frequency of the signals are controlled by the FPGA 2 . The method of the present invention can also be realized by an embedded controller or computer connected to the output of the multi-channel circuit; the multi-channel circuit 1 can also be an 8-channel or 16-channel front-end processing circuit applied to accelerator measurement.

以上所述的，仅为本发明的较佳实施例，并非用以限定本发明的范围，本发明的上述实施例还可以做出各种变化。即凡是依据本发明申请的权利要求书及说明书内容所作的简单、等效变化与修饰，皆落入本发明专利的权利要求保护范围。本发明未详尽描述的均为常规技术内容。What is described above is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Various changes can also be made to the above embodiments of the present invention. That is to say, all simple and equivalent changes and modifications made according to the claims and description of the application for the present invention fall within the protection scope of the claims of the patent of the present invention. What is not described in detail in the present invention is conventional technical contents.

Claims

1. a calibration method of multi-channel circuit asymmetry, is characterized in that, described method comprises the following steps:

Step S1, establishing the input and output response mathematical model f(f, x, n) of the multi-channel circuit, this step S1 includes: according to the input and output response function of the multi-channel circuit according to different input frequency ranges and amplitude ranges Divided into multiple first-order linear functions, the expressions of the multiple first-order linear functions are:

Among them, f is the frequency variable, x is the amplitude variable, n is the number of channels, and n≥1, F ₀ , F ₁ ,...,F _i is the frequency limit point, i is the number of intervals divided by frequency, and i≥1 , X ₀ , X ₁ ,...,X _j are the amplitude limit points, j is the number of intervals divided by the amplitude, and j≥1, (a _ijn , b _ijn ) is the coefficient factor;

Step S2, fitting to obtain the coefficient factors (a _ijn , b _ijn ) of the mathematical model f(f,x,n), the step S2 includes:

Step S21, using the n-channel signals output by a standard signal source as the input signals of n channels of the multi-channel circuit, the n-channel signals output by the standard signal source are all single-frequency sinusoidal signals, and the input signals of each channel The frequencies f _i of the signals are equal, and the amplitude of the input signal of each channel is defined X _ij1 =X _ij2 =...=X _ijn , and the output values of the n channels are respectively Y _ij1 , Y _ij2 ,..., Y _ijn ;

Step S22, controlling the initial amplitude X ₁₀₁ =X ₁₀₂ =...=X _10n =A ₀ initial frequency f ₁ =B ₁ of the input signal of the n channels of the multi-channel circuit, and collecting the initial output value Y of the n channels ₁₀₁ , Y ₁₀₂ , ..., Y _10n ;

Step S23, controlling the frequency of the input signal of the n channels of the multi-channel circuit to remain unchanged, changing the amplitude of the input signal so that X _1jn =X _1(j-1)n +A _j , where n is respectively are 1, 2, ..., n, respectively collect the output values Y _1j1 , Y _1j2 , ..., Y _1jn of n channels under the input signals of different amplitudes with frequency f ₁ , where A _j is the amplitude of the signal source The incremental value of j≥1;

Step S24, substitute the data group (X _1(j-1)n , Y _1(j-1)n ) and (X _1jn , Y _1jn ) into expression (1), and calculate the coefficient factor

a_{1 jn} = \frac{Y_{1 jn} - Y_{1 (j - 1) no}}{x_{1 jn} - x_{1 (j - 1) no}},

b_{1 jn} = \frac{Y_{1 jn} &Center Dot; x_{1 (j - 1) no} - Y_{1 (j - 1) no} &Center Dot; x_{1 jn}}{x_{1 (j - 1) no} - x_{1 jn}},

Wherein, j≥1, n is taken as 1, 2, ..., n respectively;

Step S25, changing the frequency of the input signal of the n channels of the multi-channel circuit, so that f _i =f _i-1 +B _i , initializing the amplitude of the current input signal, making X _i01 =X _i02 =...=X _i0n =A ₀ , collect the initial output values Y _i01 , Y _i02 , ..., Y _i0n of the current n channels, where B _i is the incremental value of the signal source frequency, i≥2;

Step S26, repeating step S23, to obtain the output values Y _ij1 , Y _ij2 , ..., Y _ijn of n channels under the input signals of different amplitudes with frequency f _i , wherein, i≥2, j≥1;

Step S27, repeat step S24 to obtain the coefficient factor Among them, i≥2, j≥1, and n are respectively taken as 1, 2, ..., n;

Step S3, using the peripheral actual multi-channel signal as the actual input signal of the multi-channel circuit, collecting the actual output value of the multi-channel circuit, and selecting the corresponding coefficient factor (a _ijn , b _ijn ), and according to the selected coefficient factors (a _ijn , b _ijn ), the actual output value and the expression (1), the amplitude of the calibration input signal is calculated to correct the amplitude of the actual input signal value, to calibrate the asymmetry of the multichannel circuit.

2. The method for calibrating the asymmetry of multi-channel circuits according to claim 1, characterized in that, the incremental values A _j of the amplitudes of the respective signal sources are all the same, wherein j≥1.

3. The method for calibrating the asymmetry of multi-channel circuits according to claim 1, characterized in that, the incremental values _Aj of the amplitudes of the respective signal sources are all different, wherein j≥1.

4 . The method for calibrating the asymmetry of a multi-channel circuit according to claim 1 , 2 or 3, characterized in that, the incremental values _Bi of each signal source frequency are the same, i≥2.

5 . The method for calibrating the asymmetry of a multi-channel circuit according to claim 1 , 2 or 3, characterized in that, the incremental values _Bi of each signal source frequency are different, and i≥2.

6. The method for calibrating the asymmetry of a multi-channel circuit according to claim 1, wherein the step S2 further comprises: step S28, storing the coefficient factors (a _ijn , b _ijn ), wherein, i≥ 1, j≥1.

7. The method for calibrating the asymmetry of the multi-channel circuit according to claim 1, wherein the method is realized by an FPGA, an embedded controller or a computer connected to the output of the multi-channel circuit.