CN103630176B - Double plate difference impulse type cereal flow transducer signal processing apparatus and method - Google Patents

本发明提供双板差分冲量式谷物流量传感器信号处理装置及方法，包括信号调理电路、A/D模块和微控制器应用系统等。两路信号采集通道同步采集双板差分冲量式谷物流量传感器的测量板信号和参考板信号；采用相同的数字滤波器，对两路采样信号分别进行数字滤波；对滤波之后的两路采样信号分别进行离散傅里叶变换（DFT）；然后，对两信号的DFT结果进行频域差分；对频域差分结果进行离散傅里叶反变换（IDFT），得到剔除了背景振动噪声的测产输出信号；最后，对测产输出信号进行标度变换，得到谷物产量信息。本发明可有效消除随机噪声和背景振动噪声对测产传感器输出信号的影响，提高传感器测产精度，可应用于联合收割机谷物产量在线监测。

The invention provides a signal processing device and method for a double-plate differential impulse type grain flow sensor, including a signal conditioning circuit, an A/D module, a microcontroller application system, and the like. The two signal acquisition channels synchronously collect the measurement board signal and the reference board signal of the double-plate differential impulse grain flow sensor; the same digital filter is used to digitally filter the two sampling signals respectively; the filtered two sampling signals are respectively Perform discrete Fourier transform (DFT); then, perform frequency domain difference on the DFT results of the two signals; perform inverse discrete Fourier transform (IDFT) on the frequency domain difference results to obtain the production measurement output signal that eliminates background vibration noise ;Finally, carry out scale transformation on the yield measurement output signal to obtain the grain yield information. The invention can effectively eliminate the influence of random noise and background vibration noise on the output signal of the yield measuring sensor, improve the yield measuring precision of the sensor, and can be applied to the online monitoring of the grain yield of a combine harvester.

双板差分冲量式谷物流量传感器信号处理装置及方法 Double-plate differential impulse grain flow sensor signal processing device and method

技术领域 technical field

本发明涉及联合收割机谷物测产技术领域，尤其是用于双板差分冲量式谷物流量传感器的信号处理装置及方法。 The invention relates to the technical field of grain yield measurement of a combine harvester, in particular to a signal processing device and method for a double-plate differential impulse grain flow sensor.

背景技术 Background technique

精细农业通过获取农田内作物产量和影响作物生长的环境因素的空间差异性信息，可对农田内各小区域因地制宜、按需实施定位变量农作，以提高农业投入的有效利用率，是大田农业的重要发展方向。联合收割机谷物测产是实践精细农业的核心内容之一。在各类测产装置中，冲量式谷物流量传感器因其安装方便、造价低廉、工作可靠且安全无污染等特点而成为国内外的研究热点。 By obtaining the spatial difference information of crop yields and environmental factors affecting crop growth in the farmland, precision agriculture can implement localized variable farming in each small area of the farmland according to local conditions and needs, so as to improve the effective utilization of agricultural inputs. important direction of development. Combine harvester grain yield measurement is one of the core contents of practicing precision agriculture. Among all kinds of production measuring devices, the impulse grain flow sensor has become a research hotspot at home and abroad because of its convenient installation, low cost, reliable operation, safety and no pollution.

冲量式谷物流量传感器的主要部件是弹性受力板和应变感应装置。从联合收割机谷物升运器出口抛洒出来的具有一定冲量（速度和质量）的谷物籽粒冲击到弹性受力板上，使应变感应装置产生应变，经电桥等转换为电压输出信号。由于弹性受力板固定在联合收割机谷物升运器出口的机架上，联合收割机工作过程中产生的机体振动通过谷物升运器传递到弹性受力板上，从而使冲量式谷物流量传感器的输出信号中含有大量的背景振动噪声，对其测产精度影响很大。 The main components of the impulse grain flow sensor are the elastic force plate and the strain sensing device. Grain grains with a certain momentum (speed and quality) thrown from the outlet of the grain elevator of the combine harvester impact the elastic force plate, causing the strain sensing device to generate strain, which is converted into a voltage output signal by an electric bridge. Since the elastic force plate is fixed on the frame at the outlet of the grain elevator of the combine harvester, the body vibration generated during the working process of the combine is transmitted to the elastic force plate through the grain elevator, so that the impulse grain flow sensor The output signal contains a large amount of background vibration noise, which has a great impact on the accuracy of its production measurement.

国内外学者对冲量式谷物流量传感器背景振动噪声的剔除方法进行了大量研究。其中，文献“联合收割机产量传感器的信号处理”（张凤传，张启俊，等．中国农机化，2004（4）：44-47）提出了一种积分抑噪电路用于减少机体振动对冲量式产量传感器的影响。文献“悬臂梁冲量式谷物流量传感器阻尼设计”（周俊，周围祥，等．农业机械学报，2005，（11）121-123）提出了一种弹性阻尼消振方法用于减少联合收获机机体振动噪声的影响。文献“平行梁冲量式谷物流量传感器信号处理方法”（周俊，刘成良，等．农业工程学报，2008，24（1）183-187）提出了一种自适应陷波滤波的方法，用于消除联合收获机工作环境中存在的非稳定低频振动干扰，以增加测产传感器的测量精度。以上方法都取得了一定的降噪效果，在一定程度上提高了冲量式谷物流量传感器的测产精度，但在田间变化工况下的滤波效果还有待于进一步提高。文献“双板差分冲量式谷物流量传感器设计”（胡均万，罗锡文，等．农业机械学报，2009，40（4）69-72）公开了一种双板差分冲量式谷物流量传感器，测量板与参考板结构相同且相互平行布置，振动模态基本相同，参考板专用于感应机体振动，测量板则同时承受机体振动和谷物冲击，并通过时域差分从测量板输出信号中消除参考板感应到的机体振动噪声。该方法能够较好地分离出背景噪声信号，但由于测量板信号与参考板信号的同步性难以保证，制约了传感器测产精度和稳定性的进一步提高。 Scholars at home and abroad have done a lot of research on the method of eliminating the background vibration noise of the impulse grain flow sensor. Among them, the document "Signal Processing of Combine Harvester Yield Sensor" (Zhang Fengchuan, Zhang Qijun, etc. China Agricultural Mechanization, 2004 (4): 44-47) proposed an integral noise suppression circuit to reduce the vibration of the machine body against the volume output The influence of the sensor. The document "Damping Design of Cantilever Beam Impulse Grain Flow Sensor" (Zhou Jun, Zhou Xiang, et al. Journal of Agricultural Machinery, 2005, (11) 121-123) proposed an elastic damping method to reduce the combined harvester body. The influence of vibration noise. The document "Signal Processing Method of Parallel Beam Impulse Grain Flow Sensor" (Zhou Jun, Liu Chengliang, et al. Journal of Agricultural Engineering, 2008, 24 (1) 183-187) proposed an adaptive notch filter method for Eliminate the unsteady low-frequency vibration interference existing in the working environment of the combine harvester to increase the measurement accuracy of the yield measurement sensor. The above methods have achieved a certain noise reduction effect, and improved the yield measurement accuracy of the impulse grain flow sensor to a certain extent, but the filtering effect under the changing working conditions in the field needs to be further improved. The document "Double-plate Differential Impulse Grain Flow Sensor Design" (Hu Junwan, Luo Xiwen, etc. Journal of Agricultural Machinery, 2009, 40 (4) 69-72) discloses a double-plate differential impulse grain flow sensor, measuring plate The structure is the same as that of the reference board and arranged parallel to each other, and the vibration modes are basically the same. The reference board is dedicated to inducting the vibration of the body, while the measurement board bears the vibration of the body and the impact of the grain at the same time, and eliminates the induction of the reference board from the output signal of the measurement board through time domain difference body vibration noise. This method can separate the background noise signal well, but it is difficult to guarantee the synchronization between the measurement board signal and the reference board signal, which restricts the further improvement of the measurement accuracy and stability of the sensor.

发明内容 Contents of the invention

针对现有冲量式谷物流量传感器受联合收割机背景振动噪声影响较大，测产精度难以提高的问题，本发明提供双板差分冲量式谷物流量传感器信号处理装置及方法。通过测量板信号和参考板信号的同步采集、数字滤波和频域差分等方法从测量板采样信号中剔除参考板感应到的机体振动噪声，以提高测产精度及其稳定性。 Aiming at the problem that the existing impulse type grain flow sensor is greatly affected by the background vibration noise of the combine harvester and it is difficult to improve the yield measurement accuracy, the present invention provides a signal processing device and method for a double-plate differential impulse type grain flow sensor. The body vibration noise induced by the reference board is eliminated from the sampling signal of the measurement board by synchronous acquisition of the measurement board signal and the reference board signal, digital filtering and frequency domain difference, so as to improve the accuracy and stability of the production measurement.

为了解决以上技术问题，本发明采用如下技术方案： In order to solve the above technical problems, the present invention adopts the following technical solutions:

双板差分冲量式谷物流量传感器信号处理装置，包含信号调理电路、A/D模块、微控制器应用系统和键盘显示模块(6)，信号调理电路中包含应变电桥、放大器和抗混叠滤波器，其特征在于：微控制器应用系统采用DSP模块(5)，双板差分冲量式谷物流量传感器的测量板信号输入到信号调理电路A(1)，信号调理电路A(1)的输出信号连接至A/D模块A(3)，双板差分冲量式谷物流量传感器的参考板信号输入到信号调理电路B(2)，信号调理电路B(2)的输出信号连接至A/D模块B(4)，信号调理电路A(1)与信号调理电路B(2)的电路结构和参数完全相同，A/D模块A(3)与A/D模块B(4)的电路结构和参数完全相同且在DSP模块(5)的控制下同步采样，采样输出信号都连接至DSP模块(5)，DSP模块(5)的处理结果输送到键盘显示模块(6)显示，并可接收键盘显示模块(6)输送来的设置参数。 Double-plate differential impulse grain flow sensor signal processing device, including signal conditioning circuit, A/D module, microcontroller application system and keyboard display module (6), the signal conditioning circuit includes strain bridge, amplifier and anti-aliasing The filter is characterized in that: the microcontroller application system adopts a DSP module (5), the measurement board signal of the double-plate differential impulse grain flow sensor is input to the signal conditioning circuit A (1), and the output of the signal conditioning circuit A (1) The signal is connected to the A/D module A(3), the reference board signal of the double-plate differential impulse grain flow sensor is input to the signal conditioning circuit B(2), and the output signal of the signal conditioning circuit B(2) is connected to the A/D module B(4), the circuit structure and parameters of signal conditioning circuit A(1) and signal conditioning circuit B(2) are exactly the same, the circuit structure and parameters of A/D module A(3) and A/D module B(4) The same and synchronous sampling under the control of the DSP module (5), the sampling output signals are all connected to the DSP module (5), the processing results of the DSP module (5) are sent to the keyboard display module (6) for display, and can receive keyboard display The setting parameters delivered by the module (6).

所述A/D模块A(3)、A/D模块B(4)和DSP模块(5)可由数字信号处理控制器DSP56F803实现，DSP56F803内置有多路转换开关和A/D转换器，并具有8个模拟量输入通道AIN0~AIN7，谷物流量传感器的测量板信号输入到信号调理电路A(1)，信号调理电路A(1)的输出信号连接至采样/保持器A(7)，采样/保持器A(7)的输出信号连接到DSP56F803模块(9)的AIN0引脚，采样/保持器A(7)的控制端连接至DSP56F803模块(9)的I/O接口1，谷物流量传感器的参考板信号输入到信号调理电路B(2)，信号调理电路B(2)的输出信号连接至采样/保持器B(8)，采样/保持器B(8)的输出信号连接到DSP56F803模块(9)的AIN1引脚，采样/保持器B(8)的控制端连接至DSP56F803模块(9)的I/O接口2，采样/保持器A(7)和采样/保持器B(8)同步动作，键盘显示模块(6)与DSP56F803模块(9)中的键盘/显示接口连接。 Described A/D module A (3), A/D module B (4) and DSP module (5) can be realized by digital signal processing controller DSP56F803, and DSP56F803 is built-in multiplex switch and A/D converter, and has 8 analog input channels AIN0~AIN7, the measurement board signal of the grain flow sensor is input to the signal conditioning circuit A(1), the output signal of the signal conditioning circuit A(1) is connected to the sample/hold device A(7), the sample/hold The output signal of the holder A (7) is connected to the AIN0 pin of the DSP56F803 module (9), the control terminal of the sample/holder A (7) is connected to the I/O interface 1 of the DSP56F803 module (9), and the grain flow sensor’s The reference board signal is input to the signal conditioning circuit B (2), the output signal of the signal conditioning circuit B (2) is connected to the sample/hold device B (8), and the output signal of the sample/hold device B (8) is connected to the DSP56F803 module ( 9) The AIN1 pin of the sample/hold device B (8) is connected to the I/O interface 2 of the DSP56F803 module (9), and the sample/hold device A (7) and the sample/hold device B (8) are synchronized Action, the keyboard display module (6) is connected with the keyboard/display interface in the DSP56F803 module (9).

根据所述的双板差分冲量式谷物流量传感器信号处理装置的信号处理方法，双板差分冲量式谷物流量传感器的测量板信号和参考板信号分别拥有各自独立的信号采集通道，两信号采集通道的电路结构和参数完全相同，且同步采样，其特征在于信号处理过程包含以下步骤： According to the signal processing method of the signal processing device of the double-plate differential impulse type grain flow sensor, the measuring plate signal and the reference plate signal of the double-plate differential impulse type grain flow sensor respectively have independent signal acquisition channels, and the two signal acquisition channels The circuit structure and parameters are exactly the same, and the synchronous sampling is characterized in that the signal processing process includes the following steps:

第一步，同步采集双板差分冲量式谷物流量传感器的测量板信号和参考板信号，得到测量板采样信号和参考板采样信号； The first step is to synchronously collect the measurement board signal and the reference board signal of the double-plate differential impulse grain flow sensor to obtain the measurement board sampling signal and the reference board sampling signal;

第二步，采用相同的数字滤波器，对测量板采样信号和参考板采样信号分别进行数字滤波，以滤除或衰减两采样信号中的随机噪声； In the second step, the same digital filter is used to digitally filter the sampling signal of the measurement board and the sampling signal of the reference board, so as to filter out or attenuate the random noise in the two sampling signals;

第三步，对滤波处理之后的测量板采样信号和参考板采样信号分别进行离散傅里叶变换即DFT； In the third step, the discrete Fourier transform (DFT) is performed on the sampling signal of the measurement board and the sampling signal of the reference board after filtering;

第四步，对两信号的DFT结果进行频域差分，相同频率点的幅值对应相减； In the fourth step, the frequency domain difference is performed on the DFT results of the two signals, and the amplitudes of the same frequency points are correspondingly subtracted;

第五步，对频域差分结果进行离散傅里叶反变换即IDFT，得到剔除了背景振动噪声的测产输出信号； The fifth step is to perform inverse discrete Fourier transform (IDFT) on the frequency domain difference result, and obtain the production measurement output signal that eliminates the background vibration noise;

第六步，对测产输出信号进行标度变换，得到谷物产量信息。 The sixth step is to scale the yield measurement output signal to obtain grain yield information.

所述数字滤波器可以选用低通滤波器、中值滤波器或算术均值滤波器。 The digital filter can be a low-pass filter, a median filter or an arithmetic mean filter.

本发明具有有益效果。本发明采用的频域差分处理方法不受测量板信号与参考板信号同步性的影响，可显著提高双板差分冲量式谷物流量传感器的测产精度和稳定性。 The invention has beneficial effects . The frequency domain difference processing method adopted by the invention is not affected by the synchronization of the signal of the measuring board and the signal of the reference board, and can significantly improve the yield measuring accuracy and stability of the double-plate differential impulse grain flow sensor.

附图说明 Description of drawings

图1是双板差分冲量式谷物流量传感器信号处理装置结构示意图； Fig. 1 is a schematic structural diagram of a signal processing device for a double-plate differential impulse grain flow sensor;

图2是双板差分冲量式谷物流量传感器信号处理装置实施例一图； Fig. 2 is a diagram of an embodiment of the signal processing device of the double-plate differential impulse type grain flow sensor;

图3是双板差分冲量式谷物流量传感器信号处理方法流程示意图。 Fig. 3 is a schematic flow chart of a signal processing method of a double-plate differential impulse grain flow sensor.

图中：1.信号调理电路A，2.信号调理电路B，3.A/D模块A，4.A/D模块B，5.DSP模块，6.键盘显示模块，7.采样/保持电路A，8.采样/保持电路B，9.DSP56F803模块。 In the figure: 1. Signal conditioning circuit A, 2. Signal conditioning circuit B, 3. A/D module A, 4. A/D module B, 5. DSP module, 6. Keyboard display module, 7. Sample/hold circuit A, 8. Sample/hold circuit B, 9. DSP56F803 module.

具体实施方式 detailed description

下面结合附图和具体实施例，对本发明的技术方案做进一步详细说明。 The technical solution of the present invention will be described in further detail below in conjunction with the accompanying drawings and specific embodiments.

如图1所示，双板差分冲量式谷物流量传感器信号处理装置包含信号调理电路、A/D模块、微控制器应用系统和键盘显示模块6。信号调理电路中包含应变电桥、放大器和抗混叠滤波器。其中，微控制器应用系统采用DSP模块5。双板差分冲量式谷物流量传感器的测量板信号输入到信号调理电路A1，信号调理电路A1的输出信号连接至A/D模块A3，转换为数字量信号。双板差分冲量式谷物流量传感器的参考板信号输入到信号调理电路B2，信号调理电路B2的输出信号连接至A/D模块B4，转换为数字量输出信号。信号调理电路A1与信号调理电路B2的电路结构和参数完全相同。A/D模块A3与A/D模块B4的电路结构和参数完全相同，且在DSP模块5的控制下同步采样，以保证采样信号的同步性，采样输出信号都连接至DSP模块5。DSP模块5的处理结果输送到键盘显示模块6显示，并可接收键盘显示模块6输送来的设置参数。 As shown in Figure 1, the signal processing device of the double-plate differential impulse grain flow sensor includes a signal conditioning circuit, an A/D module, a microcontroller application system and a keyboard display module 6 . The signal conditioning circuit includes strain bridges, amplifiers, and antialiasing filters. Among them, the microcontroller application system adopts DSP module 5 . The signal of the measurement board of the double-plate differential impulse grain flow sensor is input to the signal conditioning circuit A1, and the output signal of the signal conditioning circuit A1 is connected to the A/D module A3 for conversion into a digital signal. The reference plate signal of the double-plate differential impulse grain flow sensor is input to the signal conditioning circuit B2, and the output signal of the signal conditioning circuit B2 is connected to the A/D module B4, and converted into a digital output signal. The circuit structure and parameters of the signal conditioning circuit A1 and the signal conditioning circuit B2 are exactly the same. The circuit structure and parameters of A/D module A3 and A/D module B4 are exactly the same, and they are sampled synchronously under the control of DSP module 5 to ensure the synchronization of sampling signals, and the sampling output signals are connected to DSP module 5 . The processing results of the DSP module 5 are sent to the keyboard display module 6 for display, and the setting parameters sent by the keyboard display module 6 can be received.

如图2所示，为双板差分冲量式谷物流量传感器信号处理装置的一个实施例。其中，DSP56F803模块9内置有多路转换开关和A/D转换器，并具有8个模拟量输入通道AIN0~AIN7。谷物流量传感器的测量板信号输入到信号调理电路A1，信号调理电路A1的输出信号连接至采样/保持器A7，采样/保持器A7的输出信号连接到DSP56F803模块9的AIN0引脚，采样/保持器A7的控制端连接至DSP56F803模块9的I/O接口1。谷物流量传感器的参考板信号输入到信号调理电路B2，信号调理电路B2的输出信号连接至采样/保持器B8，采样/保持器B8的输出信号连接到DSP56F803模块9的AIN1引脚，采样/保持器B8的控制端连接至DSP56F803模块9的I/O接口2。采样/保持器A7和采样/保持器B8 在DSP56F803模块9的控制下同步动作，然后由DSP56F803模块9内的A/D转换器对输入到其AIN0和AIN1引脚的模拟量信号进行分时转换。由于AIN0和AIN1引脚上的信号同时进入的保持状态，所以仍属于同步采样。键盘显示模块6与DSP56F803模块9中的键盘/显示接口连接。 As shown in Figure 2, it is an embodiment of the signal processing device of the double-plate differential impulse grain flow sensor. Among them, DSP56F803 module 9 has a built-in multi-channel conversion switch and A/D converter, and has 8 analog input channels AIN0~AIN7. The measurement board signal of the grain flow sensor is input to the signal conditioning circuit A1, the output signal of the signal conditioning circuit A1 is connected to the sample/hold device A7, the output signal of the sample/hold device A7 is connected to the AIN0 pin of the DSP56F803 module 9, and the sample/hold The control end of the device A7 is connected to the I/O interface 1 of the DSP56F803 module 9. The reference board signal of the grain flow sensor is input to the signal conditioning circuit B2, the output signal of the signal conditioning circuit B2 is connected to the sample/hold device B8, the output signal of the sample/hold device B8 is connected to the AIN1 pin of the DSP56F803 module 9, and the sample/hold The control end of device B8 is connected to I/O interface 2 of DSP56F803 module 9. Sample/hold device A7 and sample/hold device B8 operate synchronously under the control of DSP56F803 module 9, and then the A/D converter in DSP56F803 module 9 performs time-sharing conversion on the analog signal input to its AIN0 and AIN1 pins . Since the signals on the AIN0 and AIN1 pins enter the hold state at the same time, they still belong to synchronous sampling. The keyboard display module 6 is connected with the keyboard/display interface in the DSP56F803 module 9 .

如图3所示，双板差分冲量式谷物流量传感器信号处理方法包含以下步骤：同步采集双板差分冲量式谷物流量传感器的测量板信号和参考板信号，得到测量板采样信号和参考板采样信号；采用相同的数字滤波器对测量板采样信号和参考板采样信号分别进行数字滤波，以滤除或衰减两采样信号中的随机噪声，数字滤波器可以选用低通滤波器、中值滤波器或算数均值滤波器等；对滤波处理之后的测量板采样信号和参考板采样信号分别进行离散傅里叶变换（DFT）；对两信号的DFT结果进行频域差分，相同频率点的幅值对应相减；对频域差分结果进行离散傅里叶反变换（IDFT），得到剔除了背景振动噪声的测产输出信号；对测产输出信号进行标度变换，得到谷物产量信息。 As shown in Figure 3, the signal processing method of the double-plate differential impulse type grain flow sensor includes the following steps: synchronously collect the measurement board signal and the reference board signal of the double-plate differential impulse type grain flow sensor, and obtain the measurement board sampling signal and the reference board sampling signal ;Use the same digital filter to digitally filter the sampling signal of the measurement board and the sampling signal of the reference board, to filter out or attenuate the random noise in the two sampling signals. The digital filter can be selected from a low-pass filter, a median filter or Arithmetic mean filter, etc.; Discrete Fourier Transform (DFT) is performed on the sampling signal of the measurement board and the sampling signal of the reference board after filtering; the DFT results of the two signals are differentiated in the frequency domain, and the amplitudes of the same frequency point correspond to the corresponding Subtraction; inverse discrete Fourier transform (IDFT) is performed on the frequency domain difference results to obtain the yield measurement output signal that eliminates the background vibration noise; scale transformation is performed on the yield measurement output signal to obtain grain yield information.

最后应当说明的是，以上实施例仅用以说明本发明的技术方案而非限制，尽管参照较佳实施例对本发明进行了详细说明，本领域的普通技术人员应当理解，可以对本发明的技术方案进行修改或等同替换，而不脱离本发明技术方案的精神和范围，其均应涵盖在本发明的权利要求范围之内。 Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention without limitation. Although the present invention has been described in detail with reference to preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be Modifications or equivalent replacements without departing from the spirit and scope of the technical solution of the present invention shall fall within the scope of the claims of the present invention.