JPH0672065U - Fast Fourier transform analyzer - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a fast Fourier transform analysis device that is small, lightweight, and inexpensive. [Structure] A fast Fourier transform analysis device is composed of a signal processing device 20 composed of one semiconductor device, a liquid crystal display device 11, and an operation switch section 12 of an interactive setting format. The signal processing device 20 includes an amplifier 21 and a central processing unit 22. The central processing unit includes an A / D converter 22a for converting an analog signal from an amplifier into a digital signal, a DMA unit 22b for storing the digital signal directly in the memory unit 22c, and a digital signal for performing a high-speed arithmetic processing of the signal from the memory unit. A processing unit 22d and a central processing unit 22e that controls an amplifier, a liquid crystal display device, a signal processing control according to an input from an operation switch, and the like are provided. By increasing the software processing by the central processing unit, reducing the number of hardware components, simplifying the operation switches, and using a liquid crystal display device, the device is small, lightweight and inexpensive.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a fast Fourier transform analysis device, and more particularly to a small fast Fourier transform analysis device.

[0002]

[Prior art]

 Conventionally, this type of fast Fourier transform analysis apparatus, for example, as shown in FIG. 3, selects only a signal having a necessary frequency from a detection signal from a sensor or the like through a filter, amplifies the amplified signal with an amplifier, and then an amplified analog signal. The signal is sampled and held, digitally converted by an A / D converter, processed by direct memory access, and stored in a memory. The stored contents are processed by the CPU at high speed, and the calculation results are output to the CRT controller according to the processing mode by the operation switch and displayed on the CRT display (CRT). As described above, the conventional fast Fourier transform analysis apparatus has a wide range of use with high accuracy and a wide measurement range of several hundred kHz and various functions.

[0003]

[Problems to be solved by the device]

 However, in the above fast Fourier transform analysis device, due to the increase in the number of circuit parts and operation switches due to high precision and high function, and the adoption of a large cathode ray tube, the device price becomes very expensive and the device becomes large. It was inconvenient to carry and could not be used easily. In particular, there has not been a low-cost fast Fourier transform analysis device that can be easily used for controlling the manufacturing process, etc., targeting up to several tens of kHz, and the development of these devices has been desired. The present invention is intended to solve the above problems, and an object thereof is to provide a small-sized, inexpensive, and easy-to-use fast Fourier transform / analysis device that enables measurement in a limited range up to several tens of kHz. To do.

[0004]

[Means for Solving the Problems]

 In order to achieve the above object, the structural features of the invention according to claim 1 are: an amplifier for amplifying an analog vibration signal, an A / D converter for converting an analog signal from the amplifier into a digital signal, and a digital signal. A digital signal that performs high-speed arithmetic processing of the signal read from the memory unit and the direct memory access unit that stores the digital signal converted by the A / D converter in the memory unit where the signal can be written and read A central processing unit comprising a semiconductor device having a processing unit and a central processing unit for controlling the operation of each of these units and the operation of the amplifier, an operation switch for inputting a processing mode by the central processing unit, and an output signal from the central processing unit. And a liquid crystal display device for displaying.

Further, the constitutional feature of the invention according to claim 2 is that in the fast Fourier transform analysis device according to claim 1, the central processing unit is composed of one or two semiconductor devices. It is in.

Further, the structural feature of the invention according to claim 3 is that in the fast Fourier transform analysis device according to claim 1 or 2, the operation switches are a cursor key switch, a set switch and a function switch. It is configured by.

[0007]

[Operation and effect of the device]

 In the invention according to claim 1 configured as described above, the central processing unit made of a semiconductor device is provided with an A / D conversion unit, a direct memory access unit, a memory unit, and a digital signal processing unit to perform a filtering process. High-speed arithmetic processing is performed, the central processing unit controls the amplifier and the liquid crystal display device, and the processing mode is controlled by operating switches. We were able to reduce the number of parts as much as possible. Also, the display device was changed from a large CRT to a lightweight and small liquid crystal display device. As a result, the frequency processing range is limited to about several tens of kHz or less, but the cost of the fast Fourier transform analysis device can be significantly reduced by reducing the number of parts such as the central processing unit, and the number of parts can be reduced. By reducing the number and adopting a liquid crystal display device, the fast Fourier transform analysis device could be made smaller and lighter.

Further, in the invention according to claim 2 configured as described above, the central processing unit is configured as a compact by configuring the central processing unit by one or two semiconductor devices, and the fast Fourier transform is performed. This can contribute to the reduction in size and weight of the analysis device and the reduction in price.

In the invention according to claim 3 configured as described above, the operation switch of the fast Fourier transform analysis device has a simple configuration including only the cursor key switch, the set switch, and the function switch. An interactive setting in which the selected process item is selected by the cursor key switch and the process item selected by the set switch is fixed while changing the screen of multiple process items displayed on the liquid crystal display by the function switch. It is in the format. Therefore, the operation of the switch becomes very easy, and it is possible to contribute to downsizing, weight reduction, and cost reduction of the fast Fourier transform analysis device.

[0010]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing the appearance of a simple fast Fourier transform analysis apparatus (hereinafter referred to as an FFT analyzer) according to the present invention. This FFT analyzer is provided with a liquid crystal display device 11 at the center of the surface, an operation switch unit 12 at the right side, a power switch 13 at the lower left side, and a signal processing device 20 inside. The FFT analyzer is 250 mm x 130 mm x 31 mm in outer dimensions and weighs 680 g, which is much smaller and lighter than conventional FFT analyzers, making it easy to carry and excellent in operability.

Next, FIG. 2 is a block diagram showing a circuit configuration of the signal processing device 20. The signal processing device 20 includes an amplifier 21 that amplifies an analog vibration signal from a sensor or the like input from the input terminal IN, and a central processing device 22. The central processing unit 22 is composed of one semiconductor integrated circuit, and has an A / D conversion unit 22a for converting an analog signal input from the amplifier 21 into a digital signal, a memory unit 22c, and a conversion unit 22c. A direct memory access unit 22b (hereinafter referred to as a DMA unit) for directly inputting the digital signal to the memory unit 22c, and a digital signal processing unit 22d (hereinafter, referred to as a high-speed calculation process and a filter process for the signal from the memory unit 22c). A DSP unit), a central processing unit 22e (which controls the amplification factor and offset of the amplifier 21, controls the display format of the liquid crystal display device 11, and performs signal processing control according to an input from the operation switch unit 12). Hereinafter, it will be referred to as a CPU section). An amplifier 21, a liquid crystal display device 11 and an operation switch section 12 are connected to the central processing unit 22.

The operation switch unit 12 includes a cursor key switch 12a, a set switch 12b, and a function switch 12c. The cursor key switch 12a is used by the operator to select a plurality of processing items displayed on the liquid crystal display device 11 or change the set values while looking at the screen. The set switch 12b is operated by the cursor key switch 12a. This is a switch that fixes the selected processing item. The function switch 12c is for changing the screen of a plurality of processing items displayed on the liquid crystal display device 11. That is, the operation switch unit 12 has an interactive setting format in which the operator selects a processing item while looking at the screen displayed on the liquid crystal display device 11.

Next, the operation of the above embodiment will be described. First, when a vibration detection sensor (not shown) is connected to the input terminal IN and the power switch of the FFT analyzer is turned on, the signal to be measured by the sensor is input from the input terminal IN. Further, a desired processing item is selected by operating the operation switch unit 12. The input measured signal is amplified by the amplifier 21 and converted into a digital signal by the A / D converter 22a of the central processing unit 22. This digital signal is directly stored in the memory unit 22c by the DMA unit 22b. The digital information stored in the memory unit 22c is read by the DSP unit 22d, and the DSP unit 22d performs high-speed product sum calculation, data sort processing, absolute value component calculation, etc. based on the read signal. Process and output. The output calculation result is compiled by the CPU 22e into a table format by display data calculation, output to the liquid crystal display device 11, and displayed on the screen.

As described above, in the FFT analyzer according to the above-described embodiment, the central processing unit including one semiconductor integrated circuit controls the amplifier, the signal filtering process and the high-speed arithmetic processing, the liquid crystal display device control, etc. By increasing the processing by software, the number of hardware components was significantly reduced, and the display device was changed from a large CRT to a lightweight and small liquid crystal display device. As a result, although the frequency processing range was limited to about 20 kHz or less, the cost of the fast Fourier transform analysis device could be significantly reduced by reducing the number of parts such as the central processing unit. Also, by reducing the number of parts and adopting a liquid crystal display, it has become possible to make the high-speed Fourier transform analysis device significantly smaller and lighter than conventional products. Therefore, it is very convenient to carry the device, and it is suitable for use in managing the manufacturing process in the factory.

Further, the operation switch of the FFT analyzer has a simple structure including only the cursor key switch, the set switch and the function switch, so that the number of operation switches can be significantly reduced as compared with the conventional FFT analyzer. This makes it possible to operate the switch easily, and contributes to downsizing, weight reduction, and cost reduction of the fast Fourier transform analysis device.

In the above embodiment, the central processing unit is composed of one semiconductor integrated circuit, but by using two semiconductor integrated circuits, the shape of the device becomes slightly large and the price is low. However, the frequency processing region can be easily increased to about 50 kHz.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of an FFT analyzer according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a circuit configuration of the FFT analyzer.

FIG. 3 is a block diagram showing a circuit configuration of an FFT analyzer according to a conventional example.

[Explanation of symbols]

11: Liquid crystal display device, 12; Operation switch, 13; Power switch, 20; Signal processing device, 21; Amplifier, 22;
Central processing unit, 22a; A / D conversion unit, 22b; DMA
Section, 22c; memory section, 22d; DSP section, 22e; C
PU department.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Fumio Otsuka 2-43 Kayaba-cho, Gifu-shi, Gifu Prefecture (72) Izumi Kato 3 Iyama, Shinome-cho, Anjo-shi, Aichi Prefecture Anden Co., Ltd.

Claims (3)

[Scope of utility model registration request] 1. An amplifier for amplifying an analog vibration signal, an A / D conversion unit for converting an analog signal from the amplifier into a digital signal, a memory unit capable of writing and reading a digital signal, and the A / D conversion. Direct memory access unit for storing the digital signal converted by the unit in the same memory unit, a digital signal processing unit for performing high-speed arithmetic processing of the signal read from the same memory unit, operation of these units and operation of the amplifier A central processing unit comprising a semiconductor device having a central processing unit for controlling the central processing unit, an operation switch for inputting a signal processing mode by the central processing unit, and a liquid crystal display device for displaying an output signal from the central processing unit. A fast Fourier transform analysis device characterized by being provided. 2. The fast Fourier transform analysis apparatus according to claim 1, wherein the central processing unit is composed of one or two semiconductor devices. 3. The fast Fourier transform analysis apparatus according to claim 1 or 2, wherein the operation switch comprises a cursor key switch, a set switch and a function switch. .