CN101441152B - A Material Testing Machine Based on USB Data Acquisition System - Google Patents

Abstract

The invention discloses a material testing machine based on an USB data acquisition system, which comprises a mechanical part, a data acquisition system, an USB communication system and a host computer system, wherein the mechanical part is connected with the data acquisition system through a motor controller, a force sensor, and a displacement sensor; the data acquisition system is connected with the USB communication system through an USB interface, while the USB communication system is connected with the host computer system through an USB interface; the data acquisition system is a load acquisition system and a displacement acquisition system. The invention has the advantages of applying intuitiveness and user-friendly interface of the data acquisition card testing system, simultaneously improving cost performance and reliability of the system, enhancing competitiveness of products, improving acquisition precision of high-force material testing machine, can be applicable for high-precision material testing machine based on the USB data acquisition system.

Description

A Material Testing Machine Based on USB Data Acquisition System

【Technical field】

The invention relates to the field of material testing machines, in particular to a material testing machine based on a USB data acquisition system.

【Background technique】

In the field of material testing machines, most of the measurement and control systems of material testing machines based on PC or industrial computer currently use PCI bus, ISA bus or RS-232 serial bus as the data acquisition mode. Although the PCI bus has a high transmission speed (132Mbps) and supports the "plug and play" function, its disadvantage is that it is troublesome to plug and unplug, and the expansion slots are limited (generally 5-6). question. Although the RS-232 serial bus is simple to connect, its transmission speed is slow (56Kbps), and the number of serial ports of the host computer is also limited. Therefore, the current general method of collecting data through data acquisition boards has the following disadvantages: installation is troublesome, and it is easy to be affected by the chassis. The interference of the internal environment leads to the distortion of the collected data, which is easily limited by the number of computer slots, addresses, and interrupt resources, and has poor scalability.

Universal Serial Bus (USB for short) is a new serial communication standard introduced by Compaq, Microsoft, IBM, DEC and other companies in 1995 in order to solve the shortcomings of traditional buses. The advantages of bandwidth and easy expansion have gradually become the development trend of modern data transmission. The USB-based data acquisition system makes full use of the above-mentioned advantages of the USB bus and effectively solves the defects of the traditional data acquisition system. The USB specification can target different performance The price ratio requires different options to meet different systems and components and corresponding different functions, which brings great convenience to use.

The inventor once developed a computer-based material testing system for Guangdong Hengyu Instrument Co., Ltd. The tester used Advantech PCI1716 data acquisition card, which has 16-bit AD conversion, 16-way analog input, 2-way analog output, and 1 external Counter, 16 channels of digital input/output, sampling rate up to 250ksps, although installing a data acquisition card in the PC is convenient for data acquisition and analysis, shortens the development cycle, and has a high data sampling rate, but there are also some disadvantages: installation trouble, price Expensive, limited by the number of computer slots, addresses, and interrupt resources, and poor scalability. At the same time, in some test sites with strong electromagnetic interference, in many cases it cannot be specially shielded electromagnetically, resulting in distortion of the collected data and anti-interference Performance is poor. Obviously, this data acquisition system cannot meet the needs of different users and various applications. Therefore, on the basis of this work, the inventor has developed a new generation of material testing equipment with high precision, fast speed, easy use, stability and reliability. Machine measurement and control equipment.

【Content of invention】

The purpose of the present invention is to overcome the deficiencies of the prior art and provide a material testing machine based on a USB data acquisition system.

The purpose of the present invention is achieved through the following technical solutions:

A material testing machine based on a USB data acquisition system, including a mechanical part, a data acquisition system, a USB communication system and a host computer system, wherein the mechanical part is connected to the data acquisition system through a motor controller, a force sensor and a displacement sensor; the data The acquisition system is connected to the USB communication system through the USB interface, and the USB communication system is connected to the upper computer system through the USB interface; it is characterized in that the data acquisition system is a load acquisition system and a displacement acquisition system;

The load acquisition system includes a force sensor, signal conditioning, an analog multi-channel switch, a programmable gain amplifier and an A/D converter; wherein, the force sensor connects the collected voltage signal to the signal conditioning, and the signal conditioning is passed through the analog multi-channel The switch guides the voltage signal to the programmable gain amplifier, and then connects the amplified voltage signal to the A/D converter, and connects the result converted by the A/D converter to the microcontroller through the serial interface;

The displacement acquisition system includes a grating encoder, a direction-judging interface circuit and an interface circuit; the displacement signal is converted into a pulse signal through the grating encoder, the pulse signal is connected to the single-chip microcomputer through the direction-judging interface circuit, and the pulse signal is connected to the single-chip microcomputer through the interface circuit ;

The A/D converter is a 24-bit oversampling analog-to-digital converter converter;

Described single-chip microcomputer is the single-chip microcomputer of 51 cores as main controller;

The mechanical part includes a motor, a transmission, a steering gear, a lead screw, a workbench and a fixture; the motor is connected to the lead screw through the speed changer and the steering gear; There are fixtures;

The USB communication system, wherein the chip used in the USB interface is selected from a single USB interface chip or a chip integrated in the USB interface, preferably a separate USB interface chip;

Described upper computer system comprises PC, printer and upper computer test software, wherein, upper computer test software is installed on the PC, mainly realizes functions such as USB upper computer communication, curve display analysis, data processing, report printing, control relay , the user directly performs a series of operations of the material test through the testing software interface of the host computer.

The positive effect of a kind of material testing machine based on USB data acquisition system of the present invention is:

(1) A USB interface chip is added between the single-chip microcomputer and the PC, so that the single-chip microcomputer and the PC function can realize data communication, the single-chip microcomputer and the A/D chip are responsible for data acquisition and processing, and the PC application program analyzes and displays the collected data, so that It can achieve the intuitiveness and interface friendliness of the application data acquisition card test system, and at the same time improve the cost performance and reliability of the system and enhance the competitiveness of the product;

(2) The USB interface is used to improve its data transmission speed, accuracy and ease of use. The lower single-chip microcomputer uses 24-bit ADS1256 as an A/D converter, which can improve the acquisition accuracy of the force value of the material testing machine and is suitable for high-precision material testing machines. Measurement and control system and data acquisition system based on USB.

【Description of drawings】

The overall structure schematic diagram of Fig. 1 the present invention;

Figure 2 is a schematic diagram of the hardware structure of the data acquisition system.

【Detailed ways】

A specific embodiment of a material testing machine based on a USB data acquisition system of the present invention is provided below.

Example 1

Please refer to Figure 1, a material testing machine based on a USB data acquisition system, including a mechanical part, a data acquisition system, a USB communication system and a host computer system, wherein the mechanical part communicates with the data acquisition through a motor controller, a force sensor and a displacement sensor The system is connected; the data acquisition system is connected to the USB communication system through the USB interface, and the USB communication system is connected to the upper computer system through the USB interface; the data acquisition system includes a load acquisition system and a displacement acquisition system;

Please refer to Fig. 2, described load acquisition system, comprises force sensor, signal conditioning, analog multi-way switch, programmable gain amplifier, A/D converter and single-chip microcomputer, wherein, force sensor collects the voltage signal, through the signal conditioning Processing and conversion, under the guidance of the analog multi-way switch, the processed voltage signal is guided to the programmable gain amplifier for amplification, and then the amplified voltage signal is converted from analog to digital, and finally the conversion result is sent to the microcontroller through the serial interface Carry out data processing and communication; the signal conditioning circuit mainly completes the conditioning and conversion of the differential analog signal output by the sensor, so that it can be accepted by the AD chip for digital-to-analog conversion. The single-chip microcomputer is the central control unit of the system, and the data acquisition USB communication is completely controlled SCM control;

The displacement acquisition system includes a grating encoder, a direction-judging interface circuit, an interface circuit and a single-chip microcomputer, wherein the displacement signal is converted into a pulse signal by the grating encoder; The signal is sent to the single-chip microcomputer, and on the other hand, the converted pulse signal is connected to the single-chip microcomputer through the interface circuit, and the displacement signal is counted and collected;

The A/D converter is a 24-bit oversampling analog-to-digital converter converter;

Described single-chip microcomputer is the single-chip microcomputer of 51 cores as main controller;

The mechanical part includes a motor, a speed changer, a steering gear, a lead screw, a workbench, and a fixture. The motor is connected to the lead screw through the speed changer and the steering gear. There are fixtures; among them, the motor drives the lead screw to rotate through the transmission and the steering gear. There are screw holes on the workbench to cooperate with the lead screw. The lead screw can only rotate and cannot move up and down. The rotation of the motor shaft is converted into the up and down movement of the workbench. One end of the S-shaped force sensor is fixed on the top platform, and the upper clamp is fixed on the other end of the force sensor. The workbench is equipped with a lower clamp. After stopping, the motor can be started to move the table up and down, and then the material to be tested will be stretched or compressed;

The USB communication system, wherein, the USB interface chip is selected from a single USB interface chip or a chip integrated with a USB interface, preferably a separate USB interface chip;

Described upper computer system comprises PC, printer and upper computer test software, wherein, upper computer test software is installed on the PC, mainly realizes functions such as USB upper computer communication, curve display analysis, data processing, report printing, control relay , the user directly performs a series of operations of the material test through the testing software interface of the host computer.

The above is only a preferred embodiment of the present invention, it should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, some improvements and modifications can also be made, and these improvements and modifications should also be considered Within the protection scope of the present invention.

Claims (6)

1. the Material Testing Machine based on the usb data acquisition system comprises mechanical part, data acquisition system (DAS), usb communication system and master system, it is characterized in that,

Described data acquisition system (DAS) comprises load acquisition system and displacement acquisition system;

Described load acquisition system, comprise force transducer, signal condition, analog multichannel switch, programmable gain amplifier, the single-chip microcomputer of A/D converter and 51 kernels, wherein, force transducer collects voltage signal, processing and conversion by signal condition, under the guiding of analog multichannel switch the voltage signal of handling well being directed to programmable gain amplifier amplifies, and then the voltage signal that amplifies carried out analog to digital conversion, at last transformation result is sent to single-chip microcomputer by serial line interface and carry out data processing and communication;

Described displacement acquisition system, comprise grating encoder, declare to interface circuit, interface circuit and single-chip microcomputer, wherein, displacement signal converts pulse signal to by grating encoder, differentiate the direction of displacement on the one hand by phase identifying circuit, and direction signal is sent to single-chip microcomputer, and the pulse signal that will adopt conversion by interface circuit is connected on the single-chip microcomputer on the other hand, and displacement signal is counted collection;

Described master system comprises PC, printer and host computer testing software, and the host computer testing software is installed on the PC;

Mechanical part is by electric machine controller, and force transducer and displacement transducer are connected with data acquisition system (DAS); Data acquisition system (DAS) links to each other with the usb communication system by USB interface as master controller with the single-chip microcomputer of 51 kernels, and the usb communication system is connected with master system by USB interface.

2. a kind of Material Testing Machine based on the usb data acquisition system according to claim 1 is characterized in that described load acquisition system comprises force transducer, signal condition, analog multichannel switch, programmable gain amplifier and 24 A/D converters; Wherein, force transducer will collect voltage signal and link to each other with signal condition, signal condition is directed to voltage signal on the programmable gain amplifier by analog multichannel switch, the voltage signal that will obtain amplifying links to each other with A/D converter again, will link to each other with single-chip microcomputer by serial line interface through the result of A/D converter conversion.

3. a kind of Material Testing Machine based on the usb data acquisition system according to claim 1 is characterized in that, described displacement acquisition system comprises grating encoder, declares to interface circuit and interface circuit; Displacement signal converts pulse signal to by grating encoder, and pulse signal links to each other with single-chip microcomputer by declaring to interface circuit, and pulse signal links to each other with single-chip microcomputer by interface circuit.

4. a kind of Material Testing Machine based on the usb data acquisition system according to claim 1 is characterized in that described mechanical part comprises motor, variator, steering gear, leading screw, worktable and anchor clamps; Motor links to each other with leading screw with steering gear by variator, and worktable is provided with screw and links to each other with leading screw, and the middle part of worktable is provided with anchor clamps.

5. a kind of Material Testing Machine based on the usb data acquisition system according to claim 1 is characterized in that, in described usb communication system, the chip that USB interface adopts is selected from a kind of of independent USB interface chip or integration USB interface chips.

6. a kind of Material Testing Machine based on the usb data acquisition system according to claim 5 is characterized in that described USB interface chip is preferably independent USB interface chip.

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