CN110580845A - A Virtual Instrument Embedded in the Comprehensive Teaching Experiment Platform - Google Patents

Abstract

the invention relates to a virtual instrument embedded in a comprehensive teaching experiment platform. The device comprises a high-precision measurement function circuit, a high-speed measurement function circuit and a power supply circuit, wherein the high-precision measurement function circuit, the high-speed measurement function circuit and the power supply circuit are respectively connected with a comprehensive teaching experiment platform. On the basis of meeting the requirements of teaching experiments on functions and performance, the invention can obviously reduce the purchasing cost of schools, reduce the waste of space resources of experiment stations, realize the integration of instruments and teaching equipment and improve the teaching effect.

Description

A Virtual Instrument Embedded in the Comprehensive Teaching Experiment Platform

technical field

The invention relates to the teaching field, in particular to a virtual instrument embedded in a comprehensive teaching experiment platform.

Background technique

In the process of higher education, especially in the teaching process of engineering and science, in order to enable students to better understand the theoretical knowledge in books, corresponding experimental courses are generally offered. One way is that the teacher demonstrates relevant knowledge through the teaching equipment; the other way is that the students directly operate the teaching equipment and conduct hands-on experiments, and through the process of hands-on experiments, they can further deepen their understanding of theoretical knowledge.

At present, the teaching experimental equipment on the market is mainly a variety of special small test boxes or large test benches. These test boxes or test benches only focus on a specific experimental circuit principle, and the excitation signals or observation signals required in the experimental process, It often needs to be used in conjunction with an independent desktop instrument, which will bring more problems. The summary is as follows:

1) Every time a school purchases a set of experimental boxes or test benches, it has to purchase corresponding desktop instruments, which increases the purchase cost to a certain extent;

2) The volume and weight of traditional desktop instruments are generally relatively large, which makes it impossible to reduce the area of the experimental workstation, which is already relatively tight, and wastes more space resources;

3) Traditional desktop instruments are generally designed for scientific research and production, and the indicators of the instruments are generally better, but for teaching applications, the indicators of traditional desktop instruments are often too high, forming a situation of big horses and small carts, resulting in a certain degree of waste of resources;

4) The communication between the traditional desktop instrument and the experimental box is inconvenient, which is not conducive to improving the correlation between the two during the experiment process, which is not conducive to improving the experimental experience, such as the synchronization between the experimental circuit and the instrument, the experimental circuit data and the instrument data The relevance and writing of experimental reports, etc.

The virtual instrument is different from the traditional instrument. The software is the instrument is its core idea. The virtual instrument does not have the display screen and operation panel of the traditional instrument, and all these are realized through the virtual software panel. Compared with traditional instruments, virtual instruments have three significant advantages: first, because the display screen and operation panel are removed, the volume and weight of the instrument are significantly reduced; The ability of virtual real-time and post-analysis processing has been significantly improved; the third is the design and production process has been simplified, and the cost has been significantly reduced. With the continuous development of instrument technology and information technology, virtual instrument technology is becoming more and more mature, and has been widely used in the industrial field, but it has not yet been found in teaching experiments.

Contents of the invention

In order to solve the technical problems in the background technology, the present invention provides a virtual instrument with multiple instrument functions. The virtual instrument can be embedded in the host computer of the miniaturized comprehensive teaching experiment platform, and forms an organic whole with the teaching experiment platform. Provide advanced teaching equipment for science and engineering teaching in higher education.

The technical solution of the present invention is: the present invention is a virtual instrument embedded in a comprehensive teaching experiment platform, and its special feature is that the virtual instrument includes a high-precision measurement function circuit, a high-speed measurement function circuit and a power supply circuit, and the high-precision The measurement function circuit, the high-speed measurement function circuit and the power supply circuit are respectively connected with the comprehensive teaching experiment platform.

Preferably, the high-precision measurement function circuit includes an input switching and protection circuit, a signal conditioning circuit, a high-precision analog-to-digital converter and an embedded processor 1, the input switching and protection circuit is connected to the signal conditioning circuit, and the signal conditioning circuit is connected to the high-precision Analog-to-digital converter, the high-precision analog-to-digital converter is connected to the embedded processor one.

Preferably, the high-speed measurement function circuit includes an embedded processor two, a dual-way 14-bit high-speed analog-to-digital converter, a dual-way 14-bit high-speed digital-to-analog converter, a programmable gate array, a direction control circuit and a static memory, and the programmable gate array It is respectively connected with the embedded processor 2, the dual-channel 14-bit high-speed analog-to-digital converter, the dual-channel 14-bit high-speed digital-to-analog converter, the direction control circuit and the static memory.

Preferably, the high-speed measurement function circuit also includes an input protection circuit, an input signal conditioning power supply and an output signal conditioning power supply. The 14-bit high-speed digital-to-analog converter is connected to the output signal conditioning power supply.

Preferably, the power supply circuit includes an embedded processor three, a digital-to-analog converter, a step-down converter, DC/DC and an output monitoring and control circuit, and the embedded processor three is respectively connected with the digital-to-analog converter and the DC/DC, and connected with the The digital-to-analog converter and the DC/DC are respectively connected to the monitoring and control circuit through the output monitoring of the step-down converter.

According to the research and analysis of some courses of higher education, the virtual instrument part should have nine types such as multimeter, oscilloscope, signal source, spectrum analyzer, logic analyzer, pattern generator, multifunctional digital IO, impedance analyzer, and program-controlled power supply. Commonly used instrument functions, some courses will also use vector network analyzers, high-resistance meters and other instruments, but considering that not most courses are used and the implementation cost is high, the virtual instrument scheme is determined to be the nine commonly used ones instrument function. Since the hardware implementation principles of some of the nine instrument functions are the same, and the difference is mainly in the realization of the virtual soft panel, it is finally determined to use three types of functional circuits to realize the nine instruments: high-precision measurement function circuit, high-speed measurement function circuit and power circuit. The high-precision measurement function circuit realizes the hardware function of the multimeter. The high-speed measurement function circuit realizes high-speed acquisition and output of analog and high-speed digital quantities, and is used to realize seven instruments of oscilloscope, signal source, spectrum analyzer, logic analyzer, code generator, multi-function digital IO and impedance analyzer hardware features. The power supply circuit realizes the hardware function of the program-controlled power supply. The invention can be applied to the experimental teaching platform of electromechanical related courses such as electronics, information, machinery, communication, instrument, electric power, etc. in middle schools and universities. The present invention has the following advantages:

1) Three kinds of virtual instrument hardware circuits realize nine kinds of instrument functions, the performance indicators meet the teaching requirements, have high cost performance, and can significantly reduce school procurement costs;

2) Small in size and light in weight, it is easy to sneak into the interior of the teaching equipment, reducing the demand for experimental station space resources;

3) Integrate with teaching equipment as a whole, realize the synchronization of control and data, and significantly improve the teaching effect.

Description of drawings

Fig. 1 is the structural block diagram of the comprehensive teaching experiment platform that the present invention applies;

Fig. 2 is the structural layout diagram of the comprehensive teaching experiment platform applied by the present invention;

Fig. 3 is a functional block diagram of the high-precision measurement function circuit of the present invention;

Fig. 4 is the functional block diagram of the high-speed measurement function circuit of the present invention;

Fig. 5 is a functional block diagram of the power supply circuit of the present invention.

The reference signs are as follows:

1. Power module; 2. Multifunctional module; 3. Virtual instrument; 4. Main control module; 5. Expansion interface; 6. Shell; 7. Experimental breadboard; 8. Control computer; 9. Course software management environment.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

Referring to Figures 1 and 2, the comprehensive teaching experiment platform for the application of the virtual instrument 3 of the present invention consists of a power supply module 1, a multi-function module 2, a virtual instrument 3 of the present invention, an expansion interface 5, a main control module 4, a housing 6 and an experimental breadboard 7 composition. The main control module 4 is respectively connected with the power supply module 1, the multi-function module 2, the expansion interface 5 and the virtual instrument 3 of the present invention. The power module 1 provides power for the work of the multi-function module 2 and the virtual instrument 3 of the present invention. The multifunctional module 2 mainly cooperates with the extended experimental circuit on the host computer, and realizes the circuit principle of the experiment through the host computer software and under the control of the main control module 4 . The virtual instrument 3 of the present invention is installed on the virtual soft panel of the upper computer and under the control of the main control module 4, it provides various source excitations and signal measurements required for the experimental circuit. The expansion interface 5 realizes the expansion connection between the host computer of the teaching experiment platform and the experimental circuit. The main control module 4 receives instructions from the upper computer, and realizes the control and data interaction of the multifunctional circuit inside the host computer and the virtual instrument 3 of the present invention. The housing 6 realizes the installation and protection of each module. The experimental breadboard 7 is plugged and unplugged on the expansion interface 5, wherein the main control module 4 mainly realizes the USB data exchange function, and realizes the data exchange between the 1-way USB communication and the 4-way USB communication, which is realized based on a commonly used USB exchange controller. Here adopt TUSB4041 to realize. The multi-function module 2 uses a 32-bit single-chip processor STM32F446 as the core, and is equipped with conventional analog acquisition circuits, analog output circuits, digital input and output circuits, and timer counter circuits for overall function realization. The multi-function module communicates with the main control module through the USB interface, and the USB interface circuit is also implemented based on the USB interface of STM32F446.

The software management environment 9 is loaded in the control computer 8, and the experimental course software calls the host hardware driver of the present invention through the course software management environment 9, and carries out data communication with the main control module 4 in the host computer through the USB bus, sends control instructions, reads and collects The data. Control computer 8 adopts common business computer based on windows operating system. After the main control module 4 receives the instruction of the control computer 8, it converts it into internal local bus data, and realizes the communication with the power supply module 1, the multi-function module 2 and the virtual instrument 3 of the present invention. Under the control of the main control module 4, the functions of each module can run at the same time without affecting each other. Data interaction with the upper computer is realized through multiple DMA channels. All input and output signals of the module are connected to the experimental breadboard through the expansion interface 5 7 to interact.

The virtual instrument 3 of the present invention includes a high-precision measurement function circuit, a high-speed measurement function circuit, and a power supply circuit, and the high-precision measurement function circuit, the high-speed measurement function circuit, and the power supply circuit are respectively connected to the main control module 4 in the comprehensive teaching experiment platform.

The virtual instrument 3 of the present invention has a multimeter, a dual-channel oscilloscope, a dual-channel signal source, a single-channel multimeter, a 16-channel logic analyzer, a 16-channel pattern generator, a 16-channel multifunctional digital IO, a single-channel impedance analyzer, and a dual-channel controller. Nine commonly used instrument functions such as power supply, the use of the virtual instrument 3 of the present invention needs to be used together with the virtual instrument software installed in the control computer 8, and the functions such as analysis, display, and storage of the virtual instrument 3 of the present invention are all based on software. User-friendly and powerful virtual panel. The test excitation signal of the virtual instrument 3 of the present invention interacts with the experimental breadboard 7 through the expansion interface 5 on the one hand, and directly leads to the panel of the housing 6 on the one hand, which is convenient for users to use directly.

See Figure 3, the multimeter function can realize DC voltage, DC current, AC voltage, AC current, resistance, continuity, diode and other test functions. The multimeter function is realized based on the high-precision measurement function circuit. According to the test function selected by the software, input switching and The protection circuit first realizes the switching of the measurement channel. At the same time, in order to prevent the damage of the overload signal to the back-end circuit, an overvoltage and overcurrent protection circuit is also designed here. The signal is switched to the corresponding input terminal of the signal conditioning circuit, and the signal conditioning circuit filters and transforms the signal, transforms it to the input range of the high-precision analog-to-digital converter and collects it by the high-precision analog-to-digital converter. The high-precision analog-to-digital converter adopts a 24-bit high-precision analog-to-digital converter, which can ensure that the overall accuracy of the system meets the requirements. After the high-precision analog-to-digital converter collects and outputs are processed by the embedded processor, commands and data are exchanged between the local bus and the main control module 4 .

See Figure 4, the other virtual instrument functions are realized by the high-speed measurement function circuit, which can realize dual-channel oscilloscope, dual-channel signal source, single-channel multimeter, 16-channel logic analyzer, 16-channel pattern generator, 16-channel multi- Functional digital IO and single channel impedance analyzer. The core of the oscilloscope is to use dual 14-bit high-speed analog-to-digital converters. The dual-channel 14-bit high-speed analog-to-digital converters are controlled by the programmable gate array FPGA for synchronous sampling. The data output by the dual-channel 14-bit high-speed analog-to-digital converters passes through the SPI bus. Enter the FIFO of FPGA for buffering, and then transfer to embedded processing two. The core of the signal source is a dual-channel 14-bit high-speed digital-to-analog converter. The data to be output is sent to the onboard memory by the embedded processor. FPGA controls the dual-channel 14-bit high-speed digital-to-analog Sequentially converted into analog signals, output after smoothing and filtering, and the phase control between the two outputs can be performed by FPGA. The impedance analyzer is implemented based on the cooperation of a dual-channel oscilloscope and a signal source. The hardware uses the circuits of these two instruments, and the rest is implemented by software algorithms. The logic analyzer, pattern generator and multi-function digital IO are all implemented based on the IO port of the FPGA in hardware. The difference between the three is that the protocol waveform and signal direction are different. The protocol waveform is generated by software and downloaded to the static memory (SRAM). The input and output direction control is realized by the direction control circuit designed at the front end of the circuit.

Referring to Fig. 5, the power supply circuit realizes 0-+15V, -15V-0V dual program-controlled power supply. As a part of the virtual instrument function, the dual-program-controlled power supply is implemented with a wide input voltage step-down converter (LDO) as the core. The DC/DC in the circuit provides input power for the step-down converter, and uses DA to output analog signals to control the step-down The output voltage of the converter, the output monitoring and control circuit can monitor the output voltage and current and feed back to the control terminal, and the embedded processing three receives the control command from the local bus to realize the output voltage and current detection and feedback control.

The invention provides a virtual instrument with multi-instrument functions, which can be embedded into the comprehensive teaching experiment platform for use, and can significantly reduce the purchase cost of the school and reduce the waste of space resources of the experimental station on the basis of meeting the functional and performance requirements of the teaching experiment , and realize the integration of instruments and teaching equipment, and improve the teaching effect.

The above are only specific implementations disclosed by the present invention, but the scope of protection disclosed by the present invention is not limited thereto, and the scope of protection disclosed by the present invention should be based on the scope of protection of the claims.

Claims (5)

1. The utility model provides a virtual instrument in comprehensive teaching experiment platform which characterized in that: the virtual instrument comprises a high-precision measurement function circuit, a high-speed measurement function circuit and a power supply circuit, wherein the high-precision measurement function circuit, the high-speed measurement function circuit and the power supply circuit are respectively connected with the comprehensive teaching experiment platform.

2. The virtual instrument embedded in the comprehensive teaching experiment platform according to claim 1, wherein: the high-precision measurement function circuit comprises an input switching and protecting circuit, a signal conditioning circuit, a high-precision analog-to-digital converter and a first embedded processor, wherein the input switching and protecting circuit is connected to the signal conditioning circuit, the signal conditioning circuit is connected to the high-precision analog-to-digital converter, and the high-precision analog-to-digital converter is connected to the first embedded processor.

3. The virtual instrument embedded in the comprehensive teaching experiment platform according to claim 2, wherein: the high-speed measurement function circuit comprises a second embedded processor, a two-way 14-bit high-speed analog-to-digital converter, a two-way 14-bit high-speed digital-to-analog converter, a programmable gate array, a direction control circuit and a static memory, wherein the programmable gate array is respectively connected with the second embedded processor, the two-way 14-bit high-speed analog-to-digital converter, the two-way 14-bit high-speed digital-to-analog converter, the direction control circuit and the static memory.

4. the virtual instrument embedded in the comprehensive teaching experiment platform according to claim 3, wherein: the high-speed measurement functional circuit further comprises an input protection circuit, an input signal conditioning power supply and an output signal conditioning power supply, wherein the input protection circuit is connected to the input signal conditioning power supply, the input signal conditioning power supply is connected to the 14-bit high-speed double-circuit analog-to-digital converter, and the 14-bit high-speed double-circuit digital-to-analog converter is connected to the output signal conditioning power supply.

5. The virtual instrument embedded in the comprehensive teaching experiment platform according to any one of claims 1 to 4, wherein: the power supply circuit comprises a third embedded processor, a DA (digital-to-analog) processor, a buck converter, a DC/DC (direct current/direct current) and an output monitoring and control circuit, wherein the third embedded processor is respectively connected with the DA and the DC/DC, and the third embedded processor is respectively connected with the DA and the DC/DC through the buck converter and the output monitoring and control circuit.