CN104049557A - Connecting rod characteristic analyzing and displaying method based on LabVIEM and single-chip microcomputer - Google Patents

Abstract

The invention discloses a connecting rod characteristic analyzing and displaying method based on a LabVIEM and a single-chip microcomputer. According to the connecting rod characteristic analyzing and displaying method based on the LabVIEM and the single-chip microcomputer, data transmission, separation and processing of a sensor network between the LabVIEM and the single-chip microcomputer are explained, the actual movement condition of a connecting rod can be simulated in real time according to requirements of a client side, and all parameters can be corrected and displayed. A LabVIEM upper computer serves as a computer display end, an upper computer program receives data which are received by a computer serial port and sent by the single-chip microcomputer every 10 ms through a VISA serial driver, error data are distinguished firstly after the data are received by the upper computer, the corresponding movement parameters of the connecting rod are calculated according to data obtained after screening, and the corresponding movement parameters of the connecting rod are displayed through a LabVIEM 2d display control.

Description

A Method of Analysis and Display of Connecting Rod Characteristics Based on LabVIEW and Single Chip Microcomputer

technical field

The invention relates to the field of characteristic analysis and simulation display of mechanical teaching aids, in particular to a connecting rod characteristic analysis and display method based on LabVIEW and a single-chip microcomputer.

Background technique

LabVIEW is a virtual instrument platform developed by National Instruments Corporation. It is a development tool for creating applications using icon codes instead of text-based programming languages. LabVIEW is powerful, providing a wealth of data acquisition, analysis and storage library functions, as well as all functional functions of various instrument communication bus standards including DAQ, GPIB, PXI, and VXI. Therefore, using LabVIEW to develop virtual instruments has more advantages than using traditional text-based languages. But the virtual instruments developed with LabVIEW are usually based on expensive data acquisition hardware supported by LabVIEW. However, although the data acquisition and processing system with single-chip microcomputer as the core has lower hardware cost, the development process is more complicated, the programming workload is larger, the cycle is long, and the efficiency is low. If a small system with a single-chip microcomputer as the core is used as the front-end data acquisition system, the collected data is transmitted to the PC main system through the serial port sub-VI provided by LabVIEW, and the data is processed and analyzed in the LabVIEW environment, which not only makes full use of LabVIEW The powerful function of the single-chip microcomputer is small, the system structure is simple, and the serial communication function provided by LabVIEW is used to combine the single-chip system with the PC, which reduces the development cost of the system and improves the efficiency. This is an extension of LabVIEW One way to apply range.

Contents of the invention

The problem to be solved by the invention is to provide a method for analyzing and displaying the connecting rod characteristics based on LabVIEW and a single-chip microcomputer.

The technical scheme that the present invention solves its technical problem adopts is: provide a kind of processing method based on the sensor network data between single-chip microcomputer and LabVIEW, specifically comprise the following steps:

1. First, use the AD conversion interface of the single-chip microcomputer to perform AD acquisition on the signal of the sensor network;

2. The single-chip microcomputer performs filtering processing on the collected raw data;

3. Convert the filtered raw data into real meaningful data, such as: angle, angular velocity, angular acceleration, etc.;

4. The data is packaged and processed, and the specific steps include the following:

1) Convert each parameter into a string format and save it in a string array;

2) Insert specific identification characters between the parameters in the string array;

3) Insert the data frame header identification bit at the beginning of the string array;

4) Insert the data frame end identification bit at the end of the string array;

5. As explained in step 4, the packaged data format will be as follows: frame header—data bit—data identification bit—…—frame tail, and the single-chip microcomputer will send the data to the computer terminal directly through the Bluetooth serial port after packing the data as above;

6. The terminal starts the LabVIEW program, opens the serial port, and connects to the corresponding serial port number, selects the baud rate, and sets the parity bit;

7. After the LabVIEW program starts, process the data and display it. The specific steps include the following:

1) Save the data received by the serial port in the form of clusters;

2) The program extracts a frame of data packets from the data cluster at an interval of 10ms;

3) Check the frame header and frame tail of the data packet, and discard the data if it does not match the predetermined format, and the program will re-extract the data from the data cluster;

4) Split the extracted data packets, and separate the data according to the identification bits, and the separated data are the measured parameters;

5) The LabVIEW program will display the parameters through related controls;

6) The LabVIEW program will enable the 2D drawing function, map each parameter to the corresponding 2D display control, and then display the movement process of the mechanism.

Beneficial effects of the present invention: the present invention is based on the analysis and display method of the connecting rod characteristics of LabVIEW and single-chip microcomputer, and sends the data processed by the single-chip microcomputer to the PC end, and realizes the movement of the LabVIEW2D drawing VI control simulation mechanism.

Description of drawings

Fig. 1 is a system flow diagram of the present invention.

Figure 2 is the LabVIEW packet decomposition program.

Figure 3 shows the program diagram of LabVIEW2D.

specific implementation plan

Below in conjunction with specific embodiment, further explain the present invention.

As shown in Figure 1, a processing method based on sensor network data between MCU and LabVIEW, including system initialization (1), mechanism operation (2), MCU data collection (3), Bluetooth sending data packets (4), LabVIEW Run (5), set the parameters (6), send to the microcontroller (7), LabVIEW receives the data packet (8), solve and correct the data packet (9), correct the error (10), then return to LabVIEW to receive the data packet (8), If the correction is correct, the data is converted into coordinates (11), and finally the 2D interface is displayed (12), which specifically includes the following steps:

1. First, initialize the entire control system, mainly including mechanism parameters, motor speed and sensor parameter initialization settings;

2. The terminal starts the LabVIEW program, opens the serial port, and connects to the corresponding serial port number, selects the baud rate, sets the parity bit, and sends the set initialization parameters to the microcontroller through the serial port;

3. After receiving the initialization data, the MCU starts to control the operation of the mechanism;

4. After the mechanism is running, the single-chip microcomputer first collects the original data of the sensor, mainly using the AD conversion interface to carry out AD collection of the signal of the sensor network;

5. The single-chip microcomputer performs filtering processing on the collected raw data;

6. Convert the filtered raw data into truly meaningful data, such as: angle, angular velocity, angular acceleration, etc.;

7. The data is packaged and processed, and the specific steps include the following:

1) Convert each parameter into a string format and save it in a string array;

2) Insert specific identification characters between the parameters in the string array;

3) Insert the data frame header identification bit at the beginning of the string array;

4) Insert the data frame end identification bit at the end of the string array;

8. Packing data format: frame header—data bit—data identification bit—…—frame tail, the single-chip microcomputer packs the data as above and sends it directly to the computer terminal through the Bluetooth serial port;

9. After the LabVIEW program starts, process the data and display it. The specific steps include the following:

1) Save the data received by the serial port in the form of clusters;

2) The program extracts a frame of data packets from the data cluster at an interval of 10ms;

3) Check the frame header and frame tail of the data packet, and discard the data if it does not match the predetermined format, and the program will re-extract the data from the data cluster;

4) Split the extracted data packets, and separate the data according to the identification bits, and the separated data are the measured parameters;

5) The LabVIEW program will display the parameters through related controls;

6) The LabVIEW program will enable the 2D drawing function, map each parameter to the corresponding 2D display control, and then display the movement process of the mechanism.

1. Using single-chip microcomputer as data acquisition port

As a data acquisition port, the single-chip microcomputer can filter, analyze and process the data, and can also be used as a data transfer station to respond and process the upstream and downstream of the data accordingly. The single-chip microcomputer and the LabVIEW host computer program are two independent control blocks, and data communication is carried out between the two through Bluetooth. This can not only reduce the burden of the LabVIEW program port, but also realize the two-way communication between the sensor and the general controller, and realize the distributed control.

2. Packaging and segmentation of raw data

In order to enable the LabVIEW program to identify the uplink data sent by the microcontroller, we pack the data in a special way. Pack the raw data into an array of strings separated by specific identifiers. details as follows:

Start character bit—sensor 0 data 0—identification character 0—sensor 0 data 1—identifier 1—sensor 1 data 0—identifier 2—… terminating identification character.

In order to avoid errors in data transmission or time deviation during reception, we use frame header and frame tail characters as inspection data.

3. LabVIEW's data processing

The split data of LabVIEW host computer is shown in Figure 2. When LABVIEW receives a frame of data packet sent by the microcontroller control end, it first needs to analyze and split the data packet, and the parsing is performed character by character according to the protocol when the data is packaged. Parsing is to extract all the data before the identification characters in the string array, and then split it into independent data according to the identifier. After LabVIEW splits the data, the data is stored in the data cluster in the order we predetermined. When a frame of data packet is to be taken out of the data cluster, the data type conversion is first performed on the data, and then the accuracy of the data can be adjusted according to actual needs. Calibration, part of the calibrated data is referenced to the waveform display VI control interface, and part of it is referenced to the 2D display control subVI.

4. Design of LabVIEW2D display interface

Part of the program for LABVIEW to realize 2D graphics display is shown in Figure 3. LabVIEW has a 2D drawing VI control, and the drawing of geometric figures such as rectangles and circles can be realized by using the drawing geometric figure subVI in the professional picture function of LabVIEW. First of all, we have drawn several standard geometric figures, and then encapsulated them into subVI controls, and referenced the corresponding data parameters to the subVI interface. The parameters are extracted from the split data cluster every 10ms. When drawing the basic graphics of the mechanism movement, these subVIs are directly called, and the data parameters are passed to the subVI controls, so that the graphics drawn by the subVI controls can produce corresponding displacement changes. Through these several basic graphic VIs, various mechanism motion mechanisms can be combined.

When simulating the movement of the mechanism, in order to make the drawn mechanism graphics respond to the corresponding movement according to the parameters, we map the parameters into corresponding coordinate changes, such as the rotation of the rod, according to the angular displacement signal transmitted by the single-chip microcomputer, after arc conversion Finally, it is converted into corresponding coordinates, and the coordinates of the graphics displayed by the drawing subVI are changed according to the coordinates, thereby realizing the dynamic display of the kinematic mechanism.

Claims (3)

1. A connecting rod characteristic analysis and display method based on LabVIEW and single-chip microcomputer is characterized in that a kind of processing method based on the sensor network data between the single-chip microcomputer and LabVIEW is provided, and the signal of the sensor network is carried out AD acquisition with the single-chip microcomputer AD conversion interface; The single-chip microcomputer performs filtering processing on the collected raw data; converts the filtered raw data into real meaningful data, such as: angle, angular velocity, angular acceleration. 2. the connecting rod characteristic analysis display method based on LabVIEW and single-chip microcomputer according to claim 1, it is characterized in that a kind of method that data is carried out packing process is provided, and each parameter is converted into character string format, and saves to a character string In the array; insert specific identification characters between the parameters in the string array; insert the data frame header identification bit at the beginning of the string array; insert the data frame end identification bit at the end of the string array; pack data format such as: frame Header—data bit—data identification bit—…—frame end. 3. the connecting rod characteristic analysis display method based on LabVIEW and single-chip microcomputer according to claim 2, it is characterized in that a kind of single-chip microcomputer is provided and data is sent to computer terminal processing data and the method for displaying through bluetooth serial port, terminal starts LabVIEW program, Open the serial port, connect the corresponding serial port number, select the baud rate, and set the parity bit; after the LabVIEW program is started, the data received by the serial port will be saved in the form of clusters; Frame data packet; check the frame header and frame tail of the data packet, discard the data if it does not match the predetermined format, and the program will re-extract the data from the data cluster; split the extracted data packet, and separate the data according to the identification bit. The final data is the measured parameters; the LabVIEW program will display the parameters through the relevant controls; the LabVIEW program will enable the 2D drawing function, map each parameter to the corresponding 2D display control, and then display the movement process of the rod.