Preface

Fortunately, I got to know Lichuang EDA. It was my first time to come into contact with RT-Thread and I decided to study it carefully. The main difficulty in building a practical industrial control monitoring system comes from the interference of complex industrial environments and software program codes.

Project requirements

In today's developed industrial manufacturing industry in our country, mesh belts are indispensable, and almost all assembly lines are inseparable from mesh belts. Mesh belts are like transportation highways transporting product production. If a failure occurs in the middle, it will paralyze the entire production and even cause serious losses. I once worked in a factory and came up with an idea. Failure is inevitable when equipment is running. If there is a system to monitor the operation of mesh belts, failures can be detected earlier and corresponding measures can be taken in a timely manner to avoid greater losses.

case analysis

The project is divided into two parts, one main board and 8 slave boards. This project is the main board host computer part. The slave boards are used to detect the operation of each motor mesh belt and have been prototyped. Will be placed in the attachment. As a host computer, ART-PI controls the start, stop and speed adjustment of the 8-channel transmission mesh belt motor, while monitoring the operation of the mesh belt. The mesh belt motor is generally a 380V industrial three-phase asynchronous motor, which adopts a frequency converter for speed regulation. The total distance between the 8 motors is about 100 meters. Due to the long distance and the complex on-site environment, the host computer and the frequency converter decided to use the 485 bus to communicate through Modbus. The protocol is used to exchange data and realize the functions of start, stop, speed addition, subtraction and display. The speed display terminal initially planned to use eight 4-digit digital tubes. Later, considering that it would take up too much space, it was decided to use a serial port screen instead. An encoder is used as speed addition and subtraction input, which is in line with workers' operating habits. The speed of each channel can be controlled by switching up and down buttons. The principle of mesh belt operation is that the motor drives the main shaft, and the main shaft sprocket drives the fulcrum to rotate through the chain. In order to avoid the fulcrum accident caused by chain breakage, it was decided to use Hall elements to detect the rotation information of the fulcrum, so a separate Hall element is needed. The component monitors the sub-board of the spindle operation and is used to collect and transmit various operation information. (Note: Our company's production line is sealed in a foam insulation box. The total length of the insulation box is about 100 meters. It is difficult to detect a break in the middle chain. When the output of the insulation box is detected, it is too late. An accident caused a loss of about several thousand yuan. The accident Frequent occurrence) When a fault occurs in the 8-way conveyor belt and stops rotating, the corresponding alarm light and buzzer will sound and light warnings.

At the same time, the serial port backup has been expanded, which can be used to connect Bluetooth 2.0 modules or other peripherals, allowing the mobile APP to control all functions through Bluetooth transparent transmission, making it more convenient to operate.

Hardware

Subsequent improvement of layout and routing

Software

to be continued