Automatic line patrol and temperature measurement car

Purpose and function: A patrol car based on thermal imaging temperature measurement, which can achieve stable control of detection costs while fully automated and unmanned detection of temperature and humidity data at each location. It solves the function of automated scheduled inspection and remote monitoring. The device can go directly to the location to be inspected as required when the user outputs a command, and then continue the inspection in the original order. The device adopts a modular design and can be connected to the Internet of Things. Various data can also be uploaded to the cloud monitoring screen through the wifi module for user viewing. It can be mainly used in substations to detect transformer temperature, environmental temperature and humidity and other data, or expanded to other fields to measure the temperature of different equipment.
(1) Ensure the accuracy of target temperature detection: Ensuring the accuracy of target temperature detection is an important basis for achieving the ultimate goal. Because the car needs to measure the temperature of different targets at multiple temperature measurement points, it cannot measure the temperature by heat conduction, so other methods must be used to ensure the accuracy of target temperature detection. In addition to the light visible to the human eye, there are also non-visible light such as ultraviolet rays and infrared rays in nature. Any object in nature with a temperature higher than absolute zero (-273℃) radiates electromagnetic waves (infrared) at any time. Therefore, infrared is the most widespread electromagnetic wave in nature, and thermal infrared is not absorbed by atmospheric smoke clouds.
(2) Achieve automation: For a patrol car, automation and unmanned operation are important ways to save resources and manpower. Automated equipment can not only better control expenditure budgets, but also improve work efficiency. In order to achieve the goal of reducing human control, automated inspection of each point is a necessary way.
(3) Introduce Internet of Things technology: With the rapid development of society, the overall environment of epidemic prevention and control is constantly developing, and 5G, smart grid, etc. have become important parts. How to use the patrol line temperature measurement car intelligently will become an issue we need to pay attention to. If the current prototype requires users to observe the display screen on the device on site, but cannot realize real-time data monitoring, it will be difficult to meet user requirements, and it will not be able to achieve the goal of automation and intelligence, and achieve the goal of saving manpower and economic costs. Therefore, the Internet of Things technology is introduced into the patrol car with thermal imaging temperature measurement. It can monitor the target points of the car and the real-time temperature, humidity and other measurement data in real time through the network connection background, and can send commands on the user side to detect the target points that need to be detected.
 
Working conditions: The inspection route needs to be set in advance, and the location where the temperature needs to be measured needs to be marked. The device to be measured needs to be within 3m of the infrared probe on the left side of the car, and the height is consistent with the infrared probe.
 
Measurement data: 1. The thermal imaging module detects the temperature of the target device 2. The DHT11 module detects the temperature and humidity of the environment
 
Basic idea: The research on a patrol car based on thermal imaging temperature measurement designed in this project involves hardware design and software design.
 
The hardware design includes core control chip module, MLX90640 thermal imaging module, DHT11 temperature and humidity module, DHT11 temperature and humidity module, human cloud USR-TCP232-302 module, four-way infrared tracking module, step-down module, L298N motor driver module, and 0.96-inch oled screen.
(1) The core control chip module is mainly responsible for data reception, processing, display, transmission and control signal output of related modules. (2) The working principle of the thermal imaging module is the blackbody radiation law. The higher the temperature of the object, the stronger the infrared radiation capacity it emits. The temperature data is obtained after chip processing, and the detected data is sent to the core control chip through serial communication. (3) The DHT11 digital temperature and humidity sensor is a temperature and humidity composite sensor with calibrated digital signal output. It uses dedicated digital module acquisition technology and temperature and humidity sensing technology, and uses single bus communication to transmit temperature and humidity data to the core control chip. (4) The human cloud module is a device that realizes direct transparent data transmission between the RJ45 network port and the RS232 interface. It receives the data packet packaged from the core control chip in the form of receiving data packets, and uploads it to the server through the local network, allowing users to view real-time data on the PC website or WeChat applet. Users can also transmit instructions through the web page. The module receives the data packet and transmits it to the core control chip for remote control. (5) The step-down module uses an IC chip to output a square wave signal to control the opening and closing of a switch tube, thereby controlling the time length of the input voltage to the output. The larger the duty cycle of the square wave signal, the higher the output voltage, and the smaller the duty cycle, the smaller the output voltage. (6) The four-way infrared tracking module uses discrete components such as infrared transmitting and receiving tubes to form a probe, and uses a voltage comparator to obtain the output signal. It is connected to the I/O port of the core control chip to receive high and low level data, so that the car can move along the predetermined trajectory. (7) The motor drive module is an electromechanical component that converts electrical pulse signals into angular displacement or linear displacement. The input quantity of the stepper motor is a pulse sequence, and the output quantity is the corresponding incremental displacement or step motion. Under normal movement, it has a fixed number of steps per revolution; when performing continuous stepping motion, its rotation speed maintains a strict correspondence with the frequency of the input pulse and is not affected by voltage fluctuations and load changes.
(8) The 0.96-inch OLED screen uses analog SPI to display real-time temperature and humidity data on the 0.96-inch OLED screen.
 
Specific applications of important modules:
1. MLX90640 thermal imaging module
Coolke MLX90640 is a low-cost non-contact infrared dot matrix temperature measurement module. The working principle is the black body radiation law. The higher the temperature of the object, the stronger the infrared radiation ability it emits. The temperature data is obtained after chip processing. This module has three ways to read data, namely serial port (TTL level), USB interface, or I2C communication method. This product has a large number of temperature measurement dot matrixes and high pixels. It can distinguish the human body shape in a general environment. Connect the 5V power supply and use serial communication to transmit temperature data. Note that the RXD port of the module is connected to the RXD port of the microcontroller, and the TXD is connected to the TXD port of the microcontroller. Set the header of the received data packet and use the array to receive data.
2. DHT11 temperature and humidity module
DHT11 digital temperature and humidity sensor uses dedicated digital module acquisition technology and temperature and humidity sensing technology. The sensor includes a capacitive humidity sensing element and an NTC temperature measuring element, and is connected to a high-performance 8-bit microcontroller. In the designed program, it is necessary to send a receive command first and then wait for the slave to respond. When the DATA pin of DHT11 detects a low level of the external signal, it waits for the low level of the external signal to end. After the delay, the DATA pin of DHT11 is in the output state, and outputs a low level of 83 microseconds as a response signal, followed by an output of a high level of 87 microseconds to notify the peripheral to prepare to receive data. The I/O of the microprocessor is in the input state at this time. After detecting a low level of I/O (DHT11 response signal), it waits for the data to be received after a high level of 87 microseconds.
3. USR-TCP232-302 module
USR-TCP232-302 is a single serial port server of the M0 series launched by USER Internet of Things Technology Co., Ltd. This is a device that realizes direct transparent data transmission between the RJ45 network port and the RS232 interface. Equipped with an ARM processor, it has low power consumption, fast speed and high stability. The TCP/IP protocol stack is integrated internally, and users can use it to easily complete the network functions of embedded devices, saving manpower, material resources and development time. The module supports WIFI@2.4 GHz 802.11b/g/n wireless standards, supports WEP/WPA/WPA2 security modes, supports AP, STA, AP+STA working modes, fully integrated serial port to wireless TCP/UDP transmission function, multiple serial port rate selection, LAN search and wireless parameter setting functions, supports TCP/UDP Client registration package mechanism, supports Simple Config/Airkiss/usrlink fast networking configuration, and supports RFC2217. Connect to the 3V power supply and transmit the data packets that need to be uploaded to the manned cloud network to the manned cloud module through serial communication.
 
Main research content:
This project designs a patrol car based on thermal imaging temperature measurement. It solves the functions of automatic scheduled patrol and remote monitoring. The device can go directly to the location that needs to be inspected as required when the user outputs a command, and then continue the patrol in the original order. The device adopts a modular design and can be connected to the Internet of Things. Various data can also be uploaded to the cloud monitoring screen through the wifi module for user viewing. It can be mainly used in substations to detect transformer temperature, environmental temperature and humidity data, or expanded to other fields to measure the temperature of different equipment.
 
Application value:
(1) Realize unmanned automated routine detection of temperature and humidity data and improve detection efficiency: The most important thing about the development of a fully automatic patrol and temperature measurement car is that it can perform temperature and humidity detection on each temperature measurement point. The scheduled cruise function makes equipment detection a normalized process. Users can read temperature and humidity data remotely, reduce labor consumption in multiple scenarios, and realize automation. At the same time, users can change the next target point after connecting to the Internet, so that users can obtain the temperature data of the target point that needs to be detected more efficiently.
(2) Reduce equipment costs: In order to detect the temperature and humidity data of each point in different environments, it is not necessary to install a temperature and humidity sensor and networking equipment at each temperature measurement point. In an environment where a large number of locations need to be detected, the detection cost can be stably controlled. The fully automatic temperature measurement car can not only detect the temperature of the transformer in the substation, but also detect the temperature and humidity in different environments, or measure the body temperature of people.
(3) Modular components: This project improves the working reliability of each module of the controller for the main control board, MLX90640 thermal imaging module, DHT11 temperature and humidity module, DHT11 temperature and humidity module, human cloud USR-TCP232-302 module, four-way infrared tracking module, step-down module, L298N motor drive module. After modularization, the components need to be replaced quickly, which is convenient for timely replacement of components. It only needs to simply connect the new module to the core control module, which greatly reduces the time for equipment maintenance and increases the power supply reliability of the user end. At the same time, various modules with different functions can be installed to achieve different goals and have more variability.