Application of ultrasonic distance measurement sensor in mine locomotive

Under the rising tide of the global new technology revolution, China has identified seven strategic emerging industries: energy conservation and environmental protection, new energy, new generation information technology, biology, high-end equipment manufacturing, new materials and new energy vehicles. At the same time, because the Internet of Things belongs to the technical extension and application of the Internet, and the continuous innovation of productivity and means of production, the mechanical and electrical equipment in coal mines has also been rapidly promoted and developed. In coal mine production, mechanical and electrical equipment occupies an increasingly important position, penetrating every link of the production line. A large number of coal mining equipment are introduced into the coal mine for use, and the mining volume of the coal mine also increases, but the increase in mining volume also brings a new problem - how to transport the mined coal safely and quickly. In response to this problem, China's coal mines have taken measures to increase the number of locomotive transport vehicles, improve the speed of electric locomotives and locomotive operation for 24 hours. In this way, the driver is prone to fatigue driving and inattention, resulting in a series of potential safety problems. Therefore, it is of great significance to design a locomotive anti-collision alarm system for coal mine safety. The key technology of this system is distance measurement - measuring the distance from the obstacle in front to the locomotive. Today's ultrasonic sensor has been tested by many industrial tasks and is an ideal solution for distance measurement and object detection. As a typical non-contact measurement method, ultrasonic ranging has been widely used in many fields, such as industrial automatic control, construction engineering measurement and robot vision recognition. Compared with other ranging methods, it is not affected by factors such as illumination, smoke, electromagnetic interference, and has been widely used in reversing radar, construction sites and some industrial sites. In recent years, it has become another important research direction of ultrasonic ranging technology to improve the measurement accuracy and anti-interference ability while improving the effective range of the ultrasonic ranging system.
Distance measuring principle of ultrasonic distance measuring sensor
Ultrasonic distance measuring instrument is composed of ultrasonic transmitter, receiver and signal processing device. As a special kind of sound wave, ultrasonic also has the basic physical characteristics of sound wave transmission. Ultrasonic distance measurement is based on its reflection characteristics. The ultrasonic transmitter continuously sends out a series of continuous pulses (such as 30 kHz ultrasonic) and provides a short pulse to the measuring logic circuit. The ultrasonic receiver also provides a short pulse to the measuring logic circuit after receiving the reflected wave reflected by the emitted ultrasonic wave when encountering obstacles, and then uses the bistable circuit to convert the two short pulses into a square wave pulse. The width of square wave pulse is the time interval between two short pulses. The distance between the transmitter and the object can be determined by measuring the width of the square wave pulse. At the same time, according to the measured width of the output pulse, that is, the time interval between transmitting and receiving the ultrasonic wave can be measured, so that the distance between the locomotive and the obstacle can be calculated [S]: [S=12vt] where: [v] is the ultrasonic speed of sound (that is, the speed of sound); [t] Is time.
Although ultrasonic ranging sensor has many advantages, the distance of ultrasonic ranging depends on the transmitting power and the receiving sensitivity. The greater the transmitting power, the stronger the returned energy, and the farther the detection distance. At the same time, the side effect is that the longer the residual time, the more difficult it is to measure objects in close range; When measuring the obstacle at a longer distance, the echo signal returned will be weaker, and it must be processed through the amplification circuit first. The greater the magnification, the higher the sensitivity, and the farther the measured distance, but at the same time, the interference signal will also be amplified, resulting in errors in the measured distance. Therefore, properly controlling the transmitting power and receiving sensitivity will make the measuring distance and stability reach a better state.
Considering the complex environment of the coal mine itself, in order to meet the purpose of ultrasonic distance measurement, the industrial mining network recommends MaxBotix high-performance sonar range finder ultrasonic sensor - MB7040. This product belongs to the industrial outdoor I2CXL-MaxSonar-WR sensor and has a solid PVC shell, providing IP67 protection capability. These sensors provide short to long range detection and narrow beam angle. On the other hand, I2CXL-MaxSonar-WR outdoor ultrasonic sensor has high power output, noise suppression and automatic calibration. In addition to the standard I2CXL-MaxSonar-WR, the F option that requires additional protection in some hazardous chemical environments has also been developed. Extremely corrosive gas or liquid will reduce or damage the operation of the sensing device. Therefore, we provide a chemically inert seal to enable our sensors to operate in all chemical environments. In addition to chemical resistance, the performance of the sensor is also improved in wet or dusty environment.