Application of Ultrasonic Obstacle Avoidance Sensor in AGV Industry

In recent years, the rapid development of microcomputer technology, artificial intelligence and sensor measurement and control technology has made AGV more intelligent and humanized, which has made AGV move towards the direction of intelligent robots. A fully functional AGV system usually consists of 3 major parts: walking mechanism, sensor system and control system. The walking mechanism is the basis for the AGV to realize movement, and determines the movement space and freedom of the AGV. The ultrasonic level transducer system determines its navigation method. The mainstream uses laser sensors, ultrasonic sensors, photoelectric sensors, magnetic sensors, CCD cameras, infrared sensors or GPS positioning. At present, when running stably in some known or unknown environments and requiring autonomous execution of tasks, the AGV must have sufficient security guarantees, using ultrasonic sensors to sense the external environment, analyze the external conditions, and then understand the environment in an appropriate way. Autonomous AGVs in complex or unconventional environments should further improve their autonomous judgment ability and rely on their own pattern recognition and obstacle recognition to achieve normal work. It is of great significance to the intelligentization of AGV.

Obstacle avoidance means that when the mobile robot senses that there are static or dynamic obstacles on its planned route during walking, it updates the path in real time according to a certain algorithm, bypasses the obstacles, and finally reaches the target point.

Whether it is for navigation planning or obstacle avoidance, sensing the surrounding environment information is the first step. In terms of obstacle avoidance, AGV industry safety is the primary consideration. AGV anti-collision obstacle avoidance can be divided into two types of designs: one is contacting design, which plays the role of anti-collision protection, commonly used contact sensors (such as piezoelectric sensors, mechanical switches) Etc.) Installed on the bottom of the car body to detect peripheral non-contact sensors (infrared, ultrasonic, laser, etc.) to detect dead angles and play a role in buffer protection; the second is the non-contact design, which plays a role in avoiding obstacles, commonly used non-contact sensor installation It is used to avoid obstacles when the vehicle is moving forward or backward when the vehicle body is slightly higher in front and back. At present, there are various ultrasonic sensors used for obstacle avoidance, each with different principles and characteristics. Let us take a closer look at the role of ultrasonic sensors in AGV obstacle avoidance.

At present, the recognition of obstacles in a large area is a common task of ultrasonic transducer distance sensors in mobile applications. Both objects and people can be identified, so actions such as parking or bypassing obstacles are taken to ensure the safety of equipment and personnel. At the same time, the ultrasonic sensor can measure the distance in real time and continuously monitor the proximity process, so it is widely used in AGV. In the anti-collision application, the principle of ultrasonic sensor anti-collision is to use the characteristics of ultrasonic waves that can reflect when encountering obstacles. According to the round-trip time of ultrasonic transmission and reception and the speed of sound, the distance to the obstacle is detected to prevent collision facing with the obstacle. Because the beam emitted by the ultrasonic wave is emitted in a certain range of space, the ultrasonic anti-collision makes up for the drawback that the laser anti-collision only has horizontal anti-collision, making the laser trackless navigation forklift anti-collision more comprehensive and safe. Because the speed of ultrasonic waves in the air is related to temperature and humidity, in more accurate measurements,which changes in temperature and humidity and other factors need to be taken into account.

In the process of practical application, AGV anti-collision and obstacle avoidance can use the  ultrasonic obstacle avoidance sensor-MB1043, which is a high-resolution (1mm), high-precision, low-power ultrasonic transducer sensor. The sensor function parameter setting and debugging can be easily achieved on the sensor, and the personalized adjustment of the ultrasonic sensor can be realized simply and clearly. It is designed not only to deal with interference noise, but also has the ability to resist noise interference. And for the targets of different sizes, and the varying supply voltage, sensitivity compensation is done. In addition, it also has standard internal temperature compensation, which makes the measuring distance data more accurate. Used in indoor environments, it is a very good low-cost solution!