Application of Ultrasonic Sensors and Lidar Sensors in Robot Avoiding Obstacles

As robots penetrate into people’s lives, such as factories, warehouses, hotels, shopping malls, restaurants and other environments, people pay more attention to the mobility of robots, and the market’s demand for intelligent equipment is increasing. So that obstacle avoidance has become an extremely critical and necessary function.

As robots penetrate into people’s lives, such as factories, warehouses, hotels, shopping malls, restaurants and other environments, people pay more attention to the mobility of robots, and the market’s demand for intelligent equipment is increasing. So that obstacle avoidance has become an extremely critical and necessary function.

Obstacle avoidance means that the mobile robot can effectively avoid obstacles according to certain methods when it detects static and dynamic objects that hinder its passage through the sensor according to the collected obstacle status information, and finally reaches the target point.

Application of Ultrasonic Sensors and Lidar Sensors in Robot Avoiding Obstacles

The necessary condition for obstacle avoidance and navigation is environmental perception. Obstacle avoidance in unknown or partially unknown environments requires sensors to obtain information about the surrounding environment, including the size, shape, and position of obstacles. Therefore, sensor technology is used in mobile robots to avoid obstacles. The barrier plays a very important role. Let me take a look at the related solutions of ultrasonic sensors and lidar sensors in robot obstacle avoidance.

At present, the common obstacle avoidance of robots on the market basically uses lidar. As an important sensor in the fields of automatic driving and robotics, lidar has always played the role of “eyes”, scanning the surrounding environment 360°, and constructing a high-precision map at the centimeter level. , To assist the follow-up obstacle avoidance navigation. Small Lidar Module-TFmini Plus is a small Lidar module, based on the TOF (Time of Flight) principle, mainly used to achieve stable, accurate, high-frequency distance measurement functions.Can be widely used in pedestrian detection, vehicle detection, altimeter, robot fall prevention and other fields

Application of Ultrasonic Sensors and Lidar Sensors in Robot Avoiding Obstacles

However, if you only use lidar as the only obstacle avoidance sensor, it will not be competent for obstacle avoidance in some complex places. The robot must be equipped with other sensors as a supplement, such as ultrasonic sensors. Its cost is very low. It is simple and can recognize transparent objects. The disadvantage is that the detection distance is short and the three-dimensional contour recognition accuracy is not good. Therefore, it is not good to recognize objects with complex contours such as table legs, but it can recognize objects such as glass and mirrors.

For example, MaxBotix Ultrasonic Human Body Detection Sensor-MB1004 is a proximity sensor with high and low level alarm signal output. The measurable range can reach 213cm, which is suitable for pedestrian detection, parking detection, etc. When a pedestrian enters the detection range, MB1004 will output an alarm signal from low level to high level. At the same time, it also has the function of outputting the specific distance of the target, and outputting the distance data through RS232. MB1004 is a very low-cost ultrasonic sensor for human detection. At the same time, it is also the best solution in the fields of proximity detection, pedestrian detection, booth/kiosk, robot automatic navigation, autonomous navigation, multi-sensor array, short-range detection and other fields.

The difference between ultrasonic sensors and lidar sensors

At present, the most common combination is to use lidar, depth camera and ultrasonic sensors for fusion obstacle avoidance navigation:

Application of Ultrasonic Sensors and Lidar Sensors in Robot Avoiding Obstacles

But, is it true that the more sensors installed on a robot product, the more effective it is to detect and avoid obstacles?

In theory, the more types and numbers of sensors installed on the robot, the more effectively the navigation and positioning system can detect risks and obstacles in the environment. But in reality, additional sensors are not the better. In addition to cost factors, unreasonable sensor combinations may cause mutual interference. In addition, there are differences between the error and noise models of each sensor. For example, the ranging accuracy of ultrasonic sensors and the azimuth accuracy of detecting obstacles are far lower than that of lidar.

Ultrasonic sensors have been widely used in mobile robot perception systems due to their high cost performance and simple hardware implementation. However, ultrasonic sensors also have certain limitations, mainly due to the large beam angle, poor directivity, and instability of distance measurement (under non-vertical reflection). Therefore, multiple ultrasonic sensors or other sensors are often used to compensate.

The Links:   FF450R12ME3 FF600R12KL4C IGBT-SUPPLIER