Application of Ultrasonic Sensors and LiDAR Sensors in Robot Avoiding Obstacles

As robots enter 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 senses static and dynamic objects that hinder its passage through sensors according to the collected obstacle status information, and finally reaches the target point.

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.

At present, the common obstacle avoidance of robots on the market uses LiDAR. As an important sensor in the fields of autonomous driving and robotics, LiDAR has always played the role of “eyes”, scanning the surrounding environment 360°, and constructing a high-precision map of centimeters. , As an aid for subsequent obstacle avoidance navigation.

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 identify 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.

The difference between ultrasonic sensors and LiDAR sensors

At present, the most common combination is to use LiDAR, depth camera, and ultrasonic sensors to perform fusion obstacle avoidance navigation.

However, 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 in the error and noise model 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.