There are many types of sensors on the market, and we will analyze them one by one. Since we determined to use Arduino as the control platform, we first filtered out the sensors that did not match it. Among the remaining sensors, we conducted related studies. During the research, we noticed an interesting article about distance measurement using Bluetooth sensors. Compared with traditional sensors, Bluetooth can not only meet our distance measurement needs but also provide additional communication features, which is greatly convenient. Our control of robots. For this reason, we also asked Tony for advice on this issue. Under his guidance, we decided to try this idea. In addition, we also selected an ultrasonic sensor as an alternative from many traditional sensors.