The flame sensor is a sensor specially used by the robot to search for the fire source. Of course, the flame sensor can also be used to detect the brightness of the light, but the sensor is particularly sensitive to flames. The flame sensor uses the characteristic of infrared light to be very sensitive to flames, uses a special infrared receiver tube to detect the flame, and then converts the brightness of the flame into high and low level signals and inputs them to the central processing unit. The central processing unit performs corresponding procedures according to the changes in the signal. handle.