I’m building a robot by raspberry pi and arduino . I want it can charge automatic.I mean the robot can find the charger station by itself. But I don’t know what kind of sensor can make it true. Wifi and bluetooth not a good choose. So any ideas can make it true? Thank you!
This problem has been solved in automated commercial vacuum cleaners. However most articles on the subject simply state the cleaners find the infrared signal and follow it back to the charger. The details are missing. Regardless we can speculate.
Consider the charger station constantly emits a modulated infrared signal similar to that of a TV remote control. Consider the robot has an infrared receiver similar to that of a TV designed to detect the modulated infrared signal.
The problem, this will not work as the infrared receiver used in TVs and other entertainment equipment contains an Automated Gain Control (AGC) circuit which will compensate for weak signals making it impossible to tell which direction the signal is the strongest in. In other words, which direction the charger is in.
To solve this we need to use an infrared beam interrupter receiver. This is similar to the infrared receivers found in TV but with out the AGC circuit. They are designed to detect when an object is in the way.
Using an infrared beam interrupter receiver, we can rotate or oscillate the robot as it moves to find the direction in which the charger is in.
The more infrared beam interrupter receivers placed on the robot and pointed in slightly different directions, the less the robot has to rotate or oscillate to find the direction in which the charger is in.