Charging

Basic principle:

About an induction loop, the robot finds the charging station where he can be charged again. In this case, as long as the induction loop traversed (clockwise) to the charging contacts of the robot detect a voltage (charging voltage). There, the robot stops.

Charger

The charger is in the cradle (or is connected to). The charger should accomplish the following things (in this case lithium-ion - Battery Lead is similar, but less critical): Load battery pack via the charging pins of the robot -Maximum Cutoff voltage / charge voltage compliance (charging voltage limit) -Maximalen Charging current compliance (charging current limit) If you are using an existing charging station, these things were implemented with high probability already there.

Robot

In the robot itself, the battery voltage is monitored (see diagram below). So it can be determined when the robot must go to the charging station. The robot and the voltage and the current during charging is controlled. So it can be determined whether the robot has reached the charger and when the battery is fully charged again. Ideally, the charging station also eat the loop transmitter:

charging station circuit:

Power supply => Charger 24V (+)----- Charging station charger pin(+)

               GND         (-)----- Charging station charger pin(-)
               Charger 24V (+)----- DC-DC converter 5V  => Perimeter sender Arduino Nano  
               Charger 24V (+)----- DC-DC converter 12V => Perimeter sender MC motor driver

robot charging circuit:

Charging station (+)---+------+-- relais ---- current sensor ----- battery (+)

                             |
                             ---- voltage sensing

Charging station (-)-- +------------------------------------------ battery (-)