Capacitive seat sensors for multiple occupancy detection using a low-cost setup

The Minibus public transportation sector and road safety remains a significant challenge in Africa. We propose a low cost system to monitor the taxi industry and encourage safe driving. A low cost capacitive proximity sensor for seat occupancy detection based on the loading mode capacitive sensing technique is designed. The capacitive sensor uses a single electrode to detect an occupant. We use ZigBee modules for a dynamic wireless system integration where sensors can be added or removed without modifications. A mathematical model of the capacitive sensor is developed and we determine the capacitance on the sensor´s electrode. The occupied capacitance is double the unoccupied capacitance. Our results show that the proposed capacitive sensor can distinguish clearly between an unoccupied and occupied seat.