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.