Energy autonomous wireless filling detector

A wireless energy autonomous filling yarn detector for an air jet weaving machine has been designed, built and tested on an opto-mechanical mock-up of the weaving loom. The energy autonomous operation of the detector is sustained by a commercially available vibrational energy harvester which can deliver several mW to the sensor node. The sensor node relies on the combination of three main blocks: an optical detector, a microcontroller and a wireless transceiver. The first block is responsible for the detection of the filling yarn, the wireless transceiver for the communication with the base station integrated with the weaving machine controller, while the microcontroller supervises and regulates the overall system operation. The node has been designed and assembled selecting commercial off-the-shelf components among the most power efficient available on the market. In order to further limit the power consumption, the trigger to wake up the sensor and start a measurement relies on the same optical link used for the filling yarn detection. After a yarn detection, the system is configured to communicate the event to the base station and go back to sleep. It has been demonstrated that at a machine speed of 1500 rpm, the vibrational energy harvester can harvest a power of 11 mW while the sensor node board only consumes 2.5 mW on the average.