Abstract: A sensor assembly for a fastener assembly comprising a nut and a bolt comprises a sensor unit mounted in a cavity in the nut of the fastener assembly having an internal opening in the internal thread of the nut. The sensor unit comprises an optical flow sensor arranged to capture an image of the external thread of the bolt through the internal opening and to sense relative movement of the external thread of the bolt.

Abstract: A sensor unit mountable on a rotatable element on a platform that is itself movable, and includes an orientation sensor arranged to take measurements that are dependent on the orientation of the sensor unit, a processor arranged to derive a rotational position signal representing the orientation of the rotatable element from the measurements, and a buffer arranged to buffer a series of recent measurements taken by the orientation sensor over a predetermined period of time. The processor derives the rotational position signal making a correction to compensate for the effect of the motion of the platform on the measurements on the basis of the overall series of measurements buffered in the buffer.

Abstract: There is provided a sensor unit for a fastener assembly, the sensor unit comprising a mounting arranged to rigidly attach the sensor unit to, or adjacent to, a fastener assembly; and a sensor, that is an optical flow sensor or an inductive sensor, configured to sense movement of the fastener assembly. The sensor unit may comprise a processor arranged to process the output of the sensor to detect loosening of the fastener assembly and to output a signal representing the status of the fastener assembly. The sensor unit may comprise a wireless communication unit arranged to communicate the signal.

Abstract: A wireless network comprises nodes, including routers having a tree-shaped communication topology and end devices, communicate in accordance a network protocol, wherein the routers transmit beacons in respective timeslots within a periodic beaconing interval, passively scan for messages, and, in response to receiving a message, transmit an acknowledgement thereof the received message. An end device that has a message that is pending transmission, passively scans for beacons transmitted from any router; and in response thereto, transmits the message, and passively scans for an acknowledgement, repeating those steps if no acknowledgement is received. This provides responsivity in an environment having rapidly changing propagation paths. To reduce power consumption, the end devices do not passively scan for beacons except when they have a message that is pending transmission, and also at predetermined times for reception of a downstream message.

Abstract: A sensor unit for a fingerboard latch assembly comprising a latch bracket and a latch rotatably mounted on the latch bracket comprises a sensor arranged to sense the orientation of the latch and a wireless, optical or other communication unit arranged to communicate the orientation of the latch sensed by the sensor. The sensor unit may be mountable on the latch and comprise an orientation sensor arranged to take measurements that are dependent on the orientation of the sensor unit, and a processor arranged to derive an orientation signal representing the orientation of the latch from the measurements, the communication unit being arranged to communicate the orientation signal. A monitoring system receives the sensed orientations from plural sensor units.

Abstract: A sensor assembly is provided for a fingerboard latch assembly that comprises: a latch bracket; bolts for mounting the latch bracket to a fingerboard; a latch; and a bracket pin rotatably supporting the latch on the latch bracket to allow rotation of the latch between an open position and a closed position. The sensor assembly has a mounting arrangement that mounts to the bolts, holding a closed-position proximity sensor probe facing downwardly for sensing proximity of a crank portion of the latch and/or the piston head in the closed position, and also holding an open-position proximity sensor probe facing forwardly for sensing proximity of an arm of the latch in the open position.

Abstract: A wireless network comprises nodes, including routers having a tree-shaped communication topology and end devices, communicate in accordance a network protocol, wherein the routers transmit beacons in respective timeslots within a periodic beaconing interval, passively scan for messages, and, in response to receiving a message, transmit an acknowledgement thereof the received message. An end device that has a message that is pending transmission, passively scans for beacons transmitted from any router; and in response thereto, transmits the message, and passively scans for an acknowledgement, repeating those steps if no acknowledgement is received. This provides responsivity in an environment having rapidly changing propagation paths. To reduce power consumption, the end devices do not passively scan for beacons except when they have a message that is pending transmission, and also at predetermined times for reception of a downstream message.

Abstract: A sensor unit for a fingerboard latch assembly comprising a latch bracket and a latch rotatably mounted on the latch bracket comprises a sensor arranged to sense the orientation of the latch and a wireless, optical or other communication unit arranged to communicate the orientation of the latch sensed by the sensor. The sensor unit may be mountable on the latch and comprise an orientation sensor arranged to take measurements that are dependent on the orientation of the sensor unit, and a processor arranged to derive an orientation signal representing the orientation of the latch from the measurements, the communication unit being arranged to communicate the orientation signal. A monitoring system receives the sensed orientations from plural sensor units.

Abstract: A sensor unit mountable on a rotatable element on a platform that is itself movable, and includes an orientation sensor arranged to take measurements that are dependent on the orientation of the sensor unit, a processor arranged to derive a rotational position signal representing the orientation of the rotatable element from the measurements, and a buffer arranged to buffer a series of recent measurements taken by the orientation sensor over a predetermined period of time. The processor derives the rotational position signal making a correction to compensate for the effect of the motion of the platform on the measurements on the basis of the overall series of measurements buffered in the buffer.

Abstract: A sensor assembly is provided for a fingerboard latch assembly that comprises: a latch bracket; bolts for mounting the latch bracket to a fingerboard; a latch; and a bracket pin rotatably supporting the latch on the latch bracket to allow rotation of the latch between an open position and a closed position. The sensor assembly has a mounting arrangement that mounts to the bolts, holding a closed-position proximity sensor probe facing downwardly for sensing proximity of a crank portion of the latch and/or the piston head in the closed position, and also holding an open-position proximity sensor probe facing forwardly for sensing proximity of an arm of the latch in the open position.

Abstract: A sensor unit for a fingerboard latch assembly comprising a latch bracket and a latch rotatably mounted on the latch bracket comprises a sensor arranged to sense the orientation of the latch and a wireless, optical or other communication unit arranged to communicate the orientation of the latch sensed by the sensor. The sensor unit may be mountable on the latch and comprise an orientation sensor arranged to take measurements that are dependent on the orientation of the sensor unit, and a processor arranged to derive an orientation signal representing the orientation of the latch from the measurements, the communication unit being arranged to communicate the orientation signal. A monitoring system receives the sensed orientations from plural sensor units.

Abstract: A sensor assembly is provided for a fingerboard latch assembly that comprises: a latch bracket; bolts for mounting the latch bracket to a fingerboard; a latch; and a bracket pin rotatably supporting the latch on the latch bracket to allow rotation of the latch between an open position and a closed position. The sensor assembly has a mounting arrangement that mounts to the bolts, holding a closed-position proximity sensor probe facing downwardly for sensing proximity of a crank portion of the latch and/or the piston head in the closed position, and also holding an open-position proximity sensor probe facing forwardly for sensing proximity of an arm of the latch in the open position.

Abstract: A sensor assembly is provided for a fingerboard latch assembly that comprises: a latch bracket; bolts for mounting the latch bracket to a fingerboard; a latch; and a bracket pin rotatably supporting the latch on the latch bracket to allow rotation of the latch between an open position and a closed position. The sensor assembly has a mounting arrangement that mounts to the bolts, holding a closed-position proximity sensor probe facing downwardly for sensing proximity of a crank portion of the latch and/or the piston head in the closed position, and also holding an open-position proximity sensor probe facing forwardly for sensing proximity of an arm of the latch in the open position.

Abstract: A sensor unit for a fingerboard latch assembly comprising a latch bracket and a latch rotatably mounted on the latch bracket comprises a sensor arranged to sense the orientation of the latch and a wireless, optical or other communication unit arranged to communicate the orientation of the latch sensed by the sensor. The sensor unit may be mountable on the latch and comprise an orientation sensor arranged to take measurements that are dependent on the orientation of the sensor unit, and a processor arranged to derive an orientation signal representing the orientation of the latch from the measurements, the communication unit being arranged to communicate the orientation signal. A monitoring system receives the sensed orientations from plural sensor units.

Abstract: A sensor assembly is provided for a fingerboard latch assembly that comprises: a latch bracket; bolts for mounting the latch bracket to a fingerboard; a latch; and a bracket pin rotatably supporting the latch on the latch bracket to allow rotation of the latch between an open position and a closed position. The sensor assembly has a mounting arrangement that mounts to the bolts, holding a closed-position proximity sensor probe facing downwardly for sensing proximity of a crank portion of the latch and/or the piston head in the closed position, and also holding an open-position proximity sensor probe facing forwardly for sensing proximity of an arm of the latch in the open position.

Abstract: A sensor unit for a fingerboard latch assembly comprising a latch bracket and a latch rotatably mounted on the latch bracket comprises a sensor arranged to sense the orientation of the latch and a wireless, optical or other communication unit arranged to communicate the orientation of the latch sensed by the sensor. The sensor unit may be mountable on the latch and comprise an orientation sensor arranged to take measurements that are dependent on the orientation of the sensor unit, and a processor arranged to derive an orientation signal representing the orientation of the latch from the measurements, the communication unit being arranged to communicate the orientation signal. A monitoring system receives the sensed orientations from plural sensor units.

Abstract: A sensor unit for a fingerboard latch assembly comprising a latch bracket and a latch rotatably mounted on the latch bracket comprises a sensor arranged to sense the orientation of the latch and a wireless, optical or other communication unit arranged to communicate the orientation of the latch sensed by the sensor. The sensor unit may be mountable on the latch and comprise an orientation sensor arranged to take measurements that are dependent on the orientation of the sensor unit, and a processor arranged to derive an orientation signal representing the orientation of the latch from the measurements, the communication unit being arranged to communicate the orientation signal. A monitoring system receives the sensed orientations from plural sensor units.

Abstract: A sensor assembly is provided for a fingerboard latch assembly that comprises: a latch bracket; bolts for mounting the latch bracket to a fingerboard; a latch; and a bracket pin rotatably supporting the latch on the latch bracket to allow rotation of the latch between an open position and a closed position. The sensor assembly has a mounting arrangement that mounts to the bolts, holding a closed-position proximity sensor probe facing downwardly for sensing proximity of a crank portion of the latch and/or the piston head in the closed position, and also holding an open-position proximity sensor probe facing forwardly for sensing proximity of an arm of the latch in the open position.

Abstract: A sensor assembly is provided for a fingerboard latch assembly that comprises: a latch bracket; bolts for mounting the latch bracket to a fingerboard; a latch; and a bracket pin rotatably supporting the latch on the latch bracket to allow rotation of the latch between an open position and a closed position. The sensor assembly has a mounting arrangement that mounts to the bolts, holding a closed-position proximity sensor probe facing downwardly for sensing proximity of a crank portion of the latch and/or the piston head in the closed position, and also holding an open-position proximity sensor probe facing forwardly for sensing proximity of an arm of the latch in the open position.

Abstract: A sensor assembly is provided for a fingerboard latch assembly that comprises: a latch bracket; bolts for mounting the latch bracket to a fingerboard; a latch; and a bracket pin rotatably supporting the latch on the latch bracket to allow rotation of the latch between an open position and a closed position. The sensor assembly has a mounting arrangement that mounts to the bolts, holding a closed-position proximity sensor probe facing downwardly for sensing proximity of a crank portion of the latch and/or the piston head in the closed position, and also holding an open-position proximity sensor probe facing forwardly for sensing proximity of an arm of the latch in the open position.