Abstract: A precision landing system is described for an unmanned aerial vehicle (UAV). The system may include one or more anchors configured for placement in proximity to a landing zone, a tag configured for securement to the UAV where the tag wirelessly communicates with at least three or more of the anchors. A controller may be configured to fly the UAV towards a centerline axis defined through a first airspace zone at a first altitude above the landing zone while descending towards the first altitude and then fly the UAV towards the centerline axis defined through a second airspace zone at a second altitude which is below the first altitude while descending towards the second altitude, and finally to fly the UAV towards the centerline axis defined through a third airspace zone at a third altitude which is below the second altitude while descending towards the landing zone.

Abstract: A precision landing system is described for an unmanned aerial vehicle (UAV). The system may include one or more anchors configured for placement in proximity to a landing zone, a tag configured for securement to the UAV where the tag wirelessly communicates with at least three or more of the anchors. A controller may be configured to fly the UAV towards a centerline axis defined through a first airspace zone at a first altitude above the landing zone while descending towards the first altitude and then fly the UAV towards the centerline axis defined through a second airspace zone at a second altitude which is below the first altitude while descending towards the second altitude, and finally to fly the UAV towards the centerline axis defined through a third airspace zone at a third altitude which is below the second altitude while descending towards the landing zone.

Abstract: An automated alert system using unmanned aerial vehicles is described where the system is configured to monitor a selected area via one or more sensors configured to monitor the selected area for an anomaly. A processor in communication with the one or more sensors may be programmed to create or alter a flight path of an unmanned aerial vehicle upon receiving an alert from the one or more sensors for investigating or verifying the anomaly.

Abstract: An automated alert system using unmanned aerial vehicles is described where the system is configured to monitor a selected area via one or more sensors configured to monitor the selected area for an anomaly. A processor in communication with the one or more sensors may be programmed to create or alter a flight path of an unmanned aerial vehicle upon receiving an alert from the one or more sensors for investigating or verifying the anomaly.

Abstract: A precision landing system is described for an unmanned aerial vehicle (UAV). The system may include one or more anchors configured for placement in proximity to a landing zone, a tag configured for securement to the UAV where the tag wirelessly communicates with at least three or more of the anchors. A controller may be configured to fly the UAV towards a centerline axis defined through a first airspace zone at a first altitude above the landing zone while descending towards the first altitude and then fly the UAV towards the centerline axis defined through a second airspace zone at a second altitude which is below the first altitude while descending towards the second altitude, and finally to fly the UAV towards the centerline axis defined through a third airspace zone at a third altitude which is below the second altitude while descending towards the landing zone.

Abstract: An automated alert system using unmanned aerial vehicles is described where the system is configured to monitor a selected area via one or more sensors configured to monitor the selected area for an anomaly. A processor in communication with the one or more sensors may be programmed to create or alter a flight path of an unmanned aerial vehicle upon receiving an alert from the one or more sensors for investigating or verifying the anomaly.

Abstract: This invention provides a railway wagon suspension unit comprising a frame mounted over a saddle accommodating an axle journal housing. The saddle can rock laterally relative to the journal housing. Suspension means are disposed between the frame and the saddle including load springs for vertical support, and a friction wedge block is mounted on the saddle and firmly biassed against the axle journal housing to provide substantially constant frictional forces against lateral motion between the saddle and the housing independently of vertical movement or loading of the frame. In this manner lateral restraints imposed on wheel set oscillations during service are not load sensitive as has been the case with some wedge-pot dampers and other suspensions hitherto.