Patent ID: 8308107

Claim:
A cargo loading system installed in a cargo compartment of an aircraft, the cargo loading system comprising: a plurality of power drive units (PDUs), each of the PDUs comprising a light detector coupled to a PDU processor and configured to receive and process an incoming light signal; at least one main control panel (MCP) mounted on the aircraft; a controller connected by a wired network to the plurality of PDUs and also to the main control panel; and at least one wireless remote control handset configured to selectively emit a coded light signal; wherein: each PDU processor is programmed to: determine whether a coded light signal received at the light detector comprises a valid command signal from the handset to be provided to the controller; and provide an appropriate first command information signal to the controller, if the received coded light signal is determined to be a valid command signal from the handset; the controller is programmed to: obtain the first command information signal provided by the PDU; determine which, if any, of said plurality of PDUs should be activated, in response to the first command information signal; and send a first PDU control signal to activate only those PDUs that the controller has determined should be activated in response to the first command information signal; and in addition to determining whether a coded light signal received at the light detector, each PDU is configured to detect whether an Unit Load Device (ULD) is overhead, based on (a) light reflected from an underside of an ULD, and (b) measurement of ambient light.