US Patent 10001776 Unmanned aerial vehicle flight control system

An onboard system for controlling flight of an unmanned aerial vehicle. The system comprises: a flight management system configured for controlling flight of the unmanned aerial vehicle; a mission control module configured to send commands to the flight management system for guiding the unmanned aerial vehicle to perform a mission; a safety module configured to communicate commands to the flight management system for guiding the unmanned aerial vehicle to fly in a safe mode; a communication control component which is switchable between a mission state in which the flight management system receives commands from the mission control module and a safety state in which the flight management system receives commands from the safety module; and a monitor module configured to determine whether a trigger condition warranting a change in mode is present or not and to cause the communication control component to switch from the mission state to the safety state when the trigger condition is present.