Patent ID: 8380375
Filing Date: 2013-02-19
Classification: G01C

Abstract:
1. A metrology device comprising: an inertial navigation system (INS) having one or more gyroscopes to detect angular velocity and one or more accelerometers to detect linear velocity and adapted to be transported by an underwater robotic apparatus or diver, and outputting position and orientation data; an aiding device to record image data, and being configured to output distance and orientation data between the aiding device and the INS; a controller having one or more processors and non-transitory memory, the controller receiving and storing in the non-transitory memory the position and orientation data from the INS and the distance and orientation data from the aiding device together with time tag data indicating when the data was output from the INS before storage and when the data was output from the aiding device before storage; an interface to connect to a control center, the interface outputting the INS data and the aiding device data from the non-transitory memory when such output is requested by the control center either in near real time or after a survey; a computer defining a control center computer, the control center computer having a processor and non-transitory memory, the memory having computer readable instructions stored therein that when executed cause the control center to execute the instructions of: measuring, responsive to collecting first subsea object data from the controller, the first subsea data including data from the INS and aiding device including first object position, range and orientation data and image data; second subsea object data from the controller, the second subsea data including data from the INS and aiding device including second object position, range and orientation data and image data; and navigated first subsea object data from the controller, the navigated first subsea object data including data from the INS and aiding device including navigated first object position, range and orientation data and image data, a difference in the 3D position of the navigated first object position and the first object position; calculating a drift correction for the INS responsive to a difference between the first subsea object position and the navigated first subsea object position; measuring a target position responsive to collecting target object data from the controller, the target object data including data from the INS and aiding device including target position, range and orientation data, image data, and a distance between the target position and the first object position to generate a measured position of the target; and correcting the measured position of the target responsive to calculated drift.