Crane jib attitude and heading reference system and method

A crane jib attitude and heading reference system, comprising:

• a plurality of crane jib angular velocity sensors, each crane jib angular velocity sensor configured to sense crane jib angular velocity and supply angular velocity signals representative thereof;
• a plurality of specific force sensors configured to sense specific forces acting on the crane jib and supply specific force sensor signals representative thereof;
• an inclinometer configured to sense crane jib roll angle and crane jib pitch angle and supply inclinometer signals representative thereof;
• a plurality of magnetometers, each magnetometer configured to sense local magnetic field at least proximate the crane jib and supply magnetometer signals representative thereof;
• and
• a processor coupled to receive the angular velocity signals, the specific force sensor signals, the inclinometer signals, and the magnetometer signals and configured, in response thereto, to:
• compute crane jib translational velocity from the sensed crane jib angular velocities and the sensed specific forces;
• compute crane jib acceleration using the computed crane jib translational velocity and the sensed crane jib angular velocities;
• use the computed crane jib acceleration to remove crane jib acceleration components from the sensed crane jib roll angle and the sensed crane jib pitch angle, and to thereby supply corrected crane jib roll angle measurements and corrected crane jib pitch angle measurements;
• apply calibration parameters to the sensed local magnetic fields, to thereby supply calibrated magnetic field measurements;
• compute crane jib heading angle from the calibrated magnetic field measurements;
• and
• using the corrected crane jib roll angle measurements, the corrected crane jib pitch angle measurements, and the computed crane jib heading angle, to estimate the attitude and heading angle of the crane jib.

A crane jib attitude and heading reference system, comprising:

• a plurality of crane jib angular velocity sensors, each crane jib angular velocity sensor configured to sense crane jib angular velocity and supply angular velocity signals representative thereof;
• an inclinometer configured to sense crane jib roll angle and crane jib pitch angle and supply inclinometer signals representative thereof;
• a plurality of accelerometers, each accelerometer configured to sense forces acting on a proof mass and supply specific force sensor signals representative thereof;
• a plurality of magnetometers, each magnetometer configured to sense local magnetic field at least proximate the crane jib and supply magnetometer signals representative thereof;
• a display device;
• and
• a processor coupled to the display device and further coupled to receive the angular velocity signals, the inclinometer signals, the specific force signals, and the magnetometer signals, the processor configured, upon receipt of the angular velocity signals, the inclinometer signals, specific force signals, and the magnetometer signals, to:
• compute corrected accelerometer measurements using the sensed forces acting on the proof mass, gravity, and predictions of accelerometer bias;
• compute corrected angular velocity measurements using the sensed angular velocity and predictions of angular velocity sensor bias;
• compute estimates of crane jib translational velocity using the corrected angular velocity measurements and compensated accelerometer measurements;
• compute corrected crane jib roll and pitch angles from the inclinometer signals and the estimates of crane jib translational velocity;
• compute crane jib heading angle from the magnetometer signals;
• implement a first filter that receives the computed estimates of crane jib velocity, computes predictions of crane jib velocity, and computes the predictions of accelerometer bias;
• implement a second filter that receives the computations of corrected crane jib roll and pitch angles and the computations of crane jib heading angle, computes the predictions of angular velocity sensor bias, and determines crane jib attitude and heading angle;
• and
• supply image rendering display commands to the display device that cause the display device to render the crane jib attitude and heading angle thereon.