Calibration system for a head-mounted display tracking system

A calibration system comprising:

• a first planar grid comprising a first plurality of fiducial markers, the first planar grid positioned at a first angle to an alignment axis;
• a second planar grid comprising a second plurality of fiducial markers, the second planar grid positioned at a second angle to the alignment axis and a side of the first planar grid and a side of the second planar grid are adjacent to each other;
• a third planar grid comprising a third plurality of fiducial markers, the third planar grid positioned above the first planar grid and the second planar grid and centered about the alignment axis, a side of the third planar grid adjacent to a portion of the first planar grid and a portion of the second planar grid;
• a movable platform configured to couple a head-mounted display (HMD), the platform configured to move the HMD positioned before the planar grids as a plurality of cameras on the HMD captures images of the planar grids, the captured images including at least a portion of one of the planar grids with fiducial markers;
• and
• a calibration controller configured to control a motion sequence of the movable platform, the calibration controller further configured to determine calibration information for each of the cameras on the HMD and calibration information for an inertial measurement unit (IMU) within the HMD, the calibration information based in part on a parameterized model of the motion sequence of the HMD coupled to the movable platform as the plurality of cameras on the HMD captures images of the planar grids.