Tracking a VuMark with a servo mounted camera

Hi,

I'm working on a robotics project where I'm trying to mount a rotating servo-mounted camera on a robot. The camera is supposed to rotate in order to keep a VuMark in its field of view, so the robot can navigate using the VuMark.

However, I've run into several problems: (Note that I'm pretty new to using Vuforia for position tracking)

-When the robot is moving too quickly, even though the VuMark is in the camera's field of view, sometimes the camera will lock onto something else (somebody's shirt, a random wall in the background, a table, etc) apparently detecting that it's a VuMark. Note that I'm only trying to track one object at a time.

-The camera apparently needs to be held almost perfectly still in order to reacquire the VuMark once it loses track. If the robot is moving or the servo is rotating at all, the camera can't lock on.

-I've gotten telemetry data from the robot that implies that the robot is constantly losing and reacquiring the VuMark. (Keeps switching between "Visible" and "Not Visible"). A maybe-related issue is that the data are noisy even when the camera is still.

-I'm using the translation data from the VuMark to determine robot position so I can rotate the camera. However, sometimes the translation data is wrong - for example, the robot might be 1000mm away and it will only read 200mm. This happens in several cases, but more often when the VuMark is closer to the edge of the field of view. This isn't a processing error, but an error in the raw data returned from Vuforia.

-Sometimes, if the VuMark is far away and the robot moves closer, it'll focus on the edge of the VuMark rather than the center. This might be related to the previous issue - it's also based on incorrect feedback from Vuforia.

Any suggestions?

Thanks a lot.