SITL: name fields when assembling vision_position_delta message

[peterbarker]

No description provided.

[rmackay9]

This is a SITL only change so it should be safe but it's been tested of course?

[peterbarker]

This is a SITL only change so it should be safe but it's been tested of course?

Enough to make sure messages come out, and that the EKF doesn't go insane instantly.

2024-03-07 13:51:29.85: VISION_POSITION_DELTA {time_usec : 5449586222, time_delta_usec : 20825, angle_delta : [0.00013999303337186575, 9.363423305330798e-05, 7.6433989306679e-06], position_delta : [0.0003720443637575954, -0.0003695455379784107, -0.02360556088387966], confidence : 0.0}
2024-03-07 13:51:29.96: VISION_POSITION_DELTA {time_usec : 5449741993, time_delta_usec : 20825, angle_delta : [5.450910248328e-05, 6.04833330726251e-05, 9.113708074437454e-06], position_delta : [0.00022753964003641158, -0.0002213119005318731, -0.023552190512418747], confidence : 0.0}
2024-03-07 13:51:29.96: VISION_POSITION_DELTA {time_usec : 5449721168, time_delta_usec : 20825, angle_delta : [5.7158871641149744e-05, 6.341454718494788e-05, 9.501302884018514e-06], position_delta : [0.00024516062694601715, -0.00023919428349472582, -0.023557515814900398], confidence : 0.0}