PreArm: VisOdom: roll/pitch diff t265

ArduCopter Copter 4.1
1

Hi all,

I’am working on copter 6 motors build with an orange Cube, I used compute module and t265 camera, so when I powerded up my copter and connect with ardupilot, if I go to Mavlink inspector I have a return from my t265, but I have a prearm error : PreArm: VisOdom: roll/pitch diff, is anyone has an idea ? here is log

01/09/2021 10:24:26 : PreArm: VisOdom: roll/pitch diff 89.0 deg (>10)
01/09/2021 10:24:26 : PreArm: Throttle below Failsafe
01/09/2021 10:24:17 : 93 : T265: Tracking confidence: Medium
01/09/2021 10:24:16 : 93 : T265: Sending vision messages to FCU
01/09/2021 10:24:16 : 93 : T265: Camera connected.
01/09/2021 10:24:16 : 93 : T265: Connecting to camera…
01/09/2021 10:24:06 : 93 : T265: Tracking confidence: Medium
01/09/2021 10:24:05 : 93 : T265: Sending vision messages to FCU
01/09/2021 10:24:04 : 93 : T265: Camera connected.
01/09/2021 10:24:04 : 93 : T265: Connecting to camera…
01/09/2021 10:23:56 : PreArm: VisOdom: roll/pitch diff 89.0 deg (>10)
01/09/2021 10:23:56 : PreArm: Throttle below Failsafe
01/09/2021 10:23:52 : EKF3 IMU1 initial vel NED = -0.0,0.0,0.0 (m/s)
01/09/2021 10:23:52 : EKF3 IMU1 initial pos NED = 0.0,-0.0,0.0 (m)
01/09/2021 10:23:52 : EKF3 IMU1 is using external nav data
01/09/2021 10:23:52 : EKF3 IMU1 yaw aligned
01/09/2021 10:23:52 : EKF3 IMU0 initial vel NED = -0.0,0.0,0.0 (m/s)
01/09/2021 10:23:52 : EKF3 IMU0 initial pos NED = 0.0,-0.0,0.0 (m)
01/09/2021 10:23:52 : EKF3 IMU0 is using external nav data
01/09/2021 10:23:52 : EKF3 IMU0 yaw aligned
01/09/2021 10:23:52 : 93 : T265: Tracking confidence: Medium
01/09/2021 10:23:51 : 93 : T265: Sending vision messages to FCU
01/09/2021 10:23:50 : 93 : T265: Camera connected.
01/09/2021 10:23:50 : 93 : T265: Connecting to camera…
01/09/2021 10:23:44 : EKF3 IMU0 tilt alignment complete
01/09/2021 10:23:44 : EKF3 IMU1 tilt alignment complete
01/09/2021 10:23:43 : AHRS: EKF3 active
01/09/2021 10:23:43 : EKF3 IMU1 initialised
01/09/2021 10:23:43 : EKF3 IMU0 initialised
01/09/2021 10:23:42 : EKF3 IMU1 buffs IMU=6 OBS=2 OF=5 EN:5 dt=0.0120
01/09/2021 10:23:42 : EKF3 IMU0 buffs IMU=6 OBS=2 OF=5 EN:5 dt=0.0120
01/09/2021 10:23:41 : RCOut: PWM:1-12
01/09/2021 10:23:41 : AHRS: DCM active
01/09/2021 10:23:41 : ArduPilot Ready
01/09/2021 10:23:40 : Initialising ArduPilot
01/09/2021 10:23:40 : Frame: HEXA/PLUS
01/09/2021 10:23:40 : IMU2: fast sampling enabled 9.0kHz/2.3kHz
01/09/2021 10:23:40 : IMU1: fast sampling enabled 9.0kHz/2.3kHz
01/09/2021 10:23:40 : IMU0: fast sampling enabled 8.0kHz/2.0kHz
01/09/2021 10:23:40 : RCOut: Initialising
01/09/2021 10:23:40 : CubeOrange 0041002D 32305107 37353437
01/09/2021 10:23:40 : ChibiOS: 08877972
01/09/2021 10:23:40 : ArduCopter V4.1.0-beta7 (96936aa4)
01/09/2021 10:23:40 : Frame: HEXA/PLUS
01/09/2021 10:23:40 : IMU2: fast sampling enabled 9.0kHz/2.3kHz
01/09/2021 10:23:40 : IMU1: fast sampling enabled 9.0kHz/2.3kHz
01/09/2021 10:23:40 : IMU0: fast sampling enabled 8.0kHz/2.0kHz
01/09/2021 10:23:40 : RCOut: Initialising
01/09/2021 10:23:40 : CubeOrange 0041002D 32305107 37353437
01/09/2021 10:23:40 : ChibiOS: 08877972
01/09/2021 10:23:40 : ArduCopter V4.1.0-beta7 (96936aa4)
01/09/2021 10:23:40 : Barometer 2 calibration complete
01/09/2021 10:23:40 : Barometer 1 calibration complete
01/09/2021 10:23:40 : Frame: HEXA/PLUS
01/09/2021 10:23:40 : RCOut: Initialising
01/09/2021 10:23:40 : CubeOrange 0041002D 32305107 37353437
01/09/2021 10:23:40 : ChibiOS: 08877972
01/09/2021 10:23:40 : ArduCopter V4.1.0-beta7 (96936aa4)

2

I think the issue is that the VISO_ORIENT parameter does not match the physical orientation of the camera. So my guess is that the camera is facing down but VISO_ORIENT = 0 (forward).

By the way, in general we’ve found pointing the camera forward works best.

3

Yes, thanks for the solution my camera was oriented in mode 1 and not mode 0, thanks :smiley:

1 Like
4

Hi @rmackay9 ,
I am getting
[ERROR] [1645160834.871891329, 122.703000000]: FCU: PreArm: EKF compass variance
[ERROR] [1645160834.872099236, 122.703000000]: FCU: PreArm: VisOdom: yaw diff 89.5 deg (>10)
for the yaw. when I use different SLAM algorithm for odometry
I have set all the compass_use params to 0 and I haven’t disabled GPS_Type to test in flight transition

5

@shubham-shahh,

I don’t know the cause of the problem but I guess the external SLAM system is providing a yaw that doesn’t agree with the EKF’s yaw. If you use VISO_TYPE = 2 then you can manually re-align them with an auxiliary switch. The setup is listed on the AP setup page for the T265 (search for RC7_OPTION).

6

Okay, I’ll look into it