Discussions

I am using very recent APM2.5 firmware 2.6.3 and Mission Planner 2.1.12 and want to know the correct units for the tlog graphs (as well as units for the TUNING plots and CSV Conversion files if different). Here is my analysis from a tlog running with APM in a car on a short one block drive with a valley in the middle of block followed by a turn around and return. Please help correct my assumptions - if someone has already done this, please point me at it. Another quick comment, the pitch and roll rate signals seem extremely noisy - the yaw is fine.I enclose the tlog for that run as well as a couple of short and simple tlogs where i tried to rotate in only one axis - ROLL and another for YAW - take a look at roll and rollspeed as well as yaw and yawspeed in the appropriately named tlogs.

Thanks much in advance

Dave

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These names are from the Mission Planner Log Graph
Units are what is shown from Mission Planner plots of tlog (NOT necessarily the units in a converted to CSV file or the units on the TUNING plots??)

GPS_RAW_INT
time_usec - time (sec) once GPS lock is available
*lat - *10 (i.e. 33.7 => 337 on plot)
*lon - /100 (i.e. -117 => -1.2 on plot)
*Alt - altitude in meters
Eph - what is this?
Epv - what is this?
*vel - forward groundspeed in centimeters/sec??? (i.e. 44 mph =>2000 on plot)
cog - what is this?

GLOBAL_POSITION
*lat - *10 (i.e. 33.7 => 337)
*lon - /100 (i.e. -117 => -1.2)
*alt - feet /2 ( 300 actual = 150)
*relative_alt - ? starts at zero at lockon - /2 (100 actual feet up from t0 = 50)
*vx - ?? speed in centimeters/sec along North axis ??
*vy - ?? speed in centimeters/sec along East axis ??
*vz - ?? speed in centimeters/sec along Down axis (down = +)??
*hdg - degrees / 10 ?

RC_CHANNELS_R
chan2_raw - counts (1000->2000)??

ATTITUDE
*roll  - degrees
*pitch - degrees
*yaw   - degrees (kept to +-180)
*rollspeed  - radians /sec (super noisy - better filtered version available?)
*pitchspeed - radians /sec (super noisy - better filtered version available?)
*yawspeed   - radians /sec  ( NOT noisy)

VFR_HUD
*airspeed - meters/sec ?? (i.e. 44 mph =>20 on plot)
*groundspeed - meters/sec?? (i.e. 44 mph =>20 on plot)
*alt - meters  (is this the baro corrected altitude?)
*climb - meters/sec??  (super noisy)
*heading -  degrees ?
throttle

WIND
wind direction - degrees?
wind speed - meters/sec ??

RAWIMU
time_usec - seconds
xacc - acceleration along x axis (forward) in meters/sec/sec ??
yacc - acceleration along y axis (lateral) in meters/sec/sec ??
zacc - 100 * g's (or maybe meters/sec/sec) in z direction ??
xgyro - rollspeed in radians/sec or degrees/sec?? (super noisy)
ygyro - pitchspeed in radians/sec or degrees/sec?? (super noisy)
zgyro - yawspeed in radians/sec or degrees/sec?? (not noisy)
xmag?
ymag
zmag

press_abs- mbars? (e.g. 1000)
press_diff- mbars? (e.g. 1000) from start - 0 at beginning
temperature ? (e.g.353) - deg celsius * 10
NOTE: Where is baro altitude corrected by GPS ?? (VFR HUD???)

2012-09-24 13-03-25.tlog

2012-09-28 11-29-10 - ROLL.tlog

2012-09-28 11-31-18 - YAW.tlog