Computed Twist from Odom is not Consistent with Publish cmd_vel

[David9696]

Hi,

When I tested this package, I realized that the computed twist from odom topic is not consistent with the my published cmd_vel.

Publish topic:

rostopic pub -r 10 /cmd_vel geometry_msgs/Twist "linear:
x: 0.1
y: 0.0
z: 0.0
angular:
x: 0.0
y: 0.0
z: 0.0"

subscribe topic: odom

header:
seq: 850
stamp:
secs: 1553266756
nsecs: 109243720
frame_id: "odom"
child_frame_id: "base_link"
pose:
pose:
position:
x: 1.21779906964
y: 0.000363451152541
z: 0.0
orientation:
x: 0.0
y: 0.0
z: -0.000137760372765
w: 0.999999990511
covariance: [0.01, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.01, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.01]
twist:
twist:
linear:
x: 0.00504117950165
y: -3.38179068928e-06
z: 0.0
angular:
x: 0.0
y: 0.0
z: 0.00039531237527
covariance: [0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0]

Could it be the sampling rate issue?

[csvance]

Hi, what do you have steps_per_meter set to, and what does /motor_enc publish during this? motor_enc will give you the raw encoder counts from the roboclaw, from which the twist is calculated. Could you also post your launch files for the nodes?