Odomentry not properly working with ackermann steering

[luj97]

Describe the bug
The odometry is fine when the vehicle moves foward/backwards, but is wrong when steering. My issue seems similar to this one #933

To Reproduce
This is my yaml file:

`controller_manager:
ros__parameters:
update_rate: 30
use_sim_time: true

  ackermann_steering_controller:
    type: ackermann_steering_controller/AckermannSteeringController
  
  forks_controller:
    type: position_controllers/JointGroupPositionController

  joint_broad:
    type: joint_state_broadcaster/JointStateBroadcaster

ackermann_steering_controller:
ros__parameters:
publish_rate: 50.0

  rear_wheels_names: [left_wheel_joint, right_wheel_joint]

  front_wheels_names: [left_steering_joint, right_steering_joint]

  front_wheel_track: 0.990
  rear_wheel_track: 1.042
  wheelbase: 1.645
  front_wheels_radius: 0.220
  rear_wheels_radius: 0.285

  front_steering: true
  use_stamped_vel: false

  max_steering_angle: 0.45

forks_controller:
ros__parameters:
joints:
- forks_joint`

Screenshots
Here is a video that shows what happens. The odometry seems fine when doing straight movements, but not when steering.

Screencast.from.20-12-23.14.48.27.webm

Is there a solution?

[kartman88]

I'm trying to reproduce your error but when I launch everything I don't have odom fixed frame in Rviz. But the odometry topic is published. Is there some param to set to enable odometry in the controller settings?

[luj97]

This: #762 (comment) solved the issue of the odometry frame for me

[ninoweg]

I'm experiencing the same issues as @luj97 and the issues reported in #933. Odometry is remapped correctly but definitely wrong when steering. Could somebody tell if this is a bug in the code or else provide a working example for ackermann steering?

[messageid]

I've the same odometry issue with ackermann kinematics: linear motion is ok, wrong with steering.

I've (probably) found the bug. In the method:
bool SteeringOdometry::update_from_position( const double traction_right_wheel_pos, const double traction_left_wheel_pos, const double right_steer_pos, const double left_steer_pos, const double dt)

The line 139:
return update_odometry(linear_velocity, angular, dt);

Should be:
return update_odometry(linear_velocity, angular * dt , dt);

The same issue is present in the other update_from_position() methods.
As I understand angular is a velocity and in the integration function it is used without the dt factor

[MCFurry]

We noticed similar issues with the outputted odometry, I believe this is the correct fix for all:
#1118