| ROS Resources: Documentation | Support | Discussion Forum | Index | Service Status | ros @ Robotics Stack Exchange |
Hi,
I have a hall effect sensor on one of my robot wheels (4 wheels in total). I use it to calculate the linear velocity for geometry_msgs/Twist message. How does one calculate angular velocity from just odometry? Are hall sensors even good enough, seeing as everyone else use wheel encoders?
You probably have differential kinematics? Am I right? Angular velocity would than be calculated from a speed difference between left and right wheels and distance between them. An example for this you can find in neo_driver package. See function execForwKin. For theory make some Internet search on differential kinematics. There are plenty of presentations from university courses.
EDIT: After clarifying the kinematics which is skid-steering one should look at diff_drive_controller which also enables skid-stearing. For start see this file.
@Hypomania: you can probably take a look at easymov/ackermann_controller (and the related packages). That could probably save you quite some time and effort. See also wiki/Ackermann Group.
@gvdhoorn, okay, I did more research, my RC car is a 4 wheel drive car with a center transfer box and center steer. There is no Ackermann geometry on it, my colleague said it "relies on torque bias and backlash from the drive system" to improve steering efficiency. It can do a perfect circle.
Asked: 2018-07-25 02:44:51 -0600
Seen: 1,739 times
Last updated: Jul 25 '18
ROS Answers is licensed under Creative Commons Attribution 3.0 Content on this site is licensed under a Creative Commons Attribution Share Alike 3.0 license.
