Difference between revisions of "PID Move"
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= Indigo = | = Indigo = | ||
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<pre> | <pre> | ||
eepp@tabor:~$ rostopic echo /pid_values | eepp@tabor:~$ rostopic echo /pid_values | ||
| − | + | x: 179.0 | |
| − | + | y: 268.794308389 | |
| − | + | z: 2.68794308389 | |
| − | + | --- | |
| − | + | x: 177.5 | |
| − | + | y: 266.532931749 | |
| − | + | z: 2.66532931749 | |
| − | + | --- | |
| − | + | x: 178.5 | |
| − | + | y: 268.061374099 | |
| − | + | z: 2.68061374099 | |
</pre> | </pre> | ||
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[[Image:PidPlot.jpg]] | [[Image:PidPlot.jpg]] | ||
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| + | = General = | ||
== References == | == References == | ||
| + | |||
| + | == Links == | ||
| + | * [http://wiki.ros.org/ros_control ros_control] | ||
| + | * [http://wiki.ros.org/control_toolbox control_toolbox] | ||
* PID Package [http://http://mediabox.grasp.upenn.edu/roswiki/doc/electric/api/control_toolbox/html/classcontrol__toolbox_1_1Pid.html control_toolbox:Pid] | * PID Package [http://http://mediabox.grasp.upenn.edu/roswiki/doc/electric/api/control_toolbox/html/classcontrol__toolbox_1_1Pid.html control_toolbox:Pid] | ||
Revision as of 12:06, 8 November 2015
Contents
Indigo
Install
sudo apt-get install ros-indigo-ros-controllers
Source
Globals
The following globals are added.
#include "control_toolbox/pid.h"
ros::Publisher pid_pub; control_toolbox::Pid pid; ros::Time last_time;
Additions to main
The following was added to main to initialize PID.
pid.initPid(1.5, 1.0, 2.0, 0.3, -0.3); last_time = ros::Time::now();
The following was added to main to publish messages that rxplot can subscribe to.
pid_plot = nh.advertise<geometry_msgs::Point>
("/pid_values", 1000);
New trackCallback
void trackCallback (const geometry_msgs::Point::ConstPtr & track_msg)
{
ros::NodeHandle nh;
geometry_msgs::Twist move_msg;
geometry_msgs::Point pid_pub_msg;
ros::Time time = ros::Time::now();
double effort = 0;
// Set the turn - turn on the z axis
move_msg.linear.x = 0;
move_msg.linear.y = 0;
move_msg.linear.z = 0;
move_msg.angular.x = 0;
move_msg.angular.y = 0;
// PID update
effort = pid.updatePid(track_msg->x - MID_X, time - last_time);
move_msg.angular.z = -effort / SCALE * MAX_POWER;
if (move_msg.angular.z > MAX_POWER) move_msg.angular.z = MAX_POWER;
if (move_msg.angular.z < -MAX_POWER) move_msg.angular.z = -MAX_POWER;
// Execute turn
mover.publish(move_msg);
// debug output
pid_pub_msg.x = track_msg->x - MID_X;
pid_pub_msg.y = - effort;
pid_pub_msg.z = move_msg.angular.z;
pid_pub.publish(pid_pub_msg);
}
Listing
Move It PID listing move_it_pid.cpp
PID Values
Using rostopic:
eepp@tabor:~$ rostopic echo /pid_values x: 179.0 y: 268.794308389 z: 2.68794308389 --- x: 177.5 y: 266.532931749 z: 2.66532931749 --- x: 178.5 y: 268.061374099 z: 2.68061374099
Plot PID
This command:
rxplot /pid_values/x,/pid_values/y /pid_values/z
Results in the following plot
General
References
Links
- PID Package control_toolbox:Pid
- Tutorial CMU PID
Jade
Doing PID under Jade is abandoned for now. Briefly experimented with the installation instructions. Decided that working through the issues would be a distraction.
cd catkin_ws/src/ wstool init wstool merge https://raw.github.com/ros-controls/ros_control/indigo-devel/ros_control.rosinstall wstool update cd .. rosdep install --from-paths . --ignore-src --rosdistro jade -y ERROR: the following packages/stacks could not have their rosdep keys resolved
