Difference between revisions of "Creating PID Tuning Graphs"
From wikidb
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motors and robot speed. It is used to help calibrate PID parameters. I didn't know how to configure | motors and robot speed. It is used to help calibrate PID parameters. I didn't know how to configure | ||
rqt_plot to display snapshots. | rqt_plot to display snapshots. | ||
| + | |||
| + | = Message Additions to the Motor Controller = | ||
| + | |||
| + | A "wheels" message of type Float64MultiArray is published in the setMotorPower function. It has | ||
| + | five elements. | ||
| + | |||
| + | * data[0]: time is seconds since the motor controller was started. | ||
| + | * data[1]: wheel 0 speed in m/sec | ||
| + | * data[2]: percent of full power applied to wheel 0 | ||
| + | * data[3]: wheel 1 speed | ||
| + | * data[4]: wheel 1 power | ||
| + | |||
| + | |||
| + | |||
| + | ros::Publisher wheel_pub_; | ||
| + | |||
| + | wheel_pub_ = n.advertise<std_msgs::Float64MultiArray>("wheels", 100); | ||
| + | |||
| + | std_msgs::Float64MultiArray wheel_data; | ||
| + | wheel_data.data.clear(); | ||
| + | ros::Time odom_time(odom_.header.stamp.sec, odom_.header.stamp.nsec); | ||
| + | ros::Duration elapsed_time = odom_time - beginning_time_; | ||
| + | wheel_data.data.push_back(elapsed_time.toSec()); | ||
| + | wheel_data.data.push_back(wheel0_speed); | ||
| + | wheel_data.data.push_back(power_wheel0_); | ||
| + | wheel_data.data.push_back(wheel1_speed); | ||
| + | wheel_data.data.push_back(power_wheel1_); | ||
| + | wheel_pub_.publish(wheel_data); | ||
| + | |||
= Plot termination Criteria = | = Plot termination Criteria = | ||
Revision as of 13:09, 22 September 2017
Overview
This page documents a Python program designed to graph the first few seconds of power applied to the motors and robot speed. It is used to help calibrate PID parameters. I didn't know how to configure rqt_plot to display snapshots.
Message Additions to the Motor Controller
A "wheels" message of type Float64MultiArray is published in the setMotorPower function. It has five elements.
- data[0]: time is seconds since the motor controller was started.
- data[1]: wheel 0 speed in m/sec
- data[2]: percent of full power applied to wheel 0
- data[3]: wheel 1 speed
- data[4]: wheel 1 power
ros::Publisher wheel_pub_;
wheel_pub_ = n.advertise<std_msgs::Float64MultiArray>("wheels", 100);
std_msgs::Float64MultiArray wheel_data;
wheel_data.data.clear();
ros::Time odom_time(odom_.header.stamp.sec, odom_.header.stamp.nsec);
ros::Duration elapsed_time = odom_time - beginning_time_;
wheel_data.data.push_back(elapsed_time.toSec());
wheel_data.data.push_back(wheel0_speed);
wheel_data.data.push_back(power_wheel0_);
wheel_data.data.push_back(wheel1_speed);
wheel_data.data.push_back(power_wheel1_);
wheel_pub_.publish(wheel_data);
Plot termination Criteria
There are two termination criteria for termination 1) cnt-c and 2) time. After one of the criteria is met, the graph is drawn.
