Real-time Logging at 1000 Hz
Closed this issue · 5 comments
Hello, is there a minimal example showing the real-time logging to CSV at 1000 Hz? I have been struggling to do that for some time. I was thinking of using threads similar to the example https://github.com/frankaemika/libfranka/blob/master/examples/joint_impedance_control.cpp . I could not find any example demonstrating real-time logging (not error/exception logging). I tried a dummy example of generating random numbers and storing them with 1000 Hz and I think it is slow. I am not an expert in C++ so any help would be appreciated.
So the logToCSV function is usually used for error cases. This is why it is a bit harder to use for normal logging. I took the generate_joint_positions_example and modified it to log to a csv file:
// Copyright (c) 2017 Franka Emika GmbH
// Use of this source code is governed by the Apache-2.0 license, see LICENSE
#include <cmath>
#include <iostream>
#include <Poco/DateTimeFormatter.h>
#include <Poco/File.h>
#include <Poco/Path.h>
#include <franka/exception.h>
#include <franka/robot.h>
#include <fstream>
#include "examples_common.h"
/**
* @example generate_joint_position_motion.cpp
* An example showing how to generate a joint position motion.
*
* @warning Before executing this example, make sure there is enough space in front of the robot.
*/
void writeLogToFile(const std::vector<franka::Record>& log) {
if (log.empty()) {
return;
}
try {
Poco::Path temp_dir_path(Poco::Path::temp());
temp_dir_path.pushDirectory("libfranka-logs");
Poco::File temp_dir(temp_dir_path);
temp_dir.createDirectories();
std::string now_string =
Poco::DateTimeFormatter::format(Poco::Timestamp{}, "%Y-%m-%d-%h-%m-%S-%i");
std::string filename = std::string{"log-" + now_string + ".csv"};
Poco::File log_file(Poco::Path(temp_dir_path, filename));
if (!log_file.createFile()) {
std::cout << "Failed to write log file." << std::endl;
return;
}
std::ofstream log_stream(log_file.path().c_str());
log_stream << franka::logToCSV(log);
std::cout << "Log file written to: " << log_file.path() << std::endl;
} catch (...) {
std::cout << "Failed to write log file." << std::endl;
}
}
int main(int argc, char** argv) {
if (argc != 2) {
std::cerr << "Usage: " << argv[0] << " <robot-hostname>" << std::endl;
return -1;
}
try {
std::vector<franka::Record> records;
franka::Robot robot(argv[1]);
setDefaultBehavior(robot);
// First move the robot to a suitable joint configuration
std::array<double, 7> q_goal = {{0, -M_PI_4, 0, -3 * M_PI_4, 0, M_PI_2, M_PI_4}};
MotionGenerator motion_generator(0.5, q_goal);
std::cout << "WARNING: This example will move the robot! "
<< "Please make sure to have the user stop button at hand!" << std::endl
<< "Press Enter to continue..." << std::endl;
std::cin.ignore();
robot.control(motion_generator);
std::cout << "Finished moving to initial joint configuration." << std::endl;
// Set additional parameters always before the control loop, NEVER in the control loop!
// Set collision behavior.
robot.setCollisionBehavior(
{{20.0, 20.0, 18.0, 18.0, 16.0, 14.0, 12.0}}, {{20.0, 20.0, 18.0, 18.0, 16.0, 14.0, 12.0}},
{{20.0, 20.0, 18.0, 18.0, 16.0, 14.0, 12.0}}, {{20.0, 20.0, 18.0, 18.0, 16.0, 14.0, 12.0}},
{{20.0, 20.0, 20.0, 25.0, 25.0, 25.0}}, {{20.0, 20.0, 20.0, 25.0, 25.0, 25.0}},
{{20.0, 20.0, 20.0, 25.0, 25.0, 25.0}}, {{20.0, 20.0, 20.0, 25.0, 25.0, 25.0}});
std::array<double, 7> initial_position;
double time = 0.0;
robot.control([&initial_position, &time,&records](const franka::RobotState& robot_state,
franka::Duration period) -> franka::JointPositions {
franka::RobotCommand last_command;
last_command.joint_positions = robot_state.q_d;
franka::Record record{robot_state,last_command};
records.push_back(record);
time += period.toSec();
if (time == 0.0) {
initial_position = robot_state.q_d;
}
double delta_angle = M_PI / 8.0 * (1 - std::cos(M_PI / 2.5 * time));
franka::JointPositions output = {{initial_position[0], initial_position[1],
initial_position[2], initial_position[3] + delta_angle,
initial_position[4] + delta_angle, initial_position[5],
initial_position[6] + delta_angle}};
if (time >= 5.0) {
std::cout << std::endl << "Finished motion, shutting down example" << std::endl;
return franka::MotionFinished(output);
}
return output;
});
writeLogToFile(records);
} catch (const franka::Exception& e) {
std::cout << e.what() << std::endl;
return -1;
}
return 0;
}
you also have to link against Poco::Foundation by adding:
target_link_libraries(generate_joint_position_motion Poco::Foundation)
into the CMakeLists.txt of the examples
I hope this helps
Thank you very much! It helps a lot!
Hello, I wanted to store logs for a longer duration. The above method works fine for 10-15 seconds and then throws a communication constraint violation error consistently across different programs. It would be great if you can suggest a way to circumvent this.
the hacky way would be to reserve as much data for the vector as you need beforehand using
records.reserve(number_of_elements);
The proper solution would probably be to write your own logging using a logging library like spdlog
Hello, thank you very much! The hacky way works good for 10 minutes which is sufficient at this point. I will look into spdlog!