Author: Yu Hang He Email: hey6@unlv.nevada.edu
Date: Last modified on <11/19/17>
Keywords: Darwin OP 2, C++/C Programming, Robotis OP 2, Computer Vision

This tutorial will demonstrate how to use vision processing capability on Darwin OP 2 to detect and track color. Darwin OP 2 have computer vision that can detect multiple colors and return x and y center position of those colors. A second class will move camera to keep track of color based on x and y position. It takes approximately 2 hours to complete.

This tutorial's motivation is to demonstrate how to use computer vision on Darwin OP 2. This tutorial assumes the reader has the following background and interests:

• Familiar with handling Darwin OP 2
• Familiar with C++/C programming language
• Familiar with C++/C codes on Darwin OP 2
• Interested in computer vision

The rest of this tutorial is presented as follows:

• Color Detection
• Camera Tracking
• Demonstration
• Final Words

The core of image processing on Darwin OP 2 is ColorFinder class. ColorFinder can find the center of mass of detected color and return its location. There is a tutorial on Robotis' online manual that can provide more insights.

ColorFinder class requires 5 input color parameters: hue, tolerance, minimum saturation, minimum value, gain, and exposure. To find the most accurate set of values for the color you want to detect, use the color_filtering program on Darwin OP 2.

Use terminal and go to directory /robotisop2/Linux/project/tutorial/color_filtering

Type in make and execute the program ./color_filtering.


Once the program is running, open web browser and type in the address http://192.168.123.1:8080


Now you can adjust the values until Darwin OP 2 properly detect your color.

In this example, I am trying to detect a blue color.

Before adjustments


Afterward


The adjusted values are:

• Hue: 225
• Tolerance: 15
• Minimum Saturation: 45
• Minimum Value: 0
• Gain: 0.3
• Exposure: 50.0

This tutorial will demonstrate how to create a new ColorFinder object and how to implement it in demo program.

main.cpp can be found under directory /robotisop2/Linux/project/demo

| main.cpp

//declare a new object of class ColorFinder
ColorFinder* finder = new ColorFinder();
//you can initiate the object with 5 input color parameters
//Example 
ColorFinder* green_finder = new ColorFinder(120, 45, 35, 0, 0.3, 40.0);
//There are default values of color you can load from ini file. Example
finder->LoadINISettings(ini, "RED"); 
//To get the position of center of mass of filtered pixels
Point2D pos;
pos = finder->GetPosition(LinuxCamera::GetInstance()->fbuffer->m_HSVFrame);
//first declare an object of class Point2D
//then set it equal to GetPosition function of ColorFinder object

| StatusCheck.cpp

//At the end of if statement Line 141
if(m_old_btn & BTN_MODE)
        ///////////////////////////
        //////////////////////////
        //////////////////////////
        else if(m_cur_mode == SPRINT) //adding LED and play mp3 for new mode
        {
            cm730.WriteByte(CM730::P_LED_PANNEL, 0x01|0x04, NULL);
            //Signaling Darwin OP 2 which LED to turn on
            LinuxActionScript::PlayMP3("../../../Data/mp3/New_Mode mode.mp3");
            //play an mp3 file (you can use any mp3 file but make sure file name matches)
        }
    }
 
// Line 267 Add
  else if(m_cur_mode == NEW_MODE)
  {
      MotionManager::GetInstance()->Reinitialize();
      MotionManager::GetInstance()->SetEnable(true);
      //initialize and enable MotionManager class
      m_is_started = 1;
      LinuxActionScript::PlayMP3("../../../Data/mp3/Start New_Mode demonstration.mp3");
      //play an mp3 file (you can use any mp3 file but make sure file name matches)
 
      // Joint Enable...
      Action::GetInstance()->m_Joint.SetEnableBody(true, true);
 
      Action::GetInstance()->Start(9);
      while(Action::GetInstance()->IsRunning() == true) usleep(8000);
 
      Head::GetInstance()->m_Joint.SetEnableHeadOnly(true, true);
      Walking::GetInstance()->m_Joint.SetEnableBodyWithoutHead(true, true);
      //Reset Gyro sensor
      MotionManager::GetInstance()->ResetGyroCalibration();
      while(1)
      {
          if(MotionManager::GetInstance()->GetCalibrationStatus() == 1)
          {
              LinuxActionScript::PlayMP3("../../../Data/mp3/Sensor calibration complete.mp3");
              break;
          }
          else if(MotionManager::GetInstance()->GetCalibrationStatus() == -1)
          {
              LinuxActionScript::PlayMP3Wait("../../../Data/mp3/Sensor calibration fail.mp3");
              MotionManager::GetInstance()->ResetGyroCalibration();
          }
          usleep(8000);
      }
  //copied status check condition from soccer mode to new mode
  //These codes initialize Darwin OP 2 for movement and walking

| main.cpp

//L317 Add
  case New_Mode:
  //implement new codes here to execute after pressing start button

In this demonstration, I created a new mode called Sprint mode following the previous step and successfully execute it on Darwin OP 2.

This tutorial's objective was to demonstrate how to add a new mode to Darwin OP 2's demo program. Follow this tutorial to quickly implement and test new codes on Darwin OP 2.

For questions, clarifications, etc, Email: hey6@unlv.nevada.edu