Camera programming progress

[nathanww]

Team 1678 started seriously integrating our kicking and tracking systems today and ran into some pretty serious speed issues which we're now optimizing. I was wondering how many people actually have a high-speed, working camera tracking system on their robot.

[TPNigl]

We've been able to move the servos and get images. We're now trying to get the tracking itself to work, but we're having problems. We posted a thread about it too.

http://www.chiefdelphi.com/forums/showthread.php?t=83015

If anyone who has gotten their camera to track could help, it would mean a lot.

[Patrick Chiang]

We're using Java and it's working for us.
We ripped the Target class of the example code, but here's our Camera class:

package pronto;

import edu.wpi.first.wpilibj.*;
import edu.wpi.first.wpilibj.camera.*;
import edu.wpi.first.wpilibj.image.*;


/**
* General parameters for the camera.
* @author Team Pronto Programmers: Patrick Chiang, Nicholas Escalona, Cody Ryu
*/
public class Camera {
static final int SENSITIVITY_CAMERA_H = 10;
static final int SENSITIVITY_CAMERA_V = 3;

int targetPosition;
double kScoreThreshold = 0.01;

Timer timer;
Servo cameraHServo,cameraVServo;
AxisCamera cam;
/**
* Class designated for initializing necessary components for the physical movement of the camera
* @param horizontalServo Servo designated for turning the camera horizontally
* @param verticalServo Servo designated for turning the camera vertically
* @param camera Camera designated for seeing things
*/
public Camera(Servo horizontalServo, Servo verticalServo, AxisCamera camera){
super();
cameraHServo = horizontalServo;
cameraVServo = verticalServo;
timer = new Timer();
cam = camera;
}
/**
* Class used to specify a joystick to control the camera
* @param cameraStick Joystick designated to control the camera
*/
public void manual(Joystick cameraStick){
if(cameraStick.getRawButton(1)){
track();
aim();
}
if(cameraStick.getRawButton(10)){
cameraHServo.set(0.5);
cameraVServo.set(0.5);
} else{
move(cameraStick);
}
}

/**
* Class for allowing constantly centering the ball in the camera's field of vision.
* @param maxAngle Maximum allowed
* @param targetNum
*/
public int track(){
// System.out.println("Target Angle: " + cameraHServo.getRaw()); //TODO uncomment
// based on code from CircleTrackerDemo

try {
if (cam.freshImage()) {
ColorImage image = cam.getImage();
Thread.yield();
Target[] targets = Target.findCircularTargets(image);
Thread.yield();
image.free();
if (targets.length == 0 || targets[0].m_score < kScoreThreshold) {
// targetNotFoundCount++; // DEBUG
// System.out.println("No target found" + targetNotFoundCount + "times"); // DEBUG
Target[] newTargets = new Target[targets.length + 1];
newTargets[0] = new Target();
newTargets[0].m_majorRadius = 0;
newTargets[0].m_minorRadius = 0;
newTargets[0].m_score = 0;
for (int i = 0; i < targets.length; i++) {
newTargets[i + 1] = targets[i];
}
} else {
// System.out.println(targets[0]); //TODO uncomment
// System.out.println("Target Angle: " + targets[targetNum].getHorizontalAngle()); //TODO uncomment
// targetFoundCount++; // DEBUG
// System.out.println("Num targets found" + targetFoundCount); // DEBUG
if(Math.abs(targets[0].getHorizontalAngle())<500){
targetPosition = (int)targets[0].getHorizontalAngle();
// System.out.println(targets[0].toString());
}
}
}
} catch (NIVisionException e) {
e.printStackTrace();
} catch (AxisCameraException e) {
e.printStackTrace();
}
return targetPosition;
}

public void aim(){
if(Utils.isBetween(targetPosition,3,252)){
cameraHServo.setRaw(cameraHServo.getRaw() + targetPosition);
} else if((cameraHServo.getRaw() + targetPosition)<3){
cameraHServo.setRaw(cameraHServo.getRaw() + 3);
} else if((cameraHServo.getRaw() + targetPosition)>252){
cameraHServo.setRaw(252);
}
}
/**
* Allows for manual operation of the camera's movement
* @param shooterStick Control stick for the camera. Controlled by Buttons 2-4
*/
public void move(Joystick shooterStick){

// camera control
if (shooterStick.getRawButton(4)) { // left
cameraHServo.setRaw(cameraHServo.getRaw() - SENSITIVITY_CAMERA_H);
}
if (shooterStick.getRawButton(5)) { // right
cameraHServo.setRaw(cameraHServo.getRaw() + SENSITIVITY_CAMERA_H);
}
if (shooterStick.getRawButton(2)) { // down
cameraVServo.setRaw(cameraVServo.getRaw() - SENSITIVITY_CAMERA_V);
}
if (shooterStick.getRawButton(3)) { // up
cameraVServo.setRaw(cameraVServo.getRaw() + SENSITIVITY_CAMERA_V);
}
}
}


Use track() and aim() together to make the robot's Servo "look" at the target. It works for side to side (horizontal) tracking, but no vertical yet.

[bronxbomber92]

What do the magical constants 3 and 252 mean in the aim method?

[Patrick Chiang]

Those prevent the servos from going below 3 or above 255. In theory, they go from 0-255, but they're there just in case.

[bronxbomber92]

Hmm, ok. I'm just surprised that works since you're treating it like an angle (since targetPosition is supposedly an angle).