Controlling Robot Through Java

Hello my good friends, i'm trying to build a Java program that when run controls a robot hand to move blocks. I have got a fair bit of the code working so far but i'm afraid i've run into a bit of a problem with moving the blocks. It just doesn't seem to work.

I have the height of all bars set to 4 and the height of all blocks set to 3. Basically what i need done is to transport each of the blocks in the source pile (column 10) and drop them off on top of the bars - the robot can only drop one block on each bar and the first block must be dropped off on top of the left-most bar (column 3). Subsequent blocks should be dropped off on the next vacant bar to the right.

Here is a picture of how it should look,



When implementing this control mechanism you must move each of the sections of the robot arm using a loop to call the corresponding arm movement method as many times as is required.

Here is the code i have so far,

import javax.swing.*;

class RobotControl
{
    private Robot r;

    public RobotControl(Robot r)
    {
        this.r = r;
    }

    public void control(int[] barHeights, int[] blockHeights)
    {
controlMechanismForStageA(barHeights, blockHeights);
}
public void controlMechanismForStageA(int barHeights[],
            int blockHeights[])
    {
        r.slowDown(2);
int h = 2;
        int w = 1;
        int pickerHeight = 1;
int sourceHeight;
        int blockHeight;
       
        int sourceLocation;
        int targetBarIndex;
        int maxBarHeight;
while (pickerHeight < 10)
        {
            r.up();
            pickerHeight++;
        }

Code (markup):

Anyone able to help me with this? Please and thankyou.