FTC Robot Behavior Model (Part 5 - OpMode)

This is part 5 of a 5 part series on a robot behavior framework.

Behaviors are connected together with events to form more complex behaviors. In this simple example, pressing the y button on the joystick will trigger a change in the active behavior from driving the robot with an an arcade style input to driving the robot with a tank style input.


The OpMode software does the following:

It begins by setting up the behavior framework in the H1TeleOp_Js2() constructor or the opmode init() method as follows:

// ConstructorBehaviors_Joystick be;
GlobalData gd;
public H1TeleOp_Js2(){
    // Setup the behavior model    gd = new GlobalData();
    be = new Behaviors_Joystick(gd);
}

In our example, the behaviors framework is called Behaviors_Joystick(). GlobalData is needed to pass information back and forth in the loop() method for the opmode as follows:

// Run periodically when sensors are read@Overridepublic void loop() {
    // Pass Joystick to the behaviors    gd.jsLeftY = gamepad1.left_stick_y;
    gd.jsRightY = gamepad1.right_stick_y;
    gd.jsLeftX = -gamepad1.left_stick_x;
    gd.buttonX = gamepad1.x;
    gd.buttonY = gamepad1.y;

    // Pass time to the behaviors    gd.deltaTime = (float)time - gd.time;
    gd.time=(float)time;

    // Run the behaviors    be.onLoop();

    // write the values to the motors    motorRight.setPower(gd.rightCmd);
    motorLeft.setPower(gd.leftCmd);

    telemetry.addData("_Behavior", be.getActiveBehavior().getName());
    telemetry.addData("Power Left", Float.toString(gd.leftCmd));
    telemetry.addData("Power Right", Float.toString(gd.rightCmd));
    telemetry.addData("Left Js Y", Float.toString(gd.jsLeftY));
    telemetry.addData("Right Js Y", Float.toString(gd.jsLeftY));

    //DbgLog.msg("Run Mode");}

The method onLoop() calls the behavior framework. When the robot first starts up, it will begin by calling the Behavior_JsArcade behavior.

For full copies of this software, see: https://github.com/dlacres/GeekMyBot.git 

This github repository has the following behaviors defined:

• Behavior_Forward - Drive forward
• Behavior_Heading - Use the dpad and the gyro to turn the robot (demonstrates a simple PID control law)
• Behavior_IrTurn - Turn toward the IR Beacon. Move forward and backward to match the signal strength.
• Behavior_JsArcade - Drive using Arcade mode
• Behavior_JsGyro - Drive using Arcade mode. Correct for drift with the gyro.
• Behavior_JsLookup - Drive using Arcade mode. Provide better low speed turns using a lookup table to shape the commands.
• Behavior_JsTank - Drive using Tank mode.

This github repository also has the following events defined:

• Event_ButtonX - Transition on the rising edge of a X button push
• Event_ButtonY - Transition on the rising edge of a Y button push
• Event_Time - Transition after a period of time

 

If you use this behavior framework, I ask that you share the love. Print out a copy of the GeekMyBot logo and put it on your robot along with the http://geekmybot.blogspot.com/ URL address. Share this Blog with your friends.

If you develop a behavior that you are particularly proud of, I ask that you add a comment to this article and share your behavior along with a link to your software.