User:Mike Barnkob/Projects/Liquid handling robot

Background

Ressources

Software

• ROBOTC
• 3rd party ROBOTC drivers
• Lego Digital Designer

Hardware

• Articles on construction of trusses by TJ Avery.
• Linear actuator by Xander Soldaat
• Aluminium beams
• Firgelli Linear actuators

Knowledge

• Introduction to the RobotC programming language by Albert W. Schueller.
• Creating own functions in RobotC By Albert W. Schueller.
• Robot C Functions help
• Introduction to robotics at Stanford Engineering.

Notebook

Week 1

Monday: Worked on the primary handling operation with a very simpel design and set up the lab space.

The linear actuator works up to aboout 1,6 cm, putting a limit on how much the pipet can be pushed down. Solutions might be: using two actuators, using a rail-design instead or adding more power to the actuator.

The design is becoming quite big. Solution might be to use the power function powers, which are smaller.

The pipet needs to be tested for accuracy.

Tuesday: Checked the pipet for accuracy, and it was way of. Found another one, Eppendorf 200 ul.

Continued working on the dispensing handling. Created a successful design with two motors that press down on the pipet. I'm a bit nervous about the stress on the motor, but for now they seem to do fine.

The battery in one of the NTX bricks already ran out. I've ordered a rechargeable battery - but no transformer, since they are not sold here. Hopefully the inlet will accepts other transformers as well.

Programmed two aspiration and dispensing programs, called 'asp & disp 1 and 2 (16-03-10).c'. The code for asp & disp 2 is:

#pragma config(Motor,  motorA,          motor_A,       tmotorNormal, PIDControl, encoder)
#pragma config(Motor,  motorB,          motor_B,       tmotorNormal, PIDControl, encoder)
//*!!Code automatically generated by 'ROBOTC' configuration wizard               !!*//

//DECLARING FUNCTIONS

//Control of the dispenser
void DispensControl (int DCmotor, int DCencode, int DCpause) {

  //Syncronizing motors
  nSyncedMotors = synchAB;
  nSyncedTurnRatio = +100; // Left motor turns 100% of right motor
  //Power up

  while( !(nMotorEncoder[motor_A]==DCencode) ) {
    motor[motor_A]=DCmotor;
    nxtDisplayClearTextLine(5);
    nxtDisplayClearTextLine(6);

    nxtDisplayString (5,"%d, %d", nMotorEncoder[motorA],nMotorEncoder[motorB]);
    nxtDisplayString (6,"%d, %d", DCencode, DCmotor);
    wait1Msec (1);
  }

  motor [motorA] = 0;

  //End pause if any
  wait10Msec(DCpause);
}


//MAIN TASK
task main () {

  nxtDisplayString (1,"DISPENSING 2");
  nMotorEncoder [motor_A] = 0;

  //Air-out
  nxtDisplayClearTextLine(3);
  nxtDisplayString (3,"Air-out");
  DispensControl(30, 30, 0);
  DispensControl(70, 60, 250);

  //Aspiring
  nxtDisplayClearTextLine(3);
  nxtDisplayString (3,"Aspiring");
  DispensControl(-15, 0, 250);

  //Dispensing
  nxtDisplayClearTextLine(3);
  nxtDisplayString (3,"Dispensing");
  DispensControl(30, 40, 0);
  DispensControl(70, 80, 250);

  //Resetting
  nxtDisplayClearTextLine(3);
  nxtDisplayString (3,"Resetting");
  DispensControl(-15, 0, 250);

}

Wednesday: Started designing the holding bay for the pipet. This will control the downward and upward motion of the pipet, but should also be able to be pulled either left or right. Decided to work with only one motor, since this would make it possible to control the entire robot with two NTX's.

Friday: Continued work on holding bay design.