Project Weekly Progress Report

Project Title:
Microcontroller Implementation of a Small Robot Arm Controller

Week of:  February 22nd, 2000

Engineers:
Megan Bern and Ritesh Patel

Advisor’s Signature:  _________________

Grade:  _______

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Objective:

        For the week of February 29th, 2000, our objective is to implement the block diagram shown in Figure 1.  Weeks 6-8 were supposed to be used to implement our menu system.  Instead we will implement the block diagram shown in Figure 1 in software so that when we do implement our menu system, we will have some values to display on the LCD.

Figure 1:
Block Diagram

Progress:

         The actual block diagram that represents our controller is shown in Figure 2.  The feedback loop contains a potentiometer gain of 0.02805.  A gain of 35.66 is used to achieve unity gain.  The gain K of the system is chosen to be 0.05.  This was placed at the input and in the feedback loop to avoid the multiplication and division of 16 bit numbers.

Figure 2:
Block Diagram of P Controller

 

         To avoid 16 bit multiplication and division by multiplying by 70, dividing by 3, and dividing by 20 in the feedback loop, we found that that same can be achieved by dividing by 6 and multiplying by 7.  The block diagram is then reduced to Figure 3.

Figure 3:
Block Diagram of P Controller

 
         This block diagram was then implemented in software.  The software, Prg4b_df.a51, is attached to this report.
 The robot arm was then connected to the EMAC board and interface hardware.  The program was ran using Keil PK51.  At first the arm was barely moving.  We found that the signal generator that was being used to generate the input signal was not set for HIGH Z.  After that problem was fixed, the robot arm was moving as expected.

Conclusion:

     Overall we implemented the block diagram shown in Figure 3 in software.  The robot arm was moving as expected.  We are on schedule.  Weeks 7-9 will be used to implement our menu system. Below is the schedule for weeks 7-12.

Schedule for Weeks 7-12

                                                                             Week 7     Menu System
                                                                             Week 8     Menu System
                                                                             Week 9     Menu System
                                                                             Week 10   Testing and Evaluation
                                                                             Week 11   Modify/add to Menus
                                                                             Week 12   Proportional-derivative Controller