Figure 1:
Block Diagram of P Controller
Progress:
Project Title:
Microcontroller Implementation of a Small Robot Arm Controller
Week of: March 7th, 2000
Engineers:
Megan Bern and Ritesh Patel
Advisor’s Signature: _________________
Grade: _______
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Objective:
For the week of March
7th, 2000, the first objective is to implement the block diagram shown
in Figure 1 in software. This block diagram does not represent unity
gain. The lack of a gain of 0.05 after the step input will give 20°
of position of the robot arm for every 1 volt input into the controller.
The second objective is to start the menu system.
Figure 1:
Block Diagram of P Controller
Progress:
The block diagram shown in Figure 1 was simulated using simulink. The output of the controller with an input of 10V is shown in Figure 2.
Figure 2:
Simulated Output of P Controller
The
output shows approximately 120° output position. This verifies
that the controller outputs 20° of position of the robot arm for every
1 volt input into the controller. The software called Prg4d_df.a51
that is attached to this progress report was then ran to verify our simulation
results. The input to the controller was a joystick. The robot
arm did not move from -90° to +90° as desired. It instead
had approximately an error of 40°.
The menu system was the next objective for the week. The menu system will begin with a main menu prompt from the LCD. It will read, "Press 1 or 2", on the first line and it will read, "1=In 2=Out For Menus", on the second line of the LCD.
There was a problem at first when trying to implement this main menu prompt. The microcontroller was writing to the LCD way too fast. The problem was solved by using an interrupt to slow down the time each character was sent to the LCD. It was decided that sending a character to the LCD every 0.05 seconds was plenty of time to delay each character. This was successfully written to the LCD. The code for the menu system used to implement the main menu is shown in Prg4d_df.a51 which is attached to this report. This is as far as we got on the menu system.
Conclusion:
Overall we implemented the block diagram shown in Figure 1 in software. The robot arm was not moving as expected. We are on schedule. Weeks 8-9 will be used to proceed with our menu system. Below is the schedule for weeks 8-12.
Schedule for Weeks 7-12
Week 8 Menu System
Week 9 Menu System
Week 10 Testing and Evaluation
Week 11 Modify/add to Menus
Week 12 Proportional-derivative Controller