CMU RI 16-711: KDC: Assignment 4: Robot Control

This assignment explores the control of a real live robot. First, a model and simulation are created to demonstrate a stable control law. Then the controller is implemented on a PUMA robot.

You will need:

A floppy disk (provided in the lab)
Source code: available on the computer in 'c:\kdc\source'

ROBOT USAGE INSRUCTIONS:

Because the PUMA robot is large and powerful (therefore dangerous), we have implemented precautions and protocals that all students will need to follow when working on the robot. If at any time you need help using the robot, email Ben at bstephens@cmu or call him at 405-255-7779. Ben is usually available on campus 8am-6pm.

You will need to take a guided intro of the robot with Ben (see Part 1a below).
You are only allowed to change the following files

control.c - your controller and trajectory loader

traj - a reference trajectory that you specify

user.cfg - allows you to load new params (like gains) without having to recompile
Min/Max values are given in the table below. You are not allowed to exceed these. If these are exceeded, the robot will shut down and alert you to this fact. You may waste a lot of time reseting the robot if this happens.
DO NOT ENTER ROBOT WORKSPACE WHILE CONTROL PROGRAM IS RUNNING
To compile and run your code:
1. Copy your source code to the directory C:\kdc\[name]\
2. Open MSDOS prompt and go to your directory ("cd \kdc\[name]")
3. Run "c:\tc\tc.exe"
4. Load the project file "robotm.prj" (Alt-P, P, Enter, Enter)
5. Select robotm.c as the primary file (Alt-C, P, Enter, Select ROBOTM.C, Enter)
6. Compile the code (Alt-C, B)
To run a trajectory on the robot:
1. Create a trajectory in the format given above
2. Turn on the control box by flipping the POWER ON switch
3. Run your program c:\kdc\[initials]\robotm.exe
4. Press 'e' to enable power
5. Press 'c' to enable the controller
6. Press the button labeled ARM POWER ON on the control box
7. Press 'T' to initiate the trajectory
8. Press 'q' to quit and diable power

	Joint 1			Joint 2			Joint 3
	Angle (rad)	Velocity (rad/s)	Torque (?)	Angle	Velocity	Torque	Angle	Velocity	Torque
Min	-1.0	---	-2500	-2.5	---	-3000	0.8	---	-3000
Max	1.0	---	2500	-0.8	---	2500	2.5	---	3000

Part 1: Get acquainted with the robot and create a realistic simulation

Part 1a. Email Ben (bstephens@cmu) to schedule a time to get a guided intro to the PUMA robot. You must do this before you use the robot. This can be done in groups.

Part 1b. Look at the robot and measure, guess, or google physical parameters (it is up to you which parameters are important). Record all of these values.

Part 1c. Create a simulation based on the estimated robot parameters. Create a controller (PD,PID,LQR,etc.) that can hold a set of desired joint angles. Demonstrate that the controller is stable when given step inputs (desired angles).

Part 2: Refine robot physical paramters through experiment

Part 2a. Generate a joint trajectory. Run the trajectory in your simulator and make sure that it can follow it.

Part 2b. Run the trajectory on the robot and save the data.

Part 2c. Use data from the robot experiment to refine your estimates of the physical parameters of the robot. Update your simulation/controller and make sure it is stable in simulation, then again on the robot.

Part 3: Feedforward Control of Robot

Part 3a. Generate feedforward torques based on your model to follow a trajectory. Compare how the robot follows the trajectory with and without feedforward torques.

Part 3b. Refine feedforward commands using learning