ARP Hoist Assignment

First Advanced and Robot Programming (ARP) assignment, by Pablo Moreno Moreno (S5646698).

Compiling and running the code

In order to compile all the processes that make up the program, you just need to execute the following command:

./compile.sh

Then, you can run the program by executing:

./run.sh

Two new windows will pop up: one corresponding to the Command Console and another corresponding to the Inspection Console.

Content of the Repository

Apart from the compile.sh and run.sh files, the repository is organized as follows:

The src folder contains the source code for the Master, Command Console, Inspection Console, Motor1, Motor2, and World processes.
The bin folder is where the executable files corresponding to the previous processes are generated after compilation.
The include folder contains all the data structures and methods used within the ncurses framework to build the two GUIs.
The log folder is where the log files corresponding to the above processes will be genearated after running the program.

Project Description

The project consists in designing and developing an interactive simulator of a hoist with 2 d.o.f. in which two different consoles allow the user to activate the hoist.

Two different motors allow the hoist to displace along two differet axes: X (horizontal) and Z (vertical). Motions along the axes have bounds: (0, 100) for the X axis and (0, 40) for the Z axis.

From the user side, there are two consoles (shell windows) that simulate a real system: the command console and the inspection console, implemented through the ncurses library as simple GUIs.

The program is made up of the following 6 processes:

Master process. It spawns all the other processes and defines all the unnamed pipes used for the IPC. It also implements the watchdog: it checks the activity of all the other processes, and in case all of them did nothing for 60 seconds, it kills all the processes, including itself.
Command Console process. It reads the velocity commands given by the user through the buttons vx-, vx stop, vx+, vz-, vz stop and vz+, sending them to the appropriate motor. It is also capable of handling the STOP and RESET signals, ignoring all user commands when activated.
Motor1 process. It simulates the motion along the X axis, receiving the velocity commands from the Command Console process, computing the estimated X position of the hoist, and sending it to the World process. It is also capable of handling the STOP signal (setting the velocity immediately to zero) and the RESET signal (rewinding the hoist to its initial position).
Motor2 process. It simulates the motion along the Z axis and handles the STOP and RESET signals in the same way as the Motor1 process.
World process. It receives the estimated X and Z positions from the Motor1 and Motor2 processes, adds a certain error to them, and sends the actual position values of X and Z (including error) to the Inspection Console process.
Inspection Console process. It receives the actual X and Z positions from the Motor1 and Motor2 processes, and reports the current hoist position on its associated window. It also manages the STOP and RESET buttons, sending the appropriate signals to the Command Console, Motor1 and Motor2 processes when they are pressed.

User Guide

After compiling and running the program as mentioned above, two new windows will pop up: one corresponding to the Command Console and another corresponding to the Inspection Console.

The user can send velocity commands to the motors by clicking the buttons vx-, vx stop, vx+, vz-, vz stop and vz+, present in the Command Console window. The velocity levels are discretized in the range [-2.0, 2.0] in increments of 0.5.

The current position of the hoist is represented in the Inspection Console window. In this window, the user can also activate the STOP and RESET signals by pressing the corresponding buttons.

After pressing the STOP button, the velocities of both motors will be immediately set to zero, regardless of the user commands. Once the hoist has stopped, the user can continue to command it.

After pressing the RESET button, the velocities of both motors will be set to -0.5 until the hoist has reached its initial position. While the hoist is rewinding to its initial position, the velocity commands given by the user will be ignored, but once it has reached the origin, the user can continue to command it.

Finally, if all processes are inactive during 60 seconds (no motion of the hoist, no pressing of the buttons...), the program will end, terminating all processes and closing all windows.

Required libraries/packages

ncurses library. You can install it with the following command:

sudo apt-get install libncurses-dev

konsole application. You can install it with the following command:

sudo apt-get install konsole

Troubleshooting

Should you experience some weird behavior after launching the application (buttons not spawning inside the GUI or graphical assets misaligned) simply try to resize the terminal window, it should solve the bug.