CSCI 458: Autonomous Mobile Robotics
Fall 2017

Course Assignments




Assignments

  1. Assignment 0: Getting Started

    Your goals for the first assignment are:
  2. Assignment 1: Servos/Movement

    Before you begin: Construct a mount for a whiteboard marker. Your robot should trace on the practice boards so that the quality of your movement can be appropriately evaluated.

    After constructing the basic wheeled bot from the Mindstorms manual (servos only, no sensors) you will complete the following programs to get the hang of the most basic output--movement.
  3. Assignment 2: Bumble Bot (a sense of touch)

    My robotic vacuum is capable of (among other things) the minimal autonomous behavior of being able to explore and avoid obstacles (and getting hung up on them). More modern incarnations are capable of more sophisticated planning and navigation.

    You should construct a robot using the available touch sensors. The robot should maneuver around the space it is in, and should react appropriately to touch input. That is, if it touches an object it should drive away from that object and continue on its way. You are expected to use all available touch sensors, and to define different behaviors based on what it is touch (e.g., run into an object on the right side vs. left vs. center). The details of your construction are up to you, but your robot should be given the ability to explore without getting hung up on obstacles, and should use its new sense of touch to do basic obstacle avoidance.

    Your build should be capable of (at minimum) moving forward, registering when it runs directly into an object, and doing some sort of avoidance before continuing to move.

    Note: You will most likely need to learn to be a bit creative w.r.t. debugging this semester given the somewhat limited hardware we are working with. You will find that the ROBOTC API has a function for emitting a noise (e.g., a beep) when something happens like receiving sensor data. Please don't overuse this for obvious reasons, but know that it can be a useful tool.
  4. Assignment 3: More Bot Less Bumble

    Augment your robot to include input from the ultrasonic sensor. You may have to tinker with placement to figure out an ideal height/angle. This assignment will consist of two parts:
    1. After adding the distance (ultrasonic) sensor write a demo program to measure the distance in front of the (stationary) bot. Your program should both measure the distance of the nearest object in front of the robot and display the distance (with units of measurement) on the built-in display. Please demo this portion of the assignment before moving on.

    2. Augment your previous build to include both the ultrasonic sensors and the bump sensors. Your robot should continue to avoid obstacles as it did before, however this time use the ultrasonic sensors for primary obstacle avoidance. When it detects an object in its path it should attempt to both avoid collisions and continue to explore its surroundings. (Unlike the touch-only bot it shouldn't have to turn away quite as much.) Your robot should stop when it gets within approximately 8-9 cm (3-4 inches) from an obstacle.

      You should continue to use the bump sensors to ensure that you don't get hung up (the ultrasonics have limitations), but your primary goal should be to avoid making contact with anything in the environment.

      Because you will have a (most likely front-facing) distance sensor you may wish to rethink touch sensor placement for a better configuration.

    Note: Again, you may experience some debugging headaches if you do not approach things from the correct direction. Before you start working on the actual code for the main project, you may wish to create a separate test executable for getting quick readouts from the ultrasonic sensors.

    Try to figure out how frequently you get readings, how accurate they appear to be, how they interact with motion, etc. Having an additional utility like this will also help you determine on the fly if something is going wrong with your sensor readings while you work.

    You will find that the LCD Display API is quite extensive, and should give you everything you need to print debugging information from the ultrasonic input device.
  5. Assignment 4: Boundary Bot

    In this assignment we will be exploring the use of the light/color sensor. The goal of this assignment is simple: create a robot that respects a boundary. The robot will be set on a practice board on an unmarked region, and it should explore again (bumble) until it reaches a boundary delineated by a black marker. The region of exploration will be be entirely enclosed by the black marker, and may be irregular in shape.

    This task will likely be best served by mounting the light/color sensor so that it faces downward. You may need to experiment to find a good distance from the ground.

    As was the case in the previous assignments, it may be a good idea do develop a separate utility that just reads and displays current light/color readings for both debugging and calibration purposes.

    Note: You may want to start exploration with the sensor's getColorRGB function. There are other methods for reading that you may require here or in the future, but this function will serve as a good jumping-off point.
  6. Assignment 5: Garbage Collector

    In this assignment we will be augmenting the hardware/software build from the previous assignment to perform a slightly modified task: clearing the region that the bot explores:
  7. Assignment 6: Line Follower

    In this assignment we will repurpose the light/color sensor from the previous build (the other elements can be stripped off) for a modified task. Rather than remaining within the confines of a bounded region you will use the light/color sensor to track/follow a line.

    For testing purposes You will be provided a map with a black line on a white background. Your robot should follow the line in a quick, accurate, and smooth (not jerky) manner.

    Your demonstration will be judged based on the following dimensions:
    1. accuracy of line tracking (avoid deviating from the course of the line),
    2. speed of line tracking (while tracking may result in slightly slower performance it should not cause an overall hindrance),
    3. smoothness of ride (not noticeably jerking back and forth as your robot glides).
    Note: Your line-following routine will be reused in the next assignment. You may wish to have it stable before proceeding.
  8. Assignment 7: Hindsight is 20/20

    After you have perfected your line following routine, your next task will be to have the robot recall the route of its journey after navigating a line-following routine. You have a number of available sources to track your original path for later reconstruction (power to servos, clock time in the machine, servo encoder readings).

    In order to get full credit your robot should:
    1. Follow a line track until some predefined stopping point (you may define stopping criteria--seeing a different color on the whiteboards, receiving a button press, etc.)
    2. Your robot should handle arbitrary straight lines, curves, and angled turns.
    3. The robot should keep track of its journey as it is following the line.
    4. After stopping your robot should give you enough time to get it set up on another board to recall its journey (waiting until a button press may be a good way of accomplishing this).
    5. Your robot should trace the resulting journey on the second board and stop in the correct position relative to its original journey. For full credit your robot should be able to trace its journey using a marker so accuracy can be compared back to the original line. (The marker will either need to be placed for the second journey or should move itself into position via a servo.)

    In this assignment I will be paying attention to accuracy of retracing the original path, with a secondary attention on smoothness of ride and speed.