In Dr. David Cappelleri's ME 551: Microprocessor Applications in Mechanical Engineering, Stevens Institute of Technologyundergraduate students spend a semester learning about the properties and interactions of components that make up programmable machines. After months of lectures, labs, and extracurricular teamwork spent designing, acquiring parts, and building a robot, the students put their creations to the test. Teams are given three attempts to navigate a maze, with points awarded for the total time required to complete the course, and points deducted for hitting a wall.
The design of these robots fits into the undergraduate Mechanical Engineering curriculum, by introducing students to fundamental concepts in the production of machines. Students are prompted to explore issues relevant to the basic criteria of individual parts and their interactions. To complete the task, students learn about item prices, energy efficiency, sensing, data communications, and system integration.
Dr. Cappelleri sets out a few criteria for the student robots, with ample room for unique designs to meet the challenges of the project. The robots require a manual data input, sensors, hardware such as motors, a visible output that displays the robot's settings, and of course a microprocessor to hold the logic processing. For extra credit, robots can be equipped with an audio output to play a victory tune upon completion of the maze.
All this must fit into a 4" x 4" x 4" volume. Otherwise, it's fair game. Some robots are spindly and race through the maze, while others are stout and inch along, slowly but surely. To see the robots in action, check out this short video of the final project competition.
"The basic challenge teams have to overcome is programming the robot so that all the sensors correctly relay information to the microprocessor," says Michael Fatovic, a ME 551 teaching assistant. "Since every sensor is different, they have to carefully look at data sheets before they buy the parts they want to use."
Although each team's solution is unique in appearance and operation, there are a few basic similarities between most robots. Proximity sensors, used to sense an approaching wall or obstacle, keep the robots from crashing at every turn in the maze. Encoders on the wheels count the number of turns completed, allowing the robots to accurately navigate the different courses of the maze according to their programming.
"To accomplish this task we cover microprocessor interfacing, electronics design, motors, and sensors," says Dr. Cappelleri. "This project brings together all of these topics at the end of the semester."