Homework 1

The following problems will be due in class.

1. A robotic vacuum cleaner has a motor control task that computes control laws for its drive motor, a contact task that detects when the robot's contact sensor is triggered by running into something, a battery status task that monitors the voltage on the battery and how much current is being taken from it, a planning task that determines the path the robot should follow, and a communication task that allows the user to set the time of day and dowload times of the day during which the robot should work. Classify each task as periodic, sporadic, or aperiodic and identify the relevant task parameters (e.g., a periodic task has a period, worst-case execution time, and relative deadline.) More than one answer may be correct, so you must justify your choices to get full credit.

   The control laws need to run at a frequency of 500 Hz. The load on the battery can change with every control law update. The robot should never travel outside the range it has planned. The planning task needs to run fast enough that the robot does not go more than 1 m between jobs in the planning task. Assume the top speed of the robot is 0.5 m/s. Be sure to describe any other assumptions you make.

2. Do problem 3.1 in the book.
3. You want to set up a lemonade stand. In no particular order, you need to:
   • mix lemon juice and water,
   • buy lemons and sugar (at the grocery store),
   • buy a table (at another store),
   • mix the lemon juice, sugar, and water,
   • set up the table and a sign,
   • make a sign, and
   • pour the lemonade into cups

   Show a precedence graph that for all these activities.

4. Do problem 4.1 from the book
5. Do problem 4.5 from the book