Challenge Team Interim Report

Team Number: 032 School Name: Las Cruces Public Schools Area of Science: Robotics Project Title: The Little Robot That Could

Problem Definition

Robots remain economically unreasonable due to the expense of microcontrollers. Besides their high cost, microcontrollers also have low amounts of memory, and slow processing speeds. Many people interested in purchasing robots have access to a home computer. If the memory and processing speed of the desktop computer could be harnessed to work with a simple robotic device, then inexpensive robotic solutions could be made available.

Problem Solution

To solve the problem of expensive robots, we are creating an inexpensive robotic device, which will implement a simple microcontroller that will communicate with a desktop computer. The desktop computer will then interpret sensor data, and send commands back to the microcontroller. Since the microcontroller will not be processing complex programs, it does not need to be complex, nor expensive.

Progress to Date

To date we have determined the methods of creation and control of the robot. We have researched multiple possibilities in all major aspects of the robots construction and operation. The computer mapping procedures have also been researched and defined.
      We considered several types of robotic mobility systems including the use of legs, wheels, or treads. From these options we eventually chose treads. We chose not to use legs due to several factors, the most important being their high cost for parts, and time investment. Due to the complexity and the necessity of advanced control systems, an excessive time investment would be required. We chose not to use wheels due to their lack of versatility in different environments. This led us to a solid conclusion to use treads because of their low cost, durability, mobility, and simplicity.
      The grapple and retrieval device will be a two-fingered claw-like device that will be able to grab and lift miscellaneous items that the robot will be sent to retrieve. The grapple device would be able to lift an object off the ground just enough to eliminate the friction of dragging the item. The tips of the grappling device's fingers will have a rubber traction pads to allow the device to grab onto most any surface, including smooth surfaces.
      For our sensing equipment we considered direct and indirect sensors. We decided not to use direct sensors due to their inefficiency at mapping, and lack of versatility. Because of these considerations, we decided to use and indirect sensing method. Viable indirect sensing options included ultrasonic, visual, and laser/infrared sensors. We decided not to use visual sensors because of the difficulty interpreting the returned images. We decided not to use laser/infrared sensors because of inefficiency of detecting objects that do not meet certain parameters, such as opacity. Therefore we decided to use ultrasonic sensors.
      Concerns of communications between the robot and computer could be met with the use of a tethered, infrared, or radio link. Our consideration for a tethered link was short lived, since a tethered link would limit the range of the robot. While very inexpensive, infrared links will not feasible work within a housing confinement because it is limited to line of sight only. We finally chose to use a radio link due to the fact that radio waves are not necessarily confined to a single room, or line of sight.
      Rewiring the toy tank is underway. The toy tank must be modified to allow the microcontroller to have complete control over the controls and motor functions of the toy tank. The rewiring process requires the detection of what wires are used for the functions of the toy tank, and then severing current connections to allow the microcontroller to be given complete control.
      For the issue of control systems we decided to use a small onboard controller to handle mundane tasks, leaving the computer to handle mapping and command functions. Out of the many available onboard controllers, we chose to use a microcontroller in the BASIC Stamp series. We chose to use a BASIC Stamp (IISX) because of the simplicity to write a program for it, whereas other controllers required programs to be written with an intimate knowledge of Assembly language. We chose to use the BASIC Stamp IISX because of its speed, capacity, and number of I/O lines.
      The theories and methods for the mapping, control, and communications that the computer will handle have been decided. The software currently analyzes two differing maps to create a composite map for the purposes of location identification. Functions for the plotting of sonar readings have also been created. The GUI has also been created, for ease of troubleshooting and data interpretation.

Expected Results

We expect to have a robot created from a motorized toy tank, modified to include a Basic Stamp IISX microcontroller with a sonar range finder, 433 MHz RF transceiver, and a robotic gripping manipulator. A second 433 MHz transceiver will be connected to the parallel port of the desktop computer to facilitate communication between the robotic device and the computer. Additionally, a computer program will be written that will map out areas such as a living room or kitchen, and then allow the robot to seek and find a requested item and then manipulate it. An example would be the robot leaving the living room to enter the kitchen, then having the robot find a soda can, pick it up, and bring it back to the living room.

Team Members

Team Mail

• William Baker
• Nathaniel Bromwell
• Jared Boxley
• Peter Failla
• Ryan Roberts

Sponsoring Teachers

• Patricia Miller
• Ed Lappin

Project Advisor(s)

• Michael Scoggin
• Stephen Miller