PowerPoint Presentation by Ax2YAZF


									                                                                                                                              Computerized Labyrinth Solver
                                                                                                     RIT Computer Engineering Senior Design Project
                                                                                                                                                      Gregory Schallert & Chad Craw
                                                                                                                                                                 February 12, 2004

                                                                The board-game ‘Labyrinth’ traditionally uses two manual controls to navigate a marble through a maze. This project
                                                                proposes to use two motors and video feedback to solve and traverse a reconfigurable maze. The maze walls will be
                                                                detected using metal contacts on the playing connecting to custom digital circuitry. This structure allows the computer
                                                                to scan the maze surface for wall segments. Once the maze has been scanned and built, a Computer will solve it
                                                                using the Lee Moore Algorithm. After a solution is found, the PC will communicate the path traversal plan to an HC12
                                                                that is connected to the two controlling motors. The HC12 will then navigate through the maze using the PC video
                                                                feedback to close the controller loop.                                                                                                                                                           To help with size constraints underneath the maze surface, and
                                                                                                                                                                                                                                                                 alleviate weight, the connection points for the dynamic walls were
                                                                                                                                                                                                                                                                 created by custom etching a board to fit the maze (above). The
                                                                                                                                                                                                                                                                 opposite side of this board was cleaned off and used as the maze
                                                                                                                                                                                                                                                                 surface itself, while these trace routes provided connections for the
                                                                                                                                                                                                                                                                 digital circuitry.
 The Maze solving system shown above uses a number of
 systems in conjunction to perform it’s task. The main
 components of the system are the CCD tracking camera,
 the HC12 motor control and maze scanning system, the                                                                                                                                                                                                            In a similar fashion to the maze surface, another board was
 digital circuitry attached to the wall detection points, and                                                                                                                                                                                                    etched to accommodate the digital multiplexer array used to scan
 the video tracking software running on an attached PC.                                                                                                                                                                                                          the maze surface for walls (below). This circuit was then
 The system uses the Serial Connection Interface with the                                                                                                                                                                                                        connected to the maze surface using two 40-pin IDE cables, and
 HC12 board to communicate data in the feedback process.                                                                                                                                                                                                         additionally connected to the HC12 controller with two 16-pin
                                                                                                                                           The maze uses a dynamic array of wall segments to create                                                              parallel socket cables.
                                                                                             Notches for the wall segments

                            The Camera used for our                                                                                        changing maze patterns. Walls are placed at arbitrary points
                            system is a Lego Mindstorms                                                                                    around the maze surface to create a path from source to
                            Visions camera, which is                                  Wall Segment
                                                                                                                                           destination. The maze is then scanned by the HC12 board and
                            actually a standard Logitech                                             …
                                                                                                                                           the data transmitted to the PC tracking software for analysis. The
                            Quickcam in a Lego Package.
                            The camera connects to a PC                 .               .                             .                    PC solves the maze preemptively and designs a path for the ball
                            via USB, and is operated using              .               .                             .                    to travel. The user starts the HC12 control system, and the PC
                                                                        .               .                             .
                            the custom tracking software                                             …                                     starts transmitting feedback to the Microcontroller.
                            designed for this project.
                                                                        Notches for Start and End tabs

Once all connections have been made and the system
powered up, the sequence of events are as follows:

   The user defines the walls location using the wall

   The connection is made between the PC and the                                                                                                                                         Using some basic laws of motion and applying them to
                                                                                                                                                   M g cos   Fs  M b a

   HC12. The HC12 sends the current wall locations to                                                                                                                                     the angular motion of the maze surface, a number of
   the PC.                                                                                                                                                                                equations were derived to help explain the ball’s
                                                                                                                  r          Fs                                                           anticipated motion in relation to the applied angle.
   The Computer solves the maze using a modified Lee                                    a                                                                                               These equations were then used to help calibrate a

   Moore Algorithm and waypoints are determined.
                                                                                                                                                       g cos                           Fuzzy PID controller for the system.
   The user selects the object they would like to track on                                                                                        a
   the PC. The PC then starts tracking the object.                                                                                                        1                                  Left of Target            At Target             Right of Target
                                                                                                                                                      1  2 
   The user presses start on the HC12 and the maze                                                                                                       mr 
   starts moving.

   When the ball reaches a waypoint a new goal is found.                    R                                                                                                                                                                                        Materials for Construction:
   Displacements are then calculated to the new goal.
                                                                                                                                                               L R d
                                                                                                                                                                  2        2     2
                                                                                                                                                   cos( )  
                                                                                                                                                                                                                                                                       Part                             Quantity   Cost
                                                                Z                                                                                                 0
                                                                                                         r                                                                                                                                                             Logitech Quickcam                1          $30.00
                 Disturbances                                                l
                                                                                                                                                                  2 Rd                                                                                                 Motorolla 68HC12 Board
                                                                                                                                                                                                                                                                       (Provided by RIT)
                                                                                                                                                                                                                                                                                                        1          ~$100.00
                                                                                                                                                                                                  Membership Function for the Error in the ball’s position
                 from surface                                                                                                                                                                                                                                          Servo Motors                     2          $15.00
                                                                                                                                                                                                                                                                       PC for Video Tracking            1          N/A
                                                                                                                                                                                                                                                                       (Provided by User)
                                                                                                                                                                                                                                                                       Lumber for construction          N/A        $25.00

                                                                                                                                                   da       g r           2              The same control system was applied to the                                   Copperplated Circuit Board       1          $5.00
       Target                   Servo        Final Ball
                                                                                                                                                                        axle            separate axes of the maze in a symmetrical                                   Etching Solution and materials   N/A        $20.00

                     +                                                        R
                                                                                                                                                         1  mr12 Rd
     Reference                  motor         position
      Position                  control                                           L
                                                                                                                                  R
                                                                                                                                                                                         fashion. One motor controlled the X axis, and the                            74LS151 8:1 Line Multiplexer     16         $10.00

                                 plant                              Z                                    d                                     d
                                                                                                                                       l                           ball                   other the Y axis. Each motor operates                                        74LS153 2:1 Line Multiplexer     2          $2.00
                                                                                                                                                                                          independently of each other, but use the same                                Various Connection pieces        N/A        $30.00
                                                                                                                                                                                                                                                                       (Headers, Jumpers, Cables)
                                                                                                                                                                                          algorithms.                                                                  Total:                                      $237.00
                          and feedback

 The whole system ties together to create a closed loop
 control system. The Video tracking determines the path
 for the ball to travel, while the HC12 concerns itself with
 controlling the motors based on input derived from the
 tracking software.

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