Embedded Systems Project III Ultrasonic 3D Digitizer (YD3-08

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					                                                                 Embedded Systems Project III: Ultrasonic 3D Digitizer (YD3-08)

                                                                 Members:                                                         Supervisor:
                                                                 KO Ka Ming                                                       Professor David K. K. YOUNG
                                                                 CHENG Cheuk Yan
                                                                 LAW Wing Hang




Introduction                                                                                                                                           System Flow Chat
In this project is to construct a ultrasonic 3D Digitizer that                                                                                        Move probe to point        Probe pointed to
                                                                                                                                                                                 object surface
used to perform the recognition of an object‘s 3D                                                                                                     to another point
                                                                                                                                                                         ON / OFF button
coordinate. The core part of this system is to use
                                                                                                                                                                                  button is pushed             Graph plotting
ultrasound sensors to measure the distance and then                                                   Receiver Array
                                                                                                                           ARM7
                                                                               Transmitting Probe                                     Time Of                            Signal Capturing
determine the three dimensional coordinates of object.                                                                                                                       Process                          Calculate target
                                                                                                                                       Flight
                                                                                                                                                                                           Time of Flight    point’s coordinate
                                                                                                                   coordinates                                                             signals
Methodology                                                                                                                                                NO
                                                                                                                                                                   Does Data capturing                      Calculate coordinate
                                                                                   Object                                                                            process finish?             YES           of Tx1 and Tx2
The working principle of our project is utilizing time of                                           Image reconstruction
flight, which is the traveling time between ultrasound                                                                                                 User’s decision
transmitters and ultrasound receivers.
   Time of flight (TOF)                                                            System Block Diagram                                               Result
                                                                                                                                                      A paper box is used to test in order to obtain the 3D
   Ultrasound                                             Ultrasound
   Transmitter                                             Receiver
                                                                                                                                                      coordinates. To measure the accuracy of the calculated
                           Transmitted Signal
                                                                                                                                                      coordinates, the 3D coordinates of all receivers needed to be
       Start counting time                      Stop counting time                                                                                    mapped accurately. And the calculation is obtained by
       when signal is emitted                   when signal is received                                                                               Trilateration Equation and least square algorithm.
                                    TOF

Get the time of flight signals between ultrasound
 transmitters and ultrasound receivers.
Convert the time of flight signals to traveling distances
Calculate the three dimensional coordinates of target
 point
Plot all points to illustrate the structure of object