Defender Turret Based Defense System Kirk Iler Brian

Defender Turret Based Defense System Kirk Iler Brian Bentz Stephen Wolf Fuhe Xu

Block Diagram

High Voltage Subsection • The transformer is designed to achieve a 510 V peak wave, and this will be rectified to 360 VRMS. • A charge enable switch will be set by the microcontroller to allow the capacitors to begin charging. • The capacitors we have acquired are rated for a maximum of 400 volts, so this is what the circuit is intended to achieve at maximum.

Capacitor Subsection • Charging Circuit: The capacitors will be charged to a set voltage by monitoring the charging circuit and stopping when the threshold is met. • Discharge Circuit: The capacitors can be slowly discharged without firing for testing and safety. • Firing Circuit: The capacitors can be quickly discharged through the coil in order to propel a projectile. The chassis mounted IGBT is rated for VCE of 600 V and a high pulse rating. It does not have a heat sink, but the time it will be allowing discharging is minimal.

Photodiode Subsection • A photodiode and phototransistor will be placed near the center of the barrel to monitor projectile position within the barrel. More will also be placed towards the end of the barrel to monitor the velocity of the projectile upon exiting. • The capacitor discharge must end when the projectile is halfway through the barrel or the projectile begins experiencing force in the opposite direction. • The photodiode will communicate to the microcontroller when the projectile has reached a certain point, and then the microcontroller will signal for the IGBT to be turned off and the capacitors to stop discharging.

Microcontroller Subsection • The microcontroller will serve as the communication center for the system. • Information will be gathered through I 2 C on charging, firing, and the state of the motors in order to be passed over USB to the Atom processor. • An I 2 C network was chosen to allow adaptability in the design. • The I 2 C network will be functioning at 100 k. Hz (0. 01 ms. ) The capacitor discharge timing only requires around 0. 1 ms of accuracy. • System commands will be taken from the Atom and sent over I 2 C to the appropriate circuit component. • Any quick calculations, such as when to stop the capacitor discharge when firing may need to take place on the microcontroller. • The microcontroller will also gather user identification data from a keypad encoder.

Atom Subsection • The Atom will be the processing center for the system. Information will be received from the microcontroller to be processed, and the determined commands will be sent back. • Image processing will be performed by the Atom in order to recognize targets and calculate how the motors need to turn. • The board will control the motors for a Canon-VC-V 50 i Pan-Tilt-Zoom camera, and the resulting images will be processed to determine where and when to aim and fire. • Audio warnings will be produced through a speaker interfaced to the board. • A computer will be connected by Ethernet to the Atom to provide the user interface.

Motor Subsection • Currently, the stepper motors will be run on a 12 V power supply. The barrel will be lightweight, so this should be sufficient. • Motors will be rotating two Lazy Susans over a limited range in order to aim at targets. • The motors will be direct drive due to simplicity, since more torque will not required.

Questions?