TEAM 9 -MRAV DESIGN CONSTRAINTS ANALYSIS by Nick Gentry
UPDATED PSSC 1. An ability to remotely monitor remaining battery life (fuel gauge). 2. An ability to hover in a stable position (based on autonomous stability / control algorithm). 3. An ability to fly in any direction (compass orientation) at a variable speed and a stable altitude (based on autonomous stability / control algorithm). 4. An ability to take off/land (ascend / descend) while remaining level (based on autonomous stability / control). 5. An ability to remotely control flight functions (e.g., ascend, descend, hover, compass orientation, forward speed).
MAJOR DESIGN CONSTRAINTS Microcontroller must be able to run PID algorithm and Kalman filter at speeds > 50Hz Microcontroller must have SPI (x1), I2C (x4), UART (x3), PWM (x4), and ADC (x6). WiFimodule must have baud rate > 400kbps to stream JPEG compressed 640x480i video at ~4fps On-board power supply must be able to source 14.8V with max current draw of 50A Motors must provide enough thrust to achieve a 2:1 thrust to vehicle weight ratio
IMU (Inertial Measurement Unit) 3-Axis Gryoscope ITG3200 (I2C interface) 3-Axis Accelerometer LIS3LV02DQ (I2C interface) 3-Axis Magnetometer HMC6343 (I2C interface)
Brushless Motors Greater than 2:1 thrust to vehicle weight ratio Current should not exceed 10A per motor @ 14.8V MK2832/35 Brushless 14-Pole Lithium Cell Count: 4 Maximum load current: 10A No load speed: 760RPM/V Maximum Thrust (10x4.5 prop): 820g per motor
Electronic Speed Control Must be able to source > 10A @ 14.8V Turnigy Basic 18A ver3.1 Lithium Cell Count: 2-4 Maximum load current: 22A Continuous Current: 18A
Battery Must be able to supply > 50A @ 14.8V Runtime > 10 minutes Turnigy Nano-Tech 14.8V / 4500mAh 25C Discharge Rate
Camera CMOS sensor with resolution >640x480 pixels On-board JPEG compression Toshiba TCM8240 Max resolution of 1300x1040 pixels 10:1 Internal JPEG compression I 2 C interface
Wireless Module Baud rate > 400kbps to achieve proper transmission of video and control data Roving Networks RN-131G 802.11 b/g WPA/WPA2 4uA sleep 40mA Rx 210mA Tx
Battery Monitor Must be able to monitor 4 Li-Po Cells Undercharge / Overcharge Protection MAXIM DS2788 1-10 Cell Li-Po Monitor Parameters: Voltage, Current, and Temperature Outputs remaining battery %
Primary Microcontroller Purpose: Run Stability Algorithm Peripherals I 2 C x2 SPI x1 UART x2 Six channels of 12-Bit ATD Four channels of PWM Texas Instruments MSP430F5438 16-Bit 25MHz 256KB Flash 16KB Ram
Secondary Microcontroller Purpose: Process video + WiFi interface Peripherals I 2 C x2 UART x2 Texas Instruments MSP430F2618 16-Bit 16MHz 116KB Flash 8KB Ram
Airframe Rigid structure Lightweight / durable material Mikrokopter MK50 Frame Extruded Aluminum beams Carbon fiber base plate 120 grams
System Block Diagram 14.8 VDC Li-Po Battery Pack Power Supply 14.8 VDC unreg 5 VDC reg via LM7805 @ 1A 3 VDC reg via LM3940 @ 300mA DB9 Reset Controller 16x2 LCD 2 2 Max232 2 Ultrasonic Range Sensor x6 3-Axis Accelerometer 6 3 RESET SPI UART ADC PWM PWM I 2 C MSP430F5438TPN PWM PWM Speed Controller Speed Controller Speed Controller Motor Motor Motor 3-Axis MEMS Gyroscope 3 I 2 C UART Speed Controller Motor 2 CMOS Camera 3 I 2 C UART 8 bits MSP430F2618TPN UART 2 Wifi Module Base Station (GUI Software) 4-Cell Battery Monitor 3 I 2 C
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