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TEAM 9 - MRAV DESIGN CONSTRAINTS ANALYSIS. by Nick Gentry. UPDATED PSSC. An ability to remotely monitor remaining battery life (fuel gauge). An ability to hover in a stable position (based on autonomous stability / control algorithm).
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TEAM 9 - MRAVDESIGN CONSTRAINTS ANALYSIS by Nick Gentry
UPDATED PSSC An ability to remotely monitor remaining battery life (fuel gauge). An ability to hover in a stable position (based on autonomous stability / control algorithm). An ability to fly in any direction (compass orientation) at a variable speed and a stable altitude (based on autonomous stability / control algorithm). An ability to take off/land (ascend / descend) while remaining level (based on autonomous stability / control). 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). • WiFi module 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 Constraints: • Greater than 2:1 thrust to vehicle weight ratio • Current should not exceed 10A per motor @ 14.8V Selection: • 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 Constraints: • Must be able to source > 10A @ 14.8V Selection: • Turnigy Basic 18A ver3.1 • Lithium Cell Count: 2-4 • Maximum load current: 22A • Continuous Current: 18A
Battery • Constraints: • Must be able to supply > 50A @ 14.8V • Runtime > 10 minutes • Selection: • Turnigy Nano-Tech • 14.8V / 4500mAh • 25C Discharge Rate
Camera • Constraints: • CMOS sensor with resolution >640x480 pixels • On-board JPEG compression • Selection: • Toshiba TCM8240 • Max resolution of 1300x1040 pixels • 10:1 Internal JPEG compression • I2C interface
Wireless Module • Constraints: • Baud rate > 400kbps to achieve proper transmission of video and control data • Selection: • Roving Networks RN-131G • 802.11 b/g • WPA/WPA2 • 4uA sleep • 40mA Rx • 210mA Tx
Battery Monitor • Constraints: • Must be able to monitor 4 Li-Po Cells • Undercharge / Overcharge Protection • Selection: • MAXIM DS2788 1-10 Cell Li-Po Monitor • Parameters: Voltage, Current, and Temperature • Outputs remaining battery %
Primary Microcontroller • Constraints: • Purpose: Run Stability Algorithm • Peripherals • I2C x2 • SPI x1 • UART x2 • Six channels of 12-Bit ATD • Four channels of PWM • Selection: • Texas Instruments MSP430F5438 16-Bit 25MHz • 256KB Flash • 16KB Ram
Secondary Microcontroller • Constraints: • Purpose: Process video + WiFi interface • Peripherals • I2C x2 • UART x2 • Selection: • Texas Instruments MSP430F2618 16-Bit 16MHz • 116KB Flash • 8KB Ram
Airframe • Constraints: • Rigid structure • Lightweight / durable material • Selection: • Mikrokopter MK50 Frame • Extruded Aluminum beams • Carbon fiber base plate • 120 grams
14.8 VDC unreg5 VDC reg via LM7805 @ 1A 3 VDC reg via LM3940 @ 300mA 14.8 VDC Li-Po Battery Pack Power Supply Speed Controller Motor 2 2 2 Motor Speed Controller Speed Controller Motor Speed Controller Motor UART I2C 8 bits MSP430F2618TPN UART I2C System Block Diagram DB9 Reset Controller 16x2 LCD Max232 2 RESET SPI UART ADC PWM PWM I2C MSP430F5438TPN PWM PWM I2C UART Ultrasonic Range Sensor x6 6 3-Axis Accelerometer 3 3-Axis MEMS Gyroscope 3 CMOS Camera 3 Base Station (GUI Software) Wifi Module 2 4-Cell Battery Monitor 3