TEAM 9 - MRAVDESIGN CONSTRAINTS ANALYSIS

by Nick Gentry

UPDATED PSSC1. 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).• 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 GryoscopeITG3200 (I2C interface)

3-Axis MagnetometerHMC6343 (I2C interface)

3-Axis AccelerometerLIS3LV02DQ (I2C interface)

Brushless MotorsConstraints:

• 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 ControlConstraints:

• 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

BatteryConstraints:

• Must be able to supply > 50A @ 14.8V• Runtime > 10 minutes

Selection:• Turnigy Nano-Tech• 14.8V / 4500mAh• 25C Discharge Rate

CameraConstraints:

• 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 ModuleConstraints:

• 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 MonitorConstraints:

• 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 MicrocontrollerConstraints:

• 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

Constraints:• Purpose: Process video + WiFi interface• Peripherals

• I2C x2• UART x2

Selection:• Texas Instruments MSP430F2618 16-Bit 16MHz• 116KB Flash• 8KB Ram

Secondary Microcontroller

Constraints:• Rigid structure• Lightweight / durable material

Selection:• Mikrokopter MK50 Frame• Extruded Aluminum beams• Carbon fiber base plate• 120 grams

Airframe

Power Supply

14.8 VDC unreg5 VDC reg via LM7805 @ 1A 3 VDC reg via LM3940 @ 300mA

14.8 VDC Li-Po Battery Pack

UARTI2C

8 bits MSP430F2618TPN UART I2C

2

3-Axis Accelerometer

3-Axis MEMS Gyroscope

Ultrasonic Range Sensor x6

Speed Controller

Speed Controller

Speed Controller

Motor

Motor

Motor

MotorSpeed Controller

DB9

Max23216x2 LCD

2

Wifi Module

Base Station (GUI

Software)

4-Cell Battery Monitor

3

3

6

Reset Controller

RESET SPI UART ADC PWM

PWMI2C MSP430F5438TPN PWM

PWM

I2C UART

2

2

3

3

CMOS Camera

2

System Block Diagram

The END