trol development framework that combines

theoretical design tools and experimental

procedures so that control engineers can eas-

ily synthesized, implement and test flight

controllers on small UAV systems in a safer,

cost effective and time efficient way.

The traditional approach used in manned

aircraft and large UAV system for synthe-

sizing, implementing and validating the

flight control system to achieve desired

objectives is time consuming and resource

intensive. Applying the same techniques

to small UAVs is not productive.

To increase the speed of the development

cycle, simulation through flight test and

improve system reliability and robustness

of the flight control system, it is important

to develop an integrated framework to the

flight control design process with a set of

design tools that enables control engineer

to rapidly synthesize, implement, analyze

and validate a candidate controller design

using iterative development cycles.

The development tools provides a system-

atic approach for an integrated flight con-

The UAV testbed used is a commercial

off-the-shelf (COTS) Radio-Controlled

(RC) plane that has conventional horizon-

tal and vertical tail with rudder and eleva-

tor control surfaces and symmetrical

airfoil wing with aileron control sur-

faces. The propulsion system consists

of a 600 watts electric outrunner motor

used to drive a 12 x 6 propeller.

The UAV is instrumented with a suite of

avionics for the flight control develop-

ment research and testing. The IMU/GPS

sensor provides angular rates, linear accel-

erations, magnetic fields, airspeed, baro-

metric altitude, GPS positions and veloci-

ties measurement data.

The flight computer uses eCos real-time

operating system. Sensor data are acquired

into the flight computer and attitude deter-

Integrated framework for flight control development

Introduction CONTENT

Introduction 1

UAV Testbed 1-2

PIL Simulator 3

MPC 5200

software

4

Simulation

software

5

UAV Testbed

Small UAV System

Research & Development Testbed N O V E M B E R 2 0 0 9 U A V R E S E A R C H G R O U P

UNIVERSITY OF MINNESOTA

Aerospace Engineering And mechanics

Ultrastick UAV testbed

P A G E 2

UAV Testbed determination is done with the acquired sensor

data. At the same time, the flight computer

outputs Pulse-Width Modulated (PWM) sig-

nals to drive the servo actuators and sends te-

lemetry data information to the wireless data

modem. A failsafe switch board is used as a

safety precaution to switch between flight

computer commands and manual RC pilot

commands.

The cost for the basic Ultrastick RC airplane is

given in Table 1 and Table 2 provides cost for

the UAV avionics system.

UAV physical geometry

Flight avionics system architecture layout

Table 1. Component cost for Ultrastick RC airplane

Component Unit cost Qty Total cost www link

Ultrastick 25e RC plane $ 170.00 1 $ 170.00 http://www.horizonhobby.com

E-flite Power 25 BL Outrunner motor $ 85.00 1 $ 85.00 http://www.horizonhobby.com

Castle Creation Phoenix 45 speed controller $ 102.00 1 $ 102.00 http://www.castlecreations.com

Thunderpower TP4200 3S2PL Li-po battery $ 125.00 1 $ 125.00 http://thunderpowerrc.com

Spektrum DX7 DSM 2 RC system $ 500.00 1 $ 500.00 http://www.spektrumrc.com/

APC 12 x 6E propeller $ 4.00 1 $ 4.00 http://www.apcprop.com

Hitec HS-225BB servo $ 21.00 4 $ 84.00 http://www.hitecrcd.com/

Total $ 1,070.00

Component Unit cost Qty Total cost www link

Phytec-phycore-MPC5200 $ 500.00 1 $ 500.00 http://www.phytec.com

ADIS16405 IMU $ 745.00 1 $ 745.00 http://www.analog.com

Thunderpower TP1320 3SPL Li-po battery $ 45.00 1 $ 45.00 http://thunderpowerrc.com

Crescent OEM GPS board $ 280.00 1 $ 280.00 http://www.hemispheregps.com

RxMux Failsafe board $ 80.00 1 $ 80.00 http://www.acroname.com

Castle Creation BEC 5 volt regulator $ 22.00 1 $ 22.00 http://www.castlecreations.com

Xtend OEM RF Modules $ 499.00 1 $ 499.00 http://www.digi.com

Total $ 2,171.00

Table 2. Component cost for UAV avionics system

Processor-in-the-loop Simulator P A G E 3

The PIL simulator setup includes the actual embedded flight computer with the simulation environment

outputting sensor data through a communication link to the target processor that executes the embedded

software code in real-time. The flight computer uses the fed back sensor data to generate control signals

which are sent back to the simulation model using another communication link to control the nonlinear

UAV simulation model. This approach provides an intermediate step to test the synthesized controller on

actual hardware target processor before the controller is put on actual flight test. The hardware compo-

nent list for the PIL setup is given Table 3.

Processor-in-the-loop system architecture

Table 3. Processor-in-the-loop hardware component list

Phytec MPC 5200 software P A G E 4

The required software needed to load, install and develop applications for the Phyetec MPC5200b-tiny using eCos (embedded

configurable operating system) in Windows XP operating system are listed in the Table 4.

The tftp server is required to load embedded programs trough Ethernet. You could use any tftd server different to

Tftp32. Also, Hyperterminal could be replaced by other serial communication software. The required software needed

to load, install and develop applications over the Phyetec MPC5200b-tiny in GNU/Linux operating system are listed

in the Table 5. The tftp server is required to load embedded programs through Ethernet. You can use any tftd server

different to tftd-hpa. Also, Cutecom can be replaced by other serial communication software.

eCos and RedBoot software are the same for Windows XP and GNU/Linux operating systems, under windows XP

eCos runs using Cygwin as Linux emulator. The functions of Cutecom and Hyperterminal are to communicate with

the embedded board and it is possible to use other program to replace Hyperterminal and Cutecom.

Table 4. Software tools for MPC5200 installation and development Table 5. Software tools for GNU/Linux

Processor-in-the-loop simulator setup

PIL Simulation Software P A G E 5

The Simulation model needs a timer counter card, NI PCI6602, to run. It is recommended to use a desktop computer

with the following specification:

• At least 1 GB of RAM memory

• At least 2 GHz Processor

• At least 128 MB Graphic card

Table 6 shows the required software to run the simulation using Matlab Real-time Windows Target Toolbox.

Table 6. Software tools required for simulation computer

107 Akerman Hall

110 Union St SE

Minneapolis, MN 55455-0153

Phone: 612-625-6561

Fax: 612-626-1558

E-mail: balas@aem.umn.edu

UAV webpage: http://www.aem.umn.edu/~uav/

Aerospace Engineering & Mechanics

University of Minnesota