DISTRIBUTED EMBEDDED SYSTEM FOR ULTRALIGHT

AIRPLANE MONITORING

J. Kotzian and V. Srovnal, Jr.

Department of Measurement and Control, FEECS, VSB – Technical University of Ostrava, 17. listopadu 15

708 33 Ostrava – Poruba, Czech Republic

Keywords: Embedded systems, graphic interface, industrial bus, industrial sensors, operating systems, control system

design.

Abstract: This paper presents distributed embedded monitoring system that is developed for small aircrafts, sports and

ultralights airplanes. System is made from modules connected by industrial bus CAN. This low cost system

is trying to solve bad situation with many ultralights without any digital measurement unit due to their

prices. The contribution shows basic architecture of the embedded monitoring system and presents some

parts of hardware and software implementation. The interface between aviator and airplane is established

using graphic user interface based on operating system uClinux.

1 INTRODUCTION

This paper is concentrated to avionic system

especially to small sporting or ultralight airplanes.

Here is basic information about small airplanes.

Figure 1: Ultralight airplane – illustrative photo.

Ultralight airplane is constructed for maximally 2

persons, with a stalling speed lower than 65km/h and

a maximum flight weight of 450 kg. (Figure 1) Its

price is much lower than professional airplanes but it

is possible to fly for thousand kilometres. There are

many standards describe ultralight league in many

countries all over the world. The specification

mentioned above is validated for Europe especially

Czech Republic.

This project is focus on developing an alternative

to high price products. The project has been

developed together with the private company

FALKON Electronics. We have developed the

system architecture, which supports a flexible

configuration. The configuration can grow from

small, which measures basic values, to a wide range

system. This is possible thanks to the module

architecture.)

System is distributed into the independent

modules that measure specific value on mechanical

parts of the airplane. System is a configurable

according type of airplane. The highest layer is

graphic user module that represents received data on

the LCD display. Sense of monitoring system is

offer customers same facilities as have pilots in the

professional aircrafts and make aviation more easier

using low cost embedded electronic system.

2 AIRCRAFT MONITORING

VA L U E S

There are two basic groups of values which can be

measured. The first group includes flying values

such as attitude and air speed, the second group is

engine values as RPM and oil temperature. There is

448

Kotzian J. and Srovnal V. (2007).

DISTRIBUTED EMBEDDED SYSTEM FOR ULTRALIGHT AIRPLANE MONITORING.

In Proceedings of the Fourth International Conference on Informatics in Control, Automation and Robotics, pages 448-451

DOI: 10.5220/0001642804480451

 SciTePress

also a third group for other values such as battery

voltage, etc.

Fly values are the following:

• Attitude

• Altitude

• Airspeed

• Vertical Speed

• Gravitation

• GPS position

• Start, Fly, Actual Time

Engine values are the following:

• RPM

• Percent Power

• Oil temperature

• Oil pressure

• Cylinders temperatures

• Cylinders exhaust temperatures

The values that are mentioned above are only

basic group for our purposes. Using embedded

distributing system architecture we are able to

extended whole system within other values.

3 MONITORING SYSTEM

ARCHITECTURE

The real-time embedded control system is designed

with a modular structure (Li and Yao 2003). This

structure supports a flexible configuration. In terms

of user requirements, the control system can be

configured in different sizes and options. (Kotzian

and Srovnal 2004) Several modules with different

options were designed. All modules are connected to

an industrial bus – so each module is the bus node.

Except the GPS module, this is connected directly to

the main control module.

The block diagram of a desk control and

monitoring system with today’s full configuration of

prototype is shown in the Figure 2.

Designed modules are the following:

• Main control module

• User interface (LCD display) module

• Motor measuring values module

• Advanced avionic data module

• Black-Box module

Figure 2: Block diagram of monitoring system

4 SYSTEM MODULES

SPECIFICATION

The basic configuration contains only the User

Interface Module and the Main Control Module. The

Main Control Module has some basic inputs. Basic

values are connected to these inputs, which have to

be in the every airplane. The configuration can

measure attitude, altitude, airspeed, gravitation,

RPM, inside air temperature and battery voltage.

4.1 Communication Protocol

Monitoring modules are connected together by using

an industrial bus (Sridhar 2003). This bus has to be

highly reliable and have enough speed. Depending

on these two main requirements a CAN bus was

selected. The main reason is that the CAN has an

extremely low probability of non-detected error. The

versatility of the CAN system has proven itself

useful in other applications, including industrial

automation as well. A CAN bus is given the

international standard ISO11898 which uses the first

two layers of ISO/OSI model (CAN-CIA 2005).

(Kotzian and Srovnal 2003)

4.2 Main Control Module

The main control node serves as master for all other

nodes. (Arnold 2001) (Figure 3,4) Requesting values

from other nodes are compared with given limits and

stored in the local memory. The main module

decides what information will be display and send to

the user interface module by the CAN bus.

DISTRIBUTED EMBEDDED SYSTEM FOR ULTRALIGHT AIRPLANE MONITORING

449

Figure 3: Main control node block diagram.

The main control module contains a real time

clock and data flash memory for storing measured

values and statistics. For measuring basic values the

main module is equipped with the following

measuring sensors:

• CSDX0811BARO for the altitude

• CSDX0025D4R for the air speed

• 3 x gyro sensor ADXRS401 for the attitude

• Accelerometer MMA7261Q

Figure 4: Main control module prototype (testing).

4.3 GPS Receiver

The GPS receiver is a small module with the passive

antenna for receiving the position information from

the global position system GPS. For its small size,

good features and low price GPS Orcam 21SB was

selected. The GPS module is integrated into the

Main Control Module. External antenna is used due

to the mounting possibility outside the plane (better

GPS signal). The GPS module is connected by using

a standard serial interface and standard GPS.

4.4 User Interface Module

The user graphic interface module serves as an

interface between the user and all monitoring

systems. There are two variants of the user interface

module, an economical and comfort version.

The economical version includes the

monochrome LCD Display GM62121 with the

320*248 pixels resolution. The economical version

is equipped with a 16bit DSP controller without any

operating system so it supports only necessary

functions.

The comfort version includes a color TFT

Display PD064 with a 640x480 pixels resolution.

This version is equipped with a 32-bit processor

(PPC or ColdFire) and operating system RT Linux

(support MMU) (Hollabaugh 2002) or uClinux

(MMU less). (

Raghavan, Lad, Neelakandan 2006) There

is also communication USB interface for storing the

measured data in to the user USB devices (Service

and diagnostic system). The operator panel of the

comfort version is shown in the figure 5. The

cheapest version uses a DSP controller as a display

content computation and FPGA as a display driver.

Figure 5: Main operator panel in cockpit.

It is possible to select the avionic screen, engine

screen or GPS map screen.

The firmware is based on embedded operating

system Linux using 240 MHz processor core. There

are implemented 4 interfaces in the operating

system. Two communication interface – CAN,

RS232 and USB and one display interface FB

(framebuffer) with the driver. Graphic system is

built on GUI – microwindows or miniGUI.

Those graphic user interfaces using two graphic

libraries SDL (Simple DirectMedia Layer) and

OpenGL ES. SDL is cross-platform multimedia

library designed to provide low level access to

ICINCO 2007 - International Conference on Informatics in Control, Automation and Robotics

450

audio, keyboard, mouse, joystick, 3D hardware via

OpenGL, and 2D video framebuffer. OpenGL ES is

a royalty-free, cross-platform API for full-function

2D and 3D graphics on embedded systems.

Software implementation is base on Eclipse

Workbench.

4.5 Black-Box Module

The black-box module controls all traffic on the

CAN bus. It reads data from CAN messages and

stores data in the local memory. The black-box

module is equipped with its own RTC timer and

stores time together with the CAN data. There is no

other connection to this module with such high

reliability.

5 DEVELOPING SYSTEM

CONFIGURATION

The project is presently in last of developing state.

We are beginning with the final versions of the

modules. The Main Control Module is designed in

its final version and is under testing.

Figure 6: Evaluation kit for operator panel in cockpit.

Low cost version is based on EvbDSP module

with a DSP56F805 controller, six 8-bits ports, CAN,

SPI and serial interfaces and FPGA graphic driver

interface (User Interface Module). The EvbHCS12

module is equipped with a MC9S12DP256

controller (Main Control Module). This module

supports a wide range of interfaces: CAN, LIN,

serial, SPI, I2C and six 8-bit ports. The smallest

module is the EvbHCS08 with a MC9S08GT60

controller, LIN, SPI and serial interfaces,

temperature and humidity sensors and four 8-bit

ports (I/O devices). The comfort version has

different User Interface Module that is based on 32-

bit ColdFire controller (EvbMCF5329) with an

integrated display controller – GUI (Figure 6). For

EvbMCF5329 was used Linux BSP.(

Yaghmour 2003)

6 CONCLUSION

The development and realization of the avionic

control and monitoring system for ultra-light

airplanes is very important for increasing the safety

and security of pilots. The number of accidents of

ultra-light planes is too high, especially during the

starting and lending stages of flights. A low cost

flight control and monitoring system is the best way

to cut down on the number of accidents. The

developed monitoring system can be configured

from a minimal version to a wide system based on

customer requirements.

ACKNOWLEDGEMENTS

This project is being completed at VSB - Technical

University of Ostrava, Czech Republic. The work

and the contribution were supported by a project of

the Grant Agency of Czech Republic – 102/65/0571

Architectures of embedded system networks and

department of measurement and control.

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Sridhar T. (2003) Design Embedded Communications

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