1

Technical Article

August 2014

Creating an Electric Aircraft

The automobile industry has seen recent significant developments

in R&D of low-emission vehicles, as evidenced by electric vehicles

(EV) and hybrid vehicles (HEV), but efforts on low-emission tech-

nology in the aviation industry have only just begun. This is because

using electric motor power was thought to be unrealistic due to

aircrafts having greater restrictions than automobiles in terms of

weight and energy density. However, with significant developments

in high-performance, low-cost electric motor systems and specific

usages and categories, electric aircrafts can now be fully achieved

with existing technology, and expectations for that are growing.

World’s First Research

At company X, the “Jisedai Koku Kenkyukai (translation: Next

Generation Aviation Research Association)” is active as a self-devel-

opment activity. Amid growing demands for electrifying aircraft

systems and the market trend for smaller and lighter bodies, this

research association is focused on the development of compact

electric aircrafts, and it is working on the research and manufac-

ture of the world’s first electric unmanned aircraft with an ultra-

lightweight motor that uses automobile mass production electric

technology. Association member, Yuichi Kawasaki discusses the

goals of the project. “Although the term ‘environmental perfor-

mance’ is now commonplace in the automobile industry, efforts to

improve the environmental performance in the aviation industry, in

particular with compact aircraft, have just begun. While there are

various methods for improving the environmental performance, our

research is looking at the method of electrifying aircraft systems. In

terms of aircraft, electrifying aircraft systems will greatly improve

not only the environmental performance but also convenience.”

Kawasaki continues, “The goal of our research is to create and fly

an electric aircraft that is large enough for someone to ride. In this

way, we are able to master the skill of creating an electric aircraft

with our own hands and create a track record of production. In

addition, we want to shed light on the usability and issues when

creating an electric aircraft, and apply those in developing the next

completely original aircraft. It is also meaningful for helping our

young employees gain new skills and for motivating them.”

During the research, the team created a prototype equipped with

an electric system using mass-produced automobile electric parts

based on an existing ultra light plane, and they performed tests

using an electric power system on the ground and in the air. An

As automobiles and transportation equipment become increasingly reliant on electronics and the implemented control software grows in scale, efficient software development has become a major challenge. Rapid prototyping, which immediately verifies the control software simulated through desk top studies, is one method for efficient development of control software. This article takes a look at the implementation of the Vector VN8900 system as a rapid prototyping application in the world’s first R&D of the electric aircraft that uses automobile mass production electric motor technology.

Electric Aircraft R&D Using VN8900

2

Technical Article

August 2014

unmanned jump flight test was held, and the following comparison

verification was performed as a performance verification.

•Assumed flight performance as estimated using the electric

power system specs

•Flight performance obtained from testing

•Flight performance of existing system

The Maxair Drifter XP503 was selected as the base model of the

prototype. The engine and fuel system of the base model were retro-

fitted with an electric power system comprising a mass-produced

automobile motor, battery, and inverter (Figs. 1 and 2).

Rapid Prototyping Using the VN8900 System

Each unit in the prototype communicates using CAN communica-

tion. Each unit is connected to the CAN controller, which determines

the output of the motor from the battery information and throttle

signal received from the radio-controlled receiver. The VN8900,

next-generation network interface from Vector, was adopted for

this CAN controller. “The units used in this research were also used

in automobiles and needed to be controlled by CAN communica-

tion. Also, because the software for mass-produced goods could

not be changed, multiple units could not be connected to the same

Fig. 2:Overview of the electric power system

Fig. 1:Changes to the prototype from the base model

3

Technical Article

August 2014

to ensure that the output matched the torque commands.

The VN8900 system can be used in a standalone operating mode

as a real-time execution PC. By downloading the configuration file

from Vector’s vehicle network development tool CANoe to VN8900;

it is possible to perform simulations without having to connect to

a user PC, enabling construction of a simple gateway ECU and use

as a rapid prototyping application. Kawasaki explains, “With a

system that had multiple CAN buses, as in this research, the ECU

must have functioned as a gateway. Because the VN8900 system

could use the CANoe configuration, it allowed very easy handling

when constructing an ECU that connected multiple CAN buses and

also operated as a gateway by using rapid prototyping. In addition,

because the system could also be used as the CANoe and CANalyzer

interface, we confirmed the values on the CAN bus via CANoe while

executing the control model connected to the system of the actual

device. This enabled us to reduce the time needed to confirm the

operations of the model.”

Multi-bus Interface Realizing High Real-time Performance

The compact and highly durable body of the VN8900 system comprises

modules embedded with the VN8910A basic unit and the plug-in

modules that of either the VN8950 (support for CAN, LIN, J1708) or

VN8970 (support for FlexRay, CAN, LIN, J1708) (Figs. 3 and 4).

CAN bus, so there was a need to provide four CAN ports on the ECU

controlling the entire body. Because both signal input from the

radio-controlled receiver and relay control output were required,

there was also a need for a few analog and digital inputs and

outputs,” Kawasaki recalls.

He continued, “As this self-development activity was held after

work hours, the time for development was limited, so we wanted

to shorten the development time using rapid prototyping. While

several companies offer solutions to achieve rapid prototyping,

all of them had extremely high functionality and were expensive,

and even the hardware alone was very much out of our reach. The

VN8900 system enabled realization of rapid prototyping, provided

the necessary number of inputs and outputs and CAN ports in a

compact body, and met the needs of our research with an extremely

high cost performance. In addition, we used the CANoe testing envi-

ronment in the office, so the ease of handling was another huge

reason for selecting the VN8900 system.”

A control model constructed with MATLAB/Simulink™ was

implemented in the VN8900 system, enabling rapid prototyping.

By turning on the main switch, each unit started up and began

communication with the CAN controller. The CAN controller deter-

mined the information sent from each unit and the signal sent from

the receiver, connected the battery, powers the inverter, and sent

torque commands to the inverter. The inverter controlled the motor

Fig. 3:(Front) VN8910A single module system, VN8970 plug-in module (support for FlexRay, CAN, LIN, J1708) and piggybacked system equipped with transceiver(Left in a vertically stood state) VN8950 plug-in module (support for CAN, LIN, J1708)(Back) Rear view of VN8910A single module system with connecting parts and keypad for standalone mode

Fig. 4:Overview of VN8900 system

4

Technical Article

August 2014

Figures:Cover image, figures 1 and 2: Company X: Jisedai Koku Kenkyukai (translation: Next

Generation Aviation Research Association)”,

Figures 3 and 4: Vector Japan

Contact in Japan for further information:Sales Division, Vector Japan Co., Ltd.

[Tokyo] Tel: +81 3-5769-6980 Fax: +81 3-5769-6975

[Nagoya] Tel: +81 52-238-5020 Fax: +81 52-238-5077

Email: sales@jp.vector.com

Find your local contact person:www.vector.com/contact

It can support up to eight CAN/LIN channels, and the inte-

grated I/O interface enables various types of access to the ECU. It

is ideal for parallel access to multiple bus channels and I/Os with

high requirements on real-time performance and latencies. It also

supports plug-and-play and can be easily configured via USB 2.0.

When using the USB interface, the USB interface latency can affect

the real-time behavior depending on the system, but the VN8900

system does not transfer real-time data via USB, thereby elimi-

nating the latency and enabling use of the USB interface without

USB latency.

Future Outlook

During this research, mass-produced automobile electric parts were

used to construct an electric system for an electric aircraft as exper-

imental research for the practical application of electric aircraft.

A prototype equipped with an electric power system based on an

ultra light plane was also created. In the next stage, a new frame

will be designed, and a completely unique prototype equipped with

this electric system is planned to be created.Kawasaki says, “The

attempt to create an electric aircraft using automobile parts has

just started, even globally. By using mass-produced parts, we were

able to quickly and inexpensively construct a system that cannot

be realized with an engine aircraft, and we were able to boost our

confidence for future development. Of course, the VN8900 system

played a huge role, and we expect it to continue be important in

future research. The VN8900 system has high potential, and it has

not been fully utilized in the current control model. In the future, we

will include the attitude control of the frame in the control model,

and we will take on other facets including automatic pilot.”