Hava aracı otopilot destek sistemi olarak bir pilot sağlık takip sistemi tasarımı, prototiplenmesi ve entegrasyonu
Design, prototyping and integration of a pilot health monitoring system as a support system for aircraft autopilot
Yazar: EFKAN YILMAZ
Danışman: DR. ÖĞR. ÜYESİ RAMAZAN YENİÇERİ
İstanbul Teknik Üniversitesi / Fen Bilimleri Enstitüsü / Mekatronik Mühendisliği Ana Bilim Dalı / Mekatronik Mühendisliği Bilim Dalı
Derece: Yüksek Lisans, 2020
Konu: Elektrik ve Elektronik Mühendisliği = Electrical and Electronics Engineering ; Mekatronik Mühendisliği = Mechatronics Engineering ; Uçak Mühendisliği = Aircraft Engineering
Dizin: Baskı devre = Printed circuit ; Baskı devre kartları = Printed circuit boards ; Biyosensörler = Biosensors ; Elektronik devreler = Electronic circuits ; Optik sensörler = Optical sensors ; Savaş uçakları = Fighter aircrafts ; Yolcu uçakları = Passenger aircrafts

Özet:
Günümüzde insan faktörü, neredeyse her sektörde önemli bir parametre olarak değerlendirilmekte ve bu yönüyle bir çok araştırmacının dikkatini çekip, çeşitli araştırmalara konu olmaktadır. Özellikle havacılık, insan faktörü konusunun daha da önem kazandığı bir sektördür. Sivil ve askeri havacılık kazaları düşünüldüğünde, bu kazaların %70-80 oranında insan hatası kaynaklı ortaya çıktığı görülmüştür. Ancak bugüne kadar çoğu kaza raporlama sistemi insan faktörünün teorik çerçevesi etrafında tasarlanmamıştır. Bu sebeple pilotların hatalı ya da eksik davranışlar sergilemesindeki temel faktörlerin kaynağı tam olarak belirlenememiştir. Gerekli olan, etrafında yeni araştırma yöntemlerinin tasarlanabileceği ve bu kazalara sebebiyet veren genel bir insan hatası çerçevesi belirlenmesidir. Son yirmi yıl boyunca, uçuş sırasında pilot iş yükünü değerlendirme ihtiyacı, yeni uçakların, sistemlerin ve işletme prosedürlerinin geliştirilmesinde önemli bir faktör haline gelmiştir. Son zamanlarda bu ihtiyaçları karşılamak için pilotların sağlık durumu ve iş yoğunluğu arasında çeşitli bağlantılar kurulması üzerine çalışmalar yapılmaktadır. Bu çalışmalar incelendiğinde, pilotların bilişsel ve fiziksel aktivitelerinin uçuş esnasında önemli parametre haline geldiği gözlenmiştir. Bu aktivitelerin tespit edilmesi, askeri uçaklarda görev etkinliğini, sivil uçaklarda ise güvenliği artırmada önemli bir yapıtaşı olacağı düşünülmektedir.

Bu tez kapsamında, hava aracı kontrolünde döngüdeki pilotun yerine otopilotun geçmesi gereken pilot sağlığı ile ilgili şartları yakalayan bir pilot iş yükü ve sağlık takibi sistemi geliştirilmiştir. Sistem, hava aracı kontrolünde pilot kaynaklı problemleri minumum seviyeye indirmeyi amaçlar. Tez çalışmasında, ataletsel ölçüm sensörü, nabız sensörü, kızılötesi sensör, ARM tabanlı mikrodenetleyici, batarya ve besleme katı barındıran bir donanım (elektronik kart) tasarlanmış ve prototiplenmiştir. Bu donanım üzerinde çalışan, pilotun baş oryantasyonunu, nabzını ve göz kırpma sıklığını ölçen, yorumlayan, otopilot ve uçuş görev bilgisayarı için çıkış üreten bir gömülü yazılım geliştirilmiştir. Kask, gözlük ve uçuş simülatörü ile entegrasyon tamamlanmış ve test uçuşları ile veri toplanmıştır. Elde edilen veriler ayıklanmış, otopilot geçişleri için kritik eşikler tespit edilmiştir. Prototipi ile test edilen sistem, otopilot entegrasyonu sürecine hazır hale getirilmiş ve bu süreç gelecek çalışma olarak önerilmiştir.

Abstract:
Nowadays, the human factor is considered as an important parameter in almost every sector, and in this respect, it attracts the attention of many researchers and is subject to various researches. In particular, aviation is a sector in which the human factor issue becomes more important. Considering civil and military aviation accidents, it has been observed that 70-80% of these accidents occurred due to human error. But so far, most accident reporting system is not designed around the theoretical framework of the human factor. For this reason, the source of the main factors in pilots' displaying erroneous or incomplete behaviors has not been determined exactly. The necessary solution is to identify a general human error framework which causes these accidents.
During the design, development, testing and evaluation of any aircraft system, the capabilities and limits of the crew on board should be considered. These limits must be correctly defined in order for the crew to process too much information in a short time without producing erroneous or incomplete behavior and to put it in logical behavior. The evaluation and definition of these limits is defined as the determination of the pilot's workload.

The progressive development of subsystems in the light of today's technologies has become a factor that alleviates the workload of the pilot. All these developments, redundancy criteria and safety procedures in aircraft make pilots the weakest link in the aircraft. For this reason, determining the workload or health status of the pilot constitutes an important place in terms of flight safety.
Although existing air force aircraft and civil aircraft have advanced technologies, they put cognitive or physical pressure on the pilot. For a more reliable completion of a flight mission, the operator's workload and health status must be monitored continuously and in a way that does not interfere with flight comfort.

When the literature on mental workload is reviewed, there are two results. This is that there is no single definition and universal measure of mental workload. The mental workload is a theoretical structure and can therefore be described as the best operational. Obviously, it concerns factors like operator stress and effort, but these concepts also require operational definitions.

Over the past two decades, the need to assess the pilot workload during flight has become an important factor in the development of new aircraft, systems and operating procedures. Recently, studies have been made to establish various connections between the health status and workload of pilots to meet these needs. When these studies were examined, it was observed that the cognitive and physical activities of the pilots became an important parameter during the flight. It is thought that determining these activities will be an important building block in increasing the task efficiency in military aircraft and security in civil aircraft. For this purpose, the health and workload of the pilot can be determined using robust and reliable techniques. For example, controlling oxygen consumption or measuring the heart rate depending on the pilot's breathing rate through the pilot mask is a common way to estimate workload. In addition, there are various studies aimed at evaluating the workload according to the blink speed and head position of the pilot.

Operator workload and cognitive status may vary proportionally according to changing flight scenarios and conditions. During normal flight, pilot workload contains a small amount of physical and cognitive load. In addition, in complex situation scenarios such as landing, take-off, dropping ammunition and refueling, this workload and cognitive state increase relative to normal flight.

In the pilot workload and health monitoring system, the physiological parameters required to monitor the workload and health status of the operator were determined as pulse rate, blink rate and head position. For this purpose, various sensors were examined for each physiological parameter and the most suitable one was selected. Besides these choices, microcontroller selection, which is at the center of the system architecture, is also an important factor. After these selection stages, design, production and integration processes were completed, test stages were performed in flight simulation.

Sensors in the system to be designed are very diverse because they use different sensing methods. Appropriate hardware components to work with these sensors have been identified and a system design has been realized. Various parameters such as price suitability, size, communication buses, power consumption, market availability are effectively evaluated during the determination of the sensors, controllers and hardware components used in the most system.

Heart rate sensors are used to measure people's heart activities. Pulse rate is the rate of the heart's beat, measured by the number of contractions per minute of the heart. Pulse rate varies according to the changing physical needs of the body, including oxygen absorption and carbon dioxide secretion. Pulse rate can be measured from various parts of the body and their numbers are equal in each region that can be measured. Pulse rate may vary in situations such as physical exercise, sleep, anxiety, stress, illness or medication. The pressure on the pilot may vary depending on the changing demands during a flight mission. These changing job demands simultaneously create an equivalent stress on the pilot. Pulse rate is one of the most effective tracking tools to detect this stress level.

Inertial measurement sensors (IMU) are electronic devices capable of measuring the specific force, angular velocity, and direction of a system using a combination of an accelerometer, gyroscope, and sometimes magnetometers. These sensors are typically used in a variety of systems, including unmanned aerial vehicles, aircraft, satellites, vehicles, electronic devices, and spacecraft. In the pilot workload and health monitoring system project, it is planned to obtain head position information for the determination of activities that will compromise the task process of the operator, such as fainting and sleep. Although it is known that there will not be unconsciousness due to high G or oxygen deficiency in the flight simulator environment, this is normal in real flights.

In the pilot workload and health monitoring system, it is planned to use blink detection module to detect indirectly increased stress levels with the increase of the workload of the operators. However, these modules must be supplied from abroad since they are not available in the domestic market. On the other hand, various difficulties can be encountered in terms of both material and time. In order to overcome all these difficulties and to progress the process as planned, this module has been developed to develop.

The software development works carried out within the scope of the project are divided into two. The first is the embedded software development, and the second is the user interface development. In the embedded software development process, there are studies on the selected development board. In this section, the relevant sensor data is processed so that the system can produce the specified outputs. The processed data are then recorded on the micro SD card located internally on the development board for analysis. In addition, the processed data is transferred to the user interface via micro USB in real time. The second stage, the user interface development section, consists of software development studies carried out to display the processed data transmitted via micro USB in the relevant sections of the user interface.

Since the development board used within the scope of the pilot workload and health monitoring system project is Teesny 3.5, the Teensyduino program integrated in the Arduino IDE compilation program is used as software. Since most programs written for Arduino can also work on Teensy, this development board offers a lot of advantages. In addition, Teensyduino is compatible with many Arduino libraries. In this way, there are ready-made libraries for many functions.

In the pilot workload and health monitoring system, it is aimed to display the pilot data received instantly on the operator screen. In this way, the pilot who performs the tasks in the flight simulator environment is instantly monitored through the user interface program. This user interface is designed on the Unity program. Unity is a game engine developed and published in Russia. It was first produced for a different purpose, and then it was used and developed to make games. But Unity 3D did not settle with this and developed itself further. Another reason for using Unity in the pilot workload and health monitoring system is that it is free.

This study consists of taking some physical changes of the operator as a parameter to determine the workload and health status of the operator during the flight, developing a suitable equipment in the light of these parameters and evaluating the workload and health status of the operator according to the changing flight scenarios. Finally, this system has been tested on the operator in a flight simulator environment and the changing health status and workload analysis of the operator has been made according to the flight scenarios determined.