The purpose of this paper is to present the effectiveness of a new teaching methods through all the graduation process for engineering students, ranging from the BSc to the MSc level. Two hundred undergraduate students in aerospace engineering at the Politecnico di Torino were involved in this teaching process. The paper presents the organization of the learning process through the different academic years. The process implicates theoretical lectures, computer laboratories, and experimental workbench, and shows how different multidisciplinary concepts and models, useful for the aerospace systems design, can be presented and then worked again in the next courses. In particular, an example concerning the flight control system is presented underlining how the models can be introduced at the third year, with the support of some engineering tools, and then reprised and developed in more details at the fifth year, with an effective and quick heritage of knowledge. Speakers Prof. Paolo Maggiore, Politecnico di Torino

1. Altair E-ATC 2015

2. Purpose of this presentation
• To present the effectiveness of a new teaching methods through all the
graduation process for engineering students, ranging from the BSc to the MSc level,
with the support of PhD students.
• The organization of the learning process is a recurring process through the different
academic years. More than two hundred undergraduate students in aerospace
engineering at the Politecnico di Torino are involved in this teaching process.

3. Purpose of this presentation
• The process implicates theoretical lectures, computer laboratories, experimental
workbench, and invited lecturers from the aerospace industry, and shows how different
multidisciplinary concepts and models, useful for the aerospace systems design, can be
presented and then worked again in the next courses.
• An example concerning the flight control system is presented underlining how the models
can be introduced at the third year (3°BSc), with the support of some engineering tools,
and then reprised and developed in more details at the fifth year (2°MSC), with an
effective and quick heritage of knowledge.

4. Courses involved
Course
code
Course Title
Ects
points
Year
01OQDMN Introduction to Aerospace Engineering 6 1° BSc
01MZBLZ Aerospace System Engineering and On-Board Systems 6 3° BSc
01PETMT Modelling, Simulation and Testing of the Aerospace Systems 12 2° MSc
01OQDMN 01MZBLZ 01PETMT
Aerospace engineering BSc Aerospace engineering MSc
3D CAD modelling
knowledge from
other courses
N° of students
enrolled >200
N° of students
enrolled >200
N° of students
enrolled ~60

5. BSc Aerospace Engineering Course
The aim of the course is to provide a global description of the aerospace systems, pointing
out how their architectures and characteristics have changed during the evolution of the
technology development; they are complex products comprised of many subsystems which
meet demanding customer and operational value requirements. This picture, applicable to
any other technologically advanced engineering product, introduces to the system theory
approach in the engineering field which is based on the necessity to cope with many inter-
connections among the disciplines that will also be explored in details in the following of the
engineering studies. This course adopts a holistic approach to the aerospace product,
understood as a system along its whole lifecycle, covering: basic systems engineering; cost
and weight estimation; basic aircraft performance; safety and reliability; lifecycle topics;
aircraft subsystems; risk analysis and management; and system realization.
This approach would provide the student with:
1) a sketch of the main characteristics and role of the different engineering disciplines
concurring to the product design,
2) the strengthening of a mental logical scheme to better understand the connections
among disciplines from the system engineering point of view.
01OQDMN Introduction to Aerospace Engineering 6 1° BSc

6. Case study: Flight Mechanics and flight controls system.
3 lessons: a general description of performed functions and inter-
connections among the other disciplines and aircraft sub-
systems are presented.
01OQDMN Introduction to Aerospace Engineering
BSc Aerospace Engineering Course

7. BSc Aerospace Engineering Course
Aircraft and spacecraft are complex products comprised of many systems which must meet
demanding customer and operational lifecycle value requirements.
The aim of this course is to provide the students with an understanding of the fundamental
concepts of aerospace systems, in multi-disciplinary applications with complex interactions
typical of the system design engineering. In particular, the course aims to expand the
students’ knowledge of airborne systems, their role, design and integration, providing
students with an appreciation of the considerations necessary when selecting aircraft on-
board systems and the effect of systems on the aircraft as a whole, with a practical and
qualitative appreciation of the systems which aircraft carry on-board to enable them to
function safely and effectively. A quick overview on space system will be also given.
Topics will include aviation fundamentals, basic airmanship, aerospace physics elements,
basic aerodynamics, performances, stability & control, safety and operating costs.
01MZBLZ Aerospace System Engineering and On-Board Systems 6 3° BSc

8. BSc Aerospace Engineering Courses
Case study: flight controls system.
6 lessons: detailed description, design principles, performances,
components and inter-connections among the other aircraft sub-
systems are presented.
01MZBLZ Aerospace System Engineering and On-Board Systems

9. BSc Aerospace Engineering Courses
Computer laboratories: 4 lessons
1) Study of the aircraft manufacturer schemes and 3D
taking of the real flight controls lines.
01MZBLZ Aerospace System Engineering and On-Board Systems

10. BSc Aerospace Engineering Courses
01MZBLZ Aerospace System Engineering and On-Board Systems
Longitudinal
mechanic
reversible control
2) 3D CAD modelling of the flight controls lines.

11. BSc Aerospace Engineering Courses
3) 3D CAD modelling of the flight controls lines.
01MZBLZ Aerospace System Engineering and On-Board Systems

12. BSc Aerospace Engineering Courses
4) Modelling of the controls lines within a multibody environment.
01MZBLZ Aerospace System Engineering and On-Board Systems
Cinematic analysis
Clashing control
Gear ratio and ergonomic
evaluation

13. MSc Aerospace Engineering Course
Subject fundamentals
This course serves as an introduction to the modelling techniques of nonlinear lumped-
parameters control systems, arising in aerospace engineering.
Applications are drawn from aerospace servo-mechanisms, with special reference to
primary flight controls.
Lectures refer to the "V"-model of Systems Engineering, with special emphasis on the
importance of the safety, requirements, and on the component and subsystem test
and integration as well as functional testing.
Moreover, the course also introduces some methods and techniques useful in the
design of complex systems like Multidisciplinary System Design Optimization (MSDO)
and Simultaneous Engineering (SE).
01PETMT Modelling, Simulation and Testing of the Aerospace Systems 12 2° MSc

14. MSc Aerospace Engineering Course
Expected learning outcomes
Demonstrate knowledge about the systems design process and understand the role
and the importance of the systems modelling, simulation and testing activities
application along the design phases. Ability to create non linear models of different
components of a typical aerospace control system. Ability to integrate low hierarchy
models to define a more complex multidisciplinary model of a system by the use of
commercial programming tools.
Demonstrate knowledge and understanding about laboratory testing activity,
managing control laws. Ability to conduct simple experiments on a laboratory
workbench, carrying out test activities.
01PETMT Modelling, Simulation and Testing of the Aerospace Systems 12 2° MSc

15. MSc Aerospace Engineering Course
Delivery modes
The course consists of lectures interspersed with hands-on practice (at least 40% of the total
number of hours for the course) followed by exercises, based on the material covered in the
lecture, with the continuous support of the teacher. The exercises are conducted in the
computer laboratory mainly by the use of Matlab-Simulink tool. Several non-linear models of
different types of recent aerospace servo-mechanisms (primary flight controls) are
developed by the student under the teacher guide. The simulation results are discussed and
compared. They are collected on a student’s individual project report to be discussed at the
final exam. Practical exercises are also provided by a laboratory workbench representing a
modern fly-by-wire primary flight controls scheme, with a position loop computer having a
parametric gain settings unit, and a dedicated data acquisition board.
The course is split into two parts: general and applicative.
01PETMT Modelling, Simulation and Testing of the Aerospace Systems 12 2° MSc

16. MSc Aerospace Engineering Course
General part
Basics of model theory and time domain numerical simulation of lumped parameter systems techniques.
System design engineering and role played by modelling, simulation and testing. "V"-model of Systems Engineering:
needs identification, requirements formulation, concept generation and selection, trade studies, preliminary and
detailed design; definition of component and subsystem test plan and integration, as well as functional verification
testing.
Types of nonlinearities of servo-mechanisms.
Primary flight controls description, with special reference to fly-by-wire architectures integrating Electro Hydrostatic and
Electro Mechanical Actuators (EHA and EMA).
Basics of safety and reliability in systems design. Fault tolerant architectures for primary flight controls. Diagnostics and
prognostics techniques in safety critical control systems.
Application of numerical simulation on nonlinear servo-mechanism.
General programming techniques for the non-linear numerical simulation starting from the existing sub-systems models;
analysis and comparison between different approaches. Trade-off analysis between dynamical models, with different
typology and complexity, of a specific component or sub-system. Relevant applications of aerospace dynamic
systems.
Commercial tools and techniques for system simulation. Analysis of the numerical problems of time domain simulation.
Outline of multidisciplinary integrated design techniques: concurrent e simultaneous engineering (SE).
Outline of the multidisciplinary design system optimization (MDSO) methodology.
Generality of aerospace systems testing. Workbench and sensors calibration. Design of experiments techniques.
Testing equipment and sensors integration.
01PETMT Modelling, Simulation and Testing of the Aerospace Systems 12 2° MSc

17. MSc Aerospace Engineering Course
Application part
Modelling of flight controls components; 1) electro-mechanical parts: DC motor, variable displacement hydraulic
pumps, screw jacks, hydraulic cylinders, flight control surfaces and mechanic links, 2) control and regulation parts:
hydraulic servo-valves, relief valves, sensors, position control loop algorithms. Several models for each components will
be developed with increasing level of complexity, including non-linear effects (clearances, coulomb friction,
saturations, hysteresis, etc..).
Complete electro-fluid-dynamic model of a servo-valve with fourth and third orders formulation. Possible simplification
to the first order and instantaneous formulation. Pros and cons comparison. High lift device actuation unit modelling:
hydraulic motor + fail safe transmission torsion shaft + linear actuators + no back brakes.
Complete electro-fluid-dynamic model of a servo-valve + hydraulic cylinder with a position control loop: sixth and fifth
order formulation. Simplification to the orders 3 and 2; pros and cons comparison.
Two stages electro-hydraulic servo-valves: spool as a second stage; types of first stage piloting control loop: flapper-
nozzle, jet-pipe, jet-deflector. Working principles jet-pipe and comparisons with the other types. Description of the
classical dynamic behaviour during the interaction of the two stages of the valve. Analysis of the effects of the model
simplifications on the actuation time constants.
Integration of the models into a complete actuation system of a fly-by-wire control, aircraft flight mechanics included.
Parametric analysis of the numerical behaviour of the developed models when simulating. Definition of figures of merit
to characterize the performance of the system model with respect of the design requirements.
Definition of a testing plan to be implemented on the experiments workbench.
Implementation of diagnostic logics, failure management criteria and fault tolerance characteristics.
Definition of a simple case study of multidisciplinary design optimization applied to a primary flight control.
01PETMT Modelling, Simulation and Testing of the Aerospace Systems 12 2° MSc

18. 1) Model theory and time domain numerical simulation of
lumped parameter systems techniques.
01PETMT Modelling, Simulation and Testing of the Aerospace Systems
MSc Aerospace Engineering Course
f
Actuator mode (20 60Hz)
18
0°
90°
27
0°
-40dB/decade
-80dB/decade
GdB

Servo-valve mode
(200400Hz)
Second order
(actuator)
Second order
(servo-valve)

19. 2) Definition of the requirements: loads, speed of
actuation, etc..
01PETMT Modelling, Simulation and Testing of the Aerospace Systems
Performance
Never exceed speed: 795 km/h (430 knots, 495 mph)
Maximum speed: 740 km/h (400 knots, 460 mph)
Stall speed: 156 km/h (84 knots, 97 mph)
Range: 1,778 km (960 nm, 1,105 miles)
Service ceiling: 12,190 m (40,000 ft)
Rate of climb: 1,438 m/min (4,720 ft/min)
Thrust/weight: 0.452:1
Acceleration limits: +7.33g (+71.9 m/s²)/−3.5g (−34 m/s²)
MSc Aerospace Engineering Course

20. 2) … and frequency response
01PETMT Modelling, Simulation and Testing of the Aerospace Systems
Frequency (Hz)
Phase(°)
-120
-100
-80
-60
-40
-20
0
0,1 1 10 100
-25
-20
-15
-10
-5
0
5
0,1 1 10 100
Gain(dB)
Frequency (Hz)
Large amplitude gain boundary
Small amplitude gain boundary
MSc Aerospace Engineering Course

21. MSc Aerospace Engineering Course
Next planned steps:
Resumption of the MotionView models of the primary flight
controls. Definition of materials and inertia characteristics,
and refinement of the model.
Analysis within the MotionSolve tool to verify some
mechanical requirements (dynamic stiffness, frequency
response, etc..).
Optimization of the configuration using HyperStudy tool,
involving control laws.
01PETMT Modelling, Simulation and Testing of the Aerospace Systems

22. MSc Aerospace Engineering Course
Verification of the optimization results with a dedicated
workbench test activities.
01PETMT Modelling, Simulation and Testing of the Aerospace Systems

23. MSc Aerospace Engineering Course
01OQDMN 01MZBLZ 01PETMT
Aerospace engineering BSc Aerospace engineering MSc
3D CAD modelling
knowledge from other
courses
Altair MotionView
Altair HyperStudy
Altair MotionSolve