UWE Bristol Engineering showcase 2015

Suihua Zhou
BENG Mechanical Engineering
Project Supervisor
Dr Quan Zhu
Adaptive control and simulation of aircraft landing gear
Basic assumptions of the model
1) Geometry of the gear is formed on a vertical plane and all of the force in
this plane.
2) Ignore the centreline of the shaft relative to the buffer offset.
3) The centre of mass of the elastic support is determined by the intersection
of the horizontal position of the centreline of the buffer and the trunnion.
4) Elastic support mass can be idealized as gathered near the trunnion rigid.
5) In addition to the horizontal deflection deformation of the outer buffer
structure. Ignores other variations buffer structure.
Coordinates: The origin of the establishment of the centre of gravity of the
aircraft, z coordinates of the vertical downward is positive; x coordinate of
the vertical z coordinates, heading in the opposite direction is positive.
Coordinate with the movement of aircraft movement.
The landing equation of motion: The mechanical model taking various gear
separating body according to dynamics theory, the following equation of
motion can be obtained as below and the force analysis as shown in figure
below:
Simulation
Design MRAC by Lyapunov stability theory
Use partial parameter optimization method designed model reference
adaptive system is not necessarily stable. In order to overcome these
shortcomings, a German scholar P.C.Parkes (1966) proposed the use of
Lyapunov the second method to derive an adaptive algorithm to ensure
that under the adaptive control system is globally asymptotically stable.
Assuming each state variable system can be obtained directly. Parameter
of control object is generally not directly adjusted.
Project summary
Aircraft has a greater impact loads during takeoff and
landing. In order to avoid excessive load generated, a
suitable design of the landing gear is important. In
the landing gear design process, in addition to
considering the static aircraft landing gear in the
force, but also need to consider the dynamic
performance during takeoff and landing phases.
During takeoff and landing, the landing gear should
be able to withstand greater loads and slow motion
of this impact in order to improve comfort and
security in order to improve comfort and security.
Project Objectives
1. Establish Trolley landing gear dynamics mechanical
model
2. Using adaptive control algorithm to research
aircraft landing gear
3. Using Matlab to simulate the model and get the
result
4. Summarizes the content and the main contribution
of this report
5. Expanding the project by CMS application as the
further work
6. Sum up the whole work of this project.
Project Conclusion
This thesis is use MRAC to describe the aircraft
landing gear systems. Established a relatively
complete landing gear landing roll dynamics model
and linear state equations. Differential equations,
each component force on the buffer system and the
tires force were given by this thesis. Used model
reference adaptive control method of landing gear
systems design and obtained control model of the
landing gear. According to the landing gear control
model, simulated and analysed the adaptive control
of the landing gear model by Matlab simulation
software.