Reference no: EM133126025

Fault Detection, Isolation and Recovery

Assignment: Fault Detection, Isolation & Recovery System for the Heading Motion of a Fixed Wing UAV

Background

Lateral Dynamics
The Lateral Dynamics of any aircraft are defined in terms of the Body-fixed velocities and corresponding Earth-fixed orientation (see Figure 1).

In this particular case the Body-fixed velocities are roll rate (p) and yaw rate (r). All other Body- fixed dynamics are regarded as constant (e.g. surge velocity) or zero (e.g. pitch). The effects of these velocities on the inertially fixed Earth-fixed axes are represented by the orientation of the aircraft relative to this reference frame. These are the roll angle (f) and yaw angle (y). In addition, the influence of sideslip on the aircraft is included in the form of the sideslip angle (b).

The corresponding inputs to the lateral dynamics of the aircraft are the aileron actuator deflection (da) and the rudder actuator deflection (dr). The ailerons control the roll motion and the rudder controls the heading or yaw. The Lateral Dynamics of an UAV can be represented by the following differential equations:

Assignment Specification

This assignment involves the development and analysis of Fault Detection, Isolation and Recovery (FDIR) Systems for the Lateral Dynamics of the UAV described above. The assignment activities are based on the development of 2 separate FDIR systems:

The "Open-Loop" FDIR System will involve the construction of a continuous time simulation of the UAV and its remote "Open-Loop" control by a ground based operator. Faults will be introduced to the rudder actuator and heading sensor output for the UAV's heading channel. The purpose of the FDIR system is to detect, isolate and determine suitable recovery options for this "Open-Loop" operation of the UAV.

The Closed-Loop FDIR System will involve the design of a control system for the heading (yawing) motion of the UAV. This control system will provide control signals for the rudder actuator, which in turn regulates the heading motion of the UAV. Faults will be introduced to the rudder actuator and heading sensor output for the UAV's heading channel. The purpose of the FDIR system is to detect, isolate and determine suitable recovery options for this Closed-Loop operation of the UAV.

In order to fulfil the requirements for this assignment you should complete the following tasks:
"Open-Loop" Operations

Construct a continuous time simulation of the Lateral Dynamics of the UAV using zero initial conditions i.e. assuming UAV is flying level with initial heading of zero.

(a) Simulate a 10°/-10° zig-zag heading manoeuvre where changes in heading can be observed. A zig-zag heading manoeuvre involves setting the rudder to ±10° and waiting until the heading reaches ±10°. Then the polarity of the rudder deflection is reversed and the process is repeated in the negative sense.

Investigate the effect of separate simulated stepwise and driftwise faults applied to the sensor in the heading channel during a 10°/-10° zig-zag manoeuvre.

Investigate the effect of separate simulated stepwise and driftwise faults applied to the rudder actuator in the heading channel during a 10°/-10° zig-zag manoeuvre.

Employ suitable fault detection and isolation mechanisms to determine when and where these faults occur during the "Open-Loop" 10°/-10° zig-zag manoeuvre.

Employ suitable recovery procedures that will enable the "Open-Loop" Operation to continue in the presence of sensor and actuator faults.
Investigate the operation of the FDIR system you have developed with simulated white noise of amplitude ±10° included in the heading output.

Closed-Loop Operations

(a) After completing the "Open-Loop" Operations stage above, remove the faults from your simulation and design a closed-loop heading flight controller for this UAV that can perform a 45° controlled heading manoeuvre by manipulating the rudder deflection.

Investigate the effect of separate simulated stepwise and driftwise faults applied to the sensor in the heading channel during a 45° controlled heading manoeuvre.

Investigate the effect of separate simulated stepwise and driftwise faults applied to the rudder actuator in the heading channel during a 45° controlled heading manoeuvre.

Employ suitable fault detection and isolation mechanisms to determine when and where these sensor and actuator faults occur during the closed-loop 45° heading manoeuvre.

Employ suitable recovery procedures that will enable the Closed-Loop Operation to continue in the presence of sensor and actuator faults.
Investigate the operation of the FDIR system you have developed with simulated white noise of amplitude ±10° included in the heading output.

Attachment:- Isolation and Recovery System.rar