Using “Real” Pilots

Building solutions using conditional feedback behaviour enables "Pilots" to be modelled.

Whilst The J2 Universal Tool-Kit has not been developed to specifically look at the design of Flight Control Systems and Fly by Wire aircraft, it is possible to construct some basic feedback loops and conditional behaviour to enable simple Autopilot functions to be implemented.

In addition to this by using conditional expressions within the response model, it is possible to create an actual reactive pilot model that will perform various activities depending upon the cues it is getting from the aircrafts response.

Further to this, the reaction time of the pilot can also be modelled to add further realism into the system.

Feedback Controls

When looking at simple feedback systems, J2 BUILDER offers this opportunity through the use of link components.

Link components can be “daisy chained” together to build up more complex systems and each can be made up from the standard signals.

• Derivative - Simple


• Derivative - Lookup Table


• Derivative - Expression


• Simple


• Lookup Table


• Expression

Conditional Behaviour

Being able to investigate simple augmented systems, enables the use of the aircrafts states to adapt the actual surface inputs. However, this information is built into the aircraft itself, and uses whatever pilot inputs are defined in the model. Typically, these inputs are in the form of a constant value (i.e. the trimmed value used in the example above) or as a time history (i.e. a series of points that outline when and what value the pilot controls are to have at any given time). Both these methods are very useful in investigating specific scenarios such as the modes of motion, or the aircraft's response to known inputs.

The The J2 Universal Tool-Kit can go a step further than these traditional methods though and allows the user to cover all cases and points in the envelope, where the manoeuvre may be dependant upon the actual behaviour of the aircraft. This is particularly useful when looking at take off, landing, and several of the FAR regulations.

To add in a more reactive and responsive pilot, we can combine several situations.

• Conditional expressions
  These expressions have 2 values, whichever is used is dependant upon the appropriate condition being met.
  


• Aircraft state feedback
  Once again using the aircraft states to determine what the desired inputs are to be.
  

Pilot Reaction and Time Delay

With the conditional inputs built in the previous section, pilot response and reaction is immediate. Obviously in reality, this is not the case, as there are certain behavioural and reactionary characteristics that need to be included.

For more information see J2 Universal Pilots US.pdf

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