Automated flight: Dufour’s cutting-edge advancements

‍Jacob Cook comes to Dufour Aerospace from NASA Langley Research Center, where he led the development of modelling and control techniques for NASA’s eVTOL aircraft. At Dufour, he’s our Flight Controls Lead Engineer and specialist in eVTOL aircraft dynamics, control, and automation — where our aircraft are designed to fly missions with less input from the pilot or operator. We sat down with Jacob to talk about automation in eVTOL and on the strides taken by Dufour in this regard.

So, Jacob, what does automation and automated flight from an aircraft controls perspective mean?

I would describe automation as operating the aircraft with minimal pilot or operator interaction beyond higher level mission directives.  The aircraft can safely fly itself; it just needs someone to tell it when to take off and where to go.  We do this by building flight plans through the use of three dimensional waypoints, the flight control system takes care of the rest.

Ok, unpack that a bit. Does automated flight represent a pilot-less operation?

No, not quite.  We still rely on an operator to make decisions about the aircraft and mission. This can include updates to the desired route, or whether to return home or perform an emergency landing in the event of an off nominal condition on board the aircraft. 

Is there a big difference between a tilt-wing aircraft and other approaches in the eVTOL space?

Tiltwings have a distinct advantage over other eVTOL aircraft because of the beneficial interaction of the main propellers with the wing. The propellers and the wing tilt together such that the propeller slipstream is always aligned with the chord line of the wing.  This energises the wing in all phases of flight.  It not only makes our control surfaces effective throughout the flight envelope (they are used for yaw control in hover and roll in forward flight), but also reduces the load on the propellers immediately when we begin the transition, allowing for a more efficient transition.

Additionally, a specific advantage over many of the lift+cruise type configurations is that the main propulsors that lift the aircraft in the hover are the same that produce thrust in the cruise.  This helps reduce the weight and drag of the aircraft.

What’s special about Dufour Aerospace’s approach? How do you and your team approach this concretely?

As with most eVTOL aircraft, the transition from hover to forward flight and vice versa is a critical phase of flight to enable the technology.  The transitions  must be done safely and efficiently, therefore we have dedicated significant effort to model the aero-propulsive dynamics in this regime and have developed a robust control architecture to keep the aircraft operating safely throughout the flight envelope.  Finally we do extensive flight testing to evaluate the performance of the aircraft and refine our models and control system.

The end goal of the flight control system is to simplify the remote operations, and we do this with successive layers of control and flight envelope protections.  The end result is an aircraft that can be operated with minimal interaction from the operator besides planning a route.

Sounds like quite a challenge. Is Dufour Aerospace prepared for this?

Ha. Yes, we are. I think our engineering team has a  great combined knowledge of tilt-wing aircraft — and possibly no other engineering house in the world can match it. This comes from both flight experience on our small and medium size demonstration aircraft and extensive research and lessons learned from past tilt-wing aircraft such as the CL-84 and XC-142 programs and the wind tunnel testing conducted to support them. 

Using our approach we are able to keep the aircraft flying safely while operating over a large flight envelope. We have developed our flight control system such that it can be commanded by virtually any guidance system — although we have our own — or an operator by a simple set of commands. I am convinced we are on the right track and our test results prove this every day.

Want to see for yourself if Jacob is right? Watch the video below of the Dufour Aerospace Aeromini in automated flight.

Prior to joining Dufour Aerospace, Jacob Cook served as a Dynamics and Control Research Engineer at NASA Langley Research Center, where he led the development of modelling and control techniques for NASA’s eVTOL aircraft, including the LA-8 tandem tiltwing, Lift+Cruise, and RAVEN aircraft. His significant contributions include the development of advanced control laws for transitioning aircraft, a traffic pattern integration algorithm for unmanned autonomous cargo vehicles, and investigating cooperative control algorithms for high-density air traffic management in urban environments. As a licensed private pilot, Jacob's expertise extends beyond theoretical research, bringing a unique perspective to the team at Dufour Aerospace.