In this article, I will introduce an important phase and practice in the development of virtual simulation models. In our case, this refers to VSKYLABS development of aircraft for the X-Plane Flight Simulator.
During development, at some point, flight testing is flown in the VR (Virtual Reality) environment. This takes place in a relatively early state of the project, where things are tight enough, yet not fully completed.
This goes for levers, buttons, dials... In many cockpits, some of the systems are located around the pilot: overhead panels, below the seat, behind the other seat, between the legs. These should be reachable as well in VR... replicating the real-world configuration.
Another 'Man-Machine' integration aspect that is evaluated in this process is the overall geometry of the panels, padding and the canopy cut-outs, which should align properly (with some adjustments) to pilot height, providing an authentic line-of-sight with the world.
Then, I place the touch controller on my seat cushion, just between my legs. The virtual and the physical cushions should 'align', and the touch controller should 'sit' on the virtual cushion.
Looking outside, around... I seek the familiar 'cockpit feeling'... try to sense the depth of the aircraft floor, trying to read the instruments... see that all fits right.
Then, I take it for a short ride, looking for unexpected issues of line-of-sight and field of view. Some aircraft are amazingly surprising when transitioning from a 2D display to VR. The combination of peripheral vision and natural head movement brings the flying experience to a whole new level of realism. In most cases, when flying in VR, it is much easier to see the runway through caged canopies during taxi, takeoff, and landings, or to manage taxiing in a tail-dragger, where the nose is set high above the runway when looking forward. In VR we can look 'over the shoulder' and past cockpit obstacles and notice ultimate peripheral cues with peripheral vision.
In the following video - cockpit operation and landing in Full-VR environment. I'm flying the VSKYLABS F-19 Stealth Fighter, in full VR environment (touch controllers and physical pedals, no physical Joystick or switches).
The VSKYLABS F-19 cockpit was designed and modeled following the F-18 late cockpit design, with only a few adaptations. All cockpit elements which were designed for human interaction in the F-18, are in full and comfortable each of the pilot in VR.
Lets set the focus on the caged cockpit of the F-19. When flying in X-Plane using 2-d display, landing the aircraft becomes a bit challenging due to the canopy cage structure, similar to the SR-71. However, when flying in VR, the addition of peripheral vision and natural head movement results with a straightforward operation, visuals with the runway and judgement to the touch-down zone.
During the development of the VSKYLABS SR-71-TB, extensive operations were tested in VR. At the time, the development of the 'synthetic' aerial refueling session was nearly complete, and since all components had been modeled in 1:1 true scale, I wanted to see how it would feel inside the cockpit in VR.
During the 'synthetic' refueling, I noticed a severe problem. Hey! This does not feel right!
The air refueling is set as a kind of a 'baked' phase (no actual formation flying). The SR-71 and the tanker are aligned, geometrically speaking, as closely as possible to the real-world conditions. Yet, even in VR, when sitting in the virtual cockpit of the SR-71, I could hardly see the designated area on the tanker that should be observed during the refuel, if it were a real-world formation flying segment.
*To note that I've 'been there, done that' for real, yet obviously not in the SR-71...still...I knew what to look for...
This was a serious issue. I re-checked everything, inspected the 3D model, the drawings, tons of references. All seemed right, yet... realistically, sitting 'in-place' with the tanker didn't feel right. It felt almost impossible to fly formation and see the tanker signals if it were an actual aerial refueling.
At the time, I was in close contact with Ret. Lt. Col. BC Thomas. We discussed many of the real-world SR-71 operational aspects with a focus on systems and flying practices. In one of our conversations I asked him: BC, something doesn't fit when I am sitting in the SR-71 model, observing the tanker... I can hardly see the tanker signal area... if I were flying this in real-time formation, I could not see the tanker's belly clearly. Was it that hard to fly formation with the tanker? Or...is it a serious modelling issue...?
His reply was amazing, and solved the issue instantly: he told me that during aerial refueling sessions he had to lower the seat so much that the stick almost hit his chin (as he described it) to see the tanker properly. He told me that once sitting lower, flying the aerial refueling was quite smooth and straightforward.
Once we ended that conversation, I launched the VSKYLABS SR-71 in VR and flew to the aerial refueling phase. Then, I lowered the seat (using the down arrow, in VR)... and... once positioned quite a few inches lower, the view was perfect! This 'lowering of the seat' action was an actual real-world SR-71 pilot technique, and it validated the cockpit geometry of the model...using VR...amazing isn't it?
VR is not only powerful for the pilot. For the developer, it becomes an engineering tool, allowing cockpit geometry and human-machine integration to be validated. It is a crucial human-factors validation tool in cockpit geometry development.
Huss
VSKYLABS
True scaling of the virtual cockpit:
To make a long story short, scaling the virtual aircraft so it represents the real-world aircraft in a true 1:1 scale is maybe the most fundamental process in the virtual aircraft development process. In X-Plane, proper scaling of the aircraft is not only crucial for proper aerodynamic calculations... it is also crucial for providing a realistic flying experience in the virtual cockpit.During development, at some point, flight testing is flown in the VR (Virtual Reality) environment. This takes place in a relatively early state of the project, where things are tight enough, yet not fully completed.
'Man-Machine' integration:
Real cockpits are tailored around a human pilot, providing seamless 'integration' with the aircraft (in most cases...). If there's a switch that should be reached by the pilot during aircraft operation and flight, the average pilot should simply reach his hand and touch it.This goes for levers, buttons, dials... In many cockpits, some of the systems are located around the pilot: overhead panels, below the seat, behind the other seat, between the legs. These should be reachable as well in VR... replicating the real-world configuration.
Another 'Man-Machine' integration aspect that is evaluated in this process is the overall geometry of the panels, padding and the canopy cut-outs, which should align properly (with some adjustments) to pilot height, providing an authentic line-of-sight with the world.
Exploring/evaluating the virtual cockpit:
When I first sit in the WIP virtual cockpit, in VR, it must simply 'feel right'. I use the touch controllers and set my hands over the throttles, going through all levers and switches... all should perfectly fit. This is the ultimate scaling validation of the cockpit and its ergonomic design, which should reflect the real-world aircraft.Then, I place the touch controller on my seat cushion, just between my legs. The virtual and the physical cushions should 'align', and the touch controller should 'sit' on the virtual cushion.
Looking outside, around... I seek the familiar 'cockpit feeling'... try to sense the depth of the aircraft floor, trying to read the instruments... see that all fits right.
Then, I take it for a short ride, looking for unexpected issues of line-of-sight and field of view. Some aircraft are amazingly surprising when transitioning from a 2D display to VR. The combination of peripheral vision and natural head movement brings the flying experience to a whole new level of realism. In most cases, when flying in VR, it is much easier to see the runway through caged canopies during taxi, takeoff, and landings, or to manage taxiing in a tail-dragger, where the nose is set high above the runway when looking forward. In VR we can look 'over the shoulder' and past cockpit obstacles and notice ultimate peripheral cues with peripheral vision.
In the following video - cockpit operation and landing in Full-VR environment. I'm flying the VSKYLABS F-19 Stealth Fighter, in full VR environment (touch controllers and physical pedals, no physical Joystick or switches).
The VSKYLABS F-19 cockpit was designed and modeled following the F-18 late cockpit design, with only a few adaptations. All cockpit elements which were designed for human interaction in the F-18, are in full and comfortable each of the pilot in VR.
Lets set the focus on the caged cockpit of the F-19. When flying in X-Plane using 2-d display, landing the aircraft becomes a bit challenging due to the canopy cage structure, similar to the SR-71. However, when flying in VR, the addition of peripheral vision and natural head movement results with a straightforward operation, visuals with the runway and judgement to the touch-down zone.
The SR-71A Blackbird Cockpit and Canopy Geometry ALL WRONG??:
Here is a fascinating 'behind-the-scenes' story from the early stage of the VR scaling validation process.During the development of the VSKYLABS SR-71-TB, extensive operations were tested in VR. At the time, the development of the 'synthetic' aerial refueling session was nearly complete, and since all components had been modeled in 1:1 true scale, I wanted to see how it would feel inside the cockpit in VR.
During the 'synthetic' refueling, I noticed a severe problem. Hey! This does not feel right!
The air refueling is set as a kind of a 'baked' phase (no actual formation flying). The SR-71 and the tanker are aligned, geometrically speaking, as closely as possible to the real-world conditions. Yet, even in VR, when sitting in the virtual cockpit of the SR-71, I could hardly see the designated area on the tanker that should be observed during the refuel, if it were a real-world formation flying segment.
*To note that I've 'been there, done that' for real, yet obviously not in the SR-71...still...I knew what to look for...
This was a serious issue. I re-checked everything, inspected the 3D model, the drawings, tons of references. All seemed right, yet... realistically, sitting 'in-place' with the tanker didn't feel right. It felt almost impossible to fly formation and see the tanker signals if it were an actual aerial refueling.
At the time, I was in close contact with Ret. Lt. Col. BC Thomas. We discussed many of the real-world SR-71 operational aspects with a focus on systems and flying practices. In one of our conversations I asked him: BC, something doesn't fit when I am sitting in the SR-71 model, observing the tanker... I can hardly see the tanker signal area... if I were flying this in real-time formation, I could not see the tanker's belly clearly. Was it that hard to fly formation with the tanker? Or...is it a serious modelling issue...?
His reply was amazing, and solved the issue instantly: he told me that during aerial refueling sessions he had to lower the seat so much that the stick almost hit his chin (as he described it) to see the tanker properly. He told me that once sitting lower, flying the aerial refueling was quite smooth and straightforward.
Once we ended that conversation, I launched the VSKYLABS SR-71 in VR and flew to the aerial refueling phase. Then, I lowered the seat (using the down arrow, in VR)... and... once positioned quite a few inches lower, the view was perfect! This 'lowering of the seat' action was an actual real-world SR-71 pilot technique, and it validated the cockpit geometry of the model...using VR...amazing isn't it?
VR is not only powerful for the pilot. For the developer, it becomes an engineering tool, allowing cockpit geometry and human-machine integration to be validated. It is a crucial human-factors validation tool in cockpit geometry development.
Huss
VSKYLABS