According to this thread (obviously it can be wrong), some of the control surfaces are electric. Are you saying that they are still hydraulic even though stated as electric?Tommy Cookers wrote: ↑09 Apr 2018, 09:58and unfortunately ....
aircraft control surface actuators (necessarily hydraulic) are these days called all-electric actuators
meaning servo-hydraulics based but now these are powered internally so there's electrical-only connection to the external
as our car's power steering is hydraulic internally and has only electrical connections
Electrically controlled hydraulically actuated. Of course you could use an electric motor only and sure it can be fast. The downside would be hysterisis without some method of damping actuation. Hydraulic activation is internally damped so much lower hysteresis is inherent.trinidefender wrote: ↑09 Apr 2018, 13:16According to this thread (obviously it can be wrong), some of the control surfaces are electric. Are you saying that they are still hydraulic even though stated as electric?Tommy Cookers wrote: ↑09 Apr 2018, 09:58and unfortunately ....
aircraft control surface actuators (necessarily hydraulic) are these days called all-electric actuators
meaning servo-hydraulics based but now these are powered internally so there's electrical-only connection to the external
as our car's power steering is hydraulic internally and has only electrical connections
http://www.airliners.net/forum/viewtopic.php?t=776097
Spoilers are the main form of roll control at mid to higher speed on commercial aircraft so I would be surprised if bandwidth wouldn't be a major design consideration.Tommy Cookers wrote: ↑09 Apr 2018, 14:25flaps slats and maybe spoilers I wouldn't call control surfaces - actuation stiffness may be required but no bandwidth
at a glance your link seems confirmation to me
DARPA had/has a research program of so-called 'all-electric' flight control actuation
'all-electric' meaning a hydraulic actuator with the hydraulically energisation onboard (the actuator)
so as far as aircraft designers and users are concerned there is no hydraulic connection hence categorisation 'all-electric'
I notice that 'all-electric' seems often to be written all-electric
Hmmmm. As an example, the autopilot system on the S76D and S76C++ (helicopters both of which I am familiar on as well as other Sikorsky products) have 2 types of actuators in the autopilot/stabilisation system. What are termed trim and series actuators. Both of which are purely electric. The series actuators are used for flight stabilisation; rate dampening of flight control movements and providing a large part of keeping the aircraft in the attitude commanded by the pilot or coupled autopilot system. The actuators have a few cm's of travel with a fairly high bandwidth (not sure if as high as 20Hz).Tommy Cookers wrote: ↑09 Apr 2018, 14:38control surface actuation on a high speed relaxed aerodynamic stability (ie combat) aircraft needs a bandwidth c. 20 Hz
impossible with electric actuation
possible with servo-hydraulic actuation due to its far higher energy density etc
The VLIMs need to move very quickly, as faster than the driver can press the throttle. On a semi-related note, what do you suppose are the time scales during combustion? And what time scales can be simulated accurately? ms, micro?trinidefender wrote: ↑09 Apr 2018, 15:22Hmmmm. As an example, the autopilot system on the S76D and S76C++ (helicopters both of which I am familiar on as well as other Sikorsky products) have 2 types of actuators in the autopilot/stabilisation system. What are termed trim and series actuators. Both of which are purely electric. The series actuators are used for flight stabilisation; rate dampening of flight control movements and providing a large part of keeping the aircraft in the attitude commanded by the pilot or coupled autopilot system. The actuators have a few cm's of travel with a fairly high bandwidth (not sure if as high as 20Hz).Tommy Cookers wrote: ↑09 Apr 2018, 14:38control surface actuation on a high speed relaxed aerodynamic stability (ie combat) aircraft needs a bandwidth c. 20 Hz
impossible with electric actuation
possible with servo-hydraulic actuation due to its far higher energy density etc
Just wrote this here because I thought it might be similar to the kind of requirements needed for this application in F1.
On another note, would the VLIM really require that high of a bandwidth? What is the time taken from idle to red line in first gear?
The VLIM's should be rpm based shouldn't they? Throttle position shouldn't affect their position.godlameroso wrote: ↑09 Apr 2018, 17:53The VLIMs need to move very quickly, as faster than the driver can press the throttle. On a semi-related note, what do you suppose are the time scales during combustion? And what time scales can be simulated accurately? ms, micro?trinidefender wrote: ↑09 Apr 2018, 15:22Hmmmm. As an example, the autopilot system on the S76D and S76C++ (helicopters both of which I am familiar on as well as other Sikorsky products) have 2 types of actuators in the autopilot/stabilisation system. What are termed trim and series actuators. Both of which are purely electric. The series actuators are used for flight stabilisation; rate dampening of flight control movements and providing a large part of keeping the aircraft in the attitude commanded by the pilot or coupled autopilot system. The actuators have a few cm's of travel with a fairly high bandwidth (not sure if as high as 20Hz).Tommy Cookers wrote: ↑09 Apr 2018, 14:38control surface actuation on a high speed relaxed aerodynamic stability (ie combat) aircraft needs a bandwidth c. 20 Hz
impossible with electric actuation
possible with servo-hydraulic actuation due to its far higher energy density etc
Just wrote this here because I thought it might be similar to the kind of requirements needed for this application in F1.
On another note, would the VLIM really require that high of a bandwidth? What is the time taken from idle to red line in first gear?
Of course, engine vacuum affects the wave harmonics, so VLIMs must take this into account.trinidefender wrote: ↑09 Apr 2018, 18:16The VLIM's should be rpm based shouldn't they? Throttle position shouldn't affect their position.godlameroso wrote: ↑09 Apr 2018, 17:53The VLIMs need to move very quickly, as faster than the driver can press the throttle. On a semi-related note, what do you suppose are the time scales during combustion? And what time scales can be simulated accurately? ms, micro?trinidefender wrote: ↑09 Apr 2018, 15:22
Hmmmm. As an example, the autopilot system on the S76D and S76C++ (helicopters both of which I am familiar on as well as other Sikorsky products) have 2 types of actuators in the autopilot/stabilisation system. What are termed trim and series actuators. Both of which are purely electric. The series actuators are used for flight stabilisation; rate dampening of flight control movements and providing a large part of keeping the aircraft in the attitude commanded by the pilot or coupled autopilot system. The actuators have a few cm's of travel with a fairly high bandwidth (not sure if as high as 20Hz).
Just wrote this here because I thought it might be similar to the kind of requirements needed for this application in F1.
On another note, would the VLIM really require that high of a bandwidth? What is the time taken from idle to red line in first gear?
Fair enough. Yamaha uses electrics for their actuators on the VLIM on their production road motorcycles (at least the ones that I've seen).godlameroso wrote: ↑09 Apr 2018, 18:34Of course, engine vacuum affects the wave harmonics, so VLIMs must take this into account.trinidefender wrote: ↑09 Apr 2018, 18:16The VLIM's should be rpm based shouldn't they? Throttle position shouldn't affect their position.godlameroso wrote: ↑09 Apr 2018, 17:53
The VLIMs need to move very quickly, as faster than the driver can press the throttle. On a semi-related note, what do you suppose are the time scales during combustion? And what time scales can be simulated accurately? ms, micro?
Well, the Boeing 787 uses both electro-hydraulic and electro-mechanical flight controls.Tommy Cookers wrote: ↑09 Apr 2018, 14:25flaps slats and maybe spoilers I wouldn't call control surfaces - actuation stiffness may be required but no bandwidth
at a glance your link seems confirmation to me
DARPA had/has a research program of so-called 'all-electric' flight control actuation
'all-electric' meaning a hydraulic actuator with the hydraulically energisation onboard (the actuator)
so as far as aircraft designers and users are concerned there is no hydraulic connection hence categorisation 'all-electric'
I notice that 'all-electric' seems often to be written all-electric