Hi, I was just reading Adrian Newey's book and there are a few pages where he talks a bit about active suspension. He describes the Williams system to be primamarily an aerodynamic platform control i.e. roll, pitch, rideheight via variable length pushrods. The spring and damper components are still present, just as they would be with a passive suspension system. After reading that I remembered that ams2 had recently introduced active suspension so I turned to google to find out more about how it's simulated. The only thing I found really is the video from the reiza youtube channel, where the active suspension is demonstrated by a car driving in a straight line with no braking or cornering. The active car is shown to have less suspension movement overall than the the passive car. To me this doesn't really fit to Newey's description of the system and more indicatove of a fully active suspension: a system that actively responds to every bump on the track in milliseconds, which is not what was run in F1. I was wondering if there is any more info or discussion of the ams2 active suspension somwhere that I didn't find?
It made sure the car was at its optimum ride height always, so the car would have less movement and maximize the aero. The system would react to every bump, curb, pitch and roll so the car would be as stable as possible. I don't understand why you feel the side view video from Reiza is wrong. It's doing what an active suspension system will do, maintain a stable ride height and minimize roll and pitch, which was what made the Williams so fast. This article explains it quite well F1’s game changer – lifting the lid on the dominant Williams FW14B - Motorsport Technology
Thanks for the link, hadn't seen that one yet. Let me explain in more detail. You can roughly categorize the forces that go into the suspension system into two groups. Low frequency and high frequency. High frequency would be bumps and kerbs, very fast inputs, that demand very fast response from the suspension. Often only one corner of the car is affected, not the whole car. Low frequency would be forces caused mainly by braking, cornering and aero downforce. Braking makes the car pitch, cornering makes it roll, downforce lowers front and rear. These forces are much slower and of longer duration, and affect not single corners but the whole so-called aerodynamic platform of the car i.e. the rideheights of the car. My understanding is that the systems used in F1 used conventional springs and dampers to handle the high frequency effects while using the active suspension (variable length pushrods) to handle the low frequency effects. In simple terms, the active suspension made sure the front of the car doesn't crash into the ground under high downforce braking, but individual bumps and kerbs are handled passively, as the fideltiy, power and response speed required to do that actively are way beyond the capabilities of the technology used at that time. Here are some relevant quotes from Newey's book: Of course, it's still possible that bump ride is better with the active system as different springs and dampers can be chosen than with a passive system. I was just wondering what exactly was being simulated in ams2.
This would be a perfectly reasonable explanation to me. But I think that the point you raised in the beginning still stands. Reiza has put effort to simulate this, but they have done too little to explain this new feature of the game. The only official sources that one could find are, as you said, the YT demo, which doesn't really provide a good understanding of the subject, and Renato's release post, which is also too generic. The point I'm trying to make is that Reiza gave us a "toy to play with" without instructions. In the past, Reiza has gone great lengths to give players insights to their creations (like here), but in this situation it has been done very little in terms of promotion and information. In an older thread, I asked what the two active suspension settings would do, since there were no in-game suggestions at the time of release, which can be usually found at the bottom of the set up menu when hovering over various settings. The thread did not reach a definitive answer as no developer answered. This has been probably patched since then, but the net result is that the trial period was useless because I did not know what each of the settings would do and so I did not buy the DLC. I wonder how many felt the same way as I did. Even if a trial period was not given, the situation wouldn't have been too different. We're still here wondering how the system achieves its purpose. I want to make sure someone at Reiza is aware of this situation so I'm going to tag @CrimsonEminence. To answer's the OT question, my understanding is also that active suspension aid to keep the car level relative to the ground. Every real car has its own aero map which is a function of pitch, roll, yaw (the latter is not controllable by active suspensions) but also absolute ride height, so the point would be to keep the platform at the peak of the map, and alternatively to reduce drag by altering the attitude of the vehicle, when needed. From this it easy to understand my confusion about settings these suspensions up, because it would only seem logical that one would want the highest frequency available (the first of the two settings). Like the quote in Newey's book suggests, a higher frequency is more desirable. So I don't see the point of this setting. It should also be mentioned that active suspensions can manage more than just ride height. They can also optimize load variations and roll stiffness at lower speeds as downforce decreases. Is this simulated? If not, how do we control the roll stiffness of the car, since it has no ARBs? But once again we were never given an explanation by the people who made this system of how it works - so we're just left wondering.
For the F-HT cars, AMS2 hard coded into the engine a suspension that recognizes load, and then adjusts the stiffness of the spring and damping to maintain the ride height set by the player. And that includes the HS and LS damping. All the user needs to do is set the (RS) "Reaction Speed", and the (ASD) "Active Suspension Damping" (ASD is basically the Damping Ratio) Then, set the ride heights, and off you go.
If that's true, then I guess we can conclude the the ams active suspension is in fact something quite different to what was run on the real cars? The real cars didn't have active springs and dampers, just variable length pushrods. Although tbh for a sim it's probably quite academic as we are not trying to optimize our aero platform to get an advantage over the other teams. From sim driving perspective, active suspension gives us the DRS mode, so I think that's where the value is to us. You can see Schumacher doing this a lot in real life in this video for example: . On a related note: does anyone have an idea what the green button is that he uses in these videos?
If we take the diagram pic above then I dont see much "conventional springs and dampers". I only see something looking like electronic controlled "actuators" - instead. Or do I need new glasses?
I don't 100% understand how the "conventional" springs and dampers thing works exactly, what I do know though is that the black cylinders in this image are the "spring packs" or "spring canisters". There is also a canister for the front but there are no images as it's in the cockpit somewhere, connected via hydraulics. And on the McLaren system you can see short coil springs in this image:
Wow, a 1989 patent about the Williams system is available online: EP0289364A2 - Vehicle suspension systems - Google Patents Interesting that they take a tyre deflection model into account for the calculations, first time I've heard about that.
Im not trying to force my view through here because just like you I dont really know. But looking at your upper pic then I dont think there is conventional spring inside your spring packs /canisters. They looks to small to leave enough space for a spring to work. But on your lower pic the "canisters" does look large enough to hold conventional springs. And I admit that if these "canisters" should be my electronic controlled "actuators" then they should be connected to some electronic wirering. Which they unfortunately dont. So... OnTheOtherSide: Looking at the patent diagram then its hard to find any conventional springs. Or do I still need new glasses?
