I've been working on a force feedback brake pedal using the guts of a dual-shock controller. I can get it to vibrate at a certain pedal position using a simple switch but it would be better to vibrate (or more to be more realistic, stop vibrating) when a wheel locks up. I can't find any insim or outgage data that would support this and a previous thread says there is none. I suppose there may be a hack from tire temps or skid sound, but that would be too slow and too confusing.

Is there no way to get wheel speeds out of the sim? If so, insim/outsim is sorely lacking.....

I followed a thread by the maker of that ivibe seat asking for similar data....the common belief was that if the makers of $20,000 simulators don't need the data, then no one else does. Total BS. There's alot of data that would be useful for motion cues aside from g-force and position data. This is just one of them...

I had the same idea for some time. But cant find a solution to enable Force Feedback & Vibration on 2 Controllers in same time.
Hope you do it better

The force feedback for the pedals would probably come from an outside of the game app and might not even be registered as a controller, just a feedback device like a motion platform, so I don't think that will be a problem. Finding a realtime source for wheelspeed seems to be the big problem. I found a set of tools (x-simulator) which will drive the feedback motors, but have found no source for wheelspeed.

*thinking out loud* I'm wondering if wheel lockup produces a different skid sound than the skid sound from turning. If so, that could prove useful.

http://www.sim-tools.de/Home/t ... nguage/de-DE/Default.aspx

there is an output for Rock´n Roll Chair maybee this can help?!

think loud too "...Different Slicksound on Lockup ....mhmmm Bass-shacker mmmhm"

Quote from SecondSkin :

but it would be better to vibrate (or more to be more realistic, stop vibrating) when a wheel locks up

Until LFS can simulate the brake failure that would result in a brake pedal vibrating, or add older generation ABS systems to cars, I think you are safe to disconnect the vibration motors all together.

As for the iVibe - the data requested was stuff like "what sort of surface is each wheel on" and such which is totally irrelevant to actual realtime calculated force feedback.

At first when I saw the title I thought it literally meant FORCE feedback. Technically, it is incorrect that the brakes in games are controlled by how far the brake pedal is depressed. In real life, the amount of pressure on the brakes is determined by how hard you push your foot down (and the brake booster helps you out, obviously). It would be nice to have a pedal that gives you resistance like a real brake pedal does, THAT would be force feedback. Vibration gives little feedback.

Agreed that it may be unrealistic as hell. But nevertheless it would be awesome if you can literally "feel" when the wheels stop turning. I imagine it would work like this:
Apply brakes -> pedal vibrates
wheel starts slipping -> decrease vibration
wheel completely stops -> stop vibration

This way you could "balance" on the maximum brake force just by feel in the foot! When you sense a decrease of vibration you just release the pressure a little bit until the vibration comes back at full volume.

I see only one issue here - You have 4 wheels, each one having a separate grip level at any given situation. I am not sure this could be handled well with only one way of feedback. Think of the rear inner wheel, sometimes not spinning at all because it just has no contact to tarmac during braking/turning in...?

I think that aural feedback through decent surround sound combined with the current ffb via the steering column would probably be a better way to handle this more accurately for everyone.

lol the brake pedal in real cars doesnt have any force feedback through it anyways except for if your unlucky enough to have ABS and that is like a vibration.

a gas cylinder with some fluid in it would give you the best feel for real brakes i would have thought. anything else is just unrealistic.

Quote from Dac :

a gas cylinder with some fluid in it would give you the best feel for real brakes i would have thought.

I disagree. I think that it would be best to have a compression spring with adjustable preload. Adjusting the preload would simulate vacuum assisted brakes. To calculate how much % of brakes to apply, LFS would have to know the preload of your pedal spring, and the location of the pedal. From that, the amount of force being applied to the pedal could be calculated. Then, the braking force could be more accurately calculated and factor in the pistons in the calipers, etc. Instead of just applying a percent. Even better would be to have a high speed motor that could turn a gear to adjust the preload automatically. That would be true force feedback, and then it could be made so that the amount of preload you get is related to the vacuum in the game. This could also simulate worn brake rotors and ABS also.

Quote from Dac :

lol the brake pedal in real cars doesnt have any force feedback through it anyways except for if your unlucky enough to have ABS and that is like a vibration.

a gas cylinder with some fluid in it would give you the best feel for real brakes i would have thought. anything else is just unrealistic.

Sorry, but in real life you do get ALOT of road feedback through your feet, from both the pedals and the floorboard. So much so that until the mid 90's an experience racer could often outbrake a stock abs system. How to quanitify that feedback and get it to the sim racer is the only real question.

I like the idea of the pedal with motor resistance, I think one day we will have that or something like it. Until then, the only way to do it may be to drive a feedback transducer via the audio signal. It may be unrealistic, but it would be good feedback and would be more like reality than the current state of affairs (which is to wait until you hear the squeal, or even worse to set the car up so its impossible to lockup. About half the setups I download are like that).

As far as realism goes, to some extent you have to exaggerate the feedback for it to make sense. Its a simple fact that as a sim racers we lack the most basic form of feedback that drivers use in the real world (g forces) and we'll likely never get more than 1g of that. We have to make up for that in some way, which is why the ffb in the wheels is exaggerated along with about any other tactile feedback. The tactile feedback doesn't feel right until its exaggerated becuase it exists in a vacuum of g-force data.

That's one reason I like the tactic the iVibe guy was on to. Realizing you can't accurately simulate g-loads, he was asking for all the other forces you can simulate -- road surface (which you can feel in reality), wheel spin, suspension movement etc. It makes more sense to get that data accurate (or slightly exaggerated) because it is easier to simulate that data than a 2g cornering load, especially considering the cost. Yet it seems that he was run out of lfs because his data isn't needed by $20,000 rigs that attempt to simulate 1g, when his device (were he still supporting it, LOL) is accessible to alot more people. End of rant, just don't call me a fanboy. I don't even own one, I just think he was on to a good idea.

Sorry, but in real life you do NOT get a lot (or, indeed, alot) of feedback through the pedals. How could you? What applies the feedback pressure to the pedal (other than ABS)? The only thing that can make the pedal push back is the caliper pistons, which could be pushed by runout on the disc. But the feel through the PEDAL doesn't change with wheel lockup.

What you get is feedback of your braking via the seat of your pants (and, yes, this includes any human:car interface, be it the steering wheel (not even counting the tugging of the wheel due to wheel lock up) or your heels touching the floor of the car. As your acceleration changes, your body interprets what is happening, and helps you 'feel' the brakes locking up. All you actually feel is a reduction of decelleration, or perhaps an increase in lateral acceleration (although of course you feel the combined force vector, rather than individual long. & lat. forces).

A sensitive driver would be able to feel the wind up of the tyres as well - perhaps even the change in ride height that would cause - in much the same way it's possible to feel them winding up with acceleration (in a fast car with sensible side wall ratios).

In the cars I've driven the brake pedal is, get this, actually connected to the chassis! So it is possible for vibration and road feedback to get to the pedal without going to through the hydraulic system, especially when there is pressure in the system creating a spot to leverage against. Maybe your reynard has a special brake pedal assembly that is magnetically suspended from the chassis?

Now I see that you are an engineer and have driven a proper race car. I have also, for several years (I was one of the drivers doing the abs testing during my years in World Challenge). There is some feedback through the pedal, in addition to the forces you have mentioned. But as I said, we are not soon going to get a fast, accurate and affordable representation of the g-force vector, much less a rapid change to it that happens on lock-up. I'm not suggesting that the feedback on the sim racing pedal is going to be perfect -- in fact in may be best applied to the pedal area -- and it may in fact be an exaggeration of reality, but it will be a hell of a lot better than what we have now, which is nothing.

Ah, so you want the pedal to vibrate chassis 'noise' at you rather than give unrealistic feedback from the braking system? That's okay though, but ultimately pointless in my opinion. Much better to have a vibrating seat if you want the sensation of vibrations.

When you're upside down in a car, if you accelerate and spin your wheels the speedometer says that you are accelerating, this would indicate that the in car speedometer is a source of wheel speed, but im not sure if when your wheels lock up it drops to zero. I just think it may be worth looking into as i think that there is some wheel speed data there.

Quote from CharlieW5025 :

this would indicate that the in car speedometer is a source of wheel speed

No. It comes from the driveshaft rotational speed. And yes, it can fluctuate wildly if you lock up the driving wheels; but it's by all means not an accurate reading.

This thread answers the questions I was pondering.

Interesting:

This new pedal system is supposed to support feedback....

http://www.lfsforum.net/showthread.php?t=51002

All we need to make this really awesome is a insim packet that can transmit what tyres are locking.

I suppose a program could be written that causes feedback to occur based on :
If the brake is applied and if the RMPs are making a sudden drop based on packets received in that past 1/2 second?? ..though this won't cover the wheels that coast or in the case of AWD cars which wheels have lesser or greater center torque split.

Anyone care to comment?

Jay Odom

if your getting feedback in your brake pedal then a few things may be wrong.
1- your brake rotors are warped
2-your rear drums are warped
3-you have worn out tie-rod ends.
4 you have sticking calipers or pads wearing uneven.

There should be absolutely no feedback in the brake pedal except for 1 occasion. you have engaged abs, which will pulsate the crap out of the brake pedal.

Take your Car to a Mechanic and have your brake pedal checked ASAP cuz something is just not right.

The only way you are going to tell if you are locking the brakes in a non-ABS car is by knowing your car. Knowing at which speed and at how much pedal pressure is being applied before a certain wheel locks. The steering wheel will tell you if your locking a wheel!

Minus the specifics you mentioned this has been discussed and said there shouldn't be any feedback (Edit: Feedback IRL). However, this would be a good feature to be able to have for brakes or even a way to vibrate the seat more accuratly since we can't have true seat of the pants feel... that is until Scawen and the boys figure out a way to manipulate our nervous systems and inject a insim packets directly to our brains. Fingers crossed and I'm willing to beta test. Just throwing that out there. Until then the ability to utilize more hardware available would be a plus. All we need is wheel spin insim packets. The third party devs will handle the rest. After all we can use H pattern gear boxes even though most all if not all H pattern gear boxes feel like controllers as apposed to a real gear box. I want realism as much as the next joe sim racer out there. But, I and other sim races would like more feedback from sim racing. This isn't a revolutionary step and nor should it be considered one. It is doable and a reasonable request.

Jay Odom

Edit: I said insim packet. I should have said outsim. My error.

Quote from white92talontsi :

if your getting feedback in your brake pedal then a few things may be wrong.
1- your brake rotors are warped
2-your rear drums are warped
3-you have worn out tie-rod ends.
4 you have sticking calipers or pads wearing uneven.

5 - ABS kicked in, which is also very very wrong.