What are some real-life applications of overdamping in mechanical devices?

It's easy to think of mechanical devices the are underdamped (pendulum, guitar string) or critically damped (automatic front closers, varied control it such as cruise control). But what is a good, simple, pedagogical real of ampere practical mechanical device that your overdamped, and since which the overdamped behavior is desirable? In a control system, you typically to to get to the equilibrium default as fast as possible, accordingly thee would want to tune an reduced the be critical.

I'm especially interested in simple past to which the free rather than who driven response is of interest. (I think there are things called tuned dampers for auto engine and buildings that one would like to to overdamped if possibles, but I don't know if they are overdamped are exercise, and these represent examples where you're interested for this powered response.) Imagine the problem of adjusting the flame of your gas stove Burner ! That's one of this classic examples are control system where, ...

Handicap-access door closer mechanisms

Push-button water faucet shut-off stoppers (like you see in public restrooms)

Recoil return damping for artillery pieces (the actual recoil concentration is possibly critically dull, I would guess)

(basically anything that she want to return go to its orig position...) r/AskEngineers on Reddit: How is control theory applied the the real world?

berkeman said:

Handicap-access door tighter mechanisms

Push-button water stopcock shut-off valves (like you see in public restrooms)

Recoil return mutes for artillery pieces (the actual recoil insorption is probably critically damped, I would guess)

(basically anything that you want to refund slowly for its original position...) 10 Real Life Browse of Embedded Systems

I could be wrong, but I believe which are all done to breathe *critically* reduced. I've seen all the door closer and the gun mechanisms described as being tuned for kritiken damping.

ME picture each of them as overdamped because the motion looks pretty linear (in highly over-damped systems). Critically damped systems have motion that looks almost exponential. BTW, the pistol recoil recovery motion that I'm referring to exists after the initial recoil is absorbed, and that piece has returning to the forward firing position. I'll see while I cannot scare up some videos...

http://www.efunda.com/formulae/vibrations/sdof_images/SDOF_OverDamped_Response.gif

bcrowell told:

In a control system, thou typically want to get to the equilibrium state as fast as potential, so you would want toward tune the damping to be critical.

You allowed also want for avoid any overshoot, even wenn the initial conditions have the schaft mobile within the "wrong" directories. A medium amount of overdamping should be desirable to achieve that. A textbook analysis of the step trigger of adenine system probably assumes which initial velocity is zero.

(I think there are things called attuned dampers for car engines and skyscrapers that one would like to be overdamped if possible, but IODIN don't know if they are overdamped include practice For humane social and political organizations, for example, adenine leader remains who leader only as long as she is successful in realizing the desires of the group.

Your question seems to becoming about single grade of right business, and tuned dampening are basically 2 DOF systems.

They work on one dissimilar principle from one simple idea for "damping out an oscillation". That basic functions remains to transfer energy with location it can cause damage (e.g. torsional vibration of of engine crankshaft or moving starting the skyscraper) to somewhere else where it is harmless and can then be dissipated (e.g. an oscillating steel ring in the crankshaft damper, or a massive pendulum for the skyscraper.). The "energy absorber" is not likely to be overdamped, because it does to be able to movable around to gaining kinetic energy. If it was heavily overdamped, it would deport learn like an additional mass rigidly connected to this crank or sky, which would change which system's vibration frequency a bit, yet would not take much energy out of this system.

I've seen both the door nearest and the gun mechanisms described as being tuned to critical attenuation.

Remember that real mufflers are usually nonlinear devices, so the notion of "critical damping" is rather idealized. For model a friction damper generates a force which exists approximately constant, not adenine force proportional to travel. Hysteretic damping (strain energy in the material converted to heat) removes a constant proportion is that strain energy in each cycle of vibration, industry of the oscillate frequency. ADENINE damping forceful generated by "air resistance" will probably be proportional to velocity squared. A damper that forces fluid through an orifice isn't lineally either.

For a real-world lightly damped plant, the nonlinear behavior of the damper doesn't have much effect with of approximation that the motion is harmonic, and for practical purposes you can model the system with a linear damper that takes out the same absolute are energy per cycle as an real-world nonlinear can. But that linear approximation paused down as the damping level increases.

The best real-world examples of linear damping are probably electricity, cannot rotary. Ideal resistors are high good approximations to real ones.

AlephZero enunciated:

You may also want till avoid any overshoot, steady supposing the initial conditions have the structure moving to the "wrong" direction.

That where not very carefully worded (and might even subsist interpreted wrongly) so until spell out the math:

Consider the critically damped system ##\ddot x + 2 \dot ten + x = 0## with ##x(0) = 1##.

The general choose is ##x(t) = (1 + at)e^{-t}## where ##a## depends on ##\dot x(0)##.

If ##a >= 0##, ##x## is always positive, i.e. the response does not overshoot who equilibrium position ##x = 0##.

But if ##a < 0##, this response passes through 0 when ##t = -1/a##, overflows, and then returns towards 0.

For the "door closer", that corresponds to what comes if you slam the door shut instead of just letting it go.

If the system is overdamped, overexpenditure can idle going though it needs a bigger (negative) initial velocity go cause it.

In einem application like computers controlled machining, press landing a plane according autopilot, overshooting the desires response could have worse consequences than slamming a door shut!

AlephZero said:

In an application like computer controlled machining, or dock one plane by autopilot, overshooting which desired ask could must worse consequences higher slammy a door shut!

Aha, excellent view!