Recent content by zoltrix

yes I was expecting some non zero initial value it is what I have been repeating and repeating... i did not share the linkage ? come on , it is just a four bar linkages ....never seen it ? I am not speaking of some esoteric device

they have ... but...uhm...Simscape is a great software , in my opinion, but support is not the best, to the least... however I agree with you, it is a so common and so important feature that I dont think it is a bug... probably I am doing or expecting something wrong, but what ? I supposed that...

I attach the scaled plot c/w with units the trend is the same as the previous one...of course

the "scope" block of simscape never quote the scale and units , you must set them elsewhere in any case a continuosly going up angular acceleration with a constant torque is meaningless,in my opinion,, regardless of units and scale

if I click on "angular acceleration" of the "transform sensing" block I expect the current angular acceleration to be plotted i.e : instantaneous accel vs time it should be a periodic curve, IMHO

it seems to me that you are speaking of velocity not of acceleration

Thanks Filip and jrmichler I suppose that the total acceleration should be periodic at each revolution since the moment of inertia at the shaft should depend only on the current geometry of the linkage So I dont expect variable spikes whose amplitude not only vary but even increase from...

I mean the angular acceleration of the crank the moment of inertia of the mechanism referred to the motor shaft is not a costant but it should be periodic in a closed mechanism the same for the angular acceleration if the torque is constant (see attached file)

yes, I even tried with the simscape examples same story

hello I am a simscape mulibody user take a four bars mechanism, no external load you apply a constant torque to the crank I would expect a periodic angular acceleration but acceleration keeps growing anybody here using simscape mechanics ? what's wrong ?

no real system is linear but this has nothing to do with the definition of linear system in science you describe a model taking into account only some parameters the math model might be linear if so , the definition of linearity can and must be exhaustive

"the superposition principle, or equivalently both the additivity and homogeneity properties" are not enough to define a linear system you must also add : " without restrictions (that is, for all inputs, all scaling constants and all time.)" the latter sentence is often omitted or given for granted

an exhaustive definition of linear system is important , for example, in automation and control if you try to control a non linear system using a theory which is valid only for a linear one then you get wrong results

where does this take me to ? in many accademic books you can find the above definition of linear system but it is a partial and consequently deceiving definition if you stick to it, a system with a variable mass or variable moment of inertia, quite common in automation, should be a linear...

hello I have doubts about linear system suppose that x is the input and y the output if x1 then y1 if x2 then y2 the system is linear if if (x1+x2) then (y1+y2) now, take a mass m you can write f = m*a however suppose that m changes with position m = m(x) above equations should be still...