# initial undershoot

If there is right half plane zero, there will be a initial undershoot in the step response.

I have a second order system as zdotdot=-g+u/m, zdotdot is double derivative of z, g is the gravity acceleration, m is mass and u is the control. If I choose different value for m, and using PID controller, there is a initial undershoot.

How can I approximate the system to see the zeros and poles? I think changing the mass will change the zeros. Do you guys have some clue?

Thanks
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## Relevant Pages

• Re: Iterative Technique for PID Controller Tuning
... Page 5 The point to point response for my 3 poles at -2*PI*10 is plotted. ... The response is a critically damped response except for when the output is saturate. ... Notice that poles are were I put them but as I said before, the zeros can go anywhere. ... Page 8 The closed loop Bode plot. ...
(sci.engr.control)
• Re: Iterative Technique for PID Controller Tuning
... Page 5 The point to point response for my 3 poles at -2*PI*10 is plotted. ... The response is a critically damped response except for when the output is saturate. ... Notice that poles are were I put them but as I said before, the zeros can go anywhere. ... Page 8 The closed loop Bode plot. ...
(sci.engr.control)
• Re: initial undershoot
... there is a right half plane zero. ... there is a initial undershoot. ... This is not a system with right-half plane zeros. ... has more inputs than the control input alone. ...
(sci.engr.control)
• Re: initial undershoot
... there is a right half plane zero. ... there is a initial undershoot. ... This is not a system with right-half plane zeros. ... has more inputs than the control input alone. ...
(sci.engr.control)
• Re: Bandpass system identification using IIRs (audio)
... You've specified the response relatively very far away from the ... location of the poles and zeros, and with only 6 digit precision, ... like it requires many more bits of precision to specify the ...
(comp.dsp)