Re: PID function in octave control not working.. why?

[Tatsuro MATSUOKA]

----- Original Message -----

> From: Lukas Reichlin 
> To: Abdul Rahman Riza <
> Cc: "address@hidden" <; shahin35ju; help-octaveg
> Date: 2015/6/26, Fri 14:23
> Subject: Re: PID function in octave control not working.. why?
> 
> On 25.06.2015, at 21:21, Abdul Rahman Riza <address@hidden> wrote:
> 
>>  Dear All,
>> 
>>  I'm using octave 3.8.2 in debian jessie 64 bit trying to run matlab 
> example here 
> http://ctms.engin.umich.edu/CTMS/index.php?example=Suspension§ion=ControlPID
>> 
>>  hereunder my suspension.m files:
>>  =============================
>>  m1 = 2500;
>>  m2 = 320;
>>  k1 = 80000;
>>  k2 = 500000;
>>  b1 = 350;
>>  b2 = 15020;
>> 
>>  nump=[(m1+m2) b2 k2];
>>  denp=[(m1*m2) (m1*(b1+b2))+(m2*b1) (m1*(k1+k2))+(m2*k1)+(b1*b2) 
> (b1*k2)+(b2*k1) k1*k2];
>>  G1=tf(nump,denp);
>> 
>>  num1=[-(m1*b2) -(m1*k2) 0 0];
>>  den1=[(m1*m2) (m1*(b1+b2))+(m2*b1) (m1*(k1+k2))+(m2*k1)+(b1*b2) 
> (b1*k2)+(b2*k1) k1*k2];
>>  G2=tf(num1,den1);
>> 
>>  numf=num1;
>>  denf=nump;
>>  F=tf(numf,denf);
>> 
>>  Kd = 208025;
>>  Kp = 832100;
>>  Ki = 624075;
>>  C = pid(Kp,Ki,Kd);
>> 
>>  sys_cl=F*feedback(F*G1,C);
>> 
>>  t=0:0.05:5;
>>  step(0.1*sys_cl,t)
>>  title('Closed-Loop Response to 0.1-m High Step w/ PID Controller')
>>  =================================
>> 
>>  I already installed and load the latest octave-control package and found 
> this error message
>> 
>>  octave:1> pkg load control
>>  octave:2> suspension
>>  warning: the 'pid' function belongs to the control package from 
> Octave Forge but
>>  has not yet been implemented.
>> 
>>  Please read <http://www.octave.org/missing.html> to learn how you can
>>  contribute missing functionality.
>> 
>> 
>>  error: 'pid' undefined near line 23 column 5
>>  error: called from:
>>  error:   /home/riza/Codes/Octave/suspension.m at line 23, column 3
>>  octave:2> 
>> 
>>  then I tried to change pid function into optiPID 
>> 
>>  =============================
>>  m1 = 2500;
>>  m2 = 320;
>>  k1 = 80000;
>>  k2 = 500000;
>>  b1 = 350;
>>  b2 = 15020;
>> 
>>  nump=[(m1+m2) b2 k2];
>>  denp=[(m1*m2) (m1*(b1+b2))+(m2*b1) (m1*(k1+k2))+(m2*k1)+(b1*b2) 
> (b1*k2)+(b2*k1) k1*k2];
>>  G1=tf(nump,denp);
>> 
>>  num1=[-(m1*b2) -(m1*k2) 0 0];
>>  den1=[(m1*m2) (m1*(b1+b2))+(m2*b1) (m1*(k1+k2))+(m2*k1)+(b1*b2) 
> (b1*k2)+(b2*k1) k1*k2];
>>  G2=tf(num1,den1);
>> 
>>  numf=num1;
>>  denf=nump;
>>  F=tf(numf,denf);
>> 
>>  Kd = 208025;
>>  Kp = 832100;
>>  Ki = 624075;
>>  C = optiPID(Kp,Ki,Kd);
>> 
>>  sys_cl=F*feedback(F*G1,C);
>> 
>>  t=0:0.05:5;
>>  step(0.1*sys_cl,t)
>>  title('Closed-Loop Response to 0.1-m High Step w/ PID Controller')
>>  =================================
>> 
>>  but there's another error message appears
>> 
>>  octave:2> edit suspension.m
>>  octave:3> suspension
>>  error: invalid use of script 
> /usr/share/octave/packages/control-2.8.2/optiPID.m in index expression
>>  error: called from:
>>  error:   /home/riza/Codes/Octave/suspension.m at line 23, column 3
>>  octave:3> 
>> 
>> 
>>  Please advise how to use PID function therefore I may run matlab examples 
> here 
> http://ctms.engin.umich.edu/CTMS/index.php?example=Suspension§ion=ControlPID
>> 
>>  Regards,
>> 
>>  Riza
> 
> There is no such thing as a "pid" function or class in the control 
> package, but you can easily define one yourself:
> 
>     pid = @(Kp, Ki, Kd) tf ([Kd, Kp, Ki], [1, 0])
> 
> Just put the expression above in your script file before your first usage of 
> the 
> "pid" function:
> 
>     C = pid (Kp, Ki, Kd)
> 
> Hope this helps,
> Lukas


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> 

> Tatsuro  
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Ah! Split to two different threads miss the timing.


For those who read this thread on the Nabble, please care that the thread 
contains two different initial posts.

1. http://octave.1599824.n4.nabble.com/Need-solution-tp4671186.html
2. http://octave.1599824.n4.nabble.com/Need-solution-tp4671186p4671229.html

Tatsuro