No, the issue and the reason why it does not work, is that old_pos and
position_command_in are always different, even if by 1 billionth.
I am rewriting some stuff.
i
On Thu, Mar 3, 2011 at 8:57 PM, Igor Chudov <ichu...@gmail.com> wrote:
>
>
> On Thu, Mar 3, 2011 at 1:45 PM, andy pugh <bodge...@gmail.com> wrote:
>
>> On 3 March 2011 16:53, Jon Elson <el...@pico-systems.com> wrote:
>>
>> > I STILL don't like it. You need a HAL component that looks at commanded
>> > position
>> > (comes from axis.8.motor-pos-cmd, I think) and compares current to last
>> > position.
>>
>> Whilst also not liking it, this custom HAL component would do the
>> trick: (It needs to be compiled with comp --install timeout.comp)
>>
>> component timeout """Reduces motor command to a predetermied value after a
>> certain number of seconds of no axis motion""";
>>
>> pin in float position-command-in "link to motor-pos-cmd";
>> pin in float current-in "link to the PID output";
>> pin out float current-out "link to the DAC";
>> param rw float timeout = 10 "timeout in seconds";
>> param rw float default-current = 0 "current output after timeout";
>> variable float old_pos;
>> variable float t = 0;
>> function _;
>> license "GPL";
>> author "Andy Pugh";
>>
>> ;;
>>
>> FUNCTION(_){
>> if (old_pos != position_command_in){
>> t = timeout;
>> }
>> else {
>> t -= fperiod;
>> }
>>
>> if (t < 0){
>> current_out = default_current;
>> }
>> else {
>> current_out = current_in;
>> }
>>
>> old_pos = position_command_in;
>> }
>>
>>
>>
> Andy, this is an awesome comp, except that it does not quite work. Here's
> the version that I use:
>
> component timeout """Reduces motor command to a predetermied value after a
> certain number of seconds of no axis motion""";
>
> pin in float position-command-in "link to motor-pos-cmd";
> pin in float current-in "link to the PID output";
> pin out float current-out "link to the DAC";
> param rw float timeout = 10 "timeout in seconds";
> param rw float default-current = 0 "current output after timeout";
> variable float old_pos;
> variable float t = 0;
> function _;
> license "GPL";
> author "Andy Pugh";
>
> ;;
>
> FUNCTION(_){
> if (old_pos != position_command_in){
> t = timeout;
> }
> else {
> t -= fperiod;
> }
>
> if (t < 0){
> current_out = default_current * current_in;
> }
> else {
> current_out = current_in;
> }
>
> old_pos = position_command_in;
> }
>
> It works in the sense that its output is equal to input.
>
> It does not work in the sense that it does not shut down after 10 seconds.
>
> Your code looks very good to me, and I think that what is happening is that
> you are trying to subtract a small number fperiod, from a large number t,
> and that does not work.
>
> The config I have says
>
> newsig pid-W-out float
> #newsig pid-W-command-in float
>
> setp w_axis_timeout.default-current 0 # current factor applied after
> timeout
> setp w_axis_timeout.timeout 10 # Timeout in seconds
>
> linksp pid-W-out <= pid.4.output # pid-W-out
> is output of pid 4
> linksp Wpos-cmd => w_axis_timeout.position-command-in #
> and it goes into timeout
> linksp pid-W-out => w_axis_timeout.current-in # and it
> goes into timeout
> linksp Woutput <= w_axis_timeout.current-out # output
> from timeout will go to motor
>
> i
>
>
------------------------------------------------------------------------------
What You Don't Know About Data Connectivity CAN Hurt You
This paper provides an overview of data connectivity, details
its effect on application quality, and explores various alternative
solutions. http://p.sf.net/sfu/progress-d2d
_______________________________________________
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users
