Control Experiments

Finally, control experiments are carried out in this page using the designed controller.

Install module for control experiments

Type the following command on kterm:

% insmod hinf_module.o

Confirm that the module is correctly installed by lsmod:

% lsmod
Module                  Size  Used by
hinf_module             5696   0 (unused) <--- this means the module is installed correctly
mbuff                   5616   3 [hinf_module]
rtl_sched              26560   0 [hinf_module]
rtl_fifo                8736   0 (unused)
rtl_posixio             6976   0 [rtl_fifo]
rtl_time                4416   0 [hinf_module rtl_sched rtl_posixio]
rtl                    17488   0 [hinf_module rtl_sched rtl_fifo rtl_posixio rtl_time]

Start the experimens

Type the following to start control experiments:
```
% ./hinf_app
	
```
The total time of the experiment is 10 seconds.
The control starts at 5 seconds after the beginning.
You can recognize the sound feeling is changed when the control is started.
Repetitive execution of hinf_app is OK to make sure the difference of the sound feeling.

Remove the module

% rmmod hinf_module
% lsmod
Module                  Size  Used by
mbuff                   5616   0
rtl_sched              26560   0
rtl_fifo                8736   0 (unused)
rtl_posixio             6976   0 [rtl_fifo]
rtl_time                4416   0 [rtl_sched rtl_posixio]
rtl                    17488   0 [rtl_sched rtl_fifo rtl_posixio rtl_time]

The howling might be occurred when controller design is not suitable.
The one possibility of such case depends on the choice of the weight transfer function. The gain of the weight should not be smaller than the actual modeling error as mentioned before.
Another possibility depends on saturation problem of the control input u. If there is saturation in u, then the closed-loop system might be unstable, even if good closed-loop system performance is estimated in the previous page.

Yasuhide Kobayashi

Last modified: Thu Jun 17 12:38:35 JST 2004