Re: [Playerstage-users] Position interface. p20s. Speed/acceleration response

[Alvaro C. <o__...@ho...>]

Hi!

In my opinion, as the max acceleration, just like the max speed and 
turnrate, seems to be intended to "limit" the dynamics of the robot for 
security issues, it would feel a little bit unsafe to touch it while the 
robot is running. Anyway, if it is so easy to implement, maybe it is not 
a bad idea to have this available...

Indeed, if one wants to modify the dynamic behaviour of a robot (rise 
time, overshot, for a given speed/turnrate command) WHILE it is running, 
it would be more intuitive to change the values of the PID.

I think the possibility to change the PID values of the robot while it 
is running would be the best alternative, and the most useful. Many 
industrial controllers apply different PID constants to control the same 
system depending on the working point of it, so why not having this 
capability in our case? Definitelly, useful!

//alvaro

Brian Gerkey wrote:

> On Fri, 8 Oct 2004, Reed Hedges wrote:
>
>> Alvaro Canivell wrote:
>>
>>> Hello,
>>>
>>> I am using Player v1.5 to control a Pioneer PeopleBot.
>>>
>>> 1)- I would like to know if there is a way to limit the maximum 
>>> acceleration in the p2os driver, just in a similar way as you can do 
>>> with the maximum speed and maximum yaw speed.
>>> 2)- As an alternative to this, is it posible to configure the PID 
>>> controller parameters of the position interface in the p2os?
>>
>>
>> Well, you can set the acceleration value in the PeopleBot 
>> microcontroller by sending it command 5 ("SETA") (send it a negative 
>> integer to set the deceleration value).  Not sure how to do this in 
>> Player, I guess it uses the default... it would be easy for you to 
>> add this parameter though, I think.
>
>
> If you just want one (non-default) setting for max acceleration, then
> we could easily add it as an config-file option to the p2os driver.
>
> If you want to change it on the fly, then we'll need a config request,
> which is more work, but doable.  As an alternative to providing a way
> to limit the acceleration, we could instead provide a way to set the PID
> values directly.  There is already a position config request to do this,
> and P2OS supports it.  Would one of these be more useful than the other?
>
>         brian.
>