[Rock-dev] <base/motion_command.h>

[Chris Müller]

On 08.11.2011 13:51, Sylvain Joyeux wrote:
> You need the time at which the actual motors are actuated according to 
> your motion command. Which is not what the motion command will provide 
> you. That was the general idea about not timestamping those: these 
> timestamps are not strictly usable for estimation.
> anyway, as it would allow the measurement of control loop latencies.
>
> However, for the purpose of a motion model, I am wondering why you 
> don't use the motors reported PWM (since you are using the hbridges, 
> you can do that). That would remove the controller => actuator driver 
> => actuator latency, and work regardless of the controller / control 
> method being used (and, for instance, of the presence of ramping).
>
That makes sense, of course.

> If your estimator is deployed in the RT scheduler, does not do an 
> memory allocation, and is using a suitable priority, then you could 
> neglect the latency and create the timestamp on input.

That sounds interesting. I know this is not part of the actual question 
anymore. Is it something I need to configure on the operating system? Or 
can i control that in one of our runtime system (orocos.rb, roby). I 
know this not part of the actual question anymore. Its only for 
extending my knowledge about the capabilities of the framework.

Chris