[Rock-dev] Proposal for adding velocity information in base::actuators::Status

[Matthias Goldhoorn]

On 05.04.2012 13:39, Sylvain Joyeux wrote:
> On 04/05/2012 12:03 PM, Javier Hidalgo Carrió wrote:
>> Hello rocks,
>>
>> In Sherpa robot we are receiving angular position and angular velocity
>> information of every joints in the robot every 40ms coming from the
>> lower level (FPGA and Monster).
>>
>> The rock data type base:actuators::Status is the data type in rock for
>> joint information, which contains:
>>
>>               struct MotorState {
>>                int      current;  //! current in mA
>>                double   position; //! position in radians
>>                double   positionExtern; //! position of external encoder
>> in radians
>>                float    pwm;      //! duty cycle in [-1; 1]
>>
>>                MotorState()
>>                    : current(0), position(0), positionExtern(0), pwm(0) {}
>>            };
>>
>> I was wondering which is the correct data type to store joint velocities
>> information and if any what about include it in base:actuators::Status
>>
>> Any suggestion?
> 1/ do not add it to Status
> 2/ my suggestion is: let's try to rationalize all that stuff.
>      Obviously, the current Status type does not scale.
> 3/ velocity and position information are redundant (since you can
>      compute one from the other). Since joint sensors are usually
>      position, we went for position. Is there a direct velocity joint
>      measurement on Sherpa ? What is the point of having both values ?
>
If we cleanup this "think" we should also remove the separation between 
internal and external encoders, this Sounds really asguard specific...

Happy Eastern....
Matthias

> Sylvain
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