Closed micko-plz closed 4 years ago
@micko-plz
1. With the torque vector I am giving to the forward dynamics function aba, can I ensure the force being applied along the lateral 'y' direction of the robot's base is zero?
This is possible, but not trivial. You should formulate a QP problem for that.
Indeed, you have to solved an equality constrained problems in your context. In other words, choosing the joint acceleration a
will change the contact forces and vice-versa. The two quantities are coupled.
I can help you with it, but I think it would much simpler to discuss it an private thread, and if you can write a simple latex document with the problem you aim to solve it would be perfect.
@micko-plz Can you do that?
Hi @jcarpent,
Thank you for your reply. I had misunderstood what frame the vector of torques acted in. The torques regarding the base which I supplied to the forward dynamics function were acting in the world frame, rather than the base frame, something which I should have noticed given the definition of the generalized coordinate vector. I have everything working for now, but thank you for your kind offer of help. I'll close the issue.
Regards, Michael
OK. Good that things work well for you now. Best continuation!
Hi all,
I'm controlling a mobile manipulator with a two wheel differential drive base (segway like) using the whole body EoM. The control policy is not respecting the constraint I am defining and I'm unsure if its due to lack of understanding of the pinocchio functions I am calling or if its a solver issue so my apologies if this post veers away from purely a pinocchio related dilemma. I am hoping you could confirm whether I am calling the relevant functions correctly via the code brief below.
Specifically:
I have simplified the code into what is pasted below, the wheels are neglected and instead assume a force can be applied in the robots local forward/back 'x' direction, and also a torque about its z direction for turning.
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Thank you in advance for your reply. Kindest regards, Michael.