Python and ZeroMQ remote API
Posted: 07 Jul 2022, 09:31
Dear Coppelia Team,
I read from https://www.coppeliarobotics.com/helpFi ... erview.htm that the legacy remote API is going to be deprecated as per CoppeliaSim V4.4, in favor of ZeroMQ remote API.
We have used the legacy API in the past with python, and we are currently trying to convert the code to ZeroMQ. However, we noticed that the performance is much worse with ZeroMQ. In particular, when moving a robot with 16 joints and sending the command via "setJointTargetPosition" this makes the movement very jittering: it takes 18 second to go through a 50 position trajectory (with no delay being specify within the loop). With the LegacyAPI the same trajectory is much smoother and we used to explicitly add a 50 ms delay in the loop to simulate a real-time movement.
One workaround we found is to use the "step-mode" in ZeroMQ, but we wonder why there is such a slow performance in non-step mode.
We also noticed that all python examples you provide which ZeroMQ API heavily rely on scripts in the scenes. We wonder if this is the only way to have smooth trajectory in non-step mode.
Thank you for your help
I read from https://www.coppeliarobotics.com/helpFi ... erview.htm that the legacy remote API is going to be deprecated as per CoppeliaSim V4.4, in favor of ZeroMQ remote API.
We have used the legacy API in the past with python, and we are currently trying to convert the code to ZeroMQ. However, we noticed that the performance is much worse with ZeroMQ. In particular, when moving a robot with 16 joints and sending the command via "setJointTargetPosition" this makes the movement very jittering: it takes 18 second to go through a 50 position trajectory (with no delay being specify within the loop). With the LegacyAPI the same trajectory is much smoother and we used to explicitly add a 50 ms delay in the loop to simulate a real-time movement.
One workaround we found is to use the "step-mode" in ZeroMQ, but we wonder why there is such a slow performance in non-step mode.
We also noticed that all python examples you provide which ZeroMQ API heavily rely on scripts in the scenes. We wonder if this is the only way to have smooth trajectory in non-step mode.
Thank you for your help