Robot Reachability Function

[moore.dr]

Hello,

I was wondering if there is any native functionality for demonstrating the Stretch’s reachable workspace given a time horizon. This would apply to not only the manipulator, but also including base movements. Please let me know if there are any resources for this. Thank you!

[bshah]

Hi @moore.dr, welcome to the forum! Could you provide a bit more detail about what you’re looking for? For example, with fixed arm robots, the task workspace might be visualized as a semi-sphere, and the reachable portion of the workspace depends on the robot’s initial configuration and dynamics. Am I correct in understanding that you’re looking for something like this for Stretch?

[moore.dr]

Thank you! Yes I was hoping that given the robot’s current kinematic position, there is a way to obtain the reachable area within a given time horizon. This would include the various positions of the arm, wrist and robot base.

[bshah]

Hi @moore.dr, I recommend taking a look at this thread on Stretch’s dynamics:

Physical aspects of the Robot for Simulation

Hi Stretch Community, We have been working towards supporting research works that use Stretch in a simulation environment and groups trying to achieve close-to-real dynamics of the real robot. Therefore, we have gathered information on accurate Mass parameters, Forces/torques, and velocity parameters for the Lift, Arm, Base, and Wrist Yaw joints. Masses and Inertial Values We now have an accurate itemized breakdown of all the masses and inertial values specific to each link mentioned in our UR…

Specifically, the section titled “Velocities” would be helpful in determine how far the mobile base can turn or travel in a given time horizon, and how far the manipulator could travel in a given time horizon. Whether the robot could reach a target goal in a time horizon would depend on how the robot moved to achieve the goal.