Padded collision checking for safety

[bsaund]

Currently Moveit an produce plans arbitrarily close to collision, or possible even in collision. During many moves there is no need to cut the margin of safety so close. This almost certainly will cause physical robot collisions eventually because:

• Victor/Val have significant error between URDF/simulation and physical robot
• The gripper collision does not exactly match the true gripper
• We will have errors in modeled objects
• Moveit can produce plans in collision due to discretization

One approach is to create a separate padded URDF, and plan using the {padded/tight} URDF depending on the situation

A better approach would be to directly have this feature in moveit. We are not the only ones:
moveit/moveit#683

[calderpg]

FYI, TRI is in the process of making public our motion planning stack as part of drake and it supports configurable self- an environment-collision padding. We don't have as broad a set of planners as MoveIt brings in from OMPL, but we have enough for all of the planning tasks we've needed to do.

[bsaund]

Good to know. Let us know when you make this public and we can evaluate

[calderpg]

An update on timeline - we've been working on internal prereqs and tooling on our end, and expect to kick off the public drake parts of this early in Q2 with the goal of everything available and well-documented before the end of the semester.