Analyzing the Utility of a Support Pin in Sequential Robotic Manipulation

TL;DR

This paper enhances robotic pick-and-place regrasp capabilities by incorporating a vertical support pin, enabling better object reorientation and successful task execution through an automated regrasp planning method.

Contribution

It introduces a novel method that uses a vertical pin for intermediate object placement, expanding reorientation options beyond flat surfaces.

Findings

Using support pins improves regrasp success rates.

Regrasp sequences are shorter with pins.

Experiments confirm the effectiveness of the approach.

Abstract

Pick-and-place regrasp is an important manipulation skill for a robot. It helps a robot accomplish tasks that cannot be achieved within a single grasp, due to constraints such as kinematics or collisions between the robot and the environment. Previous work on pick-and-place regrasp only leveraged flat surfaces for intermediate placements, and thus is limited in the capability to reorient an object. In this paper, we extend the reorientation capability of a pick-and-place regrasp by adding a vertical pin on the working surface and using it as the intermediate location for regrasping. In particular, our method automatically computes the stable placements of an object leaning against a vertical pin, finds several force-closure grasps, generates a graph of regrasp actions, and searches for the regrasp sequence. To compare the regrasping performance with and without using pins, we evaluate the success rate and the length of regrasp sequences while performing tasks on various models. Experiments on reorientation and assembly tasks validate the benefit of using support pins for regrasping.