Multi-robot grasp planning for sequential assembly operations

Abstract

Abstract-This paper addresses the problem of finding robot configurations to grasp assembly parts during a sequence of collaborative assembly operations. We formulate the search for such configurations as a constraint satisfaction problem (CSP). Collision constraints in an operation and transfer constraints between operations determine the sets of feasible robot configurations. We show that solving the connected constraint graph with off-the-shelf CSP algorithms can quickly become infeasible even for a few sequential assembly operations. We present an algorithm which, through the assumption of feasible regrasps, divides the CSP into independent smaller problems that can be solved exponentially faster. The algorithm then uses local search techniques to improve this solution by removing a gradually increasing number of regrasps from the plan. The algorithm enables the user to stop the planner anytime and use the current best plan if the cost of removing regrasps from the plan exceeds the cost of executing those regrasps. We present simulation experiments to compare our algorithm's performance to a naive algorithm which directly solves the connected constraint graph. We also present a real robot system which uses the output of our planner to grasp and bring parts together in assembly configurations.

Designing a Mechanical Tool for Robots With Two-Finger Parallel Grippers

“…Sanchez et al [20] developed a planner with orientation constraints to manipulate a tethered tool. Beyond our group, similar studies about the grasp and regrasp planning could be found in [21], [22], [23], [24], [25], etc.…”

Arm Manipulation Planning of Tethered Tools with the Help of a Tool Balancer

“…Recently, multiple work on manipulation planning has been presented. These work includes the comparison of single-arm and dual-arm algorithms for regrasping [21,2,20], a regrasp control policy that uses tactile sensors to plan adjustments for local grasp [6], a planner that computes robot configurations to grasp assembly parts for sequences of collaborative assembly operations [4] and 3D object reorientation using pivoting [7].…”

dRRT*: Scalable and informed asymptotically-optimal multi-robot motion planning

“…The topology of dual-arm manipulation has been formalized (Koga and Latombe, 1994;Harada et al, 2014) and extended to the N -arm case . It requires the consideration of multi-robot grasp planning (Vahrenkamp et al, 2010;Dogar et al, 2015), regrasping (Vahrenkamp et al, 2009), as well as closed kinematic chain constraints (Cortés and Siméon, 2005;Bonilla et al, 2017). Furthermore, force control strategies are helpful for multi-arm manipulation of a common object (Caccavale and Uchiyama, 2008).…”