Title
Introducing Multi-Convexity In Path Constrained Trajectory Optimization For Mobile Manipulators
Abstract
Mobile manipulators have a highly non-linear and non-convex mapping between the end-effector path and the manipulator's joints and position and orientation of the mobile base. As a result, trajectory optimization with end-effector path constraints takes the form of a difficult non-linear optimization problem. In this paper, we present the first multi-convex approximation to this difficult optimization problem that eventually reduces to solving a sequence of globally valid convex quadratic programs (QPs). The proposed optimizer rests on two novel building blocks. First, we introduce a set of auxiliary variables in which the non-linear constraints that arise out of manipulator kinematics and its coupling with the mobile base have a multi-affine form. Projecting the auxiliary variables to the space of actual configuration variables of the mobile manipulator involves a non-convex optimization. Thus, the second building block involves computing a convex surrogate for this non-convex projection. We show how large parts of the proposed optimizer can be solved in parallel providing the possibility of exploiting multi-core CPUs. We validate our trajectory optimization on different benchmark examples. Specifically, we highlight how it solves the cyclicity problem and provides a holistic approach where a diverse set of trajectories can be obtained by trading-off different aspects of manipulator and mobile base motion.
Year
DOI
Venue
2019
10.23919/ECC51009.2020.9143797
2020 EUROPEAN CONTROL CONFERENCE (ECC 2020)
DocType
Volume
Citations 
Journal
abs/1904.09780
0
PageRank 
References 
Authors
0.34
0
4
Name
Order
Citations
PageRank
Arun Kumar Singh17727.01
Andrei Ahonen200.34
Reza Ghabcheloo37211.82
andreas muller45010.16