Imperial College London

Dr Nicolas Rojas

Faculty of EngineeringDyson School of Design Engineering








Dyson BuildingSouth Kensington Campus






BibTex format

author = {Baron, N and Philippides, A and Rojas, N},
booktitle = {Advances in Robot Kinematics 2018},
doi = {10.1007/978-3-319-93188-3_22},
pages = {187--194},
publisher = {Springer},
title = {A geometric method of singularity avoidance for kinematically redundant planar parallel robots},
url = {},
year = {2018}

RIS format (EndNote, RefMan)

AB - Methods for avoiding singularities of closed-loop robot mechanisms havebeen traditionally based on the value of the determinant or the condition number ofthe Jacobian. A major drawback of these standard techniquesis that the closeness ofa robot configuration to a singularity lacks geometric, physical interpretation, thusimplying that it is uncertain how changes in the robot pose actually move furtheraway the mechanism from such a problematic configuration. This paper presentsa geometric approach of singularity avoidance for kinematically redundant planarparallel robots that eliminates the disadvantages of Jacobian-based techniques. Theproposed method, which is based on the properties of instantaneous centres of rota-tion, defines a mathematical distance to a singularity and provides a reliable way ofmoving the robot further from a singular configuration without changing the poseof the end-effector. The approach is demonstrated on an example robot mechanismand the reciprocal of the condition number of the Jacobian isused to show its ad-vantages.
AU - Baron,N
AU - Philippides,A
AU - Rojas,N
DO - 10.1007/978-3-319-93188-3_22
EP - 194
PB - Springer
PY - 2018///
SP - 187
TI - A geometric method of singularity avoidance for kinematically redundant planar parallel robots
T1 - Advances in Robot Kinematics 2018
UR -
UR -
ER -