Mechanism and Machine Theory 140 (2019) 389–412 Contents lists available at ScienceDirect Mechanism and Machine Theory journal homepage: www.elsevier.com/locate/mechmachtheory Hybridizing differential evolution and local search optimization for dimensional synthesis of linkages Ramon Sancibrian a,∗ , Angel Sedano b , Esther G. Sarabia c , Jesus M. Blanco d a Department of Structural and Mechanical Engineering, University of Cantabria, Avda. de los Castros s/n, 39005 Santander, Spain b Asset Management Services: Renewables, UL, C/ Larragueta 8B, 310013 Ansoain, Navarra, Spain c Department of Electronic Technology and Automatic Systems, University of Cantabria, Avda. de los Castros s/n 39005 Santander, Spain d Department of Nuclear Engineering and Fluid Mechanics, University of the Basque Country (UPV/EHU), Plaza Ingeniero Torres Quevedo. Edif. 1, 48013 Bilbao, Spain a r t i c l e i n f o Article history: Received 20 February 2019 Revised 17 May 2019 Accepted 12 June 2019 Keywords: Synthesis Hybrid optimization Evolutionary algorithm Local search a b s t r a c t This work deals with the optimal dimensional synthesis of planar linkages. The paper pro- poses a new search procedure to obtain the best linkage by means of hybridizing a Local Search (LS) approach and an Evolutionary Algorithm (EA), Hybrid Algorithms (HAs) com- bine the advantages of stochastic and deterministic optimization, enhancing their features in the search for the best solution. However, the way in which the integration of these two kinds of algorithms should be implemented is not a trivial issue and many options exist that have to be investigated. In this paper different schemes of hybrid algorithms are applied to the synthesis of planar linkages. The work discusses different approaches that use information and structures for achieving a balance between global and local searches. Differential Evolution (DE) is used together with the Generalized Reduced Gradient (GRG) approach for optimal search. Both Cluster and Elite Analyses are studied to select an effec- tive hybrid optimization strategy. The different schemes of hybrid algorithms are presented and analyzed in different examples for the design of planar linkages and the best options are highlighted. © 2019 Elsevier Ltd. All rights reserved. 1. Introduction Dimensional synthesis deals with the determination of the dimensions of the links of a mechanism in such a way that the prescribed task can be performed properly. Dimensional synthesis has been widely studied in the literature in the form of three classical problems, which are defined as path generation, function generation and rigid-body guidance [1]. All these problems lead to highly nonlinear formulations [2], which are very difficult to solve even with the help of powerful com- puters. This difficulty arises when the number of links or prescribed positions is high, as happens in the design of complex mechanisms [3]. For this reason, in the last decades, most research has been focused on the development and adaptation of accurate, efficient and robust numerical algorithms to solve the synthesis problem [4]. The goal is to solve highly nonlinear problems, subject to a set of constraints that normally appear in this type of designs. Numerical optimization is one of the main techniques used successfully in these kinds of problems [5], as it facilitates the formulation of a prescribed task as a goal function, enabling the assessment of how good a mechanism is at satisfying the imposed requirements. ∗ Corresponding author. E-mail address: sancibrr@unican.es (R. Sancibrian). https://doi.org/10.1016/j.mechmachtheory.2019.06.013 0094-114X/© 2019 Elsevier Ltd. All rights reserved.