ROBOTICA & MANAGEMENT - Vol. 23, No. 2, December 2018, pp. 27-31

New Planar Mechanisms for the Legs of Quadruped Mobile Robots

Catalina Robu (Nan) *, Ovidiu Antonescu **, Gabriela Firouzi ***

* "Tudor Vianu" High School of Giurgiu, Romania
e-mail: catalina.nan(at)
** Politehnica University of Bucharest, Romania
e-mail: oval33(at)
*** "Gh. Asachi" High School of Bucharest, Romania

 This paper presents two new kinematic schemes of articulated planar mechanisms used as the leg of a quadruped mobile robot. These mechanisms consist of 5 mobile kinematic elements, as compared to the Jansen mechanism, which is made of 7 component elements. The four mechanisms of a quadruped robot are driven by a single electric motor by means of cylindrical gears. The structure of the kinematic schemes within the mechanisms taken into consideration contains kinematic chains with four articulated triadic and tetradic elements. For each of the proposed kinematic schemes, several geometrical options regarding the position of articulations and of the fulcrum have been considered. The mobility of each kinematic scheme is assessed, and a geometrical synthesis method for generating the fulcrum of the reciprocating rod curve is given.
Keywords: kinematic scheme, planar mechanism, mobile robot, triadic chain, tetradic chain.

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