ABSTRACT Purpose - The cost of transport is one of the most important val- ues to the effciency and operation autonomy of a walking robot. This analysis involves factors as the weight, consumption of the ac- tuators, speeds, accelerations, work surfaces, step cycle model or distance travelled, which must be studied in detail to produce stable and energy-effcient locomotion. This paper presents the results ob- tained for the cost of transport of a hybrid robot with two front legs and two rear wheels, with a total weight of 50 kg in different sce- narios. Methodology/approach - The transportation cost of the pro- posed hybrid robot is obtained by carrying out a detailed analysis of the kinematics, dynamics, stability and energy consumption. Find- ings - A satisfactory value of effciency has been obtained, in terms of cost of transport, owing to a gravitationally decoupled design of the legs. The cost of transport of the robot proposed is between 0.11 and 0.24, depending on the work environment in which it op- erates, that is, walking on a smooth horizontal plane without addi- tional load. Originality/value – This work presents a new design of a gravitationally decoupled robotic leg by means of a new scheme in which the leg is composed of three four-bar mechanisms that can be synthesized independently. These three mechanisms involve frontal and vertical movement within the same plane of movement. One mechanism generates a horizontal path for tow, while another generates a vertical path and a third has the specifc mission of making the tow velocity constant when the corresponding motor is operated at a constant velocity. The overall goal of the mechanisms is to improve robot's effciency. Key words: Cost of transport, gravitationally uncoupled mo- tion, energy efficiency, experimental validation, hybrid robot. 1. INTRODUCTION Although the most widespread type of locomotion for mobile robots is wheel driven [1], the development of legged robots has increased signifcantly in the last few years owing to the improve- ments made in actuator control and effciency algorithms, among others. It is currently necessary to consider the advantages, in terms of effciency, of wheeled robots, for fat surfaces, compared to those with legs [2]. One example of this is the planetary exploration robots such as the Sojourner, Spirit, Opportunity and Curiosity. or the nu- clear accident that occurred in Fukushima in 2011, in which human access was restricted and it was necessary to use the PackBot and Warrior robots for rescue operations [3] supervision. However, robots with paws are more suitable for applications run- ning on uneven terrain [4], harmful to humans or when robots of relative small size are needed [5] such as those needed for home applications [6] and to help older people [7]. Another factor that has contributed to the proliferation of such robots is that of being able to give them an animal appearance [8] or humanoid [9]. This appearance helps its development, as it allows us to imitate its namesakes of the animal kingdom to investigate and better understand its locomotive behavior. In the case of robots with paws, the combined structure of mus- cles, joints and tendons is still far from being successfully imitated. research article / artículo de investigación 11 | ISSN-L:0012-7361 | xxxx | Vol. 96 nº 2 | March 2021 | Dyna Cod. 9828 | Mechanics | 2205.11 Applied Robotics Transport cost of a high energy efficiency hybrid robot Francisco-Javier López-Lombraña, Angel-Gaspar González-Rodríguez, Antonio González-Rodríguez, David Rodríguez-Rosa, Guillermo Rubio-Gómez, Sergio Juárez-Pérez, Fernando-José Castillo-García Francisco-Javier López-Lombraña, Angel-Gaspar González-Rodríguez, Antonio González-Rodríguez, David Rodríguez-Rosa, Guillermo Rubio-Gómez, Sergio Juárez-Pérez, Fernando-Jose Castillo-García Escuela de Ingeniería Industrial de Toledo. Av. Carlos III, Real Fábrica de Armas – 45071 Toledo (España) Transport cost of a high energy efficiency hybrid robot Costo de transporte de un robot híbrido de alta eficiencia energética To cite this article: LÓPEZ-LOMBRAÑA, Francisco-Javier; GONZÁLEZ-RODRÍGUEZ, Ángel-Gaspar; GONZÁLEZ-RODRÍGUEZ, Antonio; RODRÍGUEZ-ROSA, Da- vid; RUBIO-GÓMEZ, Guillermo; JUÁREZPÉREZ, Sergio; CASTILLO-GARCÍA, Fernando-José. TRANSPORT COST OF A HIGH ENERGY EFFICIENCY HYBRID ROBOT. DYNA, Marzo 2021, vol. 97, no. 2, 6 pp. DOI: https://doi.org/10.6036/9828 DOI: https://doi.org/10.6036/9828 Received: 17/06/2020 • Reviewing: 10/07/2020 • Acepted: 22/09/2020 RESUMEN • El costo del transporte es uno de los parámetros más importantes para estudiar la eficiencia y autonomía de operación de un robot caminante. Este análisis tiene en cuenta factores como el peso, consumo de los actuadores, velocidades, aceleraciones, superficies de trabajo, modelo de ciclo de pasos, etc. que deben estudiarse en detalle para producir una locomoción estable y energéticamente eficiente. Este artículo presenta los resultados obtenidos para el costo de trans- porte de un robot híbrido de dos patas delanteras más dos ruedas traseras con un peso total de 50 kg en diferentes escenarios. El costo de transporte del robot híbrido propuesto se obtiene realizando un análisis detallado de la cinemática, dinámica, estabilidad y consumo de energía. Se ha obtenido un valor satisfacto- rio de eficiencia, en términos de costo de transporte, debido a un diseño gravita- cionalmente desacoplado de las patas. El costo de transporte del robot obtenido se mueve entre 0,11 y 0,24, dependiendo del entorno de trabajo en el que actúe, con un valor de 0,18 para las condiciones nominales, esto es, caminando en un plano horizontal liso sin carga adicional. Este trabajo presenta un nuevo diseño de una pata robótica desacoplada gravitacionalmente mediante un nuevo esquema en el que dicha pata se compone de tres mecanismos de cuatro barras que se pueden sintetizar de forma independiente. Dichos mecanismos implican movimiento frontal y vertical dentro del mismo plano detrabajo. Un mecanismo genera una trayectoria horizontal para remolcar el robot, mientras que otro genera una trayectoria vertical, y un tercero tiene la misión específica de hacer que la velocidad de remolque sea constante cuando el motor correspondiente opera, también, a una velocidad constante, • Palabras Clave: tecnologías de asistencia, localización GPS, movilidad de perso- nas invidentes, estimulación podotáctil, interfaz vibrotáctil, sistema vestible.