The Epi.q-1 Hybrid Mobile Robot

Abstract

In this paper we propose an innovative solution for a small size hybrid mobile robot called Epi.q-1. Overall dimensions are about 160 mm 1 360 mm 1 280 mm (height 1 length 1 width). The Epi.q-1 robot moves on flat, steep or uneven ground. It can climb over obstacles or steps, even if they are non-uniform in size. Its operating mode adapts to ground conditions and changes accordingly: from rolling (on wheels) to stepping (on legs)1 thanks to its great mobility it can follow complex routes. It is easy to control with just a few actuators. Robot locomotion drive-generating units employ an original driving mechanism, where degrees of freedom (DOFs) can be limited to some extent according to the operating conditions or thanks to a switching device. Locomotion units consist of a motor linked to a gear (double epicyclical chain) and an axial device (mini-motor and lead screw system) able to lock or unlock some DOFs of the kinematic chain. Moreover, the robot locomotion unit can change its size, from small to large and vice versa, in order to be able to reach restricted spaces and to overcome even quite tall obstacles. It was experimentally tested on flat ground and slopes. It can overcome 90 mm obstacles, that are 72% of the height of the locomotion unit, and climb stairs.

A Modular Approach for a Family of Ground Mobile Robots

“…The two front driving units can be switched from a closed configuration, suitable for motion in narrow spaces, to an open configuration, useful for traversing higher obstacles and vice-versa [21]. Each driving unit is powered by a Solarbotics GM17 gear-motor, declared specifications are a no load angular speed of 60rpm and a maximum torque of almost 1N m, when it is powered at 12V.…”

“…The Epi.q-1 frame architecture is characterized by two mutually perpendicular revolute joints: the vertical joint enables robot steering, while the horizontal joint assures contact between the wheels and the ground even on a uneven terrains. The two front driving units can be switched from a closed configuration, suitable for motion in narrow spaces, to an open configuration, useful for traversing higher obstacles and vice-versa [21]. Each driving unit is powered by a Solarbotics GM17 gear-motor, declared specifications are a no load angular speed of 60rpm and a maximum torque of almost 1N m, when it is powered at 12V.…”

“…Comparison of the three prototypes 5. Future works: Epi.q Lizard Currently in the design phase, Epi.q Lizard is the last version of the Epi.q family; it should increase robot mobility on irregular and uneven terrains in comparison to previous prototypes[20,21,22]. According to Section 2, it can be classified as 4UD 4TM CT TS LJ-ATJ NSU.…”

Design and analysis of a wheel-legged hybrid locomotion mechanism

“…Locomotion mode is passively switched between wheeled and legged so that some unexpected locomotion transition will happen. [9][10][11] In this article, a wheel-legged hybrid locomotion mechanism with an active transition system, called ''TH-Wheg,'' was designed and has two kinds of locomotion modes: wheeled and legged. Mechanical design 1 was introduced in section ''TH-Wheg.''…”

RT-Mover: a rough terrain mobile robot with a simple leg–wheel hybrid mechanism

“…(3) Leg-wheel robots: These attempt to combine the advantages of both legs and wheels in various configurations. Work Partner (Halme et al 2003), Roller Walker (Endo and Hirose 2000), Zero Carrier (Yuan and Hirose 2004), Hylos (Grand et al 2004), and PAW (Smith et al 2006) are equipped with wheels placed at the ends of their legs; Chariot III Nakano 2008a,b, 2009a,b,c), RoboTrac (Six and Kecskem'ethy 1999), and a wheel chair robot (Morales et al 2006) have separate wheels and legs; Whegs (Quinn et al 2003;Daltorio et al 2009) and Epi.q-1 (Quaglia et al 2010) have four wheels composed of rotating legs or wheels; and Wheeleg (Lacagnina et al 2003) has two front legs and two rear wheels.…”