A Robot with Decoupled Mechanical Structure and Adapted State Machine Control for Both Ground and Staircase Situations

Abstract

The rapid development of e-commerce makes the last-mile problem more and more prominent. To meet the requirements of such a scenario, this paper proposes a robot with a decoupled mechanical structure. Such a hexapod robot is divided into a chassis frame with a pair of auxiliary wheel-legs for horizontal movement, a tetrapod for vertical movement, and a slide-and-rail mechanism to connect the former two parts. Such a structure is simple and, thus, cost-efficient; by managing the horizontal and vertical movements, such a robot can keep the balance and safety of the load in the various operation environments, such as roads, staircases, and even indoor ones. Meanwhile, a state-machine-based controller, which adapts well to the unique structure of the proposed robot, is also proposed, simplifying the sequential control of the robot. A prototype robot with 30-kg load ability was built, and the experimental results prove the validity of the design.

Watch the Next Step: A Comprehensive Survey of Stair-Climbing Vehicles

“…Wen [69] has driven legs which move vertically, and four wheels attached to the body frames. Moreover, [72] (not shown in Table 7) uses driven legs as Wen [69] but a different system to appreciate stairs corners.…”

“…An articulated mechanism-based robot is reported in [74]. It uses Prototype solution, autonomous driving, no self-balancing control system Wen [69] has driven legs which move vertically, and four wheels attached to the body frames. Moreover, [72] (not shown in Table 7) uses driven legs as Wen [69] but a different system to appreciate stairs corners.…”

“…It uses Prototype solution, autonomous driving, no self-balancing control system Wen [69] has driven legs which move vertically, and four wheels attached to the body frames. Moreover, [72] (not shown in Table 7) uses driven legs as Wen [69] but a different system to appreciate stairs corners. Peopler-II [70,71] has perpendicularly oriented planetary legged wheels that are used to climb and descend stairs.…”

“…Max crossable height and slope comparison for wheelchair type robots; Chen [55]; HE-LIOS-V [54]; TBW-I [53]; Lawn [52]; Morales [51]; RT-Mover PType WA [48][49][50]; WL-16 II [45,46]; Lee [47]; Zero Carrier [41,42]; Castillo [39]; Wheelchiar.q [37,38]; iBOT 4000 [35,36]; All-Terrain Wheelchair [34]; Caterwill GTS5 Lux [32]; B-Free Ranger [30]; Tao [29]; WT-Wheelchair [27,28]; TopChair-S [26]; Scewo Bro [25]. [69]; Deshmukh [68] iRobot 710 Kobra [63]; Haulerbot [62]; Yoneda [59].…”

Mechanical design and wheel–leg–body cooperation control of a step‐climbing robot

“…The rotational leg-type miniature robot can use the tail limb to adjust the angle during the climbing (Kwak & Bae, 2018). The robot designed by Yang et al (Wen et al, 2019) made a movable frame to provide space and time for climbing stairs. MAMMOTH Rover (Reid et al, 2020), Sherpa TT (Cordes et al, 2018), ASGUARD (Eich et al, 2008), and Hylos Robot (Grand et al, 2010) adopts wheel-leg hybrid structures to combine the abilities of wheel and leg.…”