Kinetostatic backflip strategy for self-recovery of quadruped robots with the selected rotation axis

Abstract

A kinetostatic approach applied to the design of a backflip strategy for quadruped robots is proposed in this paper. Inspired by legged animals and taking the advantage of the leg workspace, this strategy provides an optimal design idea for the low-cost quadruped robots to achieve self-recovery after overturning. Through kinetostatic and energy analysis, a four-stepped backflip strategy based on the selected rotation axis with minimum energy is proposed, with a process of selection, lifting, rotating, and protection. The kinematic factors that affect the backflip are investigated, along with the relationship between the design parameters of the leg and trunk being analyzed. At the end of this paper, the strategy is validated by a simulation and experiments with a prototype called DRbot, demonstrating that the strategy endows the robot a strong self-recovery ability in various terrains.

Using pose estimation and 3D rendered models to study leg-mediated self-righting by lanternflies

“…It is also illuminating to compare the righting motions observed for spotted lanternfly nymphs to those proposed for righting by legged robots (Peng et al 2017; Wang et al 2022). The planting and lifting motions used by these insects correspond to steps required for robots to assume a starting posture suitable for using the legs to support, balance, and rotate the body.…”

“…Pitching was found to correspond to a large, negative stability margin requiring stabilization by adhesion forces applied by a small number of legs until immediately before overturning; this means that even a momentary loss of contact with the ground would destabilize this method before tip-over, as observed during failed pitching attempts. (Movie 1) It is also illuminating to compare the righting motions observed for spotted lanternfly nymphs to those proposed for righting by legged robots (Peng et al 2017;Wang et al 2022). The planting and lifting motions used by these insects correspond to steps required for robots to assume a starting posture suitable for using the legs to support, balance, and rotate the body.…”

“…In a different context, robot designs inspired by the self-righting abilities of falling cats dynamically reconfigure rotational inertia (inertial morphing) so as to perform rotational reorientations at zero external torque (Cao et al, 2022; Shield et al, 2021). Although this mechanism has also been applied to self-righting robot design (Wang et al, 2022), we are not aware of any studies of animals taking advantage of poses and motions that minimize rotational inertia and hence the torque required to flip upright during terrestrial self-righting (Casarez, 2018).…”

“…Ongoing research aims at understanding how the methods used by a specific organism to self-right depend on its morphology and locomotor abilities, as well as the substrate's properties (Davis et al 2011). Animal righting behaviors also have inspired designs for robots that can recover easily from upsets-a particular concern for operating in complex terrains (Saranli et al 2004;Wang et al 2022)-using coordinated motions of artificial legs (Saranli et al 2004), wings (Li et al 2016), and tails (Casarez and Fearing 2017).…”

Deformable Morphing and Multivariable Stiffness in the Evolutionary Robotics

“…More attention has been paid to the evolutionary designs of autonomous robots working in cluttered environments. Dai et al proposed the metamorphic quadruped robot with a morphing wrist in 2012, which can adapt to various surfaces, execute changeable gaits on multiple terrains, and conquer challenging obstacles [47][48][49][50][51][52][53]. The metamorphic walker has evolved into Origaker with multi-mimicry able to transform between different working modes such as the reptile-, arthropod-, and mammal-like modes, without disassembly and reassembly based on a single-loop spatial metamorphic mechanism in 2022 [14].…”