A unified model with inertia shaping for highly dynamic jumps of legged robots

Wang, Ke; Xin, Guiyang; Xin, Songyan; Mistry, Michael; Vijayakumar, Sethu; Kormushev, Petar

doi:10.1016/j.mechatronics.2023.103040

Cited by 6 publications

(1 citation statement)

References 25 publications

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“…To avoid mathematical ambiguities that can arise when using Euler angles for calculating rotations (e.g., gimbal lock), we first performed calculations on orientations computed from the tracked coordinates using quaternion-based functions in MATLAB, and then converted the result to Euler angles (Wang et al 2023). Given the measured 3D orientations of the body and appendages in the spatial frame at times t and t + Δt , we used MATLAB functions absor (Matt 2024) and angvel to compute the corresponding angular velocity vector, 𝜔𝜔 � �⃗(𝑡𝑡), of each object.…”

Section: Measuring and Representing 3d Orientationmentioning

confidence: 99%

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

Bien

Alexander

et al. 2023

Preprint

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The ability to upright quickly and efficiently when overturned on the ground (terrestrial self-righting) is crucial for living organisms and robots. The emerging field of terradynamics seeks to understand how and why different animals use diverse self-righting strategies. We studied this behavior using high speed multiangle video in nymphs of the invasive spotted lanternfly (SLF, Lycorma delicatula), an insect that must frequently recover from falling in its native habitat. While most insect species previously studied can use wing opening to facilitate overturning, nymphs, like most robots, are wingless. SLFs were highly successful at self-righting (>92% of trials) with no significant difference in the time or number of attempts required for three substrates with varying friction and roughness. These nymphs seldom overturned using the pitching and rolling strategies observed for other insect species, instead primarily flipping upright by rotating around a diagonal body axis. To understand these motions, we used video, photogrammetry and Blender rendering software to create novel, highly realistic 3D models of SLF body poses during each strategy. These models were analyzed using the energy landscape theory of self-righting, which posits that animals use methods that minimize energy barriers to overturning, and inertial morphing, which proposes the animal adjusts its body pose to minimize the rotational inertia during overturning, a theory which has not been applied to self-righting. A combination of both theories was found to explain the observed preferred strategies of this species, indicating the value of using 3D renderings with mechanical modeling for terradynamics and biomimetic applications.

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Section: Measuring and Representing 3d Orientationmentioning

confidence: 99%

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

Bien

Alexander

et al. 2023

Preprint

View full text Add to dashboard Cite

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Bionic Jumping of Humanoid Robot via Online Centroid Trajectory Optimization and High Dynamic Motion Controller

Wang,

Guo,

et al. 2024

J Bionic Eng

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Using Pose Estimation and 3D Rendered Models to Study Leg-Mediated Self-righting by Lanternflies

Bien,

Alexander,

et al. 2024

Integrative and Comparative Biology

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The ability to upright quickly and efficiently when overturned on the ground (terrestrial self-righting) is crucial for living organisms and robots. Previous studies have mapped the diverse behaviors used by various animals to self-right on different substrates, and proposed physical models to explain how body morphology can favor specific self-righting methods. However, to our knowledge no studies have quantified and modeled all of an animal's limb motions during these complicated behaviors. Here, we studied terrestrial self-righting by immature invasive spotted lanternflies (Lycorma delicatula), an insect species that must frequently recover from being overturned after jumping and falling in its native habitat. These nymphs self-righted successfully in 92-100% of trials on three substrates with different friction and roughness, with no significant difference in the time or number of attempts required. They accomplished this using three stereotypic sequences of movements. To understand these motions, we combined 3D poses tracked on multi-view high-speed video with articulated 3D models created using photogrammetry and Blender rendering software. The results were used to calculate the mechanical properties (e.g., potential and kinetic energy, angular speed, stability margin, torque, force, etc.) of these insects during righting trials. We used an inverted physical pendulum model (a “template”) to estimate the kinetic energy available in comparison to the increase in potential energy required to flip over. While these insects began righting using primarily quasistatic motions, they also used dynamic leg motions to achieve final tip-over. However, this template did not describe important features of the insect's center of mass trajectory and rotational dynamics, necessitating the use of an “anchor” model comprising the 3D rendered body model and six articulated two-segment legs to model the body's internal degrees of freedom and capture the role of the legs’ contribution to inertial reorientation. This anchor elucidated the sequence of highly coordinated leg movements these insects used for propulsion, adhesion, and inertial reorientation during righting, and how they frequently pivot about a body contact point on the ground to flip upright. In the most frequently used method, diagonal rotation, these motions allowed nymphs to spin their bodies to upright with lower force with a greater stability margin compared to the other less frequently-used methods. We provide a concise overview of necessary background on 3D orientation and rotational dynamics, and the resources required to apply these low-cost modeling methods to other problems in biomechanics.

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A unified model with inertia shaping for highly dynamic jumps of legged robots

Cited by 6 publications

References 25 publications

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

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

Bionic Jumping of Humanoid Robot via Online Centroid Trajectory Optimization and High Dynamic Motion Controller

Using Pose Estimation and 3D Rendered Models to Study Leg-Mediated Self-righting by Lanternflies

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