scholarly journals Sprawling Quadruped Robot Driven by Decentralized Control With Cross-Coupled Sensory Feedback Between Legs and Trunk

2021 ◽  
Vol 14 ◽  
Author(s):  
Shura Suzuki ◽  
Takeshi Kano ◽  
Auke J. Ijspeert ◽  
Akio Ishiguro
Keyword(s):  
Simulation Study ◽  
Sensory Feedback ◽  
Morphological Changes ◽  
Quadruped Robot ◽  
Body Parts ◽  
Walking Gait ◽  
Quadruped Robots ◽  
Lateral Body ◽  
Limb Coordination ◽  
Control Principle

Quadruped animals achieve agile and highly adaptive locomotion owing to the coordination between their legs and other body parts, such as the trunk, head, and tail, that is, body–limb coordination. This study aims to understand the sensorimotor control underlying body–limb coordination. To this end, we adopted sprawling locomotion in vertebrate animals as a model behavior. This is a quadruped walking gait with lateral body bending used by many amphibians and lizards. Our previous simulation study demonstrated that cross-coupled sensory feedback between the legs and trunk helps to rapidly establish body–limb coordination and improve locomotion performance. This paper presented an experimental validation of the cross-coupled sensory feedback control using a newly developed quadruped robot. The results show similar tendencies to the simulation study. Sensory feedback provides rapid convergence to stable gait, robustness against leg failure, and morphological changes. Our study suggests that sensory feedback potentially plays an essential role in body–limb coordination and provides a robust, sensory-driven control principle for quadruped robots.

scholarly journals Decentralized control mechanism for body–limb coordination in quadruped running

2019 ◽  
Vol 28 (3) ◽  
pp. 151-164 ◽  
Author(s):  
Akira Fukuhara ◽  
Yukihiro Koizumi ◽  
Shura Suzuki ◽  
Takeshi Kano ◽  
Akio Ishiguro
Keyword(s):  
Decentralized Control ◽  
Sensory Feedback ◽  
Feedback Mechanism ◽  
The Body ◽  
Coordination Mechanism ◽  
Coordination Pattern ◽  
Body Parts ◽  
Efficient Manner ◽  
Limb Coordination ◽  
Dimensional Simulation

As a mechanism for survival, quadrupeds have obtained skills involving coordination between limbs and the body (i.e. body–limb coordination), providing fast and adaptive locomotion compared with motion using only limbs. Several bio-inspired robotics studies have resulted in the development of legged robots that utilize a flexible spine, similar to cheetahs. However, the control principle of body–limb coordination has not been established to date. From the perspective of a decentralized control scheme, a minimal body–limb coordination mechanism is proposed in this study, in which body parts aid each other via a sensory feedback mechanism. The two-dimensional simulation and hardware experiments reveal that bilateral sensory feedback between limbs and body is essential for the robot to adaptively generate a body–limb coordination pattern and achieve faster locomotion speed than that by only limbs in efficient manner.

scholarly journals Spontaneous Gait Transitions of Sprawling Quadruped Locomotion by Sensory-Driven Body–Limb Coordination Mechanisms

2021 ◽  
Vol 15 ◽  
Author(s):  
Shura Suzuki ◽  
Takeshi Kano ◽  
Auke J. Ijspeert ◽  
Akio Ishiguro
Keyword(s):  
The Body ◽  
Coordination Mechanisms ◽  
Body Parts ◽  
Gait Patterns ◽  
Quadruped Locomotion ◽  
Self Organized ◽  
Lateral Body ◽  
Proposed Model ◽  
Limb Coordination ◽  
Gait Transitions

Deciphering how quadrupeds coordinate their legs and other body parts, such as the trunk, head, and tail (i.e., body–limb coordination), can provide informative insights to improve legged robot mobility. In this study, we focused on sprawling locomotion of the salamander and aimed to understand the body–limb coordination mechanisms through mathematical modeling and simulations. The salamander is an amphibian that moves on the ground by coordinating the four legs with lateral body bending. It uses standing and traveling waves of lateral bending that depend on the velocity and stepping gait. However, the body–limb coordination mechanisms responsible for this flexible gait transition remain elusive. This paper presents a central-pattern-generator-based model to reproduce spontaneous gait transitions, including changes in bending patterns. The proposed model implements four feedback rules (feedback from limb-to-limb, limb-to-body, body-to-limb, and body-to-body) without assuming any inter-oscillator coupling. The interplay of the feedback rules establishes a self-organized body–limb coordination that enables the reproduction of the speed-dependent gait transitions of salamanders, as well as various gait patterns observed in sprawling quadruped animals. This suggests that sensory feedback plays an essential role in flexible body–limb coordination during sprawling quadruped locomotion.

Panda Robot: Kinematic Design and Simulation for Quadrupedal Walking

2013 ◽  
Vol 284-287 ◽  
pp. 1888-1893
Author(s):  
Chyi Yeu Lin ◽  
Yi Pin Chiu ◽  
Li Chieh Cheng ◽  
Chun Chia Huang ◽  
Po Chia Jo ◽  
...  
Keyword(s):  
Quadruped Robot ◽  
Degree Of Freedom ◽  
Body Parts ◽  
Motion Model ◽  
Mechanism Model ◽  
Quadruped Robots ◽  
Design Variables ◽  
Simulation Parameters ◽  
Important Design ◽  
Quadrupedal Walking

For most quadruped robots, their waist joints can usually pitch or yaw, but cannot roll. Thus, their gaits can only be simulated by a simple motion model based on single-legged mechanisms. When pandas move on their four feet, they swing their hips and rear legs from side to side. Thus, the purpose of this study is to develop a quadruped robot which is equipped with a waist joint of one degree of freedom (DOF) for rolling so as to imitate the waist-swinging motion of a real panda. This research starts at editing the predetermined motion conditions with lengths of all panda body parts and the mechanism model with corresponding degree-of-freedom in the CAE software. The related simulation parameters of leg motions are acquired as a reference for gait controls. The quadrupedal walking process was tested in simulators to verify important design variables and simulation validity was also verified on the actual panda robot after their buildup. With this approach, this study has effectively and successfully developed a panda robot with a waist joint that can roll.

scholarly journals Histo-morphology of cutaneous papillomatosis in indigenous cattle

2019 ◽  
Vol 1 (17) ◽  
Author(s):  
U. Ayman ◽  
S. K. Das
Keyword(s):  
Morphological Changes ◽  
Microscopic Analysis ◽  
Viral Disease ◽  
Skin Lesions ◽  
Eosin Y ◽  
Body Parts ◽  
Indigenous Cattle ◽  
Study Results ◽  
Internal Core ◽  
Perineal Region

Background: Papillomatosis is a viral disease manifested with benign cutaneous growths (skin epithelium hyperplasia) in different body parts which is encountered in cattle, goat, dog, rabbit, horse, rodent and also in human. The purpose of the present study is to detect the histo-morphological changes of cutaneous papillomatosis in indigenous cattle. Methods: Ten (10) random samples from skin lesions of warts were collected from adult indigenous cattle (10 cattle) that were diagnosed as cutaneous papillomatosis by clinical examination at Veterinary Teaching Hospital, Bangladesh Agricultural University, Mymensingh-2202, Bangladesh. For gross observations, location of appearance of warts, color and size was taken into consideration. Immediately after collection of sample, they were preserved in Bouin’s fluid followed by dehydration, clearing and infiltration and finally embedded by paraffin wax. Then samples were sectioned using rotatory microtome and stained with Harris’s Haematoxylin and Eosin Y to facilitate microscopic study. Results: The results of present study revealed that cutaneous papillomas were mostly located on the head and neck, around eyes, under the chin and perineal region in indigenous cattle. Grossly, warts in cattle are bumpy or cauliflower-like masses of various sizes and numbers that projected from the skin having grey, rough, scaly, and dry surface. When incised, its cut surface has an external layer- keratinized epithelium and an internal core- moist white connective tissue. Histopathological changes indicate hyperplastic features of the affected skin layers of epidermis. Further, the microscopic analysis also revealed orthokeratotic hyperkeratosis, acanthosis and down word hyperplasia, fibrovascular area, keratohyalin granules and koilocytes at different layers of the affected skin. Conclusion: The results of this present study might be useful for the classification and treatment of this common malady based on its histological changes.

scholarly journals The Complex Dynamic Locomotive Control and Experimental Research of a Quadruped-Robot Based on the Robot Trunk

2019 ◽  
Vol 9 (18) ◽  
pp. 3911 ◽  
Author(s):  
Dongyi Ren ◽  
Junpeng Shao ◽  
Guitao Sun ◽  
Xuan Shao
Keyword(s):  
Control Strategy ◽  
Kinematic Model ◽  
Quadruped Robot ◽  
Contact Forces ◽  
Small Magnitude ◽  
Feedback Information ◽  
Joint Torques ◽  
Trunk Motion ◽  
Quadruped Robots ◽  
Leg Motion

The research of quadruped robots is fundamentally motivated by their excellent performance in complex terrain. Maintaining the trunk moving smoothly is the basis of assuring the stable locomotion of the robot. In this paper we propose a planning and control strategy for the pacing gait of hydraulic quadruped robots based on the centroid. Initially, the kinematic model between the single leg and the robot trunk was established. The coupling of trunk motion and leg motion was elaborated on in detail. Then, the real-time attitude feedback information of the trunk was considered, the motion trajectory of the trunk centroid was planned, and the foot trajectory of the robot was carried out. Further, the joint torques were calculated that fulfillment minimization of the contact forces. The position and attitude of the robot trunk were adjusted by the presented controller. Finally, the performance of the proposed control framework was tested in simulations and on a robot platform. By comparing the attitude of the robot trunk, the experimental results show that the trunk moved smoothly with small-magnitude by the proposed controller. The stable dynamic motion of the hydraulic quadruped robot was accomplished, which verified the effectiveness and feasibility of the proposed control strategy.

scholarly journals Gait Tracking Control of Quadruped Robot Using Differential Evolution Based Structure Specified Mixed SensitivityH∞Robust Control

2016 ◽  
Vol 2016 ◽  
pp. 1-18 ◽  
Author(s):  
Petrus Sutyasadi ◽  
Manukid Parnichkun
Keyword(s):  
Tracking Control ◽  
Control Algorithm ◽  
Joint Angle ◽  
Gait Pattern ◽  
Quadruped Robot ◽  
Robust Controller ◽  
Quadruped Robots ◽  
Parameter Variations ◽  
Real Hardware ◽  
Dynamic Gait

This paper proposed a control algorithm that guarantees gait tracking performance for quadruped robots. During dynamic gait motion, such as trotting, the quadruped robot is unstable. In addition to uncertainties of parameters and unmodeled dynamics, the quadruped robot always faces some disturbances. The uncertainties and disturbances contribute significant perturbation to the dynamic gait motion control of the quadruped robot. Failing to track the gait pattern properly propagates instability to the whole system and can cause the robot to fall. To overcome the uncertainties and disturbances, structured specified mixed sensitivityH∞robust controller was proposed to control the quadruped robot legs’ joint angle positions. Before application to the real hardware, the proposed controller was tested on the quadruped robot’s leg planar dynamic model using MATLAB. The proposed controller can control the robot’s legs efficiently even under uncertainties from a set of model parameter variations. The robot was also able to maintain its stability even when it was tested under several terrain disturbances.

Stability Margin of a Metamorphic Quadruped Robot With a Twisting Trunk

2019 ◽  
Vol 11 (6) ◽  
Author(s):  
Chunsong Zhang ◽  
Chi Zhang ◽  
Jian S. Dai ◽  
Peng Qi
Keyword(s):  
Closed Loop ◽  
Stability Margin ◽  
Rigid Bodies ◽  
Quadruped Robot ◽  
Quadruped Robots ◽  
Kinematic Performance ◽  
The Stability ◽  
Twisting Angle

Abstract To date, most quadruped robots are either equipped with trunks that are rigid bodies or consist of blocks connected by passive joints. The kinematic performance of these quadruped robots is only determined by their legs. To release the mobility of trunks and enhance the performance of quadruped robots, this paper proposes a metamorphic quadruped robot with a moveable trunk (a planar six-bar closed-loop linkage), called MetaRobot I, which can implement active trunk motions. The robot can twist its trunk like natural quadrupeds. Through trunk twisting, the stability margin of the quadruped robot can be increased compared with that of a quadruped robot with a rigid trunk. The inner relationship between the stability margin and the twisting angle is analyzed in this paper. Finally, simulations are carried out to show the benefits facilitated by the twisting trunk to the quadruped robot.

scholarly journals Centre of pressure versus centre of mass stabilization strategies: the tightrope balancing case

2020 ◽  
Vol 7 (9) ◽  
pp. 200111
Author(s):  
Pietro Morasso
Keyword(s):  
Degrees Of Freedom ◽  
Sensory Feedback ◽  
Sagittal Plane ◽  
Control Variable ◽  
Variable Number ◽  
Body Parts ◽  
Centre Of Mass ◽  
Centre Of Pressure ◽  
Feedback Controllers ◽  
Neuromotor Control

This study proposes a generalization of the ankle and hip postural strategies to be applied to the large class of skills that share the same basic challenge of defeating the destabilizing effect of gravity on the basis of the same neuromotor control organization, adapted and specialized to a variable number of degrees of freedom, different body parts, different muscles and different sensory feedback channels. In all the cases, we can identify two crucial elements (the CoP, centre of pressure and the CoM, centre of mass) and the central point of the paper is that most balancing skills can be framed in the CoP–CoM interplay and can be modelled as a combination/alternation of two basic stabilization strategies: the standard well-investigated COPS (or CoP stabilization strategy, the default option), where the CoM is the controlled variable and the CoP is the control variable, and the less investigated COMS (or CoM stabilization strategy), where CoP and CoM must exchange their role because the range of motion of the CoP is strongly constrained by environmental conditions. The paper focuses on the tightrope balancing skill where sway control in the sagittal plane is modelled in terms of the COPS while the more challenging sway in the coronal plane is modelled in terms of the COMS, with the support of a suitable balance pole. Both stabilization strategies are implemented as state-space intermittent, delayed feedback controllers, independent of each other. Extensive simulations support the degree of plausibility, generality and robustness of the proposed approach.

scholarly journals Gait control in a soft robot by sensing interactions with the environment using self-deformation

2016 ◽  
Vol 3 (12) ◽  
pp. 160766 ◽  
Author(s):  
Takuya Umedachi ◽  
Takeshi Kano ◽  
Akio Ishiguro ◽  
Barry A. Trimmer
Keyword(s):  
Sensory Feedback ◽  
Soft Tissues ◽  
Sensory Information ◽  
Gait Pattern ◽  
Soft Robot ◽  
Body Parts ◽  
Gait Control ◽  
Mechanical Responses ◽  
Contact Points ◽  
Propagating Waves

All animals use mechanosensors to help them move in complex and changing environments. With few exceptions, these sensors are embedded in soft tissues that deform in normal use such that sensory feedback results from the interaction of an animal with its environment. Useful information about the environment is expected to be embedded in the mechanical responses of the tissues during movements. To explore how such sensory information can be used to control movements, we have developed a soft-bodied crawling robot inspired by a highly tractable animal model, the tobacco hornworm Manduca sexta . This robot uses deformations of its body to detect changes in friction force on a substrate. This information is used to provide local sensory feedback for coupled oscillators that control the robot's locomotion. The validity of the control strategy is demonstrated with both simulation and a highly deformable three-dimensionally printed soft robot. The results show that very simple oscillators are able to generate propagating waves and crawling/inching locomotion through the interplay of deformation in different body parts in a fully decentralized manner. Additionally, we confirmed numerically and experimentally that the gait pattern can switch depending on the surface contact points. These results are expected to help in the design of adaptable, robust locomotion control systems for soft robots and also suggest testable hypotheses about how soft animals use sensory feedback.

Sign in / Sign up

Export Citation Format

Share Document