An obstacle-avoiding and stiffness-tunable modular bionic soft robot

Robotica ◽  
2022 ◽  
pp. 1-15
Author(s):  
Zhaoyu Liu ◽  
Yuxuan Wang ◽  
Jiangbei Wang ◽  
Yanqiong Fei ◽  
Qitong Du
Keyword(s):  
Variable Stiffness ◽  
Air Pressure ◽  
Design Parameters ◽  
Soft Robot ◽  
Working Pressure ◽  
Obstacle Avoiding ◽  
Stiffness Model ◽  
Pass Through ◽  
Soft Actuators

Abstract The aim of this work is to design and model a novel modular bionic soft robot for crawling and crossing obstacles. The modular bionic soft robot is composed of several serial driving soft modules, each module is composed of two parallel soft actuators. By analyzing the influence of working pressure and manufacturing size on the stiffness of the modular bionic soft robot, the nonlinear variable stiffness model of the modular bionic soft robot is established. Based on this model, the spatial states and design parameters of the modular bionic soft robot are discussed when the modular bionic soft robot can pass through the obstacle. Experiments show that when the inflation air pressure of the modular bionic soft robot is 70 kPa, its speed can reach 7.89 mm/s and the height of obstacles passed by it can reach 42.8 mm. The feasibility of the proposed modular bionic soft robot and nonlinear variable stiffness model is verified by locomotion experiments.

scholarly journals SUBSTANTIATION OF THE FORM AND DETERMINATION OF THE CONSTRUCTIVE PARAMETERS OF THE ROTATION ROLLER OF SOIL

2018 ◽  
Vol 13 (3) ◽  
pp. 72-76
Author(s):  
Гумар Булгариев ◽  
Gumar Bulgariev ◽  
Геннадий Пикмуллин ◽  
Gennadiy Pikmullin ◽  
Ильгиз Галиев ◽  
...  
Keyword(s):  
Analytical Study ◽  
Point Of View ◽  
Design Parameters ◽  
Industrial Complex ◽  
Stage Of Development ◽  
Pass Through ◽  
Spiral Plate ◽  
Working Device ◽  
Important Design

At the present stage of development of the country’s agro-industrial complex, the technological process of surface tillage by combined soil-cultivating machines, simultaneously combining a number of operations in one pass through the field, causes the presence in their designs of the necessary set of various promising working organs. In view of the foregoing, a rotary soil ripper with a spiral-plate working member equipped with radially directed teeth and connected by means of rods with end flanges has been developed. Also, the researched ripper has the limits of penetration of the working element in the form of flat discs equipped with flanges and the radial stop have the ability to rotate around their axes independently of the ripper shaft. An analytical study of the working units of this ripper was carried out from the point of view of the influence of their size and teeth on the process of interaction with the soil, on the basis of which some of their parameters were determined. In conclusion, it was concluded that the analytical equations obtained allow us to justify the choice of the most important design parameters of the proposed new design and design a toothed rotary working device that reduces to constructive implementation after calculating their basic dimensions.

scholarly journals Self-excited air flow passage changing device for periodic pressurization of soft robot

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Toshio Takayama ◽  
Yusuke Sumi
Keyword(s):  
Mobile Robot ◽  
Rotational Motion ◽  
Air Pressure ◽  
Soft Robot ◽  
Pressure Source ◽  
Large Delay ◽  
Soft Robots ◽  
Flow Passage ◽  
Output Pressure ◽  
Air Chamber

AbstractRecently pneumatic-driven soft robots have been widely developed. Usually, the operating principle of this robot is the inflation and deflation of elastic inflatable chambers by air pressure. Some soft robots need rapid and periodic inflation and deflation of their air chambers to generate continuous motion such as progress motion or rotational motion. However, if the soft robot needs to operate far from the air pressure source, long air tubes are required to supply air pressure to its air chambers. As a result, there is a large delay in supplying air pressure to the air chamber, and the motion of the robot slows down. In this paper, we propose a compact device that changes its airflow passages by self-excited motion generated by a supply of continuous airflow. The diameter and the length of the device are 20 and 50 mm, respectively, and can be driven in a small pipe. Our proposed in-pipe mobile robot is connected to the device and can move in a small pipe by dragging the device into it. To apply the device widely to other soft robots, we also discuss a method of adjusting the output pressure and motion frequency.

scholarly journals A reduced order computational model of a semi-active variable-stiffness foot prosthesis

2020 ◽  
Author(s):  
Michael McGeehan ◽  
Peter Adamczyk ◽  
Kieran Nichols ◽  
Michael Hahn
Keyword(s):  
Body Weight ◽  
Center Of Pressure ◽  
Reaction Force ◽  
Variable Stiffness ◽  
Performance Standard ◽  
Design Parameters ◽  
Compression Tests ◽  
Static Compression ◽  
Lumped Parameter ◽  
Contact Models

INTRODUCTION: Passive energy storage and return (ESR) feet are the current performance standard in lower limb prostheses. A recently developed semi-active variable-stiffness foot (VSF) prosthesis balances the simplicity of a passive ESR device with the adaptability of a powered design. The purpose of this study was to model and simulate the ESR properties of the VSF prosthesis. METHODS: The ESR properties of the VSF were modeled as a lumped parameter overhung beam. The overhung length is variable, allowing the model to exhibit variable ESR stiffness. Foot-ground contact was modeled using sphere-to-plane contact models. Contact parameters were optimized to represent the geometry and dynamics of the VSF and its foam base. Static compression tests and gait were simulated. Simulation outcomes were compared to corresponding experimental data. RESULTS: Stiffness of the model matched that of the physical VSF (R2: 0.98, RMSE: 1.37 N/mm). Model-predicted resultant ground reaction force (GRFR) matched well under optimized parameter conditions (R2: 0.98, RMSE: 5.3% body weight,) and unoptimized parameter conditions (R2: 0.90, mean RMSE: 13% body weight). Anterior-posterior center of pressure matched well with R2 > 0.94 and RMSE < 9.5% foot length in all conditions. CONCLUSIONS: The ESR properties of the VSF were accurately simulated under benchtop testing and dynamic gait conditions. These methods may be useful for predicting GRFR arising from gait with novel prostheses. Such data are useful to optimize prosthesis design parameters on a user-specific basis.

scholarly journals Application and Analysis of an Ionic Liquid Gel in a Soft Robot

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Chenghong Zhang ◽  
Bin He ◽  
Zhipeng Wang ◽  
Yanmin Zhou ◽  
Aiguo Ming
Keyword(s):  
Ionic Liquid ◽  
Uv Light ◽  
Electroactive Polymers ◽  
Electroactive Polymer ◽  
Soft Robot ◽  
Polymer Gel ◽  
Basic Module ◽  
Soft Actuator ◽  
New Type ◽  
Soft Actuators

Due to their light weight, flexibility, and low energy consumption, ionic electroactive polymers have become a hotspot for bionic soft robotics and are ideal materials for the preparation of soft actuators. Because the traditional ionic electroactive polymers, such as ionic polymer-metal composites (IPMCs), contain water ions, a soft actuator does not work properly upon the evaporation of water ions. An ionic liquid polymer gel is a new type of ionic electroactive polymer that does not contain water ions, and ionic liquids are more thermally and electrochemically stable than water. These liquids, with a low melting point and a high ionic conductivity, can be used in ionic electroactive polymer soft actuators. An ionic liquid gel (ILG), a new type of soft actuator material, was obtained by mixing 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4), hydroxyethyl methacrylate (HEMA), diethoxyacetophenone (DEAP) and ZrO2 and then polymerizing this mixture into a gel state under ultraviolet (UV) light irradiation. An ILG soft actuator was designed, the material preparation principle was expounded, and the design method of the soft robot mechanism was discussed. Based on nonlinear finite element theory, the deformation mechanism of the ILG actuator was deeply analyzed and the deformation of the soft robot when grabbing an object was also analyzed. A soft robot was designed with the soft actuator as the basic module. The experimental results show that the ILG soft robot has good driving performance, and the soft robot can grab a 105 mg object at an input voltage of 3.5 V.

Nonlinear Stiffness Analysis of Spring-Loaded Inverted Slider Crank Mechanisms With a Unified Model

2020 ◽  
Vol 12 (3) ◽  
Author(s):  
Zhongyi Li ◽  
Shaoping Bai ◽  
Weihai Chen ◽  
Jianbin Zhang
Keyword(s):  
Variable Stiffness ◽  
Comprehensive Analysis ◽  
Unified Model ◽  
Nonlinear Stiffness ◽  
Stiffness Analysis ◽  
Constant Torque ◽  
Stiffness Model ◽  
Overall Performance ◽  
Crank Mechanism

Abstract A mechanism with lumped-compliance can be constructed by mounting springs at joints of an inverted slider crank mechanism. Different mounting schemes bring change in the stiffness performance. In this paper, a unified stiffness model is developed for a comprehensive analysis of the stiffness performance for mechanisms constructed with different spring mounting schemes. With the model, stiffness behaviors of spring-loaded inverted slider crank mechanisms are analyzed. Influences of each individual spring on the overall performance are characterized. The unified stiffness model allows designing mechanisms for a desired stiffness performance, such as constant-torque mechanism and variable stiffness mechanism, both being illustrated with a design example and experiments.

Determination of Variable Stiffness of a Human Elbow for Human-Robot Interaction

2014 ◽  
Author(s):  
Michael Boyarsky ◽  
Megan Heenan ◽  
Scott Beardsley ◽  
Philip Voglewede
Keyword(s):  
Experimental Data ◽  
Disturbance Rejection ◽  
Variable Stiffness ◽  
Important Variable ◽  
Human Motion ◽  
Human Robot Interaction ◽  
Robot Interaction ◽  
Constant Stiffness ◽  
Stiffness Model ◽  
Motor Model

This paper aims to emulate human motion with a robot for the purpose of improving human-robot interaction (HRI). In order to engineer a robot that demonstrates functionally similar motion to humans, aspects of human motion such as variable stiffness must be captured. This paper successfully determined the variable stiffness humans use in the context of a 1 DOF disturbance rejection task by optimizing a time-varying stiffness parameter to experimental data in the context of a neuro-motor Simulink model. The significant improved agreement between the model and the experimental data in the disturbance rejection task after the addition of variable stiffness demonstrates how important variable stiffness is to creating a model of human motion. To enable a robot to emulate this motion, a predictive stiffness model was developed that attempts to reproduce the stiffness that a human would use in a given situation. The predictive stiffness model successfully decreases the error between the neuro-motor model and the experimental data when compared to the neuro-motor model with a constant stiffness value.

scholarly journals Recent Developments on Modeling for a 3-DOF Micro-Hand Based on AI Methods

Micromachines ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 792
Author(s):  
Shuhei Kawamura ◽  
Mingcong Deng
Keyword(s):  
Artificial Intelligence ◽  
Degrees Of Freedom ◽  
Air Pressure ◽  
Support Vector ◽  
Input Output ◽  
Soft Actuator ◽  
Flexible Materials ◽  
Recent Developments ◽  
Soft Actuators ◽  
Three Degrees Of Freedom

Recently, soft actuators have been expected to have many applications in various fields. Most of the actuators are composed of flexible materials and driven by air pressure. The 3-DOF micro-hand, which is a kind of soft actuator, can realize a three degrees of freedom motion by changing the applied air pressure pattern. However, the input–output relation is nonlinear and complicated. In previous research, a model of the micro-hand was proposed, but an error between the model and the experimental results was large. In this paper, modeling for the micro-hand is proposed by using multi-output support vector regression (MSVR) and ant colony optimization (ACO), which is one of the artificial intelligence (AI) methods. MSVR estimates the input–output relation of the micro-hand. ACO optimizes the parameters of the MSVR model.

scholarly journals Variable Stiffness Model Construction and Simulation Verification of Coupled Notch Continuum Manipulator

IEEE Access ◽  
2019 ◽  
Vol 7 ◽  
pp. 154761-154769
Author(s):  
Haodong Wang ◽  
Zhijiang Du ◽  
Wenlong Yang ◽  
Zhi Yuan Yan ◽  
Xiaolong Wang
Keyword(s):  
Variable Stiffness ◽  
Model Construction ◽  
Stiffness Model ◽  
Continuum Manipulator

scholarly journals Dielectric Elastomer Actuator for Soft Robotics Applications and Challenges

2020 ◽  
Vol 10 (2) ◽  
pp. 640 ◽  
Author(s):  
Jung-Hwan Youn ◽  
Seung Mo Jeong ◽  
Geonwoo Hwang ◽  
Hyunwoo Kim ◽  
Kyujin Hyeon ◽  
...  
Keyword(s):  
State Of The Art ◽  
Dielectric Elastomer ◽  
Artificial Muscles ◽  
Soft Robot ◽  
Optical Components ◽  
Dielectric Characteristics ◽  
Dielectric Elastomer Actuators ◽  
Potential Applications ◽  
Working Principle ◽  
Soft Actuators

This paper reviews state-of-the-art dielectric elastomer actuators (DEAs) and their future perspectives as soft actuators which have recently been considered as a key power generation component for soft robots. This paper begins with the introduction of the working principle of the dielectric elastomer actuators. Because the operation of DEA includes the physics of both mechanical viscoelastic properties and dielectric characteristics, we describe theoretical modeling methods for the DEA before introducing applications. In addition, the design of artificial muscles based on DEA is also introduced. This paper reviews four popular subjects for the application of DEA: soft robot hand, locomotion robots, wearable devices, and tunable optical components. Other potential applications and challenging issues are described in the conclusion.

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