scholarly journals Conceptual Design of the Combinable Legged Robot Bio-Inspired by Ants’ Structure

2021 ◽  
Vol 11 (4) ◽  
pp. 1379
Author(s):  
Chin Ean Yeoh ◽  
Hak Yi
Keyword(s):  
Conceptual Design ◽  
Experimental Work ◽  
The Body ◽  
Rectangular Prism ◽  
Robot Design ◽  
Coupling Mechanism ◽  
Legged Robot ◽  
Body Frame ◽  
Robot System ◽  
Link Structure

This study presents a new combinable multi-legged modular robot that mimics the structures of ants to expand the physical capabilities of the legged robot. To do this, the robot design is focused on exploring a fusion of two robotic platforms, modular and multi-legged, in which both the body frame and the legged structure are designed to be a rectangular prism and a 3-DoF sprawling-type articulated leg structure, respectively. By imitating ants’ claws, the hook-link structure of the robot as the coupling mechanism is proposed. This study includes the platform’s development, and the experimental work on the locomotion in both single and combined modes is carried out. The result of this study proves that mimicking ants’ structure in the proposed robots successfully enhances the capability of the conventional legged robot. It is feasible to use in a multi-robot system to realize ants’ super-organized behavior.

Motion planning and implementation for the self-recovery of an overturned multi-legged robot

Robotica ◽  
2015 ◽  
Vol 35 (5) ◽  
pp. 1107-1120 ◽  
Author(s):  
Saijin Peng ◽  
Xilun Ding ◽  
Fan Yang ◽  
Kun Xu
Keyword(s):  
Motion Planning ◽  
The Body ◽  
The Self ◽  
Legged Robots ◽  
Ground Reaction Forces ◽  
Robot Design ◽  
Legged Robot ◽  
Reaction Forces ◽  
Recovery Approach ◽  
And Control

SUMMARYThis paper first presents a method of motion planning and implementation for the self-recovery of an overturned six-legged robot. Previous studies aimed at the static and dynamic stabilization of robots for preventing them from overturning. However, no one can guarantee that an overturn accident will not occur during various applications of robots. Therefore, the problems involving overturning should be considered and solved during robot design and control. The design inspirations of multi-legged robots come from nature, especially insects and mammals. In addition, the self-recovery approach of an insect could also be imitated by robots. In this paper, such a self-recovery mechanism is reported. The inertial forces of the dangling legs are used to bias some legs to touch the ground, and the ground reaction forces exerted on the feet of landing legs are achieved to support and push the body to enable recovery without additional help. By employing the mechanism, a self-recovery approach named SSR (Sidewise-Self-Recovery) is presented and applied to multi-legged robots. Experiments of NOROS are performed to validate the effectiveness of the self-recovery motions. The results show that the SSR is a suitable method for multi-legged robots and that the hemisphere shell of robots can help them to perform self-recovery.

A Simple Analytical Tool for Legged Robot Design

2012 ◽  
Author(s):  
Zhuohua Shen ◽  
Justin Seipel
Keyword(s):  
Analytical Solutions ◽  
Inverted Pendulum ◽  
Legged Locomotion ◽  
Robot Design ◽  
Slip Model ◽  
Legged Robot ◽  
Biologically Relevant ◽  
Analytical Approximations ◽  
Energy Conserving ◽  
Spring Loaded Inverted Pendulum

Although legged locomotion is better at tackling complicated terrains compared with wheeled locomotion, legged robots are rare, in part, because of the lack of simple design tools. The dynamics governing legged locomotion are generally nonlinear and hybrid (piecewise-continuous) and so require numerical simulation for analysis and are not easily applied to robot designs. During the past decade, a few approximated analytical solutions of Spring-Loaded Inverted Pendulum (SLIP), a canonical model in legged locomotion, have been developed. However, SLIP is energy conserving and cannot predict the dynamical stability of real-world legged locomotion. To develop new analytical tools for legged robot designs, we first analytically solved SLIP in a new way. Then based on SLIP solution, we developed an analytical solution of a hip-actuated Spring-Loaded Inverted Pendulum (hip-actuated-SLIP) model, which is more biologically relevant and stable than the canonical energy conserving SLIP model. The analytical approximations offered here for SLIP and the hip actuated-SLIP solutions compare well with the numerical simulations of each. The analytical solutions presented here are simpler in form than those resulting from existing analytical approximations. The analytical solutions of SLIP and the hip actuated-SLIP can be used as tools for robot design or for generating biological hypotheses.

Mechanism Design and Simulation of the ULTRA Spine: A Tensegrity Robot

2015 ◽  
Author(s):  
Andrew P. Sabelhaus ◽  
Hao Ji ◽  
Patrick Hylton ◽  
Yakshu Madaan ◽  
ChanWoo Yang ◽  
...  
Keyword(s):  
Mechanism Design ◽  
Design Process ◽  
Inverse Kinematics ◽  
Gear Ratio ◽  
Forward Kinematics ◽  
Robot Design ◽  
Link Structure ◽  
Iterative Design ◽  
Quadruped Robots ◽  
Ongoing Effort

The Underactuated Lightweight Tensegrity Robotic Assistive Spine (ULTRA Spine) project is an ongoing effort to create a compliant, cable-driven, 3-degree-of-freedom, underactuated tensegrity core for quadruped robots. This work presents simulations and preliminary mechanism designs of that robot. Design goals and the iterative design process for an ULTRA Spine prototype are discussed. Inverse kinematics simulations are used to develop engineering characteristics for the robot, and forward kinematics simulations are used to verify these parameters. Then, multiple novel mechanism designs are presented that address challenges for this structure, in the context of design for prototyping and assembly. These include the spine robot’s multiple-gear-ratio actuators, spine link structure, spine link assembly locks, and the multiple-spring cable compliance system.

Electric Bus Body Lightweight Design Based on Multiple Constrains

2012 ◽  
Vol 538-541 ◽  
pp. 3137-3144 ◽  
Author(s):  
Wen Wei Wang ◽  
Cheng Jun Zhou ◽  
Cheng Lin ◽  
Jiao Yang Chen
Keyword(s):  
Finite Element ◽  
Lightweight Design ◽  
Element Model ◽  
The Body ◽  
Body Frame ◽  
Electric Bus ◽  
Free Model ◽  
Bus Body ◽  
The Finite Element Model ◽  
Torsion Condition

The finite-element model of pure electric bus has been built and the free model analysis, displacement and stress analysis under bending condition and torsion condition have been conducted. Optimally design the pure electric bus frame based on multiple constrains. Reduce the body frame quality by 4.3% and meanwhile meet the modal and stress requirements.

Interlaced Attitude Estimation for Spacecraft Using Vector Observations

2021 ◽  
Vol 01 (03) ◽  
Author(s):  
Lubin Chang
Keyword(s):  
Prior Information ◽  
State Of The Art ◽  
Estimation Method ◽  
Attitude Estimation ◽  
The Body ◽  
Body Frame ◽  
Initial Value ◽  
Initial State ◽  
Initial Errors ◽  
Initial Attitude

This paper proposes an interlaced attitude estimation method for spacecraft using vector observations, which can simultaneously estimate the constant attitude at the very start and the attitude of the body frame relative to its initial state. The arbitrary initial attitude, described by constant attitude at the very start, is determined using quaternion estimator which requires no prior information. The multiplicative extended Kalman filter (EKF) is competent for estimating the attitude of the body frame relative to its initial state since the initial value of this attitude is exactly known. The simulation results show that the proposed algorithms could achieve better performance compared with the state-of-the-art algorithms even with extreme large initial errors. Meanwhile, the computational burden is also much less than that of the advanced nonlinear attitude estimators.

scholarly journals A Novel Neural Network-Based SINS/DVL Integrated Navigation Approach to Deal with DVL Malfunction for Underwater Vehicles

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Wanli Li ◽  
Mingjian Chen ◽  
Chao Zhang ◽  
Lundong Zhang ◽  
Rui Chen
Keyword(s):  
Neural Network ◽  
Autonomous Navigation ◽  
Underwater Vehicles ◽  
The Body ◽  
Doppler Velocity ◽  
Integrated Navigation ◽  
Body Frame ◽  
Short Term ◽  
The Neural Network ◽  
Nonlinear Autoregressive

A navigation grade Strapdown Inertial Navigation System (SINS) combined with a Doppler Velocity Log (DVL) is widely used for autonomous navigation of underwater vehicles. Whether the DVL is able to provide continuous velocity measurements is of crucial importance to the integrated navigation precision. Considering that the DVL may fail during the missions, a novel neural network-based SINS/DVL integrated navigation approach is proposed. The nonlinear autoregressive exogenous (NARX) neural network, which is able to provide reliable predictions, is employed. While the DVL is available, the neural network is trained by the body frame velocity and its increment from the SINS and the DVL measurements. Once the DVL fails, the well trained network is able to forecast the velocity which can be used for the subsequent navigation. From the experimental results, it is clearly shown that the neural network is able to provide reliable velocity predictions for about 200 s–300 s during DVL malfunction and hence maintain the short-term accuracy of the integrated navigation.

scholarly journals Age-Related Differences in Fixation Pattern on a Companion Robot

Sensors ◽  
2020 ◽  
Vol 20 (13) ◽  
pp. 3807
Author(s):  
Young Hoon Oh ◽  
Da Young Ju
Keyword(s):  
Older Adults ◽  
Physical Attractiveness ◽  
The Body ◽  
Robot Design ◽  
Body Parts ◽  
Gaze Behavior ◽  
Younger Adults ◽  
The Gaze ◽  
Age Related ◽  
Companion Robots

Recent studies have addressed the various benefits of companion robots and expanded the research scope to their design. However, the viewpoints of older adults have not been deeply investigated. Therefore, this study aimed to examine the distinctive viewpoints of older adults by comparing them with those of younger adults. Thirty-one older and thirty-one younger adults participated in an eye-tracking experiment to investigate their impressions of a bear-like robot mockup. They also completed interviews and surveys to help us understand their viewpoints on the robot design. The gaze behaviors and the impressions of the two groups were significantly different. Older adults focused significantly more on the robot’s face and paid little attention to the rest of the body. In contrast, the younger adults gazed at more body parts and viewed the robot in more detail than the older adults. Furthermore, the older adults rated physical attractiveness and social likeability of the robot significantly higher than the younger adults. The specific gaze behavior of the younger adults was linked to considerable negative feedback on the robot design. Based on these empirical findings, we recommend that impressions of older adults be considered when designing companion robots.

Time-optimal trajectory planning method for six-legged robots under actuator constraints

2019 ◽  
Vol 233 (14) ◽  
pp. 4990-5002
Author(s):  
Zhijun Chen ◽  
Feng Gao
Keyword(s):  
Trajectory Planning ◽  
Optimal Trajectory ◽  
Optimization Problem ◽  
The Body ◽  
Planning Method ◽  
Legged Robots ◽  
Legged Robot ◽  
Time Optimal ◽  
Actuator Constraints ◽  
Optimal Trajectory Planning

Current studies on time-optimal trajectory planning centers on cases with fixed base and only one end-effector. However, the free-floating body and the multiple legs of the legged robot make the current methods inapplicable. This paper proposes a time-optimal trajectory planning method for six-legged robots. The model of the optimization problem for six-legged robots is built by considering the base and the end-effectors separately. Both the actuator constraints and the gait cycle constraints are taken into account. A novel two-step optimization method is proposed to solve the optimization problem. The first step solves the time-optimal trajectory of the body and the second step solves the time-optimal trajectory of the swinging legs. Finally, the method is applied to a six-parallel-legged robot and validated by experiments on the prototype. The results show that the velocity of the optimized gait is improved by 17.8% in contrast to the non-optimized one.

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