Article
Engineering, Mechanical
Masoumeh Safartoobi, Morteza Dardel, Hamidreza Mohammadi Daniali
Summary: This paper presents the application of an internal damping mechanism to the mathematical description of the simplest passive walking model, making walking natural and efficient. By using viscoelastic legs and precise boundary conditions, the biped starts walking from a stable condition and exhibits stable period-one gait cycles. Numerical simulations demonstrate that the overall effect of viscoelastic legs on passive walking is efficient in terms of stability and energy dissipation.
NONLINEAR DYNAMICS
(2022)
Article
Chemistry, Multidisciplinary
Long Li, Zhongqu Xie, Xiang Luo, Juanjuan Li
Summary: This study focused on the impact of gait pattern generation on the walking quality of biped robots, particularly comparing the energy efficiency of maintaining a vertical torso versus having torso pitch motion during walking. Results showed that torso pitch motion saves over 12% energy compared to maintaining a vertical torso, with the main energy-saving factor being the reduction of energy consumption of the swing knee in the double support phase.
APPLIED SCIENCES-BASEL
(2021)
Article
Computer Science, Artificial Intelligence
Guifu Luo, Ruilong Du, Shiqiang Zhu, Sumian Song, Haihui Yuan, Hua Zhou, Mingguo Zhao, Jason Gu
Summary: This study proposes a compliant leg configuration that meets the requirements of the spring-loaded inverted pendulum (SLIP) model and verifies its feasibility through numerical modeling and experiments. The leg configuration is characterized by high stiffness and mass concentration in the hip, enabling spring-like walking for biped robots.
JOURNAL OF INTELLIGENT & ROBOTIC SYSTEMS
(2022)
Article
Computer Science, Artificial Intelligence
Long Li, Zhongqu Xie, Xiang Luo, Juanjuan Li, Yufeng He
Summary: This study introduces a gait pattern with pitch motion of the torso during walking, which is optimized to be more energy-efficient compared to the traditional torso vertical gait pattern.
JOURNAL OF INTELLIGENT & FUZZY SYSTEMS
(2021)
Article
Engineering, Biomedical
Vahideh Moradi, Mohammad Ali Sanjari, Nick Stergiou
Summary: This study evaluated the effect of asymmetric prosthesis on individuals with unilateral transfemoral amputation. The results showed that under prosthetic modifications, the intact limb step length increased and the prosthetic step length decreased for most participants. However, the prosthetic modifications did not have significant effects on Floquet multiplier, step length, and step time variability.
CLINICAL BIOMECHANICS
(2022)
Article
Engineering, Biomedical
Lydia G. Brough, Steven A. Kautz, Richard R. Neptune
Summary: This study aimed to determine the underlying causes of propulsion, leg swing initiation, and knee flexion deficits in individuals post-stroke. The results emphasize the multiple causes of propulsion asymmetry in individuals post-stroke, highlighting the need for more effective rehabilitation strategies. Individual causes of propulsion and knee flexion deficits need to be identified for designing better rehabilitation strategies.
JOURNAL OF NEUROENGINEERING AND REHABILITATION
(2022)
Article
Engineering, Multidisciplinary
Peng Sun, Yunfei Gu, Haoyu Mao, Zhao Chen, Yanbiao Li
Summary: A kinematics analysis was conducted on a new hybrid mechanical leg for bipedal robots, and the walking gait of the robot on flat ground was planned. The kinematics of the hybrid mechanical leg were analyzed and relevant models were established. The robot walking was divided into three stages using the inverted pendulum model for gait planning, and the trajectories of the robot centroid motion and swinging leg joints were calculated. The feasibility of the mechanism design and gait planning was verified through dynamic simulation of the robot's virtual prototype. This study provides a reference for the gait planning of hybrid mechanical legged bipedal robots and lays the foundation for further research on the robots involved in this thesis.
Article
Acoustics
Yao Zhang, Zhigang Song
Summary: This study used wireless inertial measurement units (IMUs) to monitor the acceleration of center of masses (COMs) of 6 volunteers walking, and found discrepancies between the acceleration peaks simulated by BM and those observed in experiments at different step frequencies, with errors reaching up to 60% when the step frequency is higher than 2.0 Hz. Further research on the accuracy of BMs and modification methods is needed for civil engineering applications.
SHOCK AND VIBRATION
(2021)
Article
Multidisciplinary Sciences
E. A. Parra Ricaurte, J. Pareja, S. Dominguez, C. Rossi
Summary: Quadrupeds can achieve efficient gaits with their flexible trunk, utilizing oscillations of the system to store and release elastic energy. This study proposes a new model that explores how leg mass generates flexing force to help efficient locomotion in quadrupedal robots.
SCIENTIFIC REPORTS
(2022)
Article
Engineering, Multidisciplinary
Wafa Znegui, Hassene Gritli, Safya Belghith
Summary: This paper aims to develop an improved closed-form analytical expression for analyzing the complex walking behavior and stability of a passive-dynamics biped walker. By linearizing and approximating the hybrid dynamics, an enhanced closed-form expression of the Poincaré map and an analytical expression for the computation of step period are designed. A simplification of these expressions is achieved by decreasing dimension and providing a Jacobian matrix expression for investigating the stability of the designed simplified Poincaré map.
APPLIED MATHEMATICAL MODELLING
(2021)
Article
Robotics
Murat Demirel, Gokhan Kiper, Giuseppe Carbone, Marco Ceccarelli
Summary: This paper presents a novel cable-constrained parallel mechanism which is a lightweight, low-cost leg mechanism design for walking machines on flat surfaces. The mechanism has three translational degrees of freedom and is based on two specific hybrid kinematic topologies. The paper conducts kinematic analysis and position performance evaluation to confirm the main characteristics and uses 3D CAD model and simulations to demonstrate the feasibility of the proposed design. A prototype has been built and tested, and an enhanced prototype has been designed and built. Experimental validation is carried out to track a planar walking trajectory, and the results validate the operation characteristics and feasibility of the proposed mechanism for legged walking machines.
Article
Engineering, Biomedical
Xuesen Wang, Xiaohu Fu, Wei Li, Qining Wang, Kuan Zhang, Songhua Yan
Summary: This study investigated the muscle activation patterns in cerebral palsy children with hindfoot valgus. It was found that compared to typically developing children, cerebral palsy children had delayed muscle activation onset and offset times, increased muscle activation duration, decreased electromyography amplitude, and higher co-activation level between tibialis anterior and peroneal longus.
CLINICAL BIOMECHANICS
(2023)
Article
Engineering, Mechanical
Guanfeng Zhou, Xianfei Hui, Jiarui Chen, Guirong Jiang
Summary: This paper investigates a two-DoF semi-passive compass-like biped model with nonlinear impulse thrust. The existence and stability conditions for period gaits of the linearized system are obtained. The conditions for flip bifurcation of periodic gait are derived and bifurcation control is rigorously studied. The results show the importance of impulse thrust and the angle between two legs at the impact in modifying the stability of the biped model and causing chaos through flip bifurcation. Bifurcation control can be used to improve the stability of the model.
NONLINEAR DYNAMICS
(2023)
Article
Robotics
Mathieu Hobon, Victor De-Leon-Gomez, Gabriel Abba, Yannick Aoustin, Christine Chevallereau
Summary: The study aims to define the feasible speed range for two walking motions of a particular planar biped robot, revealing that the first gait is more energy-efficient at moderate to fast velocities, while the second gait is more efficient at low walking speeds. The results were obtained through numerical calculations and a parametric optimization algorithm.
Article
Engineering, Mechanical
Fakang Liao, Yali Zhou, Qizhi Zhang
Summary: This paper proposes a variable legs stiffness damper-spring-loaded inverted pendulum model with robustness and stability achieved through a controller design, and the walking speed is changed by a gait switching strategy.
NONLINEAR DYNAMICS
(2022)
Article
Engineering, Mechanical
Antonella Castellano, Pietro Stano, Umberto Montanaro, Marco Cammalleri, Aldo Sorniotti
Summary: This paper proposes a new control strategy for hybrid electric vehicles, called Model Predictive Control (MPC), and considers the losses in transmission gears. Through a case study on Chevrolet Volt, the results show that the simplified internal model has a minor impact on fuel consumption performance.
MECHANISM AND MACHINE THEORY
(2024)
Article
Engineering, Mechanical
Rui Peng, Gregory S. Chirikjian
Summary: This article introduces a method of designing morphable thick-panel origami structures using reconfigurable linkages, which improves the potential of origami techniques for different tasks and solves the limitations of one-DOF and multiple-DOF folding structures.
MECHANISM AND MACHINE THEORY
(2024)
Article
Engineering, Mechanical
Gaohan Zhu, Weizhong Guo, Yinghui Li, Youcheng Han
Summary: Comprehensive and accurate performance evaluation is crucial for profile synthesis and analysis of higher pair mechanisms. This paper proposes evaluation indices and methods for the transmission performance of planar higher pair mechanisms from different perspectives. It subdivides the transmission performance into element-based performance and joint-based performance and develops novel indices specific to higher pair mechanisms. A graphical mapping method based on element-based performance is also proposed for intuitive analysis. Practical examples validate the effectiveness of the proposed indices and methods for evaluating the performance of higher pair mechanisms.
MECHANISM AND MACHINE THEORY
(2024)
Article
Engineering, Mechanical
Ke Wu, Gang Zheng, Guimin Chen, Shorya Awtar
Summary: Researchers proposed a new modeling method, namely Body-frame Beam Constraint Model (BBCM), to predict and optimize the design of high-precision compliant mechanisms (CMs).
MECHANISM AND MACHINE THEORY
(2024)
Article
Engineering, Mechanical
Youcheng Han, Weizhong Guo, Changjie Zhao, Ziyue Li, Ze Fu, Yinghui Li
Summary: This study proposes a structural synthesis methodology that considers motion, force, and energy characteristics simultaneously to design efficient mechanisms.
MECHANISM AND MACHINE THEORY
(2024)
Article
Engineering, Mechanical
Cristian Enrico Capalbo, Daniel De Gregoriis, Tommaso Tamarozzi, Giuseppe Carbone, Domenico Mundo
Summary: This study proposes a novel flexible multibody formulation that enables efficient updating of models while maintaining small size and high accuracy. Numerical validation demonstrates its wide applicability across various materials and mechanisms, showing promising results in terms of accuracy.
MECHANISM AND MACHINE THEORY
(2024)
Article
Engineering, Mechanical
Weihao Zhao, Junbei Liao, Wei Qian, Haoyong Yu, Zhao Guo
Summary: This paper presents a newly designed compliant actuator using a tensile springs array to address the challenges in achieving linear and consistent elastic properties, low friction, minor hysteresis, and good compliance in series elastic actuators (SEA). The unique geometry of the spring array enables the SEA to have consistent rotary stiffness with minimal friction and hysteresis. The device's performance is evaluated using PID and sliding mode control, demonstrating its constant low rotary stiffness and torque tracking bandwidth, making it suitable for human-robot interaction requirements.
MECHANISM AND MACHINE THEORY
(2024)
Article
Engineering, Mechanical
Mohui Jin, Yukang Luo, Xing Xu, Bowei Xie, Weisheng Wang, Zewei Li, Zhou Yang
Summary: This paper presents a method for evaluating the contact interaction between compliant mechanisms and external objects. By establishing a numerical model and introducing contact springs to describe the contact forces, the deformation and normal contact force/stress can be accurately calculated. The static equilibrium configuration and contact force/stress can be obtained by minimizing the total potential energy function of the system.
MECHANISM AND MACHINE THEORY
(2024)
Article
Engineering, Mechanical
Alejandro G. Gallardo, Martin A. Pucheta
Summary: This paper presents a method for the synthesis of parallel flexure systems using Screw Theory and Linear Algebra. The method is validated through three case studies and offers a simple and precise design with decoupled actuators.
MECHANISM AND MACHINE THEORY
(2024)
Article
Engineering, Mechanical
Xiao Wang, Chenglin Liu, Haoxiang Sun, Hanwen Song
Summary: This paper presents a new decomposition mode for robot-world calibration, which decomposes the Ad(SE(3)) equation using Chasles' motion. A two-step method based on point set matching is proposed. The superiority of this method is verified through simulations and experiments.
MECHANISM AND MACHINE THEORY
(2024)
Article
Engineering, Mechanical
Yanlin Chen, Xianmin Zhang, Yanjiang Huang, Yanbin Wu, Jun Ota
Summary: This study establishes an error model for a 3-RRR+UR spherical parallel mechanism and analyzes the sensitivity of error parameters. A design structure is proposed to reduce input errors based on the analysis. Experimental results show that the multiloop circuit incremental method provides more accurate results.
MECHANISM AND MACHINE THEORY
(2024)
Article
Engineering, Mechanical
Vu Linh Nguyen, Chin-Hsing Kuo, Po Ting Lin
Summary: This paper presents a method for analyzing the performance of gravity-balanced serial robotic manipulators under dynamic loads and uses a three-degree-of-freedom planar serial manipulator as a case study. The significance of this method is demonstrated by evaluating the impact of dynamic loads on gravity-balanced performance and proposing a step-by-step design procedure to improve it.
MECHANISM AND MACHINE THEORY
(2024)
Article
Engineering, Mechanical
Shifeng Rong, Jiange Zhang, Xing Zhang, Keliang Li, Kaibin Rong, Zhenyu Zhou, Han Ding
Summary: This article proposes a data-driven dry cutting tool collaborative optimization model to improve the economic and environmental attributes of facehobbing hypoid gears. An innovative ease-off tooth contact analysis method is introduced to establish accurate relations between ease-off flank and loaded contact performance evaluations. The proposed model significantly improves sustainability in terms of economic and environmental assessments.
MECHANISM AND MACHINE THEORY
(2024)
Article
Engineering, Mechanical
Kemal Eren, Soley Ersoy, Ettore Pennestri
Summary: This research investigates the instantaneous kinematics of the terminal link of a planar two-link open chain using the complex-number technique and higher-order instantaneous invariants.
MECHANISM AND MACHINE THEORY
(2024)
Article
Engineering, Mechanical
Bo Han, Zhantu Yuan, Jiachuan Zhang, Yundou Xu, Jiantao Yao, Yongsheng Zhao
Summary: This paper proposes novel deployable mechanism units with self-limiting position function, and constructs ring truss deployable mechanisms. The degrees of freedom (DOF) of deployable units are analyzed and it is proved that the constructed ring truss deployable mechanisms have only one DOF. The dynamic model of the deployable mechanism unit with passive actuation is established and verified by simulation. The deployable mechanism units proposed in this paper have the advantages of good scalability and stability, and have broad application prospects.
MECHANISM AND MACHINE THEORY
(2024)