An articulated spine and ribcage kinematic model for simulation of scoliosis deformities

2021 ◽  
Author(s):  
Hamed Shayestehpour ◽  
John Rasmussen ◽  
Pavel Galibarov ◽  
Christian Wong
Keyword(s):  
Kinematic Model

SCREW KINEMATIC MODEL FOR ROBOT CALIBRATION WITH PC-ROBOT COMMUNICATION OVERVIEW

2017 ◽  
Author(s):  
Lucas Kato ◽  
Tiago Pinto ◽  
Henrique Simas ◽  
Daniel Martins
Keyword(s):  
Kinematic Model ◽  
Robot Calibration ◽  
Robot Communication

Multi-criteria optimization of the four-finger gripper mechanism

2020 ◽  
Vol 8 (4) ◽  
pp. 276-286
Author(s):  
Vu Duc Quyen ◽  
Andrey Ronzhin
Keyword(s):  
Multicriteria Optimization ◽  
Kinematic Model ◽  
Objective Functions ◽  
Nsga Ii ◽  
Suction Nozzle

Three posterior algorithms NSGA-II, MOGWO and MOPSO to solve the problem of multicriteria optimization of the robotic gripper design are considered. The description of the kinematic model of the developed prototype of the four-fingered gripper for picking tomatoes, its limitations and objective functions used in the optimization of the design are given. The main advantage of the developed prototype is the use of one actuator for the control of the fingers and the suction nozzle. The results of optimization of the kinematic model and the dimensions of the elements of robotic gripper using the considered posterior algorithms are presented.

Developing a Kinematic Estimation Model for a Climbing Mobile Robotic Welding System

2010 ◽  
Author(s):  
Aaron T. O’Toole ◽  
Stephen L. Canfield
Keyword(s):  
Kinematic Model ◽  
Robotic Welding ◽  
Estimation Model ◽  
Mobile Platforms ◽  
Low Profile ◽  
Turning Radius ◽  
Equivalence Model ◽  
Kinematic Equivalence ◽  
Welding System ◽  
Robot Platform

Skid steer tracked-based robots are popular due to their mechanical simplicity, zero-turning radius and greater traction. This architecture also has several advantages when employed by mobile platforms designed to climb and navigate ferrous surfaces, such as increased magnet density and low profile (center of gravity). However, creating a kinematic model for localization and motion control of this architecture is complicated due to the fact that tracks necessarily slip and do not roll. Such a model could be based on a heuristic representation, an experimentally-based characterization or a probabilistic form. This paper will extend an experimentally-based kinematic equivalence model to a climbing, track-based robot platform. The model will be adapted to account for the unique mobility characteristics associated with climbing. The accuracy of the model will be evaluated in several representative tasks. Application of this model to a climbing mobile robotic welding system (MRWS) is presented.

Cold gas studies of a z = 2.5 protocluster

2020 ◽  
Vol 15 (S359) ◽  
pp. 136-140
Author(s):  
Minju M. Lee ◽  
Ichi Tanaka ◽  
Rohei Kawabe
Keyword(s):  
Galaxy Evolution ◽  
High Redshift ◽  
Kinematic Model ◽  
Molecular Gas ◽  
General View ◽  
Massive Galaxies ◽  
Star Forming ◽  
Gas Kinematics ◽  
Narrow Band Filter ◽  
Stellar Masses

AbstractWe present studies of a protocluster at z =2.5, an overdense region found close to a radio galaxy, 4C 23.56, using ALMA. We observed 1.1 mm continuum, two CO lines (CO (4–3) and CO (3–2)) and the lower atomic carbon line transition ([CI](3P1-3P0)) at a few kpc (0″.3-0″.9) resolution. The primary targets are 25 star-forming galaxies selected as Hα emitters (HAEs) that are identified with a narrow band filter. These are massive galaxies with stellar masses of > 1010Mʘ that are mostly on the galaxy main sequence at z =2.5. We measure the molecular gas mass from the independent gas tracers of 1.1 mm, CO (3–2) and [CI], and investigate the gas kinematics of galaxies from CO (4–3). Molecular gas masses from the different measurements are consistent with each other for detection, with a gas fraction (fgas = Mgas/(Mgas+ Mstar)) of ≃ 0.5 on average but with a caveat. On the other hand, the CO line widths of the protocluster galaxies are typically broader by ˜50% compared to field galaxies, which can be attributed to more frequent, unresolved gas-rich mergers and/or smaller sizes than field galaxies, supported by our high-resolution images and a kinematic model fit of one of the galaxies. We discuss the expected scenario of galaxy evolution in protoclusters at high redshift but future large surveys are needed to get a more general view.

scholarly journals Observation and analysis of diving beetle movements while swimming

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Debo Qi ◽  
Chengchun Zhang ◽  
Jingwei He ◽  
Yongli Yue ◽  
Jing Wang ◽  
...  
Keyword(s):  
Swimming Speed ◽  
High Speed ◽  
Kinematic Model ◽  
Movement Pattern ◽  
Unmanned Vehicles ◽  
Power Stroke ◽  
Cross Sectional ◽  
Motion Data ◽  
The Cross ◽  
Diving Beetle

AbstractThe fast swimming speed, flexible cornering, and high propulsion efficiency of diving beetles are primarily achieved by their two powerful hind legs. Unlike other aquatic organisms, such as turtle, jellyfish, fish and frog et al., the diving beetle could complete retreating motion without turning around, and the turning radius is small for this kind of propulsion mode. However, most bionic vehicles have not contained these advantages, the study about this propulsion method is useful for the design of bionic robots. In this paper, the swimming videos of the diving beetle, including forwarding, turning and retreating, were captured by two synchronized high-speed cameras, and were analyzed via SIMI Motion. The analysis results revealed that the swimming speed initially increased quickly to a maximum at 60% of the power stroke, and then decreased. During the power stroke, the diving beetle stretched its tibias and tarsi, the bristles on both sides of which were shaped like paddles, to maximize the cross-sectional areas against the water to achieve the maximum thrust. During the recovery stroke, the diving beetle rotated its tarsi and folded the bristles to minimize the cross-sectional areas to reduce the drag force. For one turning motion (turn right about 90 degrees), it takes only one motion cycle for the diving beetle to complete it. During the retreating motion, the average acceleration was close to 9.8 m/s2 in the first 25 ms. Finally, based on the diving beetle's hind-leg movement pattern, a kinematic model was constructed, and according to this model and the motion data of the joint angles, the motion trajectories of the hind legs were obtained by using MATLAB. Since the advantages of this propulsion method, it may become a new bionic propulsion method, and the motion data and kinematic model of the hind legs will be helpful in the design of bionic underwater unmanned vehicles.

scholarly journals Improved hybrid A* path planning method for spherical mobile robot based on pendulum

2021 ◽  
Vol 18 (1) ◽  
pp. 172988142199295
Author(s):  
Ziang Zhang ◽  
Yixu Wan ◽  
You Wang ◽  
Xiaoqing Guan ◽  
Wei Ren ◽  
...  
Keyword(s):  
Mobile Robots ◽  
Common Ground ◽  
Kinematic Model ◽  
Point Contact ◽  
Shell Shape ◽  
Spherical Robot ◽  
Trajectory Tracking Control ◽  
Novel Method ◽  
Turning Radius ◽  
Spherical Mobile Robot

This article proposes a modification of hybrid A* method used for navigation of spherical mobile robots with the ability of limited partial lateral movement driven by pendulum. For pendulum-driven spherical robots with nonzero minimal turning radius, our modification helps to find a feasible and achievable path, which can be followed in line with the low time cost. Because of spherical shell shape, the robot is point contact with the ground, showing different kinematic model compared with common ground mobile robots such as differential robot and wheeled car-like robot. Therefore, this article analyzes the kinematic model of spherical robot and proposes a novel method to generate feasible and achievable paths conforming to kinematic constraints, which can be the initial value of future trajectory tracking control and further optimization. A concept of optimal robot’s minimum area for rotation is also proposed to improve search efficiency and ensure the ability of turning to any orientation by moving forward and backward in a finite number of times within limited areas.

Reliability of a simplified kinematic model for clinical gait analysis

2020 ◽  
Vol 81 ◽  
pp. 281-282
Author(s):  
S. Pitarch-Corresa ◽  
C. Herrera-Ligero ◽  
J.Y. Torres-Villanueva ◽  
E. Medina-Ripoll ◽  
F. Parra-González ◽  
...  
Keyword(s):  
Gait Analysis ◽  
Kinematic Model ◽  
Clinical Gait Analysis
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