Full Bicycle Dynamic Model for Interactive Bicycle Simulator

2005 ◽  
Vol 5 (4) ◽  
pp. 373-380 ◽  
Author(s):  
Qichang He ◽  
Xiumin Fan ◽  
Dengzhe Ma
Keyword(s):  
Dynamic Model ◽  
Degrees Of Freedom ◽  
Vibration Response ◽  
Road Surface ◽  
Six Degrees Of Freedom ◽  
Bicycle Dynamics ◽  
Motion System ◽  
The Stability

An interactive bicycle simulator with six degrees of freedom motion system could bring the rider a very realistic riding feeling. An important component of the simulator is the full bicycle dynamic model that simulated the two-wheeled bicycle dynamics. It consists of two slightly coupled submodels: The stability submodel and the vibration submodel. The stability submodel solves the stability of the bicycle under rider’s active maneuvers and the vibration submodel evaluates the vibration response of the bicycle due to uneven road surface. The model was validated by several experiments and successfully applied to the interactive bicycle simulator.

Model Tests of a Caisson in Wet Towing for Assessing Resistance and Stability in Calm Water and Waves

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Chang-Wook Park ◽  
Jeonghwa Seo ◽  
Shin Hyung Rhee
Keyword(s):  
Degrees Of Freedom ◽  
Model Tests ◽  
Added Resistance ◽  
Power Requirement ◽  
Effective Power ◽  
Six Degrees Of Freedom ◽  
Calm Water ◽  
Improved Stability ◽  
Scale Ratio ◽  
The Stability

A series of model tests of a caisson in wet towing were conducted in a towing tank to assess the stability and effective power requirement in calm water and head sea conditions. The scale ratio of the model was 1/30, and the model-length-based Froude number in the tests ranged from 0.061 to 0.122, which is equivalent to 2 and 4 knots in the full scale, respectively. During the towing of the model, tension on the towline and six-degrees-of-freedom (6DOF) motion of the model were measured. Under the calm water condition, the effects of towing speed, draft, and initial trim variation on the towing stability and effective power were investigated. Initial trim improved stability and reduced required towing power. In head seas, effective power and towing stability were changed with the wavelength. It increased as the wavelength became longer, but the added resistance in long waves also stabilized the model with reduced yaw motion.

Design of a Robust H∞ PID Control for Industrial Manipulators

1999 ◽  
Vol 122 (4) ◽  
pp. 803-812 ◽  
Author(s):  
Jonghoon Park ◽  
Wankyun Chung
Keyword(s):  
Pid Control ◽  
Degrees Of Freedom ◽  
Performance Tuning ◽  
Motion Controller ◽  
Six Degrees Of Freedom ◽  
Stability Robustness ◽  
Industrial Manipulators ◽  
And Performance ◽  
The Stability ◽  
L2 Gain

Industrial manipulators are under various limitations against high quality motion control; for example, both frictional and dynamic disturbances should be dealt with a simple PID control structure. A robust linear PID motion controller, called the reference error feedback (REF), is proposed, which solves the nonlinear L2-gain attenuation control problem for robotic manipulators. The stability, robustness, and performance tuning of the proposed controller are analyzed. Making use of the fact that the single parameter of the induced L2-gain γ controls the performance with stability attained, we propose a simple and stable method of performance tuning called “the square law.” The analytical results are verified through experiments of a six-degrees-of-freedom industrial manipulator. [S0022-0434(00)00104-0]

A Three-Dimensional Dynamic Model for Determining the Equilibrium Configurations of Buoyantly Unstable Icebergs

1990 ◽  
Vol 112 (3) ◽  
pp. 253-262
Author(s):  
R. G. Jessup ◽  
S. Venkatesh
Keyword(s):  
Dynamic Model ◽  
Degrees Of Freedom ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Static Potential ◽  
Initial State ◽  
Model Simulations ◽  
Six Degrees Of Freedom ◽  
Equilibrium Configurations ◽  
Variation Range

This paper describes a dynamic model developed for the purpose of determining the final equilibrium configurations of buoyantly unstable icebergs. The model places no restrictions on the size, shape, or dimensionality of the iceberg, or on the variation range of the configuration coordinates. Furthermore, it includes all six degrees of freedom and is based on a Lagrangian formulation of the dynamic equations of motion. It can be used to advantage in those situations in which the iceberg has a complicated potential function and can acquire enough momentum and kinetic energy in the initial phase of its motion to make its final configuration uncertain on the basis of a static potential analysis. The behavior of the model is examined through several model simulations. The sensitivity of the final equilibrium position to the initial orientation and shape of the iceberg is clearly evident in the model simulations. Model simulations also show that when an iceberg is released from a nonequilibrium initial state, the time taken for it to settle down varies from about 40 s for a growler to nearly 400 s for a large iceberg. While these absolute times may change with better parameterization of the forces, the relative variations with iceberg size are likely to be preserved.

Model-Based Verifying and Design of Autonomous Airship

2011 ◽  
Vol 66-68 ◽  
pp. 1748-1754
Author(s):  
Yu Liu ◽  
Yi Lin Wu
Keyword(s):  
Dynamic Model ◽  
Degrees Of Freedom ◽  
Boundary Layer Theory ◽  
Wind Effect ◽  
Nonlinear Dynamic Model ◽  
Kirchhoff Equations ◽  
Six Degrees Of Freedom ◽  
Motion Characteristics ◽  
Linearized Model ◽  
Rotational Damping

Based on the Kirchhoff equations, Newton-Euler laws, boundary layer theory and mass definition, the six degrees of freedom dynamic model of airship complete with aerodynamic forces, wind effect is presented. Then, the nonlinear dynamic model is divided into three group equations by restricting airship motion in different planes respectively. The motion characteristics of airship, including stability, the effect of ballast position and rotational damping, are studied using linearized model. The results of simulation verify the correctness of the theoretical analysis and airship design.

Theory and Experiments on the Compliance Control of Redundant Robot Manipulators

1990 ◽  
Vol 112 (4) ◽  
pp. 653-660 ◽  
Author(s):  
H. Kazerooni ◽  
K. G. Bouklas ◽  
J. Guo
Keyword(s):  
Degrees Of Freedom ◽  
Control Method ◽  
Robot Manipulators ◽  
Industrial Robot ◽  
Redundant Robot ◽  
Control Approach ◽  
Six Degrees Of Freedom ◽  
The Stability ◽  
Control Methodology ◽  
Theory And Experiments

This work presents a control methodology for compliant motion in redundant robot manipulators. This control approach takes advantage of the redundancy in the robot’s degrees of freedom: while a maximum six degrees of freedom of the robot control the robot’s endpoint position, the remaining degrees of freedom impose an appropriate force on the environment. To verify the applicability of this control method, an active end-effector is mounted on an industrial robot to generate redundancy in the degrees of freedom. A set of experiments are described to demonstrate the use of this control method in constrained maneuvers. The stability of the robot and the environment is analyzed.

scholarly journals Reducing Cybersickness in 360-Degree Virtual Reality

2021 ◽  
pp. 1-17
Author(s):  
Iqra Arshad ◽  
Paulo De Mello ◽  
Martin Ender ◽  
Jason D. McEwen ◽  
Elisa R. Ferré
Keyword(s):  
Heart Rate ◽  
Virtual Reality ◽  
Degrees Of Freedom ◽  
Simulator Sickness ◽  
Six Degrees Of Freedom ◽  
Head Mounted Display ◽  
Motion System ◽  
Translational Movement ◽  
Vestibular Cues ◽  
Self Motion

Abstract Despite the technological advancements in Virtual Reality (VR), users are constantly combating feelings of nausea and disorientation, the so-called cybersickness. Cybersickness symptoms cause severe discomfort and hinder the immersive VR experience. Here we investigated cybersickness in 360-degree head-mounted display VR. In traditional 360-degree VR experiences, translational movement in the real world is not reflected in the virtual world, and therefore self-motion information is not corroborated by matching visual and vestibular cues, which may trigger symptoms of cybersickness. We evaluated whether a new Artificial Intelligence (AI) software designed to supplement the 360-degree VR experience with artificial six-degrees-of-freedom motion may reduce cybersickness. Explicit (simulator sickness questionnaire and Fast Motion Sickness (FMS) rating) and implicit (heart rate) measurements were used to evaluate cybersickness symptoms during and after 360-degree VR exposure. Simulator sickness scores showed a significant reduction in feelings of nausea during the AI-supplemented six-degrees-of-freedom motion VR compared to traditional 360-degree VR. However, six-degrees-of-freedom motion VR did not reduce oculomotor or disorientation measures of sickness. No changes were observed in FMS and heart rate measures. Improving the congruency between visual and vestibular cues in 360-degree VR, as provided by the AI-supplemented six-degrees-of-freedom motion system considered, is essential for a more engaging, immersive and safe VR experience, which is critical for educational, cultural and entertainment applications.

A nonlinear six degrees of freedom dynamic model of planetary roller screw mechanism

2018 ◽  
Vol 119 ◽  
pp. 22-36 ◽  
Author(s):  
Xiaojun Fu ◽  
Geng Liu ◽  
Ruiting Tong ◽  
Shangjun Ma ◽  
Teik C. Lim
Keyword(s):  
Dynamic Model ◽  
Degrees Of Freedom ◽  
Six Degrees Of Freedom ◽  
Roller Screw ◽  
Screw Mechanism

Multiple-Mode Dynamic Model for Piezoelectric Micro-Robot Walking

2016 ◽  
Author(s):  
Jinhong Qu ◽  
Kenn R. Oldham
Keyword(s):  
Dynamic Model ◽  
Degrees Of Freedom ◽  
Beam Theory ◽  
Body Motion ◽  
Six Degrees Of Freedom ◽  
Robot Locomotion ◽  
Multiple Mode ◽  
Micro Robot ◽  
Actuation Scheme ◽  
Robot Body

A multiple-mode dynamic model is developed for a piezoelectrically-actuated micro-robot with multiple legs. The motion of the micro robot results from dual direction motion of piezoelectric actuators in the legs, while the complexity of micro robot locomotion is increased by impact dynamics. The dynamic model is developed to describe and predict the micro robot motion, in the presence of asymmetrical behavior due to non-ideal fabrication and variable properties of the underlying terrain. The dynamic model considers each robot leg as a continuous structure moving in two directions derived from beam theory with specific boundary condition. Robot body motion is modeled in six degrees of freedom using a rigid body approximation. Individual modes of the resulting multimode robot are treated as second order linear systems. The dynamic model is tested with a meso-scale robot prototype having a similar actuation scheme as micro-robots. In accounting for the interaction between robot and ground, the dynamic model with first two modes of each leg shows good match with experimental results for the mesoscale prototype, in terms of both magnitude and the trends of robot locomotion with respect to actuation conditions.

scholarly journals A Force/Position Hybrid Controller for Rehabilitation Robot

2019 ◽  
Vol 14 (5) ◽  
pp. 615
Author(s):  
Jin Hua ◽  
Lile He ◽  
Zhiqiang Kang ◽  
Keding Yan
Keyword(s):  
Degrees Of Freedom ◽  
Ageing Population ◽  
Rehabilitation Robot ◽  
Simulation Environment ◽  
Rehabilitation Care ◽  
Robot Operating System ◽  
Six Degrees Of Freedom ◽  
Motion System ◽  
Hybrid Controller ◽  
The Relationship

The growing ageing population in China poses a huge demand for rehabilitation care, which can be satisfied by the latest robot technology. Focusing on the motion system of a six degrees-of-freedom (DOF) robot, this paper explores the relationship between the force, torque, velocity and the postures of the end effector and joint. Drawing on robot control theories, the existing manipulator force/position hybrid controllers were reviewed, and a force/position hybrid controller was designed for path planning of rehabilitation robot. Then, the robot was modelled on the Robot Operating System (ROS), using the Unified Robot Description Format (URDF) file and the MoveIt! Setup Assistant. Finally, our controller was tested in the ROS virtual simulation environment. The results show that our controller can facilitate and optimize the design of the path of rehabilitation robot.

scholarly journals Individual mandibular movement registration and reproduction using an optoeletronic jaw movement analyzer and a dedicated robot: a dental technique

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Massimo Carossa ◽  
Davide Cavagnetto ◽  
Paola Ceruti ◽  
Federico Mussano ◽  
Stefano Carossa
Keyword(s):  
Degrees Of Freedom ◽  
Reference Points ◽  
Production Costs ◽  
Mandibular Movement ◽  
Time Saving ◽  
Additional Advantage ◽  
Jaw Movement ◽  
Six Degrees Of Freedom ◽  
Motion System ◽  
Occlusal Surfaces

Abstract Background Fully adjustable articulators and pantographs record and reproduce individual mandibular movements. Although these instruments are accurate, they are operator-dependant and time-consuming. Pantographic recording is affected by inter and intra operator variability in the individuation of clinical reference points and afterwards in reading pantographic recording themselves. Finally only border movements can be reproduced. Methods Bionic Jaw Motion system is based on two components: a jaw movement analyzer and a robotic device that accurately reproduces recorded movements. The jaw movement analyzer uses an optoelectronic motion system technology made of a high frequency filming camera that acquires 140frames per second and a custom designed software that recognizes and determines the relative distance at each point in time of markers with known geometries connected to each jaw. Circumferential modified retainers connect markers and do not cover any occlusal surfaces neither obstruct occlusion. The recording process takes 5 to 10 s. Mandibular movement performance requires six degrees of freedom of movement, 3 rotations and 3 translations. Other robots are based on the so-called delta mechanics that use several parallel effectors to perform desired movements in order to decompose a complex trajectory into multiple more simple linear movements. However, each parallel effector introduces mechanical inter-component tolerances and mathematical transformations that are required to transform a recorded movement into the combination of movements to be performed by each effector. Bionic Jaw Motion Robot works differently, owing to three motors that perform translational movements and three other motors that perform rotations as a gyroscope. This configuration requires less mechanical components thus reducing mechanical tolerances and production costs. Both the jaw movement analyzer and the robot quantify the movement of the mandible as a rigid body with six degrees of freedom. This represents an additional advantage as no mathematical transformation is needed for the robot to reproduce recorded movements. Results Based on the described procedure, Bionic Jaw Motion provide accurate recording and reproduction of maxillomandibular relation in static and dynamic conditions. Conclusion This robotic system represents an important advancement compared to available analogical and digital alternatives both in clinical and research contexts for cost reduction, precision and time saving opportunities.

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