A New Approach to Model Constant Curvature Continuum Robot Dynamics

2019 ◽  
Author(s):  
Yujiong Liu ◽  
Pinhas Ben-Tzvi
Keyword(s):  
Constant Curvature ◽  
Inverse Dynamics ◽  
Virtual Work ◽  
Robot Dynamics ◽  
Real Time Control ◽  
Continuum Robots ◽  
New Approach ◽  
Time Control ◽  
Proposed Model ◽  
Vector Representations

Abstract Inspired by nature, continuum robots show their potential in human-centered environments due to the compliant-to-obstacle features and dexterous mobility. However, there are few such robots successfully implemented outside the laboratory so far. One reason is believed to be due to the real time control challenge for soft robots, which require a highly efficient, highly accurate dynamic model. This paper presents a new systematic methodology to formulate the dynamics of constant curvature continuum robots. The new approach builds on several new techniques: 1) using the virtual work principle to formulate the equation of motion, 2) using specifically selected kinematic representations to separate integral variables from the non-integral variables, and 3) using vector representations to put the integral in a compact form. By doing so, the hard-to-solve integrals are evaluated analytically in advance and the accurate inverse dynamics are established accordingly. Numerical simulations are conducted to evaluate the performances of the newly proposed model.

RESEARCH ON RIGID BODY INVERSE DYNAMICS OF A NOVEL 6-PRRS PARALLEL ROBOT

2018 ◽  
Vol 18 (08) ◽  
pp. 1840037
Author(s):  
YUBIN LIU ◽  
GANGFENG LIU
Keyword(s):  
Dynamic Model ◽  
Inverse Dynamics ◽  
Virtual Work ◽  
Equations Of Motion ◽  
Parallel Robot ◽  
Simulation Software ◽  
Real Time Control ◽  
Dynamical Equations ◽  
Time Control ◽  
Systematic Methodology

A systematic methodology for solving the inverse dynamics of a 6-PRRS parallel robot is presented. Based on the principle of virtual work and the Lagrange approach, a methodology for deriving the dynamical equations of motion is developed. To resolve the inconsistency between complications of established dynamic model and real-time control, a simplifying strategy of the dynamic model is presented. The dynamic character of the 6-PRRS parallel robot is analyzed by example calculation, and a full and precise dynamic model using simulation software is established. Verification results show the validity of the presented algorithm, and the simplifying strategies are practical and efficient.

Inverse Dynamics of a 6-DOF Decoupling Manipulator

2014 ◽  
Author(s):  
Taoran Liu ◽  
Feng Gao ◽  
Xianchao Zhao ◽  
Chenkun Qi
Keyword(s):  
Inverse Kinematics ◽  
Inverse Dynamics ◽  
Virtual Work ◽  
Principle Of Virtual Work ◽  
Real Time Control ◽  
Model Accuracy ◽  
Lower Weight ◽  
Time Control ◽  
Speed Reducer ◽  
Forward And Inverse Kinematics

In this paper, the kinematics and inverse dynamics of a 6-dof full decoupling parallel manipulator is presented. The forward and inverse kinematics solution can be easily obtained and simplify the real-time control due to 6 dof motion full decoupling. Three motors are embedded into the moving platform to realize rotational motion, simple kinematics and isotropic configurations due to the motors and speed reducers have a lower weight. An effective inverse dynamics of the manipulator is derived by the principle of virtual work. The existence of speed reducer for motors have advantages of decreasing mechanical couplings between axes and the full varying inertias are not directly onto each motor output shaft. Since the presence of speed reducer and in order to improve dynamic model accuracy, the inertia of motor rotor-reducer should be computed. Finally, numerical simulation of the inverse dynamics provides that the actuating torques created by gravity, velocity, acceleration and decoupling torque, coupling torque have been computed.

Development of Equations of Motion for a Stewart Platform Under Prescribed Mount Motion

2018 ◽  
Author(s):  
Takeyuki Ono ◽  
Ryosuke Eto ◽  
Junya Yamakawa ◽  
Hidenori Murakami
Keyword(s):  
Rigid Body ◽  
Virtual Work ◽  
Equations Of Motion ◽  
Base Plate ◽  
Stewart Platform ◽  
Euler Method ◽  
Moving Frame ◽  
Real Time Control ◽  
Precise Positioning ◽  
Time Control

Analytical equations of motion are critical for real-time control of translating manipulators, which require precise positioning of various tools for their mission. Specifically, when manipulators mounted on moving robots or vehicles perform precise positioning of their tools, it becomes economical to develop a Stewart platform, whose sole task is stabilizing the orientation and crude position of its top table, onto which various precision tools are attached. In this paper, analytical equations of motion are developed for a Stewart platform whose motion of the base plate is prescribed. To describe the kinematics of the platform, the moving frame method, presented by one of authors [1,2], is employed. In the method the coordinates of the origin of a body attached coordinate system and vector basis are expressed by using 4 × 4 frame connection matrices, which form the special Euclidean group, SE(3). The use of SE(3) allows accurate description of kinematics of each rigid body using (relative) joint coordinates. In kinetics, the principle of virtual work is employed, in which system virtual displacements are expressed through B-matrix by essential virtual displacements, reflecting the connection of the rigid body system [2]. The resulting equations for fixed base plate reduce to those for the top plate, obtained by the Newton-Euler method. A main result of the paper is the analytical equations of motion in matrix form for dynamics analyses of a Stewart platform whose base plate moves. The control applications of those equations will be deferred to subsequent publications.

Linearization and Sensitivity Models of the Newton-Euler Dynamic Robot Model

1986 ◽  
Vol 108 (3) ◽  
pp. 272-276 ◽  
Author(s):  
J. J. Murray ◽  
C. P. Neuman
Keyword(s):  
Numerical Evaluation ◽  
Controller Design ◽  
Robot Dynamics ◽  
Recursive Algorithms ◽  
Real Time Control ◽  
Control Applications ◽  
Trajectory Sensitivity ◽  
Time Control ◽  
Physical Insight ◽  
Simulation Parameter

Within the framework of the Newton-Euler formulation of robot dynamics, linearized and trajectory sensitivity models are constructed about a nominal trajectory. The approach illustrates the property that linearization of the O(N) recursive Newton-Euler formulation leads to O(N) recursive algorithms. These algorithms are conceived for simulation, parameter identification, and real-time control applications which require the numerical evaluation of the linearized or trajectory sensitivity models. The O(N) linearized recursive algorithms complement their O(N5) linearized Lagrange (Lagrange-Euler) counterparts which are conceived for physical insight, and manipulator and controller design.

Kinematics optimization and static analysis of a modular continuum robot used for minimally invasive surgery

2017 ◽  
Vol 232 (2) ◽  
pp. 135-148 ◽  
Author(s):  
Fei Qi ◽  
Feng Ju ◽  
Dong Ming Bai ◽  
Bai Chen
Keyword(s):  
Minimally Invasive Surgery ◽  
Minimally Invasive ◽  
Invasive Surgery ◽  
Virtual Work ◽  
Structural Parameters ◽  
Real Time Control ◽  
Time Control ◽  
Payload Capacity ◽  
Continuum Robot ◽  
The Relationship

For the outstanding compliance and dexterity of continuum robot, it is increasingly used in minimally invasive surgery. The wide workspace, high dexterity and strong payload capacity are essential to the continuum robot. In this article, we investigate the workspace of a cable-driven continuum robot that we proposed. The influence of section number on the workspace is discussed when robot is operated in narrow environment. Meanwhile, the structural parameters of this continuum robot are optimized to achieve better kinematic performance. Moreover, an indicator based on the dexterous solid angle for evaluating the dexterity of robot is introduced and the distal end dexterity is compared for the three-section continuum robot with different range of variables. Results imply that the wider range of variables achieve the better dexterity. Finally, the static model of robot based on the principle of virtual work is derived to analyze the relationship between the bending shape deformation and the driven force. The simulations and experiments for plane and spatial motions are conducted to validate the feasibility of model, respectively. Results of this article can contribute to the real-time control and movement and can be a design reference for cable-driven continuum robot.

A New Approach for Real-Time Control of Urban Traffic Networks

1983 ◽  
Vol 16 (4) ◽  
pp. 237-241 ◽  
Author(s):  
M. Drouin ◽  
H. Abou-Kandil ◽  
G. Dib ◽  
P. Bertrand
Keyword(s):  
Real Time ◽  
Urban Traffic ◽  
Traffic Networks ◽  
Real Time Control ◽  
New Approach ◽  
Time Control ◽  
Urban Traffic Networks

Real-Time Control Using Explicit Dynamic Solutions of a Two-Motion-Modes Mobile Robot

1994 ◽  
Vol 208 (3) ◽  
pp. 157-167 ◽  
Author(s):  
Y Y Cha ◽  
D G Gweon
Keyword(s):  
Mobile Robot ◽  
Real Time ◽  
Dynamic Control ◽  
Robot Dynamics ◽  
Real Time Control ◽  
Inverse Dynamic ◽  
Time Dynamic ◽  
Time Control ◽  
Motion Modes ◽  
Velocity Motion

In this study a two-motion-modes mobile robot is developed. The motion of the mobile robot is controlled by three d.c. servo-motors, two of which drive two wheels independently and one of which steers the wheels simultaneously. The two motion modes of the mobile robot, different velocity motion (DVM) and equal velocity motion (EVM), are analysed. Kinematic and dynamic analyses of the two motion modes are performed. For the implementation of real-time control considering mobile robot dynamics, the forward and inverse dynamic solutions are derived explicitly. Through a simulation, the path-tracking and control performance of the mobile robot considering dynamics is compared with the considering kinetics only, and the possibility of real-time dynamic control is proved.

Arterial-Friendly Local Ramp Metering Control Strategy

2021 ◽  
pp. 036119812199458
Author(s):  
Yao Cheng ◽  
Gang-Len Chang
Keyword(s):  
Real Time ◽  
Time Of Day ◽  
Ramp Metering ◽  
Real Time Control ◽  
Simulation Experiments ◽  
Traffic Conditions ◽  
Time Control ◽  
Proposed Model ◽  
Time Extension ◽  
Base Module

To prevent local streets being blocked by overflowing on-ramp queues, a standard practice of ramp metering control is to restrain its function when a series of preset conditions are identified by on-ramp queue detectors. Such a trade-off between potential ramp queue spillback and the restraint resulting from the operation of metering control may often fail to either effectively mitigate bottlenecks caused by on-ramp waving or convince arterial users and local traffic agencies of the need for ramp metering operations. This study, therefore, presents an arterial-friendly local ramp metering system (named AF-ramp) that can achieve the target metering rate to produce optimal freeway conditions without ramp queues spilling back onto local streets. This is achieved by concurrently optimizing the signal plans for those intersections that send turning flows to the ramp. At this stage, this system has been developed for time-of-day control. It could also serve as the base module for extending to real-time control, or multi-ramp coordinated operations. The AF-ramp model, with its ability to optimize the arterial signals concurrently with the ramp metering rate, can ensure the best use of the capacity of local intersections and prevent any gridlock caused by overflows from on-ramp queue spillback or arterial turning traffic. With extensive simulation experiments, the evaluation results confirmed the AF-ramp model’s effectiveness in improving traffic conditions on both the freeway and its neighboring arterial links at the same time. This study has also introduced the real-time extension of the proposed model and a framework of a transition from the time-of-day control to fully responsive real-time operations.

scholarly journals A New Approach for Solving the Inverse Kinematics of Continuum Robot Based on Piecewise Constant Curvature Model

2021 ◽  
Author(s):  
Haoran Wu ◽  
Jingjun Yu ◽  
Jie Pan ◽  
Xu Pei
Keyword(s):  
Motion Control ◽  
Constant Curvature ◽  
Inverse Kinematics ◽  
Clustering Method ◽  
Continuum Robots ◽  
New Approach ◽  
Piecewise Constant ◽  
Continuum Robot ◽  
Distinct Sequence ◽  
The Continuum

Abstract The inverse kinematics of continuum robot is an important factor to guarantee the motion accuracy. How to construct a concise inverse kinematics model is very essential for the motion control of continuum robot. In this paper, a new method for solving the inverse kinematics of continuum robot is proposed based on the geometric and numerical method. Assumed that the deformation of the continuum robot is Piecewise Constant Curvature model (PCC), the envelope surface of the continuum robot based on single-segment is modeled and calculated. The clustering method is used to calculate the intersection of the curves. Then, a distinct sequence is designed for solving the inverse kinematics of continuum robot, and it is also suitable for the multi-segment continuum robots in space. Finally, the accuracy of the inverse kinematics algorithm is verified by the simulation and numerical experiment. The experiment results illustrate that this algorithm is with higher accuracy compared with the Jacobian iterative algorithm.

scholarly journals An adaptive predictive approach for river level forecasting

2012 ◽  
Vol 15 (2) ◽  
pp. 232-245 ◽  
Author(s):  
José V. Aguilar ◽  
Pedro Langarita ◽  
Lorenzo Linares ◽  
Manuel Gómez ◽  
José Rodellar
Keyword(s):  
Real Time ◽  
River Basin ◽  
Real Data ◽  
Flood Management ◽  
Real Time Control ◽  
New Approach ◽  
Prediction Horizon ◽  
Time Control ◽  
Alternative Approach ◽  
Saint Venant Equations

Efficient flood management requires accurate real-time forecasts to allow early warnings, real-time control of hydraulics structures, or other actions. Commercially available computing tools typically use hydraulic models derived from the numerical approximation of Saint-Venant equations. These tools need powerful computers, accurate knowledge of the riverbed topography, and skilled operators with a not insignificant hydraulic background. This paper presents an alternative approach in which the river basin is modeled as a network of cascade interconnected input–output systems. Each system is modeled by an adaptive predictive expert model, which provides real-time fast and accurate forecasts over a moving prediction horizon. The approach is evaluated using real data from the Ebro river basin in Spain. The main concluded advantages of the new approach are: (1) the formulation is simple with low computational burden; (2) it does not require topographic information on the river waterbeds; (3) the forecast may be performed autonomously.

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