Kinematics and Tip-Over Stability Analysis for a Hybrid Serial-Parallel Mobile Manipulator

2011 ◽  
Author(s):  
Jose Antonio Souza-Jimenez ◽  
Victor J. Gonzalez-Villela
Keyword(s):  
Stability Analysis ◽  
Computer Simulations ◽  
Parallel Manipulator ◽  
Center Of Mass ◽  
Stewart Platform ◽  
Mobile Manipulator ◽  
Uneven Terrain ◽  
Stable Motion ◽  
Kinematical Model ◽  
Simulation Results

This paper shows the geometry and the kinematical model for a compounded serial-parallel wheeled mobile manipulator. The parallel manipulator, Stewart Platform, is an interface that helps the whole system to accomplish stable motion when handling heavy objects and to improve mobility over uneven-terrain by repositioning their center of mass. To evaluate the possibility of tip over, a stability analysis is performed; some criteria are established. Computer simulations and experiments are carried out and the influences of different robotic postures on the tip-over stability are analyzed through simulation results.

Tip-Over Stability Analysis for a Wheeled Mobile Manipulator

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Shuai Guo ◽  
Tao Song ◽  
Fengfeng (Jeff) Xi ◽  
Richard Phillip Mohamed
Keyword(s):  
Stability Analysis ◽  
Path Planning ◽  
Static Load ◽  
System Stability ◽  
Mobile Manipulator ◽  
Inertial Forces ◽  
Horizontal Position ◽  
Reaction Forces ◽  
Simulation Results

A method is presented for tip-over stability analysis of a wheeled mobile manipulator. A wheeled mobile manipulator may tip over resulting from its operation. In this study, first a Newton–Euler formulation is applied to formulate the manipulator’s reaction forces and moments exerted onto the mobile platform. Tip-over criterion is derived to judge the system stability. Three load and motion analyses are carried on. The first static load deals with links and payload to show the effect of the horizontal position of the system’s center of gravity (CG). The second and third are the inertial forces resulting from joint speeds and accelerations, respectively. Case study is path planning with tip-over criterion result which can make the system stable along the path. The simulation results demonstrate the effectiveness of the proposed method.

Kinematics and tip-over stability analysis for the mobile modular manipulator

2005 ◽  
Vol 219 (3) ◽  
pp. 331-342 ◽  
Author(s):  
Y Li ◽  
Y Liu
Keyword(s):  
Stability Analysis ◽  
Theoretical Analysis ◽  
Computer Simulations ◽  
Practical Method ◽  
Mobile Platform ◽  
Mobile Manipulator ◽  
Stability Criteria ◽  
Kinematics Model ◽  
Direct Differentiation Method ◽  
Differentiation Method

This paper presents a practical method to establish the kinematics model for the mobile modular manipulator. A tough issue is resolved by decomposing a given task into motions performed by both the manipulator and the mobile platform. A direct differentiation method is used to analyse the differential kinematics. Stability analysis of the mobile manipulator is performed to evaluate the possibility of tip-over; some stability criteria are established. Computer simulations are carried on a real mobile modular manipulator, and ideal results are received to show that the theoretical analysis is feasible and correct.

Relay Feedback PID Tuning of a Parallel Manipulator

2003 ◽  
Author(s):  
Zhonghua Wang ◽  
Brian Surgenor ◽  
George Mann
Keyword(s):  
Pid Controller ◽  
Critical Period ◽  
Parallel Manipulator ◽  
Stewart Platform ◽  
Trial And Error ◽  
Relay Feedback ◽  
Pid Tuning ◽  
Simulation Results ◽  
Analytical Approaches

This paper demonstrates modified relay feedback PID tuning as applied to a 6-DOF Gough-Stewart Platform (GSP) based parallel manipulator. The nature of the GSP is such that analytical approaches to obtain the PID controller gains do not apply, and a trial and error approach is commonly used. Simulation results demonstrate that a modified relay approach can be successfully applied to the PID tuning of a GSP. The modification involves the weighting of the critical period.

Computer Simulation of an Synthetic Ultraviolet Absorbent in the Interface of DMB and DMF

2010 ◽  
Vol 146-147 ◽  
pp. 966-971
Author(s):  
Qi Hua Jiang ◽  
Hai Dong Zhang ◽  
Bin Xiang ◽  
Hai Yun He ◽  
Ping Deng
Keyword(s):  
Computer Simulation ◽  
Computer Simulations ◽  
Density Functional ◽  
Density Functional Method ◽  
Mean Field ◽  
Functional Method ◽  
Dynamic Density ◽  
Interface Phase ◽  
Simulation Results

This work studies the aggregation of an synthetic ultraviolet absorbent, named 2-hydroxy-4-perfluoroheptanoate-benzophenone (HPFHBP), in the interface between two solvents which can not completely dissolve each other. The aggregation is studied by computer simulations based on a dynamic density functional method and mean-field interactions, which are implemented in the MesoDyn module and Blend module of Material Studios. The simulation results show that the synthetic ultraviolet absorbent diffuse to the interface phase and the concentration in the interface phase is greater than it in the solvents phase.

Stability analysis of an asbestos removal mobile manipulator for safe grinding trajectories

2019 ◽  
pp. 2349-2358
Author(s):  
Siddharth Maraje ◽  
Jean-Christophe Fauroux ◽  
Chedli-Belhassen Bouzgarrou ◽  
Lounis Adouane
Keyword(s):  
Stability Analysis ◽  
Mobile Manipulator

scholarly journals Terrain-Perception-Free Quadrupedal Spinning Locomotion on Versatile Terrains: Modeling, Analysis, and Experimental Validation

2021 ◽  
Vol 8 ◽  
Author(s):  
Hongwu Zhu ◽  
Dong Wang ◽  
Nathan Boyd ◽  
Ziyi Zhou ◽  
Lecheng Ruan ◽  
...  
Keyword(s):  
Motion Tracking ◽  
Center Of Mass ◽  
Kinematic Model ◽  
Linear Quadratic Regulator ◽  
Small Scale ◽  
Small Range ◽  
Linear Quadratic ◽  
Stability Margins ◽  
Uneven Terrain ◽  
Quadruped Robots

Dynamic quadrupedal locomotion over rough terrains reveals remarkable progress over the last few decades. Small-scale quadruped robots are adequately flexible and adaptable to traverse uneven terrains along the sagittal direction, such as slopes and stairs. To accomplish autonomous locomotion navigation in complex environments, spinning is a fundamental yet indispensable functionality for legged robots. However, spinning behaviors of quadruped robots on uneven terrain often exhibit position drifts. Motivated by this problem, this study presents an algorithmic method to enable accurate spinning motions over uneven terrain and constrain the spinning radius of the center of mass (CoM) to be bounded within a small range to minimize the drift risks. A modified spherical foot kinematics representation is proposed to improve the foot kinematic model and rolling dynamics of the quadruped during locomotion. A CoM planner is proposed to generate a stable spinning motion based on projected stability margins. Accurate motion tracking is accomplished with linear quadratic regulator (LQR) to bind the position drift during the spinning movement. Experiments are conducted on a small-scale quadruped robot and the effectiveness of the proposed method is verified on versatile terrains including flat ground, stairs, and slopes.

scholarly journals Quaternary regenerative CMOS logic circuits with high-impedance output state

2005 ◽  
Vol 18 (3) ◽  
pp. 505-514
Author(s):  
Dusanka Bundalo ◽  
Branimir Ðordjevic ◽  
Zlatko Bundalo
Keyword(s):  
Computer Simulation ◽  
Computer Simulations ◽  
Delay Time ◽  
Propagation Delay ◽  
Logic Circuits ◽  
Output State ◽  
High Impedance ◽  
Multiple Valued Logic ◽  
Propagation Delay Time ◽  
Simulation Results

Principles and possibilities of synthesis and design of quaternary multiple valued regenerative CMOS logic circuits with high-impedance output state are de- scribed and proposed in the paper. Two principles of synthesis and implementation of CMOS regenerative quaternary multiple-valued logic circuits with high-impedance output state are proposed and described: the simple circuits with smaller number of transistors, and the buffer/driver circuits with decreased propagation delay time. The schemes of such logic circuits are given and analyzed by computer simulations. Some of computer simulation results confirming descriptions and conclusions are also given in the paper.

Computation of Madalines' Sensitivity to Input and Weight Perturbations

2006 ◽  
Vol 18 (11) ◽  
pp. 2854-2877 ◽  
Author(s):  
Yingfeng Wang ◽  
Xiaoqin Zeng ◽  
Daniel So Yeung ◽  
Zhihang Peng
Keyword(s):  
Probability Theory ◽  
Computer Simulations ◽  
Structural Characteristics ◽  
Analytical Formula ◽  
Single Neurons ◽  
Important Measure ◽  
Simulation Results ◽  
Theoretical Results ◽  
Good Agreement

The sensitivity of a neural network's output to its input and weight perturbations is an important measure for evaluating the network's performance. In this letter, we propose an approach to quantify the sensitivity of Madalines. The sensitivity is defined as the probability of output deviation due to input and weight perturbations with respect to overall input patterns. Based on the structural characteristics of Madalines, a bottomup strategy is followed, along which the sensitivity of single neurons, that is, Adalines, is considered first and then the sensitivity of the entire Madaline network. Bymeans of probability theory, an analytical formula is derived for the calculation of Adalines' sensitivity, and an algorithm is designed for the computation of Madalines' sensitivity. Computer simulations are run to verify the effectiveness of the formula and algorithm. The simulation results are in good agreement with the theoretical results.

Stabilized Walking of Humanoid NAO using Enhanced Spring-Loaded Inverted Pendulum Model on Uneven Terrain

2022 ◽  
Vol 13 (1) ◽  
pp. 0-0
Keyword(s):  
Path Length ◽  
Inverted Pendulum ◽  
Center Of Mass ◽  
Humanoid Robots ◽  
Slip Model ◽  
Turning Angle ◽  
Uneven Terrain ◽  
Inverted Pendulum Model ◽  
Pendulum Model ◽  
Spring Loaded Inverted Pendulum

In the coming decades, humanoid robots will play a rising role in society. The present article discusses their walking control and obstacle avoidance on uneven terrain using enhanced spring-loaded inverted pendulum model (ESLIP). The SLIP model is enhanced by tuning it with an adaptive particle swarm optimization (APSO) approach. It helps the humanoid robot to reach closer to the obstacles in order to optimize the turning angle to optimize the path length. The desired trajectory, along with the sensory data, is provided to the SLIP model, which creates compatible COM (center of mass) dynamics for stable walking. This output is fed to APSO as input, which adjusts the placement of the foot during interaction with uneven surfaces and obstacles. It provides an optimum turning angle for shunning the obstacles and ensures the shortest path length. Simulation has been carried out in a 3D simulator based on the proposed controller and SLIP controller in uneven terrain.

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