Improving the stability level for on-line planning of mobile manipulators

Robotica ◽  
2009 ◽  
Vol 27 (3) ◽  
pp. 389-402 ◽  
Author(s):  
Changwu Qiu ◽  
Qixin Cao ◽  
Leibin Yu ◽  
Shouhong Miao
Keyword(s):  
Mobile Robot ◽  
Planning Process ◽  
Robot Dynamics ◽  
Mobile Manipulators ◽  
Line Planning ◽  
On Line ◽  
Resolution Algorithm ◽  
The Stability ◽  
Redundant Kinematics ◽  
Velocity Level

SUMMARYThis paper presents a quadratic programming (QP) form algorithm to realize on-line planning of mobile manipulators with consideration for improving the stability level. With Lie group and screw tools, the general tree topology structure mobile robot dynamics and dynamic stability attributes were analysed. The stable support condition for a mobile robot is constructed not only in a polygonal support region, but also in a polyhedral support region. For a planar supporting region, the tip-over avoiding requirement is formulated as the tip-over prevent constraints with the reciprocal products of the resultant support wrench and the imaginary tip-over twists, which are constructed with the boundaries of the convex support polygon. At velocity level, the optimized resolution algorithm with standard QP form is designed to resolve the inverse redundant kinematics of the Omni-directional Mobile ManipulatorS (OMMS) with stability considerations. Numerical simulation results show that the presented methods successfully improve the stability level of the robot within an on-line planning process.

scholarly journals Maximum Allowable Dynamic Load of Mobile Manipulators with Stability Consideration

2015 ◽  
Vol 45 (3) ◽  
pp. 3-22
Author(s):  
H. R. Heidary
Keyword(s):  
Mobile Robot ◽  
Dynamic Load ◽  
System Stability ◽  
Mobile Manipulators ◽  
Uneven Terrain ◽  
Stability Limitation ◽  
The Stability ◽  
Maximum Allowable Dynamic Load ◽  
Stability Consideration ◽  
Mobile Base

Abstract High payload to mass ratio is one of the advantages of mobile robot manipulators. In this paper, a general formula for finding the maximum allowable dynamic load (MADL) of wheeled mobile robot is presented. Mobile manipulators operating in field environments will be required to manipulate large loads, and to perform such tasks on uneven terrain, which may cause the system to reach dangerous tip-over instability. Therefore, the method is expanded for finding the MADL of mobile manipulators with stability consideration. Moment-Height Stability (MHS) criterion is used as an index for the system stability. Full dynamic model of wheeled mobile base and mounted manipulator is considered with respect to the dynamic of non-holonomic constraint. Then, a method for determination of the maximum allowable loads is described, subject to actuator constraints and by imposing the stability limitation as a new constraint. The actuator torque constraint is applied by using a speed-torque characteristics curve of a typical DC motor. In order to verify the effectiveness of the presented algorithm, several simulation studies considering a two-link planar manipulator, mounted on a mobile base are presented and the results are discussed.

Study on Fault-Tolerant Method of Mobile Robot Integrated Navigation

2013 ◽  
Vol 300-301 ◽  
pp. 468-474
Author(s):  
Jing Zeng ◽  
Xiao Song Guo ◽  
Guo Liang Zhang
Keyword(s):  
Mobile Robot ◽  
Feature Recognition ◽  
Fault Tolerant ◽  
Dead Reckoning ◽  
Integrated Navigation ◽  
Integrated Navigation System ◽  
On Line ◽  
Finite Memory ◽  
The Stability ◽  
Association Error

As for the SLAM/DR/MEMS integrated navigation system of mobile robot constructed on the self-made SaecROB-H mobile robot, there exist mutant faults which are likely to occur, such as environment feature recognition error and data association error during mobile robot SLAM procedure, or dead reckoning failure caused by wheel slipping and so on. According to these mutant faults, mutant fault detecting and fault-tolerant filtering method was presented in this paper based on finite memory on-line prediction. At last, simulation was carried out and the results show that the method can improve the stability of mobile robot integrated navigation efficiently.

On Operational Space Tracking Control of Robotic Manipulators With Uncertain Dynamic and Kinematic Terms

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Kamil Cetin ◽  
Enver Tatlicioglu ◽  
Erkan Zergeroglu
Keyword(s):  
Tracking Control ◽  
Joint Space ◽  
Robot Dynamics ◽  
Robust Controller ◽  
Operational Space ◽  
Asymptotic Tracking ◽  
Robust Adaptive ◽  
And Performance ◽  
The Stability ◽  
Velocity Level

In this study, a continuous robust-adaptive operational space controller that ensures asymptotic end-effector tracking, despite the uncertainties in robot dynamics and on the velocity level kinematics of the robot, is proposed. Specifically, a smooth robust controller is applied to compensate the parametric uncertainties related to the robot dynamics while an adaptive update algorithm is used to deal with the kinematic uncertainties. Rather than formulating the tracking problem in the joint space, as most of the previous works on the field have done, the controller formulation is presented in the operational space of the robot where the actual task is performed. Additionally, the robust part of the proposed controller is continuous ensuring the asymptotic tracking and relatively smooth controller effort. The stability of the overall system and boundedness of the closed loop signals are ensured via Lyapunov based arguments. Experimental results are presented to illustrate the feasibility and performance of the proposed method.

scholarly journals Delayed Trilateral Teleoperation of a Mobile Robot

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
D. Santiago ◽  
E. Slawiñski ◽  
V. Mut
Keyword(s):  
Stability Analysis ◽  
Mobile Robot ◽  
Shared Environment ◽  
Time Varying ◽  
Control Parameters ◽  
Simple Test ◽  
Control Loop ◽  
Teleoperation System ◽  
Human Operators ◽  
The Stability

This paper analyzes the stability of a trilateral teleoperation system of a mobile robot. This type of system is nonlinear, time-varying, and delayed and includes a master-slave kinematic dissimilarity. To close the control loop, three P+d controllers are used under a position master/slave velocity strategy. The stability analysis is based on Lyapunov-Krasovskii theory where a functional is proposed and analyzed to get conditions for the control parameters that assure a stable behavior, keeping the synchronism errors bounded. Finally, the theoretical result is verified in practice by means of a simple test, where two human operators both collaboratively and simultaneously drive a 3D simulator of a mobile robot to achieve an established task on a remote shared environment.

Robust Impedance Control of Manipulators Carrying a Heavy Payload

2010 ◽  
Vol 132 (5) ◽  
Author(s):  
Farhad Aghili
Keyword(s):  
Force Measurement ◽  
Impedance Control ◽  
Stability And Convergence ◽  
Robot Dynamics ◽  
Control Input ◽  
Heavy Load ◽  
Impedance Model ◽  
Force Moment ◽  
Loop Feedback ◽  
The Stability

A heavy payload attached to the wrist force/moment (F/M) sensor of a manipulator can cause the conventional impedance controller to fail in establishing the desired impedance due to the noncontact components of the force measurement, i.e., the inertial and gravitational forces of the payload. This paper proposes an impedance control scheme for such a manipulator to accurately shape its force-response without needing any acceleration measurement. Therefore, no wrist accelerometer or a dynamic estimator for compensating the inertial load forces is required. The impedance controller is further developed using an inner/outer loop feedback approach that not only overcomes the robot dynamics uncertainty, but also allows the specification of the target impedance model in a general form, e.g., a nonlinear model. The stability and convergence of the impedance controller are analytically investigated, and the results show that the control input remains bounded provided that the desired inertia is selected to be different from the payload inertia. Experimental results demonstrate that the proposed impedance controller is able to accurately shape the impedance of a manipulator carrying a relatively heavy load according to the desired impedance model.

scholarly journals A Modified Artificial Bee Colony for the Non-Smooth Dynamic Economic/Environmental Dispatch

2018 ◽  
Vol 8 (5) ◽  
pp. 3321-3328 ◽  
Author(s):  
Ι. Marouani ◽  
A. Boudjemline ◽  
T. Guesmi ◽  
H. H. Abdallah
Keyword(s):  
Artificial Bee Colony ◽  
Random Search ◽  
Line Planning ◽  
Bee Colony ◽  
Search Mechanism ◽  
Loading Effects ◽  
On Line ◽  
Explosion Method ◽  
Metaheuristic Techniques ◽  
Emission Dispatch

This paper presents an improved artificial bee colony (ABC) technique for solving the dynamic economic emission dispatch (DEED) problem. Ramp rate limits, valve-point loading effects and prohibited operating zones (POZs) have been considered. The proposed technique integrates the grenade explosion method and Cauchy operator in the original ABC algorithm, to avoid random search mechanism. However, the DEED is a multi-objective optimization problem with two conflicting criteria which need to be minimized simultaneously. Thus, it is recommended to provide the best solution for the decision-makers. Shannon’s entropy-based method is used for the first time within the context of the on-line planning of generator outputs to extract the best compromise solution among the Pareto set. The robustness of the proposed technique is verified on six-unit and ten-unit system tests. Results proved that the proposed algorithm gives better optimum solutions in comparison with more than ten metaheuristic techniques.

Determination of the base position and working area for mobile manipulators

2016 ◽  
Vol 36 (1) ◽  
pp. 80-88 ◽  
Author(s):  
Shunan Ren ◽  
Xiangdong Yang ◽  
Jing Xu ◽  
Guolei Wang ◽  
Ying Xie ◽  
...  
Keyword(s):  
Operation Mode ◽  
Mobile Manipulator ◽  
Planning Problem ◽  
Mobile Manipulators ◽  
Line Planning ◽  
Content Type ◽  
Practical Applications ◽  
Base Position ◽  
Intersection Area ◽  
Intersection Line

Purpose – The purpose of this paper is to determine the base position and the largest working area for mobile manipulators. The base position determines the workspace of the mobile manipulator, particularly when the operation mode is intermittent (i.e. the mobile platform stops when the manipulator conducts the task). When the base of the manipulator is in the intersection area of the Base’s Workable Location Spaces (BWLSes), the end effector (EE) can reach all path points. In this study, the intersection line of BWLSes is calculated numerically, and the largest working area is determined using the BWLS concept. The performance of this method is validated with simulations on specific surface segments, such as plane, cylinder and conical surface segments. Design/methodology/approach – The BWLS is used to determine the largest working area and the base position in which the mobile manipulator can reach all path points with the objective of reducing off-line planning time. Findings – Without considering the orientation of the EE, the base position and the working area for the mobile manipulator are determined using the BWLS. Compared to other methods, the proposed algorithm is beneficial when the planning problem has six dimensions, ensuring the reachability and stability of the EE. Originality/value – The algorithm needs no manual configuration, and its performance is investigated for typical surfaces in practical applications.

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