scholarly journals On path following control of nonholonomic mobile manipulators

2009 ◽  
Vol 19 (4) ◽  
pp. 561-574 ◽  
Author(s):  
Alicja Mazur ◽  
Dawid Szakiel
Keyword(s):  
Control Algorithm ◽  
Dynamic Control ◽  
Path Following ◽  
Mobile Manipulator ◽  
Mobile Manipulators ◽  
Control Laws ◽  
Kinematic Control ◽  
Motion Constraints ◽  
Path Following Control ◽  
Cascade Structure

On path following control of nonholonomic mobile manipulatorsThis paper describes the problem of designing control laws for path following robots, including two types of nonholonomic mobile manipulators. Due to a cascade structure of the motion equation, a backstepping procedure is used to achieve motion along a desired path. The control algorithm consists of two simultaneously working controllers: the kinematic controller, solving motion constraints, and the dynamic controller, preserving an appropriate coordination between both subsystems of a mobile manipulator, i.e. the mobile platform and the manipulating arm. A description of the nonholonomic subsystem relative to the desired path using the Frenet parametrization is the basis for formulating the path following problem and designing a kinematic control algorithm. In turn, the dynamic control algorithm is a modification of a passivity-based controller. Theoretical deliberations are illustrated with simulations.

Decentralized Dynamic Control of a Nonholonomic Mobile Manipulator Collective: A Simulation Study

2008 ◽  
Author(s):  
Hao Su ◽  
Venkat Krovi
Keyword(s):  
Control Algorithm ◽  
Null Space ◽  
Dynamic Control ◽  
Mobile Manipulator ◽  
Mobile Manipulators ◽  
Level Control ◽  
Individual Agent ◽  
End Effector ◽  
High Level ◽  
Task Accomplishment

In this paper, we present a decentralized dynamic control algorithm for a robot collective consisting of multiple nonholonomic wheeled mobile manipulators (NH-WMMs) capable of cooperatively transporting a common payload. In this algorithm, the high level controller deals with motion/force control of the payload, at the same time distributes the motion/force task into individual agents by grasp description matrix. In each individual agent, the low level controller decomposes the system dynamics into decoupled task space (end-effector motions/forces) and a dynamically-consistent null-space (internal motions/forces) component. The agent level control algorithm facilitates the prioritized operational task accomplishment with the end-effector impedance-mode controller and secondary null-space control. The scalability and modularity is guaranteed upon the decentralized control architecture. Numerical simulations are performed for a 2-NH-WMM system carrying a payload (with/without uncertainty) to validate this approach.

scholarly journals Formation tracking of multiple amphibious robots with unknown nonlinear dynamics

2020 ◽  
Vol 17 (5) ◽  
pp. 172988142093854
Author(s):  
Di Wu ◽  
Lichao Hao ◽  
Xiujun Xu ◽  
Hongjian Wang ◽  
Jiajia Zhou
Keyword(s):  
Nonlinear Dynamics ◽  
Tracking Control ◽  
Control Algorithm ◽  
Dynamic Control ◽  
Lyapunov Theory ◽  
Kinematic Control ◽  
Formation Tracking ◽  
Control Stage ◽  
Cooperative Tracking ◽  
Unknown Nonlinear Dynamics

Cooperative tracking control problem of multiple water–land amphibious robots is discussed in this article with consideration of unknown nonlinear dynamics. Firstly, the amphibious robot dynamic model is formulated as an uncoupled nonlinear one in horizontal plane through eliminating relatively small sway velocity of the platform. Then cooperative tracking control algorithm is proposed with a two-stage strategy including dynamic control stage and kinematic control stage. In dynamic control stage, adaptive consensus control algorithm is obtained with estimating nonlinear properties of amphibious robots and velocities of the leader by neural network with unreliable communication links which is always the case in underwater applications. After that, kinematic cooperative controller is presented to guarantee formation stability of multiple water–land amphibious robots system in kinematic control stage. As a result, with the implementation of graph theory and Lyapunov theory, the stability of the formation tracking of multiple water–land amphibious robots system is proved with consideration of jointly connected communication graph. At last, simulations are carried out to prove the effectiveness of the proposed approaches.

Potential function-based path-following control of an autonomous underwater vehicle in an obstacle-rich environment

2016 ◽  
Vol 39 (8) ◽  
pp. 1236-1252 ◽  
Author(s):  
Basant Kumar Sahu ◽  
Bidyadhar Subudhi
Keyword(s):  
Potential Function ◽  
Obstacle Avoidance ◽  
Autonomous Underwater Vehicle ◽  
Path Following ◽  
Underwater Vehicle ◽  
Repulsive Force ◽  
Control Laws ◽  
Path Following Control ◽  
Avoidance Control ◽  
Solid Obstacles

This paper presents the development of simple but powerful path-following and obstacle-avoidance control laws for an underactuated autonomous underwater vehicle (AUV). Potential function-based proportional derivative (PFPD) as well as a potential function-based augmented proportional derivative (PFAPD) control laws are developed to govern the motion of the AUV in an obstacle-rich environment. For obstacle avoidance, a mathematical potential function is used, which formulates the repulsive force between the AUV and the solid obstacles intersecting the desired path. Numerical simulations are carried out to study the efficacy of the proposed controllers and the results are observed. To reduce the values of the overshoots and steady-state errors identified due to the application of PFPD controller a PFAPD controller is designed that drives the AUV along the desired trajectory. From the simulation results, it is observed that the proposed controllers are able to drive the AUV to track the desired path, avoiding the obstacles in an obstacle-rich environment. The results are compared and it is observed that the PFAPD outperforms the PFPD to drive the AUV along the desired trajectory. It is also proved that it is not necessary to employ highly complicated controllers for solving obstacle-avoidance and path-following problems of underactuated AUVs. These problems can be solved with the application of PFAPD controllers.

A Path-Following Control Algorithm for Manufacturing Systems Based Upon the Decomposed Contour Error

1998 ◽  
Vol 14 (1) ◽  
pp. 49-55
Author(s):  
Hsin-Chiang Ho ◽  
Jia-Yush Yen
Keyword(s):  
Control Algorithm ◽  
Manufacturing Systems ◽  
Tracking Error ◽  
Normal Component ◽  
Path Following ◽  
Tangential Component ◽  
Experimental Results ◽  
Contour Error ◽  
Control Problems ◽  
Path Following Control

ABSTRACTWe propose a new path following control algorithm. The algorithm decomposes the trajectory errors into tangential and normal components. The normal component minimizes the tracking error, while the tangential component maintains the desired speed. Experimental results using an X-Y table indicate that the proposed method possesses satisfactory tracking characteristics. It resolves certain previously difficult to control problems.

scholarly journals Integrated Lateral and Longitudinal Control with Optimization-Based Allocation Strategy for Autonomous Electric Vehicles

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Adorjan Kovacs ◽  
Istvan Vajk
Keyword(s):  
Autonomous Vehicle ◽  
Path Following ◽  
Allocation Problem ◽  
Cost Functions ◽  
Test Vehicle ◽  
Novel Approach ◽  
Path Following Control ◽  
Cascade Structure ◽  
Time Test ◽  
Autonomous Electric Vehicles

This paper presents a novel approach for path-following control of a four-wheeled autonomous vehicle. The rear wheels of the vehicle are driven independently, all four wheels can be braked independently, and the front wheels are steered together. The proposed cascade structure consists of two convex optimization-based parts: one for path-following and another for the control allocation problem of the actuators. The control algorithm presents cost functions for the allocation problem focusing on safety. The proposed cost functions were examined and compared to former ones in a simulation environment. After all, the controller was tested in real-time test on a Lotus Evora test vehicle developed by ThyssenKrupp.

Sub-optimal trajectory planning for mobile manipulators

Robotica ◽  
2014 ◽  
Vol 33 (6) ◽  
pp. 1181-1200 ◽  
Author(s):  
Grzegorz Pajak ◽  
Iwona Pajak
Keyword(s):  
Optimal Trajectory ◽  
Control Algorithm ◽  
Nonholonomic Constraints ◽  
Mobile Manipulator ◽  
Reference Trajectory ◽  
Mobile Manipulators ◽  
Control Constraints ◽  
Manipulability Measure ◽  
And Control ◽  
Optimal Trajectory Planning

SUMMARYThis paper presents a method of planning a sub-optimal trajectory for a mobile manipulator subject to mechanical and control constraints. The path of the end-effector is defined as a curve that can be parameterised by any scaling parameter—the reference trajectory of a mobile platform is not needed. Constraints connected with the existence of mechanical limits for a given manipulator configuration, collision avoidance conditions and control constraints are considered. Nonholonomic constraints in a Pfaffian form are explicitly incorporated to the control algorithm. To avoid manipulator singularities, the motion of the robot is planned in order to maximise the manipulability measure.

scholarly journals Position-force control of mobile manipulator – nonadaptive and adaptive case

2017 ◽  
Vol 27 (4) ◽  
pp. 487-503 ◽  
Author(s):  
Mirela Kaczmarek ◽  
Wojciech Domski ◽  
Alicja Mazur
Keyword(s):  
Force Control ◽  
Control Algorithm ◽  
Parametric Uncertainty ◽  
Mobile Manipulator ◽  
Control Law ◽  
Mobile Manipulators ◽  
Constrained Dynamics ◽  
Holonomic Constraint ◽  
System A ◽  
Theoretical Considerations

AbstractThis article presents a control algorithm for nonholonomic mobile manipulators with a simple, geometric holonomic constraint imposed on the robot’s arm. A mathematical model in generalized, auxiliary and linearized coordinates is presented, as well as the constrained dynamics of the robotic system. A position-force control law is proposed, both for the fully known robot’s model, as well as for the model with parametric uncertainty in the dynamics. Theoretical considerations are supported by the results of computer simulations.

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