scholarly journals Adaptive Reinforcement Learning-Enhanced Motion/Force Control Strategy for Multirobot Systems

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Phuong Nam Dao ◽  
Duy Khanh Do ◽  
Dinh Khue Nguyen
Keyword(s):  
Reinforcement Learning ◽  
Force Control ◽  
Tracking Control ◽  
Dynamic Control ◽  
Additional Term ◽  
Control Law ◽  
Force Coefficient ◽  
Constraint Force ◽  
Control Scheme ◽  
Force Tracking

This paper presents an adaptive reinforcement learning- (ARL-) based motion/force tracking control scheme consisting of the optimal motion dynamic control law and force control scheme for multimanipulator systems. Specifically, a new additional term and appropriate state vector are employed in designing the ARL technique for time-varying dynamical systems with online actor/critic algorithm to be established by minimizing the squared Bellman error. Additionally, the force control law is designed after obtaining the computation of constraint force coefficient by the Moore–Penrose pseudo-inverse matrix. The tracking effectiveness of the ARL-based optimal control is verified in the closed-loop system by theoretical analysis. Finally, simulation studies are conducted on a system of three manipulators to validate the physical realization of the proposed optimal tracking control design.

Tracking Control of Robot Manipulators Using a Robust Deterministic Control Law

1998 ◽  
Vol 120 (4) ◽  
pp. 537-541 ◽  
Author(s):  
C.-G. Kang ◽  
R. Horowitz ◽  
G. Leitmann
Keyword(s):  
Dynamic Systems ◽  
Tracking Control ◽  
Robot Manipulators ◽  
Experimental Studies ◽  
Control Law ◽  
Direct Drive ◽  
Control Scheme ◽  
Deterministic Control ◽  
Two Degree Of Freedom ◽  
Theoretical Developments

There have been theoretical developments on the control of dynamic systems based on deterministically uncertain and singularly perturbed models in recent years. In this paper, a robust deterministic control scheme proposed originally by M. Corless et al. is modified, and is applied to the tracking control of robot manipulators. Simulation and experimental studies for a two degree of freedom, direct drive SCARA manipulator are conducted to evaluate the effectiveness of the control scheme.

Multi-Level Phase Shift (MLPS) Control Enabled Variable Displacement Gerotor/Geroler

2007 ◽  
Author(s):  
QingHui Yuan ◽  
Brian Armstrong
Keyword(s):  
Phase Shift ◽  
Tracking Control ◽  
Control Algorithm ◽  
Control Law ◽  
Family Selection ◽  
Control Scheme ◽  
Variable Displacement ◽  
Multi Level ◽  
Velocity Tracking ◽  
Peak Value

The research focuses on enabling gerotor/geroler, a traditional fixed displacement device, with the variable displacement capability by integrating electronically controlled digital valves and the corresponding control algorithm. Each digital valve controls polarity of each corresponding chamber of the fixed displacement device. A novel Multi-Level Phase Shift (MLPS) control scheme is developed such that the instantaneous displacement of such a system can be controlled. This control law is characteristic of classifying all the possible valve configuration into several displacement families where the peak value within each family would be identical. Given a desired displacement, both displacement family selection and phase shift technology are utilized to achieve better performance. In the experimental study, MLPS control has been verified, and successfully achieves a closed loop velocity tracking control of a hydraulic geroler motor.

An Adaptive Approach to Motion and Force Control of Multiple Coordinated Robots

1993 ◽  
Vol 115 (1) ◽  
pp. 60-69 ◽  
Author(s):  
Yan-Ru Hu ◽  
A. A. Goldenberg
Keyword(s):  
Contact Force ◽  
Force Control ◽  
Lyapunov Stability Theory ◽  
Internal Force ◽  
Object Motion ◽  
Tracking Accuracy ◽  
Unknown Parameters ◽  
Adaptive Law ◽  
Control Scheme ◽  
Force Tracking

In this paper an approach to motion and force control of multiple coordinated robots, based on an adaptive scheme, is developed. The approach can be used to control the motion of an object held by the robots, the contact force between the object and the environment, and the internal force which do not contribute to the object motion and contact force. Three subsystem error equations are generated, i.e., position error subsystem, contact force error subsystem, and internal force error subsystem. The adaptive law is derived to estimate the unknown parameters of the multiple coordinated robots, the object, and the environment in terms of the three error subsystem equations. The convergence of the position, contact, internal force errors, and parameter errors is analyzed based on the Lyapunov stability theory. The paper shows that the adaptive control scheme improves the position, and the internal and contact force tracking accuracy for a class of robotic systems with uncertain knowledge of the dynamic model.

scholarly journals Hybrid velocity/force control for robot navigation in compliant unknown environments

Robotica ◽  
2006 ◽  
Vol 24 (6) ◽  
pp. 745-758 ◽  
Author(s):  
Dushyant Palejiya ◽  
Herbert G. Tanner
Keyword(s):  
Lyapunov Functions ◽  
Closed Loop ◽  
Position Control ◽  
Dynamic Control ◽  
Control Law ◽  
Closed Loop System ◽  
Multiple Lyapunov Functions ◽  
Unknown Environments ◽  
Control Scheme ◽  
Novel Method

We combine a “hybrid” force-/position-control scheme with a potential field approach into a novel method for collision recovery and navigation in unknown environments. It can be implemented both on manipulators and mobile robots. The use of force sensors allows us to locally sense the environment and design a dynamic control law. Multiple Lyapunov functions are used to establish asymptotic stability of the closed-loop system. The switching conditions and stability criteria are established under reasonable assumptions on the type of obstacles present in the environment. Extensive simulation results are presented to illustrate the system behavior under the designed control scheme, and verify its stability, collision recovery, and navigation properties.

Force Tracking of Pneumatic Servo Systems Using On/Off Solenoid Valves Based on a Greedy Control Scheme

2011 ◽  
Vol 133 (5) ◽  
Author(s):  
Minh Quyen Le ◽  
Minh Tu Pham ◽  
Richard Moreau ◽  
Jean Pierre Simon ◽  
Tanneguy Redarce
Keyword(s):  
Steady State ◽  
Flow Rate ◽  
Control Law ◽  
Tracking Problem ◽  
Pwm Control ◽  
Control Vector ◽  
Servo Systems ◽  
New Approach ◽  
Control Scheme ◽  
Force Tracking

This paper presents a new predictive greedy control law for the control of electropneumatic systems using solenoid valves. The method is based on a predictive model of the mass flow rate of the valves. For this strategy, a control vector, depending on the number of possible configurations for the solenoid valves, is defined. In order to evaluate the new approach, a comparison has been performed with a classical PWM control for a force tracking problem. The experimental results show that not only the accuracy in steady state but also the dynamic behavior of the pressures is better in the case of greedy control than PWM control.

scholarly journals Adaptive Backstepping Tracking Control for an over–Actuated DP Marine Vessel with Inertia Uncertainties

2018 ◽  
Vol 28 (4) ◽  
pp. 679-693 ◽  
Author(s):  
Anna Witkowska ◽  
Roman Śmierzchalski
Keyword(s):  
Least Squares ◽  
Tracking Control ◽  
Weighted Least Squares ◽  
Evaluation Criteria ◽  
Control Law ◽  
Hydrodynamic Damping ◽  
Control Scheme ◽  
Least Squares Algorithm ◽  
Quadratic Programming Method ◽  
Adaptive Control Law

Abstract Designing a tracking control system for an over-actuated dynamic positioning marine vessel in the case of insufficient information on environmental disturbances, hydrodynamic damping, Coriolis forces and vessel inertia characteristics is considered. The designed adaptive MIMO backstepping control law with control allocation is based on Lyapunov control theory for cascaded systems to guarantee stabilization of the marine vessel position and heading. Forces and torque computed from the adaptive control law are allocated to individual thrusters by employing the quadratic programming method in combination with the cascaded generalized inverse algorithm, the weighted least squares algorithm and the minimal least squares algorithm. The effectiveness of the proposed control scheme is demonstrated by simulations involving a redundant set of actuators. The evaluation criteria include energy consumption, robustness, as well accuracy of tracking during typical vessel operation.

scholarly journals Oriented manifold-based error tracking control for nonholonomic wheeled autonomous vehicles on Lie group for curvilinear approach

2021 ◽  
Vol 3 (6) ◽  
pp. 3608-3626
Author(s):  
Penã Fernández
Keyword(s):  
Autonomous Vehicles ◽  
Tracking Control ◽  
Dynamic Control ◽  
Invariant Subspaces ◽  
Perturbation Approach ◽  
Oriented Manifold ◽  
Trajectory Tracking Control ◽  
Kinematic Constraints ◽  
Control Scheme ◽  
Small Factor

This paper considers the trajectory tracking control of wheeled autonomous vehicles (WAV) with slipping in the wheels, i.e., when the kinematic constraints are not satisfied. Usually, the coordinates system used to represent all control problems suggest invariant subspaces mutually orthogonal, but this  approach can not be enough to treat curvatures significative large at different navigation speed. In order to get a slight im- provement on this topic, there are previous works showing that the kinematic problem (commonly associated with an outer loop) can be resynthesized by using other invariant subspaces, i.e., another representation of the configuration space. For this reason, the proposal reported here uses an oriented-manifold parametrized by a coordinate system on a curve viewpoint of the trajectory to describe the kinematic problem, however, the dynamic control law remains faithful to the singular perturbation approach with invariant subspaces mutually orthogonal, thus, it is possible to include the flexibility through a small factor in the dynamic model (well-known as ε), responsible to avoid the good-performance of the kinematic constraints. Only a common curvature-transformation between orthogonal and curve coordinates will be used to couple both approaches. Finally, it will be observed that when the controller is applied to the control scheme the behavior of the tracking is meaningfully improved.

scholarly journals Position/Force Control of Manipulator in Contact with Flexible Environment

2019 ◽  
Vol 13 (1) ◽  
pp. 16-22 ◽  
Author(s):  
Piotr Gierlak
Keyword(s):  
Neural Networks ◽  
Significant Influence ◽  
Contact Surface ◽  
Force Control ◽  
Tracking Control ◽  
Control Algorithm ◽  
Control Law ◽  
Controlled System ◽  
End Effector ◽  
Control Purpose

Abstract The paper presents the issue position/force control of a manipulator in contact with the flexible environment. It consists of the realisation of manipulator end-effector motion on the environment surface with the simultaneous appliance of desired pressure on the surface. The paper considers the case of a flexible environment when its deformation occurs under the pressure, which has a significant influence on the control purpose realisation. The article presents the model of the controlled system and the problem of tracking control with the use of neural networks. The control algorithm includes contact surface flexibility in order to improve control quality. The article presents the results of numerical simulations, which indicate the correctness of the applied control law.

scholarly journals Underactuated tracking control of underwater vehicles using control moment gyros

2018 ◽  
Vol 15 (1) ◽  
pp. 172988141775075 ◽  
Author(s):  
Ruikun Xu ◽  
Guoyuan Tang ◽  
De Xie ◽  
Daomin Huang ◽  
Lijun Han
Keyword(s):  
Tracking Control ◽  
Control Algorithm ◽  
Underwater Vehicles ◽  
Control Law ◽  
Biologically Inspired ◽  
Trajectory Tracking Control ◽  
Control Moment ◽  
Single Frame ◽  
Control Scheme ◽  
Error Dynamics

This article studies the trajectory tracking control of underactuated underwater vehicles using control moment gyros through a biologically inspired approach based on homeomorphism transformation and Lyapunov functions in the horizontal plane. First, a series of assumptions and simplifications need to be made to build the kinematic and dynamic equations of the underwater vehicle under a single-frame pyramid configuration structured with four control moment gyros. Second, the error dynamics analysis of the submarine based on the control moment gyros is derived from the equations, and a tracking control algorithm is proposed to demonstrate the feasibility and stabilization of this tracking control scheme from theoretical analysis. Finally, the numerical simulation results are given for verifying the effectiveness and feasibility of the rendered control law.

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