PID Control Of Robot Manipulators Research Articles

Analyzing stability and structural aspects of embedded fuzzy type 2 PID controller for robot manipulators

This study delves into the development and analysis of a novel Embedded Fuzzy Type 2 PID Controller for Robot Manipulators, motivated by the increasing need for enhanced control systems in robotic applications to improve precision and stability. In the background section, the limitations of conventional PID controllers in addressing uncertainties and disturbances, especially in complex tasks performed by robot manipulators, are presented. The concept of fuzzy logic and the Type 2 fuzzy system is introduced, highlighting their potential to manage imprecise and uncertain information. Through rigorous analysis and simulation, the superior performance of the Embedded Fuzzy Type 2 PID Controller is demonstrated when compared to traditional PID controllers and even Type 1 fuzzy controllers. The results showcase enhanced tracking accuracy, disturbance rejection, and adaptability, making it a promising solution for advanced robotic applications. In conclusion, this research provides a robust solution for improving the control of robot manipulators in uncertain and dynamic environments. The Embedded Fuzzy Type 2 PID Controller offers a new paradigm in control theory, ensuring stability and precision even in the face of unpredictable factors. This innovation holds great promise for advancing the capabilities of robotic systems and underlines the potential for further research in embedded fuzzy control systems.

Constrained neural adaptive PID control for robot manipulators

The problem of designing an analytical gain tuning and stable PID controller for nonlinear robotic systems is a long-lasting open challenge. This problem becomes even more intricate if unknown system dynamics and external disturbances are involved. This paper presents a novel adaptive neural-based control design for a robot with incomplete dynamical modeling and facing disturbances based on a simple structured PID-like control. Radial basis function neural networks are used to estimate uncertainties and to determine PID gains through a direct Lyapunov method. The controller is further augmented to provide constrained behavior during system operation, while stability is guaranteed by using a barrier Lyapunov function. The paper provides proof that all signals in the closed-loop system are bounded while the constraints are not violated. Finally, numerical simulations provide a validation of the effectiveness of the reported theoretical developments.

An Adaptive PID Control for Robot Manipulators Under Substantial Payload Variations

Significant payload variations often occur in many practical tasks for robotic applications. But its adequate control is a formidable challenge to control designers, and previous research works have exhibited either limited performance or noticeable difficulties in implementation. In this article, we have proposed an adaptive PID control that is simple, model-free, and robust against payload variations. These advantages, already verified from the adaptive time-delay control (TDC), have been inherited to the proposed PID control through the equivalence relationship between the two controls. As a result, the proposed PID shares the simplicity, robustness, and the model free property, as well as the high levels of stability and performance with the adaptive TDC. In particular, the selection of its gains becomes especially simple and straightforward, while the adaptation becomes efficient under substantial payload variations. These positive attributes have been verified through simulations and experiments on robots under substantial payload variation. In particular, the proposed PID control was applied to the control of a WAM robot holding a baseball bat, with a result better than a standard PID control.

PID control of robot manipulators actuated by BLDC motors

Few control schemes exist for brushless direct-current (BLDC) motors provided with formal global stability proofs. Moreover, most of these works are constrained to control velocity in single motors actuating on simple linear mechanical loads. Inspired by a recent proposal in the literature, we present a control scheme for direct-drive BLDC motors, which is provided with a global stability proof, when actuating on n-degrees of freedom rigid robots. Thus, we solve the position control problem in n direct-drive BLDC when actuating on a complex, nonlinear and highly coupled mechanical load. Another important feature of our proposal is its simple control law when compared to control schemes previously presented in the literature.

Design and simulation of self-tuning fractional order fuzzy PID controller for robotic manipulator

Two-link robotic manipulator system is completely nonlinear and time-varying multi-input-multiple output. In this research, the fractional order fuzzy PID (FOFPID) controller is proposed in order to control the robotic manipulator position. Since real control systems are generally nonlinear systems, therefore, better control of these systems requires the usage of an adaptive or nonlinear controller. So we applied a fuzzy system in order to determine the coefficients of a FOPID controller based on particle swarm optimization (PSO) algorithm. In definition of fitness function for this optimization, we considered integral of absolute error (IAE) and integral of absolute change in controller output (IACCO). Finally, in order to compare this controller with the FPID controller, numerical simulations were performed on the robotic manipulator. The results demonstrate that the overshoot of FOFPID controller is less than the FPID and proposed controller has less oscillations amplitude, totally, its performance is better than the FPID controller.

Design and simulation of self-tuning fractional order fuzzy PID controller for robotic manipulator

Design and simulation of self-tuning fractional order fuzzy PID controller for robotic manipulator

Global PID Control of Robot Manipulators Equipped with PMSMs

AbstractThis paper is concerned with PID position regulation of robot manipulators actuated by permanent magnet synchronous motors (PMSMs). We present a global asymptotic stability proof when the electric dynamics of these actuators is taken into account. Our controller is so simple that it differs from standard field oriented control (SFOC) of PMSMs in only three simple nonlinear terms that have to be added and a nonlinear PID controller which is used instead of a classical PID controller. Thus, our proposal represents the closest result to SFOC of PMSMs provided with a formal global asymptotic stability proof. We present an advancement, if modest, towards presenting a global stability proof for SFOC when used in robotics.

Correction to “Global Asymptotic Saturated PID Control for Robot Manipulators” [Nov 10 1280-1288

Correction to “Global Asymptotic Saturated PID Control for Robot Manipulators” [Nov 10 1280-1288

Passivity-Based Analysis for Partially Variable Nonlinear PID Controller for Robot Manipulators

This paper presents a passivity-based analysis of a PID controller for robot manipulators where a theorem of interconnected passive systems is used to proof that the unique equilibrium of the system in closed loop is asymptotically stable in a global sense. The structure of the PID controller is formed by variable PD gains that improve system performance, allowing getting better transient responses, and a constant I gain. A controller with fixed gains is limited because it is not adaptable to new operation conditions. A system with variable PD gains and constant I gain is better because the gains are selected online and the integral gain avoid the necessity of calculate the gravity forces vector into the control law. As consequence variable PD gains and constant I gain make possible to obtain the most adequate torque output that get better response of the outputs. An evaluation in simulation to verify the theoretical results is realized

A novel PID tuning method for robot control

Purpose– This paper aims to address a new iterative tuning method of PID control for robot manipulators.Design/methodology/approach– This tuning method uses several properties of the robot control, such as any PD control can stabilize a robot in regulation case, the closed-loop system of PID control can be approximated by a linear system, the control torque to the robot manipulator is linearly independent of the robot dynamic.Findings– Compared with the other PID tuning methods, this novel method is simple, systematic, and stable. The transient properties of this PID control are better than the other normal PID controllers.Originality/value– In this paper, a new systematic tuning method for PID control is proposed. The paper applies this method on an upper limb exoskeleton, and real experiment results give validation of our PID tuning method.

Global Stability of a Saturated Nonlinear PID Controller for Robot Manipulators

This paper presents a simple and global stable nonlinear proportional-integral-derivative (N-PID) controller incorporated with a new saturated function design. The new class of saturated function is derived from quasi-natural potential function to shape the position and velocity errors. The coordinate of the saturated function is either in joint space or in Cartesian space, and the function is adjustable by changing the function parameters. The new controller formulation differs from traditional SP-ID control in that a nonlinear velocity (D-) control term is added. The global asymptotic stability of the controlled system is analyzed. Experiments performed on a two-link robot manipulator demonstrate the improved performance of the proposed nonlinear PID controller.

PID control of robot manipulators equipped with brushless DC motors

SUMMARYThis paper is concerned with PID control of rigid robots equipped with brushless DC (BLDC) motors when the electric dynamics of these actuators is taken into account. We show that an adaptive PID controller yields global stability and global convergence to the desired link positions. Moreover, we also show that virtually the PID part of the controller suffices to achieve the reported global results. We present a theoretical justification for the torque control strategy, commonly used in practice to control BLDC motors. Our controller does not require the exact knowledge of neither robot nor actuator parameters.

Semiglobal stability of saturated linear PID control for robot manipulators

This paper addresses the position regulation problem of robot manipulators under control input constraints. It is proven that the robot system under a saturated linear PID control is semiglobally asymptotically stable, if the torque bounds are larger than gravitational torques, and if the proportional gain is large enough and the integral gain is small enough. The stability analysis makes use of singular perturbation tools and the results are illustrated via numerical simulations.

A tuning procedure for stable PID control of robot manipulators

SummaryIn this paper we propose some simple rules for PID tuning of robot manipulators. The procedure suggested requires the knowledge of the structure of the inertia matrix and the gravitational torque vector of the robot dynamics, but only upper bounds on the dynamics parameters are needed. This tuning procedure is extracted from the stability analysis by using a suitable Lyapunov function together with the LaSalle invariance principle. We show that with this guideline, the overall closed-loop system is asymptotically stable. This procedure is illustrated for a two degrees-of-freedom robot