This paper proposes an adaptive control for a class of nonlinear mechanisms with guaranteed transient and steady-state performance. A performance function characterizing the convergence rate, maximum overshoot, error is used output transformation, such that stabilizing transformed system sufficient to achieve tracking original priori prescribed continuously differentiable friction model adopted account nonlinearities, which primary parameters are online updated. novel high-order neural...

For parameter identifications of robot systems, most existing works have focused on the estimation veracity, but few literature are concerned with convergence speed. In this paper, we developed a control/identification scheme to identify unknown kinematic and dynamic parameters enhanced rate. Superior traditional methods, information error was properly integrated into proposed identification algorithm, such that performance achieved. Besides, Newton-Euler (NE) method used build model, where...

Summary This paper studies adaptive parameter estimation and control for nonlinear robotic systems based on errors. A framework to obtain an expression of the error is proposed first by introducing a set auxiliary filtered variables. Then three novel laws driven are presented, where exponential convergence proved under conventional persistent excitation (PE) condition; direct measurement time derivatives system states avoided. The modified via sliding mode technique achieve finite‐time...

Due to strongly coupled nonlinearities of the grasped dual-arm robot and internal forces generated by objects, control with uncertain kinematics dynamics raises a challenging problem. In this paper, an adaptive fuzzy scheme is developed for robot, where approximate Jacobian matrix applied address kinematic control, while decentralized logic controller constructed compensate robotic arms manipulated object. Also, novel finite-time convergence parameter adaptation technique estimation...

Most of the available control schemes for pure-feedback systems are derived based on backstepping technique. On contrary, this paper presents a novel adaptive design nonlinear without using backstepping. By introducing set alternative state variables and corresponding transform, state-feedback system can be viewed as output-feedback canonical system. Consequently, is not necessary previously encountered explosion complexity circular issue also circumvented. To estimate unknown states newly...

This paper proposes an adaptive control for vehicle active suspensions with unknown nonlinearities (e.g., nonlinear springs and piecewise dampers). A prescribed performance function that characterizes the convergence rate, maximum overshoot, steady-state error is incorporated into design to stabilize vertical pitch motions, such both transient suspension response are guaranteed. Moreover, a novel law used achieve precise estimation of essential parameters mass body moment inertia motion),...

This paper presents a new adaptive fuzzy control scheme for active suspension systems subject to input time delay and unknown nonlinear dynamics. First, predictor-based compensation is constructed address the effect of in closed-loop system. Then, logic system (FLS) employed as function approximator nonlinearities. Finally, enhance transient response, novel parameter estimation error-based finite-time (FT) algorithm developed online update FLS weights, which differs from traditional methods,...

In this paper, an approximation-free funnel feedback controller is proposed for a class of nonlinear servomechanisms to achieve prescribed tracking error performance. An improved function guarantee the transient and asymptotic behavior within given boundary. The removes imposed assumption used in conventional controls (e.g., systems with relative degree one or two) avoids potential singularity problem performance controls. Moreover, extended state observer (ESO) address effect unknown...

This paper investigates the path-tracking control issue for autonomous ground vehicles with integral sliding mode (ISMC) considering transient performance improvement. The is converted into yaw stabilization problem, where sideslip-angle compensation adopted to reduce steady-state errors, and then yaw-rate reference generated purpose. lateral velocity roll angle are estimated measurement of rate rate. Three contributions have been made in this paper: first, enhance estimation accuracy...

This paper proposes an adaptive funnel control (FC) scheme for servo mechanisms with unknown dead-zone. To improve the transient and steady-state performance, a modified variable, which relaxes limitation of original FC (e.g., systems relative degree 1 or 2), is developed using tracking error to replace scaling factor. Then, by applying transformation method, transformed into new variable used in controller design. By improved function dynamic surface procedure, proposed guarantee that...

This paper presents a novel control strategy for nonlinear uncertain vehicle active suspension systems without using any function approximators [e.g., neural networks (NNs) or fuzzy logic (FLSs)]. Unlike previous results that neglect the effect of actuator dynamics, this incorporates dynamics hydraulic is used to create required forces into controller design. To address nonlinearities system, an approximation-free method introduced. In method, widely NNs and FLSs are not needed. leads...

Most function approximator (e.g., neural network or fuzzy system) based control designs can only prove uniform ultimate boundedness of the controlled system due to unavoidable approximation errors. Moreover, transient response conventional adaptive may be sluggish because high-gain learning is not preferable for guaranteeing safety. To address these issues, this paper proposes and experimentally validates an alternative robust servo mechanisms with unknown dynamics bounded disturbances. This...

Most of the existing control methods for servo systems driven by hydraulic actuators have been developed using a backstepping scheme and assuming that all system states (including internal signals) are measurable. In this paper, we propose new design method high-order with actuator dynamics, where is avoided only output (e.g., motion displacement) required implementation. For purpose, model first transformed into canonical form, unknown dynamics in lumped as one term. Then, introduce simple...

This article proposes an unknown system dynamics estimator (USDE) based sliding mode control for servo mechanisms with and modeling uncertainties. An invariant manifold is first constructed by introducing auxiliary variable on a first-order low-pass filter. used to design USDE only one tuning parameter (i.e., time constant the filter) simpler structure than other estimators. The compensate effect of lumped since it can be easily incorporated into synthesis. Moreover, avoid chattering...

In this paper, a force sensorless control scheme based on neural networks (NNs) is developed for interaction between robot manipulators and human arms in physical collision. scheme, the trajectory generated by using geometry vector method with Kinect sensor. To comply external torque from environment, paper presents admittance approach joint space an observer approach, which used to estimate torques applied operator. deal tracking problem of uncertain manipulator, adaptive controller...

Although adaptive control design with function approximators, for example, neural networks (NNs) and fuzzy logic systems, has been studied various nonlinear the classical laws derived based on gradient descent algorithm σ-modification or e-modification cannot guarantee parameter estimation convergence. These nonconvergent learning methods may lead to sluggish response in system make tuning complex. The aim of this paper is propose a new strategy driven by error alternative servo systems....

This paper proposes an online adaptive approximate solution for the infinite-horizon optimal tracking control problem of continuous-time nonlinear systems with unknown dynamics. The requirement complete knowledge system dynamics is avoided by employing identifier in conjunction a novel law, such that estimated weights converge to small neighborhood their ideal values. An steady-state controller developed maintain desired performance at steady-state, and designed stabilize error manner. For...

SUMMARY An alternative adaptive control with prescribed performance is proposed to address the output tracking of nonlinear systems a dead zone input. appropriate function that characterizes convergence rate, maximum overshoot, and steady‐state error adopted incorporated into an transformation, thus stabilization transformed system sufficient achieve original performance. The represented as time‐varying Nussbaum‐type functions are utilized deal unknown gain dynamics. A novel high‐order...