Presents a dynamical friction model structure which allows accurate modeling both in the sliding and presliding regimes. Transition between these two regimes is accomplished without switching function. The incorporates hysteresis function with nonlocal memory arbitrary transition curves. These last aspects prove essential for that encountered real physical situations. as whole can also handle Stribeck effect stick-slip behavior has been demonstrated by validation on KUKA IR 361 robot. In...

This paper discusses experimental robot identification based on a statistical framework. It presents new approach toward the design of optimal excitation trajectories, and formulates maximum-likelihood estimation dynamic model parameters. The differences between existing approaches lie in parameterization trajectory optimization criterion. for each joint is finite Fourier series. guarantees periodic which advantageous because it allows: 1) time-domain data averaging; 2) characteristics...

A novel, multistate friction model is presented, which obtained from the Maxwell-slip by replacing usual Coulomb law at slip a rate-state law. The form of latter state equations arrived comparison with recently developed generic as well limiting behavior cases. particularly suitable for quick simulation and control purposes, being both easy to implement high fidelity. This communication situates model, outlining its development background structure, highlights basic characteristics.

This paper focuses on time-optimal path tracking, a subproblem in motion planning of robot systems. Through nonlinear change variables, the tracking problem is transformed here into convex optimal control with single state. Various convexity-preserving extension are introduced, resulting versatile approach for tracking. A direct transcription method presented that reduces finding globally trajectory to solving second-order cone program using robust numerical algorithms freely available....

The use of periodic excitation is the key feature presented robot identification method. Periodic allows us to integrate experiment design, signal processing, and parameter estimation. This integration simplifies procedure yields accurate models. Experimental results on an industrial manipulator show that estimated dynamic model can accurately predict actuator torques for a given motion. Accurate torque prediction fundamental requirement models are used offline programming, task...

This note presents a modification of the integrated friction model structure proposed by Swevers et al. (2000), called Leuven model. The allows accurate modeling both in presliding and sliding regimes without use switching function. incorporates hysteresis function with nonlocal memory arbitrary transition curves. two modifications A first overcomes recently detected shortcoming original model: discontinuity force which occurs during certain transitions presliding. second modification, using...

Uncompensated friction forces compromise the positioning and tracking accuracy of motion systems. A unique error known as quadrant glitch is result complex nonlinear behavior at reversal or near-zero velocity. Linear-feedback control strategies such PID, cascade P/PI, state-feedback have to be extended with model- nonmodel-based friction-compensation acquire sufficiently high path accuracy. This paper analyzes validates experimentally three different for a linear motor-based <i...

This brief presents a data-driven constrained norm-optimal iterative learning control framework for linear time-invariant systems that applies to both tracking and point-to-point motion problems. The key contribution of this is the estimation system's impulse response using input/output measurements from previous iterations, hereby eliminating time-consuming identification experiments. estimated used in controller, where actuator limitations can be formulated as inequality constraints....

SUMMARY This paper presents synthesis conditions for the design of gain‐scheduled dynamic output feedback controllers discrete‐time linear parameter‐varying systems. The state‐space matrix representation plant and controller can have a homogeneous polynomial dependency arbitrary degree on scheduling parameter. As an immediate extension, multiobjective ℋ︁ ∞ 2 are also provided. parameters vary inside polytope assumed to be priori unknown, but measured in real‐time. If bounds rate parameter...

Under the increasing demand for more accurate high-performance motion systems, various friction models appropriate control purpose of mechanical systems have been proposed. Most these formulate a heuristic dynamical model based on few observed typical properties (e.g. Stribeck curve constant velocities and hysteresis behaviour in presliding regime). This paper presents novel model, called generalized Maxwell-slip (GMS) purpose, physically motivated i.e. generic which simulates contact...

Friction modeling has been steadily gaining in interest over the last two decades. Despite persistent and painstaking efforts, however, no satisfactory, comprehensive, practicable friction model that captures all of experimentally observed aspects force dynamics one formulation is available. comprises multiscale processes requiring theories. This article presents an example comprehensive building, which, starting from generic mechanisms behind friction, leads to construction a explains...

This paper describes a new feedforward algorithm for accurate tracking control of nonminimal phase systems. Accurate calculation involves prefilter design using the inverse system model. Nonminimal systems cause problems with this design, because unstable zeros become poles in The zero error (ZPETC) consists substitution scheme, which removes zeros. scheme introduces small gain error, increases frequency, but no error. investigates additional properties give more insight into ZPETC...

Time-optimal path following considers the problem of moving along a predetermined geometric in minimum time. In case robotic manipulator with simplified constraints, convex reformulation this optimal control has been derived previously. However, many applications robotics feature constraints such as velocity-dependent torque or rate that destroy convexity. The present paper proposes an efficient sequential programming (SCP) approach to solve corresponding nonconvex problems by writing...

This paper extends a recently developed interpolation-based approach to design gain-scheduled controllers for linear parameter-varying systems with thorough evaluation, comprising both simulations and experiments, on an overhead crane system. In the first step of approach, time-invariant are designed local working conditions system using multiobjective <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex...

This technical note presents an approach to deal with model uncertainty in iterative learning control (ILC). Model generally degrades the performance of conventional algorithms. To this problem, a robust worst-case norm-optimal ILC design is introduced. The problem reformulated as convex optimization which can be solved efficiently. also shows that proposed equivalent trial-varying parameters; accordingly, tradeoff between robustness and convergence speed analyzed.