Important robotic tasks could be most effectively done by powerful and accurate manipulators. However, high accuracy is generally unattainable in manipulators capable of producing high task forces due to such factors as high joint, actuator, and transmission friction and link elastic and geometric distortions. A method called Base Sensor Control (BSC) has been developed to compensate for nonlin...

In prior work of the authors and co-workers, a vision-based system was developed for characterizing the tribological behavior of silicon-micromachined linear microball bearings. Plain difference methods introduce amplitude and/or phase distortion in computing the derivative signals (e.g., velocity and acceleration) based on the position snapshots. In this paper frequency-dependent amplitude and...

In this paper, we provide a broad overview of a number of recent automotive applications in a tutorial fashion where several analytical design tools of the sliding mode control theory were primarily used. The design methods utilized are first discussed from a theoretical point of view in three main categories: online functional optimization, disturbance/state estimation and friction compensatio...

This paper describes a preliminary work devoted to the design of a control architecture for a defective haptic interface, i.e. an underactuated haptic interface not able to apply forces along arbitrary directions. This interface is intended to be used for grasping tasks, where unilateral constraints are usually present. The main control problems considered in this paper concern the study of fri...

We present a new design for a compact stand-alone force and friction microscope. Both the force sensor and the scanning unit are mounted on the microscope head, thus allowing the investigation of virtually all surfaces, independent of thickness and size, and minimizing the geometrical dimension. The beam deflection method in a collinear arrangement is used to detect the normal force and the fri...

INTRODUCTION Precision positioning systems are essential in precision industry. These positioning systems often have one or more elements that introduce friction. Friction is well known to cause steadystate errors and limit cycles, and to slow the motion of the mechanism. Thus, it is important to consider friction compensation in controller design. Simple controllers like PID controllers do not...

Aimed at the problems of low control accuracy and weak robustness influenced by external disturbance, friction, load changes, modeling errors and other issues in ammunition auto-loading robot control system, a new robust adaptive fuzzy sliding mode controller based on fuzzy compensation is proposed. The control architecture employs fuzzy systems to compensate adaptively for plant uncertainties ...

The rolling process is an excellent method for processing new high performance polymers. Skew rolling, as a highly accurate and highly efficient rolling technology, has been commonly used to enhance mechanical properties and productivity. However, the complexity of the mechanics in the skew rolling process of polymers is a significant challenge for manufacturers and researchers. In this work, m...

1. Read the attached two papers (Friedland and Park, 1991 and Yazdizadeh and Khorasani, 1996) on adaptive friction compensation in motion control systems such as simple one-mass systems, robot manipulators etc. Summarize a compensation algorithm step by step for a single mass system (with m = 1) and show clearly which is known/measured, which is to be estimated and which is the tuning parameter...

A direct-drive arm is a mechanical arm in which the shafts of articulared joints are directly coupled to the rotors of motors with high torque. Since the arm does not contain transmission mechanisms between the motors and their loads, the drive system has no backlash, small friction, and high mechanical stiffness, all of which are desirable for fast, accurate, and versatile robots. First, the p...