A survey of models, analysis tools and compensation methods for the control of machines with friction

http://cats-fs.rpi.edu/~wenj/ECSE446S06/astrom_friction.pdf

Friction Models and Friction Compensation

A new nonlinear disturbance observer (NDO) for robotic manipulators is derived in this paper. The global exponential stability of the proposed disturbance observer (DO) is guaranteed by selecting design parameters, which depend on the maximum velocity and physical parameters of robotic manipulators. This new observer overcomes the disadvantages of existing DOs, which are designed or analyzed by linear system techniques. It can be applied in robotic manipulators for various purposes such as friction compensation, independent joint control, sensorless torque control and fault diagnosis. The performance of the proposed observer is demonstrated by the friction estimation and compensation for a two-link robotic manipulator. Both simulation and experimental results show the NDO works well.

/pdf/a-nonlinear-disturbance-observer-for-robotic-manipulators-8kcsekd4de.pdf

A nonlinear disturbance observer for robotic manipulators

Ambient energy harvesting has been in recent years the recurring object of a number of research efforts aimed at providing an autonomous solution to the powering of small-scale electronic mobile devices. Among the different solutions, vibration energy harvesting has played a major role due to the almost universal presence of mechanical vibrations. Here we propose a new method based on the exploitation of the dynamical features of stochastic nonlinear oscillators. Such a method is shown to outperform standard linear oscillators and to overcome some of the most severe limitations of present approaches. We demonstrate the superior performances of this method by applying it to piezoelectric energy harvesting from ambient vibration.

/pdf/nonlinear-energy-harvesting-1c9nlmso3f.pdf

Nonlinear energy harvesting.

This chapter will discuss several kinds of sensors and actuators used to determine and control spacecraft attitude [26, 44, 54, 66]. The history of attitude sensor development has emphasized increased resolution and accuracy as well as decreased size, weight, and power (often abbreviated as SWaP). Actuator technologies have also been scaled down to be appropriate for microsatellites and cubesats. We begin with a brief introduction to redundancy considerations, and then consider some specific sensors and actuators.

Sensors and Actuators

Adaptive Friction Compensation with Dynamic Friction Model

Illustrates the application of a model-based friction compensation scheme to an industrial six degrees of freedom Schilling Titan II hydraulic manipulator. The dynamic friction model and the control structure studied in Canudas de Wit et al. (1995) are used as a basis for this work. First, a low level nonlinear torque controller is developed to provide a high bandwidth and performance torque response of the hydraulic actuators. This inner loop controller is based on a nonlinear model of the servovalve and the hydraulic actuator. Friction compensation is then developed. An off line identification method for the estimation of the different friction model parameters is proposed. Then an adaptative friction compensation presented in Canudas de Wit and Lischinsky (1997) is applied to the hydraulic manipulator, assuming that the nominal identified model is suitably structured. Both the torque control capabilities and the friction compensation efficiency are largely illustrated through experimental results.

P. Lischinsky

Papers

Adaptive Friction Compensation with Dynamic Friction Model

Friction compensation of a Schilling hydraulic robot

Tracking control of a induction motor: an output feedback approach