Friction modeling with temperature effects for industrial robot manipulators

Abstract

In this paper we present a new friction model for industrial robot manipulators that takes into account temperature effects. In particular, after having shown that friction might change very significantly during robot operations, two solutions based on a polynomial description of the joint friction are proposed and compared. In both cases the models proposed do not need a measurement of the joint temperature, but just of the environmental temperature, so as to be easily applied in industry. Experimental results demonstrate the effectiveness of the applied methodology

A review of friction models in interacting joints for durability design

“…The focus of several recent researches has been the modelling of friction in manipulators [4][5][6][7][8]. The extended problem also requires the formulation of a suitable control system.…”

On the Inclusion of Temperature in the Friction Model of Industrial Robots

“…One of them is the polynomial form, which is usually able to model the friction term satisfactorily at both low and high velocities, including also the Stribeck effect (Simoni et al, 2015). However, in some cases (as it will be clear in section 3 where we will show the different temperature effects at low and high velocities), it might be useful to expand this relation by adding a term that is able to explicitly consider the Stribeck effect (see (van Geffen, 2009)) in order to better consider the variation during the passage between static and dynamic friction.…”

“…Examples of friction static models are the Coulomb model, in which friction force is constant and it depends on the sign of the velocity, and the viscous model, in which friction force is linearly dependent on the velocity. Other static models are, for example, the Stribeck model, in which an exponential function represents the transition between static friction (friction force when the velocity is zero) and dynamic friction (friction force when the velocity is not zero) or the polynomial one (see (Visioli and Legnani, 2002;Simoni et al, 2015;Legnani et al, 2016)), in which a polynomial function describes the relation between speed of motion and friction force. On the contrary, dynamic models are those in which friction force or torque is dependent on a state function that is able to consider also the history of the system, and not only the actual situation like the static models.…”

“…Recently, the role of the temperature in friction models has been highlighted, as it has been recognized that this is an important issue (Bittencourt and Axelsson, 2014). In particular, modelling strategies that do not require a measurement of the joint temperature have been pursued (Simoni et al, 2015;Carlson et al, 2016) as the use of additional sensors is somewhat impractical in an industrial framework. In this paper we further develop the method already proposed in (Simoni et al, 2015) for a polynomial friction model, by extending it to a more complex friction model that takes into account the Stribeck effect explicitly (by means of an exponential term).…”

“…In particular, modelling strategies that do not require a measurement of the joint temperature have been pursued (Simoni et al, 2015;Carlson et al, 2016) as the use of additional sensors is somewhat impractical in an industrial framework. In this paper we further develop the method already proposed in (Simoni et al, 2015) for a polynomial friction model, by extending it to a more complex friction model that takes into account the Stribeck effect explicitly (by means of an exponential term). In this way, we show that the idea of changing the model parameters linearly with the temperature can be applied in a more general framework, provided that suitable identi-fication experiments are performed.…”