Search results for " robots"
showing 10 items of 63 documents
Hibrid Adaptive/EKF Motion Control and Data Fusion for Ground Vehicles with Kinematical and Dynamical Uncertainties
2006
This paper considers the motion control problem of ground vehicles with nonholonomic constraints and parametric uncertainties both in the kinematic and in the dynamic model. The presence of uncertainties above is treated using adaptation laws where the Lyapunov's stability of the position and orientation errors is proved. Now, if the feedback signals are position and orientation provided by incremental encoders only, then noises of the odometric sensors above can damage the control in terms of difference between the desired and the actual motion of the vehicle and in terms of performances of the parametric adaptation. So an extended Kalman's filter (EKF) is inserted in the feedback for meas…
Noised Trajectory tracking Control based on Fuzzy Lyapunov approach for Wheeled Vehicles
2005
This paper solves a trajectory tracking control problem whit outside perturbations for wheeled nonholonomic vehicles using a Fuzzy Lyapunov method. Trough a symbiosis between classical backstepping techniques and fuzzy logic, the control system ensures a good robustness with respect to outside perturbations. Possible causes of perturbations are the characteristics of the ground and the contact between the wheels and the ground. These perturbations can interact with the vehicle, they are sources of uncertainty for the system model and can perturb the validity of the nonholonomic constraints. The convergence of the tracking errors to the origin and the asymptotic stability of the equilibrium …
Do robots complement or substitute for older workers?
2021
Abstract The impact of robotization on labor market outcomes has been recently empirically investigated along several directions, including employment, wages and labor productivity. This work contributes to this literature by looking for heterogeneous effects of robots on the workforce, analyzed by age cohorts. Relying on a panel of data from IFR (2019) and EU KLEMS (2009) over the years 1994–2005, we find consistent evidence of higher complementarity between robots and older workers (hours worked by employees aged 50 and over), and a greater substitutability among robots and younger cohorts of the labor market. These findings are robust to age group disaggregation and specific capital pric…
Are robots in rich countries a threat for employment in emerging economies?
2022
The effects of robotization on labor market outcomes have been widely investigated within developed countries. Conversely, few studies have tried to assess how automation in advanced economies affects less industrialized countries. In this work, we analyze the impact of robotization in a group of developed European countries (EU15) on employment dynamics in a country-industry panel data of emerging markets. Our findings indicate that EU15 robotization is associated with a decline of sectoral employment in emerging economies, especially in Asia, tradable and more robotized industries. Ultimately, a small set of major European countries - namely, Germany, Italy, Denmark and United Kingdom - s…
Robot Shift from Industrial Production to Social Reproduction
2015
This chapter analyses people’s attitudes towards the use of robots in the different domains of life and, specifically, in the domain of social reproduction. The analysis is based on Eurobarometer 382 “Public Attitudes towards Robots” data (N = 26,751), which was carried out among EU citizens aged 15 and over in 27 member states in 2012. The results of the study show that on average European perceptions of robots are positive and permissive. The life domains in which robots have already been used for a long time (e.g. space exploration, manufacturing, military and security business, search and rescue work) turn out to be the most popular areas for the further penetration of robots. The least…
On-line adaptive neural network in very remote control system
2006
Remote control involves several issues that degrade seriously the performance of the plant to be controlled. This paper presents a strategy improving the characteristics of the remote control system, using an on-line adaptive neural net, in order to learn the variations of the remote system parameters to minimize the errors. This strategy is successfully applied to a client-server remote control system for a two link robot arm. Tests show that an error position in a remote control brushless motor can be highly reduced since its first "reference command" using a prevision of that error to modify the original reference. The neural net, used only by the client, is previously trained using loca…
Fuzzy Adaptive EKF Motion Control for Nonholonomic and Underactuated Cars with Parametric and non Parametric Uncertainties
2007
A new fuzzy adaptive motion control system including on-line extended Kalman''s filter (EKF) for wheeled underactuated cars with non-holonomic constraints on the motion is presented. The presence of parametric uncertainties in the kinematics and in the dynamics is treated using suitable differential adaptation laws. We merge adaptive control with fuzzy inference system. By using fuzzy system, the parameters of the kinematical controller are functions of the lateral, longitudinal and orientation errors of the motion. In this way we have a robust control system where the dynamics of the motion errors is with lower time response than the adaptive control without fuzzy. Also Lyapunov''s stabili…
Assistive robotic walker parameter identification for estimation of human thrust without force sensors
2017
In this paper we propose a parameter identification procedure for the wheel-motor dynamic of a robotic walker, i.e. a commercial trolley for elderly people endowed with cognitive, sensing and guidance capabilities. The objective of the wheel-motor dynamic model is to generate a suitable time reference to be used in an estimation algorithm. The ultimate goal of the estimation algorithm is to retrieve the thrust, i.e. torque and force, that the older adult user of the robotic walker applies to the platform. These quantities are of paramount importance in order to adopt intelligent and comfortable walker guidance algorithms. The novelty of this approach is the avoidance of additional costly se…
Social networks and robot companions: Technology, ethics, and science fiction
2019
Information technologies have become part of our everyday lives and are increasingly acting as intermediaries in our workplaces and personal relationships or even substituting them. This growing interaction with machines poses several questions about which we have no previous experience, nor can we reliably predict how they will influence the evolution of society. This has led to the convergence of technoscience and humanities in an ethical debate that is starting to bear fruit, not only with the setting of regulations and standards, but also with educational initiatives in university teaching, professional improvement, and the conformation of public opinion. Interestingly, science fiction …
Compensation of compliance errors in parallel manipulators composed of non-perfect kinematic chains
2012
The paper is devoted to the compliance errors compensation for parallel manipulators under external loading. Proposed approach is based on the non-linear stiffness modeling and reduces to a proper adjusting of a target trajectory. In contrast to previous works, in addition to compliance errors caused by machining forces, the problem of assembling errors caused by inaccuracy in the kinematic chains is considered. The advantages and practical significance of the proposed approach are illustrated by examples that deal with groove milling with Orthoglide manipulator.