Search results for "automatic"
showing 10 items of 730 documents
Racecar Longitudinal Control in Unknown and Highly-Varying Driving Conditions
2020
This paper focuses on racecar longitudinal control with highly-varying driving conditions. The main factors affecting the dynamic behavior of a vehicle, including aerodynamic forces, wheel rolling resistance, traction force resulting from changing tire-road interaction as well as the occurrence of sudden wind gusts or the presence of persistent winds, are considered and assumed to have unknown models. By exploiting the theory on delayed input-state observers and using measurement data about the vehicle and wheel speeds, a dynamic filter that allows the online reconstruction of the above-mentioned unknown time-varying quantities is derived. Moreover, by exploiting the notion of effective tir…
Input-Output Feedback Linearization Control of Linear Induction Motors Including the dynamic End-Effects
2014
This paper proposes the theoretical framework and the consequent application of the input-output feedback linearization (FL) control technique to linear induction motors (LIM). LIM, additionally to RIM, presents other strong non-linearities caused by the dynamic end effects, leading to a space-vector dynamic model with time-varying inductance and resistance terms and a braking force term. This paper, starting from a recently developed dynamic model of the LIM taking into consideration its end effects, defines a FL technique suited for LIMs, since it inherently considers its dynamic end effects. The proposed approach has been validated experimentally on a suitably developed test set-up. Furt…
Computer-assisted orientation and drawing of archaeological pottery.
2018
Archaeologists spend considerable time orienting and drawing ceramic fragments by hand for documentation, to infer their manufacture, the nature of the discovery site and its chronology, and to develop hypotheses about commercial and cultural exchanges, social organisation, resource exploitation, and taphonomic processes. This study presents a survey of existing solutions to the time-consuming problem of orienting and drawing pottery fragments. Orientation is based on the 3D geometry of pottery models, which can now be acquired in minutes with low-cost 3D scanners. Several methods are presented: they are based on normal vectors, or circle fittings, or profile fittings. All these methods see…
Integrating DSS in public transportation monitoring systems
2010
Abstract Decision Support Systems (DSS) ensure the computer-based support for the conscientious decision-making in solving problems that require a large amount of information processing and complex scenarios. DSS for Transportation (DSST) are intelligent systems that are used at operational and organizational management levels. Operating a DSST in a public transportation web-based monitoring system is presented in this paper.
A multi-sensor multi-rate algorithm for motor rehabilitation with Augmented Reality devices
2016
Using Augmented Reality (AR) could offer stimuli to rehabilitation from neuro-motor disorders, since the patient can be aided in a better known reality than Virtual Reality (VR). The main goal for an AR system is to achieve a good quality of tracking the real object to align with virtual contents. Often a single sensor could not provide enough information to that end due to a low updating rate; therefore joining an other high updating rate sensor could be indispensable, but how to combine data from different sensors especially when they work all at different rates? In this paper an approach based on recursive parameter estimation, focusing on multi-rate tracking in AR devices is suggested. …
Motion Control of Four-Wheel Independently Actuated Electric Ground Vehicles considering Tire Force Saturations
2013
A vehicle stability control approach for four-wheel independently actuated (FWIA) electric vehicles is presented. The proposed control method consists of a higher-level controller and a lower-level controller. An adaptive control-based higher-level controller is designed to yield the vehicle virtual control efforts to track the desired vehicle motions due to the possible modeling inaccuracies and parametric uncertainties. The lower-level controller considering tire force saturation is given to allocate the required control efforts to the four in-wheel motors for providing the desired tire forces. An analytic method is given to distribute the high-level control efforts, without using the num…
A Laboratory Project for Advanced Control Methods: Control of a Neutralization Process
2003
Abstract A neutralization process is used in a laboratory project for experimenting advanced control techniques. Students may choose among several techniques to experience the behaviour of advanced controller action: adaptive control, GMG control, fuzzy control, self tuning fuzzy control, neural control, neuro-fuzzy control. The experience in advanced self tuning controller based on fuzzy logic is proposed for the control of a neutralization process. The test of a self tuning controller based on fuzzy logic is a very important case because the resulting structure of the controller is easy to implement and modify: the final results are compared with those deriving from the application of a c…
An adaptive control law for robotic manipulator without velocity feedback
2003
In this paper, a new adaptive control law is designed for robotic manipulators, based on the use of reference velocities instead of the actual ones and feedback signals generated from position errors. The law in question is suitable for trajectory tracking and positioning tasks. Its peculiarities are implementation without velocity measurements and estimation, high signal-to-noise ratio in control torques and absence of parameter drift in positioning tasks. Experimental tests are shown with the aim to confirm the validity of the control law and to illustrate its actual effects on the behaviour of the system.
Globally convergent adaptive and robust control of robotic manipulators for trajectory tracking
2004
This paper deals with a globally convergent adaptive and robust control of robotic manipulators for trajectory tracking in the presence of friction modelled as static nonlinearities. Two control loops are designed according to the cascade control scheme: (a) an inner adaptive control loop, which includes computed torque and PD control actions and friction compensation and (b) an outer robust control loop for unmodelled dynamics compensation. With reference to item (a), two friction compensation schemes are presented; one of them uses both the reference and the actual velocities, whereas the other employs only the actual velocity. Experimental tests carried out on a two-link SCARA manipulato…
A CONTROL LAW FOR ROBOTIC MANIPULATORS BASED ON A FILTERED SIGNAL TO GENERATE PD ACTION AND VELOCITY ESTIMATES
2007
This paper deals with an adaptive control law for robotic manipulators based on a filtered signal to generate both the PD action and velocity estimates of the joints, suitable for trajectory tracking tasks, with the particular aim of reducing the harmonic content of the mechanical torques developed at the joints and thus avoiding excitation of unmodelled dynamics and instability. The practical aspects relative to the implementation of the control law are considered as relevant and, consequently, are detailed. In particular, several methods suitable to compute velocity estimates are discussed and compared with the method described in the paper. All of the above methods are illustrated by mea…