A Data-Driven Slip Estimation Approach for Effective Braking Control under Varying Road Conditions

The performances of braking control systems for robotic platforms, e.g., assisted and autonomous vehicles, airplanes and drones, are deeply influenced by the road-tire friction experienced during the maneuver. Therefore, the availability of accurate estimation algorithms is of major importance in the development of advanced control schemes. The focus of this paper is on the estimation problem. In particular, a novel estimation algorithm is proposed, based on a multi-layer neural network. The training is based on a synthetic data set, derived from a widely used friction model. The open loop performances of the proposed algorithm are evaluated in a number of simulated scenarios. Moreover, different control schemes are used to test the closed loop scenario, where the estimated optimal slip is used as the set-point. The experimental results and the comparison with a model based baseline show that the proposed approach can provide an effective best slip estimation

Ball Detection and Predictive Ball Following Based on a Stereoscopic Vision System

In this paper we describe an efficient software architecture for object-tracking, based on a stereoscopic vision system, that has been applied to a mobile robot controlled by a PC. After analyzing the epipolar rectification required to correct the original stereo-images, it is described a new valid and efficient algorithm for ball recognition (indeed circle detection) which is able to work in different lighting conditions and in a manner faster than some modified versions of Circle Hough Transform. Then, we show that stereo vision, besides giving an optimum estimation of the 3D position of the object, is useful to remove lots of the false identifications of the ball, thanks to the advantages of epipolar constraint. Finally, we describe a new strategy for ball following, by a mobile robot, which is able to look for the object whenever it comes out of the cameras view, by taking advantage of a block matching method similar to that of MPEG Video

Decentralized controller for the robust stabilization of a class of MIMO dynamical systems

This work deals with the problem of the robust stabilization of a class of multi-input multi-output (MIMO) dynamical systems. A simple decentralized controller is proposed, which reduces to the classical PID controller in case of single-input single-output dynamical systems. Such a controller includes integral actions for the compensation of the entire dynamics of the system. The paper is completed with an application to robotic systems

Hedging point policies remain optimal under limited backlog and inventory space

In this note, we consider a fluid flow, single part-type, single unreliable machine production system with a bounded backlog/inventory space. We prove that, as in the unbounded case, the problem of minimizing an infinite horizon average demand loss/backlog/surplus cost is solved by a hedging point policy. An implicit equation is given, whose structure easily allows to numerically evaluate the optimal safety stock. The effect of system parameters on the optimal safety stock is analyzed and some numerical examples illustrate the presented results

A decentralized controller for the robust stabilization of a class of MIMO dynamical systems

This work deals with the problem of the robust stabilization of a class of multiinput multi-output (MIMO) dynamical systems. A simple decentralized controller is proposed, which reduces to the classical PID controller in case of single-input single-output dynamical systems. Such a controller includes integral actions for the compensation of the entire dynamics of the system. The paper is completed with an application to robotic systems. © 1994 by ASME

A decentralized controller for the robust stabilization of a class of MIMO linear systems

This work deals with the problem of the robust stabilization of a class of minimum phase multi-input multi-output (MIMO) linear systems. A simple decentralized controller has been proposed, including integral actions for the compensation of the entire dynamics of the system. © 1992

Asymptotic stabilization of a class of continuous-time linear periodic systems

In this paper, the problem of the asymptotic stabilization of a class of continuous-time linear periodic systems is considered. First, under a simplifying assumption, necessary conditions, involving the concept of left eigenvector, are derived for the asymptotic stabilization of continuous-time linear periodic systems belonging to such a class. Then, under the same simplifying assumption, conditions are given under which a static state feedback control law can be designed, in an iterative manner, so that the closed-loop system is p-stable

A PID controller for the robust stabilization of SISO linear systems

This work deals with the problem of the robust stabilization of minimum phase single-input single-output (SISO) systems. A PID controller is proposed for their stabilization, under the assumption that the relative degree and the sign of the high frequency gain are known. © 1992