13 research outputs found
User-Centric Future Internet and Telecommunication Services
This paper analyses the current service creation trends in telco and
Web worlds, showing how they are converging towards a future Internet of usercentric
services embracing typical telco capabilities. The OPUCE platform is
presented as the next step towards this integrated, user-centric future: a platform
which offers intuitive tools for graphical service creation aimed at individuals
with no specific skills in computer science or programming and a serviceoriented
execution environment capable of a seamless interoperation of Web
Services and telco applications based on operator-owned infrastructure. The
OPUCE platform is compared to existing mashup creation tools to show its
advantages and how is compared to existing mashup creation tools to show its
advantages and how it could be used to implement a converged and open service
marketplace for the Future Internet
Service Discovery Suite for User-Centric Service Creation
Two emerging trends are impacting the CIT world: service
orientation and user centricity. The OPUCE project aims at
developing a platform to mix together both philosophies into an
environment where end-users are capable of building highly
personalized services integrating Information Technologies and
communication capabilities. Such a platform has the potential to
become an open marketplace in order for telco operators to
implement innovative business models, and as such imposes
specific requirements over the discovery mechanisms to help users
locate services fitting their needs. This paper presents the
discovery suite implemented in the OPUCE platform
Automatic Steering of Vehicles Involving Feedforward of the Estimated Track Curvature
Automatic track guiding of vehicles is of increasing interest for Intelligent Vehicle/ Highway Systems [1--3]. Track guided vehicles are used in automated production facilities, ship docks, and for city busses which drive in special narrow lanes. The primary task of such a system is to follow a path as well as possible. Track guiding systems have been designed for various controller structures [4--8]. In the present paper it will be shown how to follow a given path error-free under some idealistic assumptions by feedforward of the estimated curvature of the reference path. For practical use this concept is not directly applicable, mainly due to unknown plant parameters and limited actuator force. However, a modified control concept based on this result yields good performance under realistic conditions. 1 Model of the Steering Dynamics The 2-wheel single-track model by Riekert-Schunck [9] is used to obtain a mathematical description of the vehicle dynamics. A schematic representation o..
Robust Yaw Damping of Cars with Front and Rear Wheel Steering
For a linear model of active car steering a robust decoupling control law by feedback of the yaw rate to front wheel steering was derived earlier. In the present paper this control law is extended by feedback of the yaw rate to rear wheel steering. A controller structure with one free damping parameter kD is derived with the following properties: i) Damping and natural frequency of the yaw mode are independent of speed. ii kD can be adjusted to the desired damping level. iii) A variation of kD has no influence on the natural frequency of the yaw mode and no influence on the steering transfer function by which the driver keeps the car --- considered as a mass point at the front axle --- on his planned path. Simulations with a nonlinear car steering model show significant safety advantages of the new control concept in situations when the driver of the conventional car has to stabilize unexpected yaw motions. I Introduction Recently several car manufacturers (Nissan, Honda, Mazda, Mitsu..
Robust Control Goes PARADISE
This paper presents a new toolbox for robust control design and analysis. 1 Introduction The basis of robust control as it is considered in this paper is a physically motivated model of the plant, where the plant parameters q = [q 1 q 2 . . . q # ] T enter into the system description. The dependency of the system description on the uncertain parameters may be arbitrary, e.g. also nonlinear parameter dependency is possible. In general, the uncertain parameters are independent of each other and lie between upper and lower bounds. The uncertainty domain Q := {q| q i # [q - i ; q + i ], i = 1, 2, . . . , #} is then a hyperrectangle. As an example consider a model of a vehicle for automotive control, where the important parameters are load mL , velocity v, and road adhesion factor µ. All these parameters vary in given bounds. A system description, e.g. the linearized state space model, depends on these operating parameters [mL v µ] T . For details on parametric modelling and ..
Robust Automatic Steering Of A Bus
Introduction Automatic steering of cars is of practical interest, e.g. for transport vehicles in factories and ship docks, for busses on separate, narrow (i.e. cheap) lanes, and in the future as part of an integrated system of automated highway traffic. It is assumed that the vehicle has a displacement sensor measuring the lateral distance from a reference guideline in the road. This reference may consist of the magnetic field from an electrically supplied wire or from permanent magnets in the road. The sensor is mounted in the center of the front end of the vehicle. The displacement signal is fed back through a compensator to the actuator for the steering angle. The primary task of this control loop is to track the guideline, i.e. to keep the displacement small. Typical reference maneuvers are ffl transition from a straight line into a circle, ffl entering into a narrow bus stop bay, ffl transition from manual to automatic o
Robust automatic steering control for look-down reference systems with front and rear sensors
This paper describes a robust control design for automatic steering of passenger cars. Previous studies [l-3] showed that' reliable automatic driving at highway speed may not be achieved under practical conditions with look-down reference systems which use only one sensor at the front bumper to measure the lateral displacement of the vehicle from the lane reference. An additional lateral displacement. sensor is added here at the tail bumper to solve the automatic steering control problem. The control design is performed stepwise: First, an initial controller is determined using the parameter space approach in an invariance plane. This controller is then refined to accommodate practical constraints and finally optimized using the multi-objective optimization program MOPS. The performance and robustness of the final controller was verified experimentally at California PATH in a series of test runs
Robust Automatic Steering Control for Look-down Reference Systems with Front and Rear Sensors
This paper describes a robust control design for automatic steering of passenger cars. Previous studies [1--3] showed that reliable automatic driving at highway speed may not be achieved under practical conditions with look-down reference systems which use only one sensor at the front bumper to measure the lateral displacement of the vehicle from the lane reference. An additional lateral displacement sensor is added here at the tail bumper to solve the automatic steering control problem. The control design is performed stepwise: First, an initial controller is determined using the parameter space approach in an invariance plane. This controller is then refined to accommodate practical constraints and finally optimized using the multi-objective optimization program MOPS. The performance and robustness of the final controller was verified experimentally at California Path in a series of test runs. Keywords: Automotive, Robust Control, Automatic Steering I. Introduction Automatic ste..