Showing papers by "Giuseppe Buja published in 2010"

Dependable design assessment of Integrated Power Systems for All Electric Ships

Abstract: For future All Electric Ships (AESs), setting up of a dependable Integrated Power System (IPS) requires a dedicated design procedure, more articulated than the traditional ones. As a matter of fact, traditional procedures need to be revised and supplemented using an appropriate approach in order to make the IPS dependable. Such an approach should bear in mind the recently formalized dependability theory and exploit the so-called enforcing techniques (fault prevention, fault tolerance, fault removal, fault forecasting). The aim of this paper is to introduce the basic terminology and formal methods of the dependability theory into the traditional design steps of an IPS for large AESs. Basic guidelines are given to conceptually determine how to proceed in the design of future dependable IPSs.

A distributed driving and steering system for electric vehicles using rotary-linear motors

Abstract: The paper presents the activities ongoing in the framework of a two-year Italian National Research Project aimed at developing a distributed Driving and Steering (DaS) system for Electric Vehicles (EVs). The system is built up around an actuation module embedding a rotary-linear motor and including a power converter and a local Electronic Control Unit (ECU) to supply and control the motor. The actuation module is intended to make a wheel active so as to give it propelling and steering capabilities. The DaS system, in turn, includes a central ECU and a fieldbus to govern and network the system, and a power supply stage. The Project under consideration is focused on a DaS system with two active wheels for a light-duty EV.

Propulsion systems for Light Electric Vehicles

Abstract: The paper is concerned with the development of the propulsion system for two Light Electric Vehicles (LEVs), namely a city scooter and an electric bicycle. The propulsion system of the city scooter consists of a wheel motor for the traction and a lithium-ion battery for the energy storage. The propulsion system of the electric bicycle utilizes a fuel cell assisted by a supercapacitor bank for the energy supply.

A high-performance application protocol for fault-tolerant CAN networks

Abstract: CAN is a communication protocol largely used in automotive and industrial appliances because of the simple procedure for its parameterization and the low cost of its circuitry. The native CAN, however, does not assure the fault-tolerance level required by safety-critical appliances and somewhat sophisticated protocols have been introduced for their networking. In an attempt to keep on the advantages of CAN, several application protocols have been developed to supplement the native CAN with the aim of giving the CAN networks safety features. This paper continues such a research trend by proposing a CAN application protocol termed time-triggered bus-redundant CAN (TTBR-CAN) that outdoes the performance of the existing ones. After describing the architecture of TTBR-CAN, details are given on its implementation and experimental results are reported to demonstrate its effectiveness.

Control-oriented analysis of a distributed steering apparatus

Abstract: The paper is concerned with a vehicle where each front wheel is equipped with a steering equipment. Aim of the paper is to analyze the behavior of the resulting driving apparatus during the steering maneuver in order to subsequently develop a suitable control system. The analysis is carried out in two stages, termed kinematic and dynamic. The kinematic analysis describes the steering maneuver when no lateral forces are exerted on the vehicle whilst the dynamic analysis accounts for them. The study has been carried out by an analytical approach and has been documented by simulation. As a case study, a minicar is considered.

Application protocols for safety-critical CAN-networked systems

Abstract: In the industrial and automotive appliances, distributed systems are more and more frequently used. They require the coordinate action of several units for the systems to operate correctly. Therefore the units must exchange each other information on their activities and this is done through serial communication networks. CAN is a simple protocol that rules the operation of these networks. However, the native CAN does not have such features like determinism and fault tolerance, which are required by safety-critical appliances. To get round of the CAN limitations, there are two solutions, namely the recourse to the so-called time-triggered (TT) protocols or the supplement of the native CAN with ad-hoc developed application protocols. After reviewing the CAN limitations, the paper discusses at first the TT protocols and then the application protocols enhancing determinism and fault tolerance of the CAN networks. At last, a novel CAN application protocol that outperforms the existing ones is outlined.