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This article discusses the design and implementation aspects of ACP 245, a telematic communication protocol, in the vehicle location equipment. The ACP 245 is an open protocol created by DENATRAN (National Traffic Department) to meet Resolution No 245 of CONTRAN (National Traffic Council), which made mandatory the use of antitheft equipment in new vehicles coming out of factory, domestic or imported. The Resolution No. 245 initiated a process of adaptation of products and services - within the operational context called SIMRAV (Integrated System for Monitoring and Automatic Vehicle Registry) - outlined by DENATRAN in partnership with automakers, vehicle location equipment manufacturers, SIM Cards manufacturers, monitoring services providers and mobile communication operators among others.

In the recent years the urban transport system known as BRT (Bus Rapid Transit System) is gaining importance due to the growing demands from alternatives to rail systems. However, unlike rail systems, the performance of BRT depends on the driver's ability to perform accurate docking maneuvers on the bus stop platform and to travel in narrow bus lane quickly and safely. In this scenario, the automation of the bus through the technology of automated steering shows up as a viable alternative, with excellent prospect of operational performance improvement. This article shows how sensing technologies (including magnetic and optical), computational intelligence and electromechanical actuator can transform standard bus in automatically guided vehicle. In addition, it discusses the importance of integrating automated vehicle guidance system (AVGS) with Intelligent Transport System (ITS) to increase operational performance and safety of the BRT.

The Magnetic Guidance System - MGS - is a control system, developed in Brazil, for use in urban bus corridors known as “BRT - Bus Rapid Transit Corridors”. MGS technology can be applied to any kind of vehicle and aims to minimize the lane width (thus diminishing the expropriate costs and urban space impact), to raise the transport capacity (through the increase of the average speed) and to improve passenger accessibility (because the MGS stops in a uniform and small distance from the bus platform in a repetitive fashion during all the operation time, procedure known as “Precision Docking”). In the actual stage MGS does the lateral guidance of the vehicle and the human driver controls the speed using the conventional accelerator and brake pedals. When the lateral automatic guidance is active, MGS controls the steering system of the vehicle using a magnetic track as reference (the magnetic track is a sequence of discrete magnets spaced from 1m to 2m in the pavement).

This work presents the lateral vehicle position detection algorithm developed for MGS project (Magnetic Guidance System), which controls the lateral position of a vehicle based on its deviation in relation to a reference magnetic track. Initially, the general requirements which guide the algorithm operation are presented, including constraints imposed by real world. Next, the algorithm's context is described, including the architecture of the system where de algorithm operates, the information supplied to the algorithm and the information got in return. Finally, the algorithm itself is presented in terms of the operations executed over the input data to determine the desired results.

This paper describes the approach used, in accordance with IEC-61508 Standard, to define and allocate the safety requirements of a Magnetic Guidance System applied to urban buses. This paper covers the concept and design activities specific to the system safety lifecycle encompassing the Concept, Overall Scope Definition, Hazard and Risk Analysis, Overall Safety Requirements and Safety Requirements Allocation phases. Highlights of the adopted methodology include the application of the Controllability principle for determining the system risks, and the relevant role played by the FTA (Fault Tree Analysis) technique.