A hardware and software architecture suitable for a safety-critical steer-by-wire systems is presented. The architecture supports three major failure modes and features several safety protocols and mechanisms. Failures due to component failures, software errors, and human errors are handled by the architecture and safety protocols. A test implementation using replicated communication channels, controllers, sensors, and actuators has been performed. The test implementation uses the CAN protocol, Motorola S12 microcontrollers, and Microchip MCP250XX components with a steering wheel and road wheel simulator. The focus of the paper is on the application level, using system engineering principles which incorporate a holistic approach to achieve safety at various levels.

This paper describes the design of a drive-by-wire system for a commercial lift truck using the FlexCAN communication architecture. FlexCAN is a recently developed architecture based on the CAN protocol to support deterministic and safety-critical applications. The main features of FlexCAN are its simplicity and ready implementation based on COTS CAN components. The main steer-by-wire design tasks are listed and a description of how each of the tasks was accomplished using the FlexCAN architecture is detailed. A performance evaluation of the design is included.

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The theory of experiential learning is briefly reviewed and a model of the learning process is presented. The paper then discusses and characterizes a virtual learning environment and its relationship to experiential learning and learning styles. An approach for designing virtual learning environments is presented taking into account the technology for learning. A prototype for a virtual learning environment designed and built by the author and known as LeProf is then discussed along with its application in the design of an educational site for learning electrical circuits.