M3S system prototype - a comprehensive system with straightforward implementation

There is a growing demand for powered wheelchairs to provide mobility for people with upper-limb impairments, i.e., individuals suffering from cerebral palsy, paraplegia, or multiple sclerosis, and others who may depend on a human-friendly wheelchair to conduct their daily activities. The design of the multiple master multiple slave ("M3S") architecture provides a flexible system in which individual devices can be added or removed to accommodate specific needs. The M3S provides a two-level safety system for each device. The two levels are a central safety monitor and the two independent wired-OR safety lines connected to each device on the bus, and the system is configured such that in the event of failure, system shutdown can be independently enabled at each separate safety level. We have implemented a prototype with DSP cores and additional circuitries that provide safety enhancements to the M3S protocol, and configured the input subsystems and output prime mover to fit into this novel system.