Practical Design of Electronic Emergency Stop Devices for Machine Safety

A variety of safety protective devices (SPDs) are currently available on the machinery safety market. SPD complexity and cost depend on the safety feature implemented as required for a specific piece of machinery in its working environment. However, one type of inexpensive SPD is mandatory for many types of machines: the emergency stop device (ESD). This paper introduces a novel ESD recently developed by the authors. This electronic ESD is capable of automatically performing emergency stop actions as commanded by a suitable external supervisory safety system connected to it, which may replace or reinforce the human action expected for the provision of safety. In addition, the device allows integration with any emergency stop circuit already designed for machinery by means of configurable features. Both practical design and implementation issues are discussed in detail through a fully exemplified concept-design-prototype-validation procedure.