Designer's guide to accelerometers: choices abound

摘要

Also known as inertial sensors, ac-celerometers are critical elements in key applications such as automotive air-bag deployment, smartphone motion tracking, and industrial predictive maintenance. These varying needs have resulted in an even more varied array of accelerator products from which designers can choose. Fortunately, by focusing on a handful of key decisions, developers can quickly zero in on the right kinds of devices for their application.Despite the multitude of options available, accelerometers are all based on the same basic principle: inertia. A proof mass within the accelerometers structure can readily move in at least one dimension. Because of inertia, that proof mass will tend to stay in place when the surrounding structure undergoes acceleration (i.e., changes its motion) along that same direction. Sensing systems within the accelerator detect the proof mass's movement relative to the surrounding structure, and interface circuits deliver a corresponding signal to the outside. A spring of some kind provides a restoring force to return the proof mass to its initial position once the acceleration has ended.