Sensors and Actuators

The data which are a result of the sensing and converting of any given state or change of state in temperature, presence of gases, location and so forth usually go from the sensor hub or IoT gateway to the cloud or a datacenter. However, given the described movement to the edge and the increasing functions of IoT gateways and IoT platforms a lot of IoT data processing and preparation (including analysis) can happen close to the devices (the edge) or in the mentioned gateways and platforms.

Actuators in a sense are the opposite of sensors. They receive a signal or feel a force or change of state (in a non-IoT context this can also be a manual actions), which makes them set in motion an operation in the physical world. Examples include the switching on of sprinklers when heat is detected, turning off heating and ventilation systems, triggering a robot to take an action, putting a vibration or location-related correction system in action, anything really. Just as there are many types of sensors, there are many types of actuators for various potential purposes. Actuators are what enable semi-autonomous or autonomous decisions take place in the physical part of the cyber-physical system.

The data received by IoT actuators are digital (electric) in nature and include a control system. The instructions get turned into another type of signal and energy, from switching things on or off, rotations, pressure and so forth. Typically actuators then also report data back so the taken action is known and, combined with other data, can be used for more insights, analysis or simply alerts.

The combination of smart sensors and actuators is what really makes IoT fulfil many real-life applications.