Every robot out there needs some way to create, store and maintain motions. In this article, we discuss an elegant and simple solution to that problem i.e. the linear actuators.
Robots of different size, complexity and function can be found everywhere around us. They are manufacturing goods at factories, assembling everything from cars to toys, performing tasks too dangerous or too mundane for a human being. Yet there is one thing common to all of them – they use some sort of actuators.
A robot without an actuator is akin to a car without an engine (in fact, the function of actuators and engines is also similar). It’s actuators that allow robots to move their appendages, perform rotational movements, interact with physical objects, and much more.
Types of Different Linear Actuators
There are several types of actuators currently in common usage. Some of them are outdated and slowly disappearing from use, though.
The oldest actuators currently in usage, use pressurized air (or some other gas) to generate operating energy. They gradually being replaced by other actuator types, as the pneumatic type is unwieldy and require more maintenance than other options.
The most common option used nowadays, which uses electricity. More compact, more reliable and safer that pneumatic actuators. Due to the smaller size and good price-quality ratio, electric actuators are the main option for robotics.
The newest, but the most pricey actuators available, they use piezoelectricity (a phenomenon of electric polarization of certain materials under mechanical stress). Very precise, but costs a lot. May be used where that precision is really needed, but usually, it’s better to stick with the electric type.
5 Actuators Ideas For Your Robotics Project
Functioning similarly to our own muscles, this type of actuator consists of a braided mesh tube with its ends clamped, and a clamped balloon inside of it. When the balloon is inflated, it can’t expand along tube’s length, and so it expands radially, creating a pneumatic muscle. The most obvious use of this actuator in robotics is to duplicate the functions of the human muscles – flexing, extending, etc.
This kind of actuator uses an energized electric coil to pull or push an iron rode. Solenoids are widely used in the electric locks (including vehicular ones) and door-bells.
This pneumatic actuator is worth mentioning for its incredible ability to maintain constant movement. Once activated, a pneumatic cylinder requires little to no additional force to be used. As an additional bonus, they’re also pretty durable.
Motor Threaded Rods
Consisting of a drill, a battery, a threaded rod, and some nuts, this actuator is one of the most precise ones out there. Considering you can easily make one yourself, this actuator is great for beginners as well as for those who need a lot of them. The most common usage of such actuator is in 3D printers.
Used for turning the rotational movement into the linear one, a scotch yoke is a simple yet effective addition to any robot that relies on the traditional motors.
Robotics and everything connected to it develops really fast these days, and linear actuators are no exception. But, sometimes, there’s just no need to reinvent the wheel – any of the mechanisms discussed here will do a fair job improving your robotic project.