Servo motors also called “servos” or “control motors”, are electrical devices used for the precise control of position, torque, or speed of an object. They can help in rotating or pushing items at a certain angle or distance. This actuation device has been around for quite some time. In fact, servo motors application is something widely practiced in different industries.
Servo Motor Applications
A servo motor can be small but it is packed with capabilities that can make a certain object function more effectively. Projects that require maximum precision rely on this electrical device. For heavier loads, this motor high torque can be used to handle them properly. These versatile servo motors can adjust to any kind of environment. Let’s take a look at some of the surprising uses of servo motors.
You know those cute, sushi trains you see on Japanese restaurants? They use servo motors. Due to lack of staff, Yoshiaki Shiraishi developed a sushi train to be able to serve sushi straight to customers. Sushi trains are made with a conveyor belt. The ability of a servo to deliver perfect repeatability of motion serves a great purpose in sushi trains.
Those who are seeking an adventure will love escape rooms. You and your friends will have to complete a mission for you to literally “escape”. The doors are installed with a servo motor controller that will only open if your team is able to solve the puzzle. Props and supplies as well as other interactive parts of the game also use servo motors.
We usually see these doors in business centers, shopping malls, and other commercial establishments. It’s not magic but they operate through servo motors. How? Automated doors have infrared sensors that detect the presence of an individual. The data collected through the infrared sensors are sent to the motors which in turn open the door.
Whatever remote-controlled toy or object it may be, it is guaranteed to be equipped with a servo motor. A user controls the toy using a transmitter which sends a signal through radio waves. The signal is then sent to the toy through an antenna and circuit board. Upon receipt of these signals, the motors then steer the wheels in a toy car, operate the toy helicopter’s propellers, or do whatever the command is.
Advanced cameras like Canon or Nikon use servo motors for their auto-focus feature. You can see the feature “AF Servo” in some digital cameras. Based on the camera’s settings, autofocus allows photographers to capture perfect images even if the subject is moving. The servo motors are programmed with an intelligent algorithm. With just one click, it looks for angles that deliver great focus in auto mode. This is most helpful for photographers focused on sports or wildlife.
Super High-Tech Fashion
Perhaps the most interesting in this list, servo motors prove that its application is sometimes beyond human imagination. In 2013, Anouk Wipprecht, an iconic Dutch designer, designed a one-of-a-kind outfit called “Spider Dress”. This dress is like no other. Each shoulder pad has two 12-channel Maestro servo controllers that move through embedded sensors. The triggers involve stress levels or when someone comes close around the wearer.
Also known as “cobot”, this type of robot is different from a traditional robot because it isn’t something placed behind a cage. They are programmed to work in partnership with humans to complete a certain task. Servo motors provide these robots the intelligence that a simple cc motor will not be able to give. Also, advanced sensors and servo drive technology enable cobots to adapt to different environments.
Types of Servo Motors
There are various classifications of servo motors available. They are categorized depending on the nature of where it will be used. The shape and size also vary on the application of the motor.
DC Servo Motors
DC currents control DC servo motors. They are suited for smaller applications because of their ability to handle smaller current surges more. For machines programmed with mathematical controls, DC motors are preferred. This is because of their swift reaction to commands and motions. However, they have stability issues and may need more maintenance compared to AC servo motors.
AC Servo Motors
AC currents control AC servo motors. Compared to their DC counterparts, these servos can take higher current surges. That is why they are mainly preferred for CNC and industrial machinery, as well as in automation. In this type of servo, there is an integrated encoder that allows closed-loop control and feedback. Stability is also not an issue with this servo. Furthermore, frequent maintenance is not required.
Positional Rotation Servo Motors
This kind of servo is considered as the most common and important among all such motors. They are typically used in an aircraft, toy, or robot servo. This servo comes with a shaft that can rotate up to 180 degrees. To make sure it won’t surpass this limit, the servo is also equipped with gear mechanisms with physical stops that guard the rotation sensor.
Continuous Rotation Servo Motors
These motors are somewhat similar to a positional rotation model but with limited operations. They can move in any direction but the distance results are indefinite. Instead of directing the motor in a fixed position, the control signals handle the servo’s speed and direction of rotation. Their unlimited rotation and directional control features make them ideal for radar dishes or servo motor for robots.
Linear Servo Motors
Another kind of servo that is similar to a positional rotation model is the Linear servo motor. The difference is that this type of servo motor has extra gears that allow linear movements or forward/backward motions. They are rare but can be found in hobby stores. A hobby or higher-model airplane, small vehicle build, and even a robot use linear motors as actuators.
How Is a Servo Motor Controlled
Servo motors can rotate 90 degrees from either direction and can turn up to a maximum of 180 degrees. It cannot exceed this number because of their’s built-in mechanical stop. A Pulse Width Modulated (PWM) signal controls the servo motors which are sent into the control wire. Every 20 milliseconds (ms), the motor expects to receive a pulse. The PWM received by the motor sends a command as to how the shaft will position. Moreover, the duration of the pulse forwarded via the control wire directs the rotor in which position to turn to.
Take a look at this study about a robot arm’s movement that can be controlled via Internet access. Here, the control signal came from someone behind the computer. The robotic arm servo motors react differently according to the pulse width received. With a pulse width of 0.6 mS, the shaft moved -45 degrees. Then the pulse width increased to 1.5 mS causing the shaft to return to 0 degrees. Lastly, the pulse width increased again to 2.4 mS which shifted the shaft to 45 degrees.
If excellent precision is what you require for a project, servo motors are the solution that you’re looking for. The application of this actuation device is rampant in different industries. You’ll find servo motors in a collaborative robot, sushi bar, and even in an out-of-this-world fashion.
Their classifications depend on the servo motors application. When it comes to movement, the command comes through PWM signals. The width of the pulse received dictates the position of the shaft.
The Internet is already full of content that it’s difficult to identify which are true and not. With the Design Web Kit, you don’t need to worry about getting the wrong information. We offer a collection of articles about various website trends. Find out more here.