control engineering surprising applications of servo motors, servo motors working, what are servo motors
Hi Friends! Hope you're well today. I welcome you on board. In this post, we'll discuss surprising applications of servo motors. 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. Servo motors are widely practiced in different industries.

Servo Motor Applications

A servo motor may appear small but this tiny beast is packed with countless capabilities that make certain objects function more effectively. Projects that require maximum precision rely on this electrical device. You should also have a look at Servo Motor Control using Arduino. A servo motor with high torque is an ideal pick to handle heavy loads properly. These versatile servo motors can quickly adapt to any kind of environment. I have also posted on Servo Motor interfacing with PIC Microcontroller. Let’s take a look at some of the valuable uses of servo motors.
1. Sushi Bars
Have you seen those cute, sushi trains in Japanese restaurants? They use servo motors. Due to lack of staff, Yoshiaki Shiraishi developed a sushi train 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.
2. Escape Rooms
Those who seek 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 solves the puzzle. Props and supplies as well as other interactive parts of the game also use servo motors.
3. Automated Doors
We usually see these doors in business centers, shopping malls, and other commercial establishments. They all operate through servo motors. How? Automated doors have infrared sensors that detect the presence of an individual. The data collected through the infrared sensors is sent to the servo motors which in turn open the door.
4. Remote-Controlled Toys
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 servo motors then steer the wheels in a toy car, operate the toy helicopter’s propellers, or do whatever the command you apply.
5. Camera Auto-Focus
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 with great focus in auto mode. This is helpful for photographers working on sports or wildlife.
6. Super High-Tech Fashion
Sometimes servo motors serve purposes beyond human imagination. In 2013, Anouk Wipprecht, an iconic Dutch designer, designed a one-of-a-kind outfit called “Spider Dress”. This dress is, no doubt, unprecedented. 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.
7. Collaborative Robots
Also known as “cobot”, this type of machine is different from a traditional robot. They are programmed to work in partnership with humans to complete a certain task. Servo motors provide these robots a remarkable intelligence that you cannot expect from a simple cc motor. Also, advanced sensors and servo drive technology enable cobots to adapt to different environments.

Types of Servo Motors

There are scores of servo motors available in the market. They are categorized in terms of size and shape based on the nature of the application.
control engineering surprising applications of servo motors, servo motors working, what are servo motors
1. DC Servo Motors 
DC current controls DC servo motors. They are the right fit for smaller applications for their ability to handle smaller current surges. Due to their swift reaction to commands and motions, DC motors are preferred for machines programmed with mathematical controls. They have, however, stability issues and may need more maintenance compared to AC servo motors.
2. AC Servo Motors
AC current controls AC servo motors. Compared to their DC counterparts, these servos can take higher current surges. The reason they are 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.
3. Positional Rotation Servo Motors
This kind of servo is considered as the most common and important among all servo 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.
4. Continuous Rotation Servo Motors
These servo motors are somewhat similar to a positional rotation model 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.
5. 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 are available in hobby stores. A hobby or higher-model airplane, small vehicle build, and even a robot use linear servo motors as actuators.

Working of Servo Motors

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 its built-in mechanical stop. A Pulse Width Modulated (PWM) signal controls the servo motors which are sent to the control wire.
control engineering surprising applications of servo motors, servo motors working, what are servo motors
Every 20 milliseconds (ms), the servo 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.

Conclusion

If excellent precision is required, servo motors are the solution 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 classification depends 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 occupied with countless content where it’s difficult to identify the right one. With the Design Web Kit, you don’t need to worry about getting the wrong information anymore. We offer a collection of articles about various website trends.