What, How and Why of Servo Motors in Robotics

In robotics, servo motors or simply servo are utilized in applications that need clear-cut positioning. Many of the things we used in our daily lives are powered by a servo. Let’s take a closer look at how these tiny yet tough motors work before we delve deeper into their robotic benefits and implications.

What are Servos?

A servo is an accurate, robust device that translates rotational motion into a linear type. Ithascertaincomponents, includingthefollowing:

  • Electronic Assembly – this comprises the following:
  • an alternating current or direct current electric motor
  • a potentiometer
  • a controlboard
  • Case – this is simply the flexible material that houses the motor and other parts.
  • Drive Gears – these gears are responsible for the reduction of the fast motor output to a reduced speed, higher torque return.
  • Output Spline – linked to the shaft, this component is the ultimate connection spot between the motor and the item where the motion is made. For an instance, in an airplane steered by a remote, the spline may be connected through a control pole to a control surface, like a rudder. How the servo moves will cause the plane turn in a corresponding manner.

How Do Servos Work?

Let’s be more technical. So, how does servos work?

Simple: when a motion controller generates a cue, the servo will receive it.

The incoming cue has a so-called pulse width modulation (PWM). The amount of shifting the servo will make is dependent on the signal’s PWM. When not active, the spline is normally at 0°.

At a 20-millisecond pulse frequency, here are the expected motion of the spline:

  • If the pulse width is 1.5 milliseconds, the spline will turn 90° in a certain direction.
  • If 2 milliseconds, it will further move 90°, positioning itself at 180°.
  • If 1 millisecond, it will go back to 0°, turning 180° backward.

Continuously monitoring the spline’s position is the potentiometer. Once the spline gets to the spot based on the cue, the power transmitted to the servo is then discontinued, with the servo actively retaining the position until another message is received.

Servos has one unique characteristic: proportional operation. This means that a servo can function only as quickly as demanded to turn from its present location to the next. A servo held in a 180° will move speedily to reach 0°, while one that is retained close to 0° will turn more gradually to reach it.

How are They Utilized in Robotics?

Servo motors prove to be very beneficial in robotics. Not only are they tough and precise, but they are also compact and can be effortlessly programmed. However, the most essential attribute of servos is allowing for motion repeatability that is close to perfection.

Servos are widely utilized in robotic applications that include the following:

  • Robotic vehicles – Uncontrolled cars that are employed to demilitarize bombs have servo motors installed in their steering setups.
  • Robotic welding – In robotic welding arms, servos are placed in its every joint to actuate motion and enhance dexterity.