Robotic applications that require precision positioning implement servo motors. Robots perform a wide number of tasks like moving from one place to other at a certain speed, pick up objects from a specific point and place it at another, and other such functions that demand accuracy. Servo motors help them to achieve this target. In this article, we talk about the servo motors, their working, and how they are used in robotics.
Understanding Servo Motor
Servo motor is an electronic device that converts rotational motion into linear motion. It is one of the main components used for industrial motor control. Also known as a servo, it uses a sensor in order to measure position, velocity, and torque of the motor at any given instance. The servo circuitry is built inside the motor unit and has a shaft fitted with a gear that can be positioned as needed.
Working of a Servo
Motion controller sends a signal to a servo and depending on the pulse width modulation (PWM), it rotates at a certain angle. When at rest, the output spline of a servo is 0 degree. The pulse width of 1.5ms makes it rotate by 90 degrees in one direction while that of 1ms makes it rotate 180 degrees backward to the starting position.
The position of the output spline is measured by a potentiometer. When the desired position is reached, the power supply is cut and the motor holds that position until the next signal. Proportional operation is an important feature. If the motor stops at 180 degrees while it needs to be at 0 degrees, the movement is swift. However, if it stops closer to 0 degrees, it will move slowly to get there.
Why robotics implements servo motor?
1. Servo motors are small and powerful. They can be easily programmed and allow almost perfect repeatability of motion.
2. They are easy to control. It is a combination of mechanical and electronic modules and has potentiometer to measure the feedback.
3. It is very easy to make your own servo with the help of gears, a motor, a basic comparator circuit, and some other components.
4. The precision delivered by a servo is incredible because of the ability to control angle based on a feedback system.
5. A servo can be used to make humanoids, bipeds, hexapods, and so on. They are also useful in controlling a camera position,
6. As compared to the stepper motors, they are more reliable and lighter. The only limitation is their range as only a few servos have a 360-degree non-continuous operation. Continuous rotation servos use encoders instead of potentiometer, which is a lined sheet of substance and photo-emitter detector pair.
Application of Servo in Robotics
1. Robotic Welding: Servo motors are instrumental in actuating movement and adding dexterity to a robotic welding arm.
2. Robotic Vehicles: The autonomous vehicles used to disarm and dispose of bombs use servo motors in their steering system.
Robotics use servo motors for works that are repetitive in nature or involve tasks that are beyond the physical limitations of a human being. Precision is the key and therefore, the inevitable dependency of robotics on servos.
Author bio: Jeson Pitt works with the marketing department of D & F Liquidators in Hayward, CA and regularly writes to share his knowledge while enlightening people about electrical products and solving their electrical dilemmas. He’s got the industry insights that you can count on along with years of experience in the field. Jeson lives in Hayward, CA and loves to explore different cuisines that the food trucks in the Bay area have to offer.
