Servomotors: The first step towards your Robot

Posted by Madison on August 12th, 2018

These devices are considered one of the raw materials in the design and construction of robots. If we combine and manage the movements in a suitable mechanical assembly, a variable group of servomotors can give motricity and locomotion to locally or remotely controlled systems. From small didactic applications to the most complex robotic design. The limits are your imagination and your desire to learn.

A servomotor is basically a mechanical actuator based on a motor and a set of gears that allow multiplying the torque of the final system, which has control elements to constantly monitor the position of a mechanical element that will be the link to the outside world. That is to say before an action induced electronically to a servo motor, we will obtain as a result a controlled mechanical response. For example, the motors that are part of a printer, together with the control systems of advance or retraction of the paper, form a servo motor.

A classic servomotor for simple applications

The applications of these slave systems can be observed mainly in model aircraft and robotics, but they are not exclusive to these uses. Any system that requires a precise and controlled mechanical positioning will depend on a servo system or servomechanism, acted, of course, by a servo motor for robot. The zoom of a camera, the autofocus of an optical assembly, a system of mobilization of surveillance cameras and even the automatic doors of an elevator are simple examples of its application.

The engine has the characteristic of turning at a good speed, which decreases by the gearboxes of the gearbox that take advantage of this speed to transform it into a workforce. When rotating the last gear coupled to the output shaft we obtain a remarkably reduced speed, despite the fact that, inside the system, the motor is rotating at high speeds.

The servo control signal

As mentioned at the beginning, servomotors are controlled by variable-width pulses that must be refreshed periodically. This means that if we stop sending the control signal at the time in which the servomotor needs it, it (in spite of being energized) will stop maintaining the pre-established position and will adopt any guidance governed by the effort to which it is subjected. That is, if we do not maintain the control signal effectively as long as necessary, the system will be at the mercy of the external forces to which it is subjected. For example, a lever arm will stop holding an object and will drop the entire mechanical path that can travel. To lock the servomotor in one position it is necessary, then, to continuously send the signal to the desired position. In this way, the control system will continue to operate and the servo will retain its position and will resist external forces that try to change its position.