How Servo Motors Work

How Servo Motors Work

Servo motors are a key component in industrial equipment and robotics, and as they can move with incredible precision, they can have a big impact on production.serve motor But they also have a lot of moving parts, making them complex to understand and work with. Whether you're an engineer building robots, or just a hobbyist trying to understand how they work, a little understanding can open the doors to expanded projects.

A serve motor is a specialized DC motor that can control the direction, speed and position of its output shaft, all at the same time.serve motor This allows a machine to achieve precise motion and positioning, even when working with large inertial loads. This makes them common in packaging machines, such as form, fill and seal (FFS) or bottling systems, as well as cartoning and labeling equipment.

The heart of a servo motor is the sensor that monitors its speed, movement and rotational angle and sends feedback signals to the controller.serve motor The controller is an analog or digital circuit that compares the feedback signals with the desired setpoint signal from the outside world and generates control commands to adjust the motor's voltage or current accordingly. This is called closed-loop control.

This process is done through three different loops that work in optimized synchrony to provide smooth and accurate control of the servo motor: a position loop, velocity loop and a current loop.serve motor The current loop is a power amplifier that turns the low-power control signal into high-power voltage and current that drives the servo motor to move its output shaft in the direction specified by the command. The current loop also monitors the actual current flow through the motor and subtly adjusts its own current to maintain a constant velocity at the desired position.

If the servo motor moves out of its desired position, the error signal is sent back to the sensor and the system repeats the cycle of sending the position pulse and the corresponding feedback pulse.serve motor This happens in milliseconds, allowing the motor to be driven with extreme precision and responsiveness.

As the servo rotates, it interacts with a pair of carbon brushes that look similar to pencil lead.serve motor These are called brushless DC servo motors and are more efficient than traditional servo systems because they do not discharge the energy that caused the servo to move by releasing it into the air as heat. Instead, a more energy-efficient servo regenerates that energy, putting it back on the power lines to be reused.

However, energy must still be used to drive the servo motor and even though it is regenerating energy, there will always be some loss due to friction between the brushes and the rotor. This is why most servo motors use a discharge resistor to release that wasted energy, converting it to heat and transmitting it into the air. Some servos have eliminated this wasted energy by switching to an electronic power regeneration system. This reclaims the energy that would otherwise be released as waste, saving 30-40 percent in total energy costs.