Without activation, robots are just metal, plastic, vibranium, or whatever you made them from, pieces. Motors inspire life into these components. Picking the correct engine is of essential significance to your robot’s effectiveness.
Actuators in Mechanical Technology
The market of engines offers a wide range of models. But, not all of them are suitable for robotic purposes. Let’s consider three big groups of engines:
The pneumatic engine, also called packed air engine, is a specific kind of engine that uses compacted air extension to convert it into mechanical energy through straight or rotating development.
Pneumatic engines have existed for a few centuries in various shapes and sizes, from versatile turbines to control motors up to a few hundred steeds. Many compacted air motors improve their performance by warming the approaching air or the motor itself. Pneumatic engines are found in compact hardware, although there are persistent endeavors to grow their utilization in the vehicle business. These motors are characteristically solid, however, they are in second place for inexactness of speed and position control.
The hydraulic engine converts pressure into torque, it provides the precise speed and movement coordination and has enough capacity to-weight proportions. But these engines have additional hazards related to spillages or with the liquid changing its characteristics as temperature varies.
The electric engine retains electrical energy and changes it into mechanical. These actuators are the favored choice in robotics because:
- These components are appropriate for all robot sizes. They can be small and lightweight, however, they enhance high torque, astounding precision, and repeatability
- Contamination (e.g., from spills) in the workplace is near to zero
- Electric activation frameworks are simple to keep up
How Does an Electric Motor Work?
In an electric motor, the electrical energy supplied to a coil covered by the current is transformed into mechanical energy. An electric motor generally consists of a fixed part (stator) and a mobile part (rotor). A rectangular loop of rigid conductor wire, mounted on an axis on which it is free to rotate, is immersed in a magnetic field perpendicular to the axis of rotation, generated by the poles of a magnet.
When the coil is crossed by an electric current the action of the magnet produces a pair of forces that force it to rotate. At this point, using a special device called the collector, the direction of the current in the loop is reversed, the action of the forces is also inverted, and the coil continues to rotate in the same direction. The rotation of the loop is transmitted to a rotating shaft.
Electric actuators have their subtypes, for example:
- Rotating current (AC) motors
- Direct current (DC) components
In an AC alternating current motor, the magnetic field is obtained from the difference in angular velocity between the stator currents and those generated in the rotor. The rotor is composed of an electrical circuit made up of two rings at the ends and the bars that connect them. AC motors are very robust, having neither wear parts nor magnets.
In the DC motor, the magnetic field is generated by the stator. These motors have good characteristics of robustness and reliability; they are simple to build and to control. As far as torque is concerned, it is enough to check the current supplied to the motor to control the speed.
Servos are frameworks with a controller and a feedback circuit built-in, which saves space and ensures the effective performance of a motor.
The stepper motor, often called step or stepper, is a synchronous direct current brushless electric motor that can divide its rotation into many steps. It is considered to be an ideal choice for all those applications that require precision in angular displacement and rotation speed.
Frameless engines are brushless synchronous alternating-current actuators with a thermal meter. The technology enables getting impressive power from a compact footprint.
Robot engine choice tips
Finding the perfect robot engine seems to be a difficult task. To move forward, start with ONE BIG question:
For what do you need a robot?
For example, you are focusing on the Food industry as your target one. Commonly, they would like to have a pick-and-place robot, with a wide range of ambient temperature and advanced payload.
Since you are finished with the BIG question, settle down the fundamental qualities of your robot engine. Concentrate on:
Chosen drives ought to have the option to create enough torque to beat powers influencing your instrument during movement and to move the determined payload.
A robot engine should move with a speed that is enough for its planned assignments.
Think about how precisely your robot/ actuator should move. +/-1mm or +/-100mm?
A robot engine should reach instructed positions with unfailing accuracy every time, step after step.
You must comprehend whether your engine incorporates wearable parts and to know its interim among disappointments as well as ensured lifetime cycle.
Consider how you will supply capacity to the robot (e.g., from an AC or DC source) and how much power it will expend.
When in doubt, modest costs mean low quality. Nonetheless, if a cheap engine is enough for your projects, maybe, you ought not to go for more expensive steppers or servos.
Use the above-given recommendations to work out your selection checklist for robot motors. Ensure your servo matches the robot or its specific segments in size and power or think about its customization.