Robotics , as an industry and a whole suite of technologies, is rapidly changing and evolving. Whether you're a hobbyist or an experienced robotics engineer, you need to understand every component, both internal and external. In some cases, you should also know how to choose between several different variations.
This is the case with robot motors. No matter how intelligent a robot's joints are, you need the right products to provide the movement, power, and range of motion for all metals and plastics.
What types of robot motors are there?
There are multiple categories of robot motors. Each has subtypes, each with its own applications and advantages. Here is a summary of the types available today.
There are three types of actuators in robot actuators:
Pneumatic actuators: These actuators use compressed air to operate. With very few moving parts, they are reliable and easy to maintain. They lack the control over other types of speed, position, and precision, but they are ideal for warehousing tasks such as picking and storing.
Hydraulic actuators: These are a good option for large robots with heavy loads. They use an air-pumped oil-based fluid instead of air to provide motion. Although they are larger and noisier than other types, they are accurate, but fluid leakage can occur over time.
Electric actuators: Electric motors convert electrical energy into mechanical energy. These are the most common type of actuator across all robot categories today because electricity is a relatively abundant resource. They also work well in robots of all sizes, are compact relative to their power output, and are easy to maintain with virtually zero pollution.
Although electric actuators are the most common and have the widest range of applications in robotics, they can pose risks in environments containing explosives. They also require more complex command systems compared to other types of electric motors.
electric motor
Within the category of electric motors, there are several different types. This category includes the following types:
Alternating current ( AC ) motors: Powered by alternating current from a standard wall socket. AC motors utilize this abundant energy source to generate electromagnetic induction. Engineers prefer to use AC machinery in situations requiring consistent speed. However, they are rarely seen outside of high-torque industrial-scale robotics.
Direct Current ( DC ) Motors: DC motors typically replace wall sockets and are powered by batteries. Compared to plug-in models, DC motors offer a wide range of sizes, a broad range of loads, fast response times, and high mobility.
Servo motors, also simply called "servos," including industrial servos, are some of the most precise motors available. They support near-instantaneous error correction during operation. These motors are ideal for robotic arms and other types of robots and collaborative robots if you require precise positioning and high torque in a small package. There can be latency between movements when a servo system is operating.
Stepper motors: Stepper motors operate in very small increments to provide high torque while holding an object in place — and precise positioning with each step. The accuracy of these motors is often on the order of 0.01 degrees and 0.1 mm . The total torque is similar to that of a servo motor. In terms of power required, stepper motors are more expensive to operate than other types of motors.
How to choose the right motor for a robot?
You can review the points above to narrow down your choices of motors for your next robot project. However, before rereading everything, create a list of essential features you need for your robot.
What task will it perform, and where is your motion error located?
Carefully examine the regulatory environment to understand your tolerance for contamination. Motor contamination is not only a major cause of motor failures, but also a threat to product quality in a risk-averse manufacturing environment.
In other words, you don't have to match hydraulic actuators with high-precision, high-cleanliness equipment such as those used in food and pharmaceutical manufacturing.
These are some other key points to look for when researching various types of robot motors:
Size / Power Ratio: How large is your target scale? Does the robot need to navigate in confined spaces, or is raw power more important than size?
Load Limitation: The type of drive you choose for the robot needs to have sufficient torque to handle the load it is expected to bear.
Accuracy: What is the tolerance for abnormal movement when the robot is in motion? Do you require motors that provide instant, accurate error correction?
Reliability: How well-staffed is your maintenance department? How often do you plan to perform maintenance on the robot?
Resource consumption: Not every robot motor is as environmentally friendly as others. Stepper motors consume power even in standby mode, but sometimes they are the only option.
Each robot has a motor.
From consumer-level applications to large-scale robotic deployments, motors are everything. If you research regulations and the work environment beforehand, you'll quickly discover that every robotics project involves a specific type of motor.
