Kshitij Tiwari Ph.D.

10 Types of robot motors for navigation

9 min read

Mobile robots are becoming increasingly popular in various industries and applications. They are used for tasks such as transportation, exploration, manufacturing, and surveillance. Robot motors are crucial component that enables the movement from one place to another. But given the variety of robot motors, it can be overwhelming to choose the right one for your mobile robot.

In this blog post, we will discuss the 10 types of motors commonly used in mobile robots, highlighting their strengths, weaknesses, and typical applications.

 

What purpose do robot motors serve?

Robot motors serve the purpose of enabling movement in mobile robots. They are responsible for powering the wheels, legs, or other locomotion mechanisms of the robot. Without motors, a robot would be immobile and unable to navigate its surroundings. Robot motors convert electrical energy into mechanical motion, allowing the robot to move from one place to another. Different types of motors offer different advantages and are suitable for specific applications. In the following sections, we will explore the 10 types of robot motors commonly used in mobile robots.

 

Types of robot motors

Over the years, several types of robot motors have come into existence, each with their own pros and cons stemming from the design. Below are 10 such variants available for mobile robots.

 

1. DC Motors

DC (Direct Current) motors are widely used in mobile robots due to their simplicity and affordability. These motors operate on the principle of electromagnetic induction and provide continuous rotation. They are ideal for applications where precise speed and position control are required.

Pros:

  • Simple and affordable, making them widely used in mobile robots.

  • Offer continuous rotation, ideal for precise speed and position control.

Cons:

  • Prone to wear and tear due to the presence of brushes.

  • Lower efficiency compared to brushless motors.

2. Servo Motors

Servo motors are a type of DC motor that offers high precision and control. They are commonly used in robotic arms and autonomous vehicles. Servo motors allow for accurate positioning and are capable of holding a specific angle even under load.

Pros:

  • Provide high precision and control, commonly used in robotic arms and autonomous vehicles.

  • Capable of holding a specific angle even under load.

Cons:

  • Relatively higher cost compared to standard DC motors.

  • Limited continuous rotation compared to other motor types.

3. Stepper Motors

Stepper motors are another popular choice in mobile robotics due to their precise control and high torque output. They operate by dividing a full rotation into a series of steps. Stepper motors are commonly used in applications that require accurate positioning or smooth motion control.

Pros:

  • Offer precise control and high torque output.

  • Ideal for applications requiring accurate positioning or smooth motion control.

Cons:

  • Can experience resonance issues at certain speeds.

  • Higher power consumption when holding a position.

4. Brushless DC Motors

Brushless DC (BLDC) motors eliminate the need for brushes, resulting in improved performance and longer lifespan compared to traditional DC motors. They are commonly used in mobile robots that require high efficiency, low maintenance, and quiet operation.

Pros:

  • Improved performance and longer lifespan compared to traditional DC motors.

  • Low maintenance and quiet operation due to the absence of brushes.

Cons:

  • More complex control and drive circuitry.

  • Higher initial cost compared to brushed DC motors.

5. AC Motors

AC (Alternating Current) motors are commonly used in larger mobile robots or those that require high power output. They operate on the principle of magnetic induction and provide continuous rotation. AC motors are known for their robustness and ability to deliver high torque.

Pros:

  • Commonly used in larger mobile robots or those requiring high power output.

  • Robust and capable of delivering high torque.

Cons:

  • More complex control compared to DC motors.

  • Require an external power inverter for variable speed control.

6. Linear Motors

Linear motors offer a unique advantage for specific mobile robot applications that require linear motion instead of rotational motion. These motors provide direct linear force, eliminating the need for additional mechanical components such as gears or pulleys.

Pros:

  • Provide direct linear force, eliminating the need for additional mechanical components.

  • Suitable for applications requiring linear motion instead of rotational motion.

Cons:

  • Higher cost compared to traditional rotational motors.

  • Limited to specific linear motion applications.

7. Pneumatic Motors

Pneumatic motors use compressed air to generate rotational motion. They are lightweight and can deliver high power-to-weight ratios. Pneumatic motors are commonly used in mobile robots that require quick movements or in environments where electric motors may not be suitable, such as in explosive atmospheres.

Pros:

  • Lightweight with high power-to-weight ratios.

  • Suitable for quick movements and use in explosive atmospheres.

Cons:

  • Require a reliable source of compressed air.

  • Lower power density compared to electric motors.

8. Hydraulic Motors

Hydraulic motors use pressurized fluid to generate rotational motion. They are capable of delivering high torque and are commonly used in heavy-duty applications that require significant power output. Hydraulic motors are often found in large mobile robots, such as construction or agricultural machinery.

Pros:

  • Capable of delivering high torque in heavy-duty applications.

  • Commonly used in large mobile robots, such as construction or agricultural machinery.

Cons:

  • Require a hydraulic fluid supply and associated plumbing.

  • Higher maintenance and potential for fluid leaks.

9. Piezoelectric Motors

Piezoelectric motors operate based on the piezoelectric effect, where the material deforms when an electric field is applied. These motors are commonly used in micro-robotics or applications that require precise movements on a small scale.

Pros:

  • Operate on a small scale and provide precise movements.

  • Suitable for micro-robotics and applications requiring fine adjustments.

Cons:

  • Limited to low power output applications.

  • Can be more complex to control compared to traditional motors.

10. Magnetic-Field Motors

Magnetic-field motors, such as magnetic linear actuators, use the principles of magnetism to generate motion. They offer high precision and are often used in mobile robots that require accurate position control, such as in medical robotics or laboratory automation.

Pros:

  • Offer high precision and accurate position control.

  • Commonly used in medical robotics and laboratory automation.

Cons:

  • Require complex control algorithms for optimal performance.

  • Higher cost compared to some other motor types.

 

Selecting the right motor for robot

Choosing the appropriate motor for your robot is a critical step in ensuring its optimal performance and functionality. The right motor will directly impact the robot’s speed, torque, precision, and power consumption. To make an informed decision, consider the following essential criteria:

  1. Torque Requirement: Evaluate the torque needed to drive your robot’s mechanical components and perform tasks effectively. Consider both the continuous and peak torque requirements to ensure the motor can handle the loads without overheating or stalling.

  2. Speed and Motion Control: Analyze the desired speed range and motion control capabilities for your robot’s applications. Different motor types offer varying speed ranges and control mechanisms, such as continuous rotation, precise positioning, or smooth motion control.

  3. Power Supply and Efficiency: Assess the available power supply and the efficiency of the motor in converting electrical energy into mechanical output. A highly efficient motor will contribute to the robot’s overall energy savings and extended battery life.

  4. Physical Size and Weight: Consider the space available in your robot’s design for motor placement. Choose a motor that fits within the constraints of your robot’s structure while maintaining an acceptable weight-to-performance ratio.

  5. Environmental Considerations: Determine the operating environment of your robot. If it will be exposed to extreme temperatures, moisture, or dust, opt for motors with appropriate protection and sealing to ensure reliable operation.

  6. Motor Control Complexity: Evaluate the complexity of motor control required for your robot’s tasks. Some motor types, such as DC motors, are relatively straightforward to control, while others, like stepper motors, may require more sophisticated control algorithms.

  7. Cost and Budget: Factor in the cost of the motor and its compatibility with your budget. While high-performance motors may offer superior features, they might be cost-prohibitive for certain applications.

  8. Maintenance and Reliability: Consider the required maintenance for the motor. Brushed DC motors may require brush replacements over time, while brushless motors offer longer lifespans and lower maintenance needs.

  9. Availability and Lead Time: Ensure the chosen motor is readily available in the market, and consider lead times if you are on a tight schedule for your robot’s development.

  10. Integration with Robot Control System: Verify that the motor is compatible with your robot’s control system and interfaces seamlessly with the microcontroller or motor driver.

  11. Future Scalability: Anticipate future developments or expansions in your robot’s functionalities. Opt for motors that allow for easy scalability and integration of additional features.

By thoroughly evaluating these criteria and understanding the specific requirements of your robot’s intended tasks, you can confidently select the motor that best suits your application.

Keep in mind that motor selection is a critical engineering decision, and consulting with experts or conducting performance tests can further refine your choice and lead to the successful implementation of your robot’s intended capabilities.

 
 

Key takeaways

Motors play a vital role in the functionality and mobility of mobile robots. The wide variety of motor types available allows designers and engineers to choose the most suitable option based on the specific requirements of their robot. Whether it’s DC motors for simplicity and affordability or hydraulic motors for heavy-duty applications, each motor type has its strengths and applications in the world of mobile robotics. By understanding the different types of motors and their capabilities, we can continue to innovate and advance the field of mobile robotics.