15 Different Types of Robots | Explained

Artificial Intelligence (AI) and Robotics are undoubtedly two of the most promising fields of study right now. These two will certainly define the future of humanity.

At present, we have ultra-modern machines with sleek designs and agile and highly capable bodies, which can perform a wide range of tasks with efficiency. We also have machine intelligence, which is literally revolutionizing the way we do most of our work.

While AI is always an interesting subject to talk about, as we did countless times here on our website, let’s talk about robots today. As you might know, there are many different ways in which one could differentiate robots. I am sure that you know at least some of them, but there is always more.

Basically, robots can be divided into two broad categories:

  1. Based on their applications
  2. Based on their kinematics or locomotion.

Below, we have only classified robots based on kinematics. Why is it so? Well, the application of any subject, especially robots, vaguely describes its characteristics. For instance, two different types of robots can perform the same job, yielding the same result.

We have only mentioned major robotic types, and they are further subdivided based on kinematics. 

Did you know? 

The word “robot” originates from the Czech word “robota,” meaning forced labor. This term was introduced by Karel Čapek in his 1920 play “R.U.R.” (Rossum’s Universal Robots). 

Robotic Arms or Stationary Robots

1. Cartesian Robots

Cartesian-coordinate-robotImage Courtesy: Florian Schäffer/ An implementation of the cartesian robot

Cartesian robots are perhaps the most common type of robot used for both industrial and commercial purposes. Sometimes known as gantry robots, they have three linear axes, enabling them to move in straight lines, and they are mounted at right angles.

The mechanical arrangement of cartesian robots is far simpler than most other stationary robots.

They can be customized to meet specific application requirements. This includes modifications to the size of the workspace, payload capacity, and the type of end-effector (tool or gripper) attached to the robot.

Applications: Manufacturing, assembly, packaging, material handling, and CNC (Computer Numerical Control) machining.

2. Cylindrical Robot


Unlike Cartesian robots that operate within a rectangular coordinate system (X, Y, and Z axes), Cylindrical Robots use a polar coordinate system to define their movements. 

Illustrated in the diagram, a cylindrical robot operates along three axes. On the Z axis, it rotates and moves vertically, and on the Y axis, it engages in linear motion. They are well-suited for tasks that involve rotational and circular motions.

Sometimes, these cylindrical robots are mistakenly regarded as SCARA robots or vice versa. Even though their work mechanism is almost similar, both their structures and field of application are poles apart.

Applications: Automotive manufacturing, electronics assembly, and tasks like welding seams on cylindrical structures.

3. SCARA robots

SCARA_rightGif Source: Wikimedia Commons

SCARA, which stands for Selective Compliance Assembly/Articulated Robot Arm, is widely preferred for assembly tasks, thanks to its straightforward and unobstructed mounting.

SCARA Robots typically feature a serial architecture, where one base motor bears the load of all the other installed motors. The typical configuration includes a series of joints that allow for both rotational and translational movements.

However, a drawback is their higher cost compared to traditional Cartesian robots. They also require sophisticated and complex software for operation.

Applications: They are industrial robots commonly used in assembly processes, material handling, pick-and-place operations, and packaging. 

4. Parallel robots


Parallel robots are more commonly known as Parallel manipulators, in which a bunch of machine-controlled robotic chains support the end effector (or simply the end platform).

One of the best examples of this type of robot is flight simulators, which military and commercial pilots use to enhance their flight abilities by simulating real-life situations.

The word ‘parallel’ should not be misunderstood as it does not imply a geometric setting but rather a unique characteristic of the robot type in computer science. Here, parallel means that the endpoint of each individual linkage is completely different from others.

The parallel robot is specially designed to remain rigid and resist all unwanted disturbances and movements, which is contrary to serial manipulator robots.

Even though each actuator works with a degree of freedom, its flexibility is eventually constrained by the other actuators. Its rigidity and stiffness separate parallel manipulators from serial chain robots.

Applications: Aerospace, automotive manufacturing, medical surgery, and other uses that require precise and dynamic motion.

5. Articulated robots


When people discuss industrial robots, they likely mean articulated robots. Unlike many other robot types mentioned earlier, articulated robots excel in versatility and are well-suited for industrial tasks.

Their flexibility is attributed to having extra axes, usually ranging from four to six but sometimes extending up to 10. Generally, they have six degrees of freedom (6-DOF), corresponding to the six major axes of movement: three translational axes (X, Y, Z) and three rotational axes (pitch, yaw, roll).

Applications: Automotive manufacturing, electronics, aerospace, and general manufacturing. They are widely used in tasks ranging from welding car bodies to assembling electronic components. 

6. Spherical robots

spherical-robotImage Courtesy: Seelio.com

A spherical robot is a mid-sized robot housed within a spherical ball, propelled by an Internal Driving Unit (IDU). In terms of sophistication, spherical robots fall between Cartesian or cylindrical robots and highly advanced articulated robots.

They are often used in areas where omnidirectional movement is crucial, such as in tight spaces, crowded environments, or areas that require high agility.

Applications: These mobile spherical robots prove highly effective for surveillance and monitoring tasks and can even operate underwater. 

Wheeled and Legged Robots

7. Single Wheel Robots

Most of us have ridden a bicycle or motorcycle, but how many have tried a unicycle? I attempted it once and struggled just to sit properly. The challenge with unicycles is their lack of stability compared to bicycles, making balancing tough without proper support.

Creating a single-wheeled robot is a tricky task for engineers as it requires dynamic stability and efficiency. An example of such a robot is MURATA GIRL.

Murata Girl, or Murata Seiko-chan, is a unicycle robot manufactured by the Japanese electronics company Murata. According to the company, she has advanced gyro sensors that allow her to maintain balance, a Bluetooth device for communication, and an ultrasonic sensor for target detection.

Applications: They serve as platforms for learning about control systems, robotics programming, and physics principles.  

8. Two-Wheel Robots

two-wheeled-robotImage Courtesy: David P. Anderson 

As the name suggests, two-wheel robots, are a type of mobile robot that features two wheels for movement and balance. They use a differential drive system (or similar mechanisms) where the speed and direction of each wheel can be controlled independently. 

This allows the robot to achieve various maneuvers, such as forward and backward motion, rotation in place, and curved paths.

But like any other robot, they also have their own flaws. Two-wheeled robots have poor balance, and they always have to be in motion to maintain an upright position. To enhance stability, batteries are typically positioned directly beneath their bodies.

Applications: Educational settings to teach robotics principles and control systems, and as a platform for testing control algorithms and navigation strategies. 

9. Three Wheel Robots


Three-wheel robots can be categorized into two types based on the steering mechanism of the wheels. In the first type, two wheels are independently powered, and the third wheel rotates freely for balance (differentially steered). In the second type, two wheels are powered by one source, while the third wheel is powered by another source.

In differentially steered three-wheel robots, adjusting the relative rate of rotation of the two powered wheels changes the robot’s direction. If the two wheels rotate at the same rate and in the same direction, the robot continues moving straight.

Applications: Educational settings to teach basic robotics concepts and programming. As unmanned ground vehicles for applications like surveillance, exploration, or indoor navigation.

10. Humanoid Robots

humainoidTOPIO, a humanoid robot, played T.T at IREX, Tokyo

As the name suggests, a humanoid robot is a type of robot that resemble and mimic the physical characteristics and behaviors of humans. 

Their design makes them fairly distinct from the other types of mobile robots. A typical humanoid robot consists of a head, two arms, a torso, and two legs, just like a human.

One of the main components of a humanoid robot is sensors, which play a pivotal role in robotic paradigms. There are two types of sensors: Proprioceptive and Exteroceptive sensors. The former is responsible for the robot’s orientation, position, and other motor skills, while the latter includes visionary and sound sensors.

Applications: Humanoid robots can perform specific jobs, such as inspection and disaster response at power plants, routine tasks for astronauts in space travel, and personal assistance and caregiving.

11. Tripedal and Quadrupedal robots

four-legsBoston Dynamics’ WildCat

While tripedal or three-legged robots are not so common, a robotics and mechanism laboratory in Virginia has developed a radical three-legged robot named STriDER. It uses a fairly new concept of passive dynamic locomotion to walk in all directions. This highly efficient robot can also be guided with minimal control.

In contrast to tripedal robots, four-legged robots are more popular. The four-legged robots, also known as quadrupedal robots, have more stability, especially when they are not in motion. Many quadrupedal robots use the alternating technique (in pairs) to walk.

Some of the best examples of quadrupedal robots are WildCat, Cheetah, and Big Dog.

Applications: Exploring unknown or hazardous environments, navigating disaster-stricken regions to locate and assist survivors, and providing reconnaissance or carrying out tasks in military applications. 

12. Hexapod Robots

Types of Robots - hexa machines

In geometry, a Hexagon implies a six-sided polygon, so a hexapod would mean a robot with six legs, right? Yes, that is the case here. Although a robot can be perfectly stable on just three legs, the extra legs of a hexapod robot provide a great deal of flexibility and increase its capabilities.

Many, if not all, hexapod designs draw inspiration from the locomotion of Hexapoda, the family of insects with six legs. They are used to test various biological theories about insect locomotion and motor control. These hexapods utilize various types of gaits to make a move. The most common are:

  • Alternating tripod: Out of possible six, only three legs stay on the ground at a time
  • Crawl: only one leg stays on the ground at a time, giving the impression of crawling

Applications: Traversing environments with obstacles where traditional wheeled or tracked robots may face challenges, navigating complex and confined spaces, and conducting surveillance in regions where stability and adaptability are essential.

13. Hybrid Robot

Boston Dynamics, a robotics company, introduced a research robot called Handle, breaking away from traditional legged and wheeled designs. This innovative robot stands at an impressive height of up to 6.5 feet and can travel short distances at a speed of 9 mph. It can also jump vertically up to 4 feet.

While Handle incorporates fundamental working principles seen in quadruped robots, such as balance and mobile manipulation, it stands out by utilizing only ten actuated joints. This simplicity sets it apart from other walking robots. 

By combining wheels (efficient on flat surfaces) and legs (effective for rough terrain), ‘Handle’ demonstrates versatility and can adeptly navigate various environments.

Applications: Material handling in warehouses and logistics settings; perfect for tasks such as palletizing and transporting goods.

14. Flying Robots

Without a shadow of a doubt, flying robots have become the most popular type of robots. Major multinational companies are currently considering integrating these automated flying machines into their daily operations. These robots are not only impressive but also robust and aerodynamically efficient.

They use different propulsion systems like rotors or propellers to generate lift and control their movement in the air. Some mimic the design of traditional airplanes with fixed wings — they achieve lift through the shape of their wings and are typically more efficient for covering longer distances.

Applications: Aerial photography/videography, surveying, mapping, search and rescue, and package delivery. 

In some regions, Amazon has started shipping products through flying drones. These fully electric and autonomous drones can fly up to 15 miles and deliver packages weighing 5 pounds in less than 30 minutes.

Read: 14 Unique Early Experimental Flying Planes

15. Swimming Robots

different types of robots - swimming bots

And why should flying robots get all the limelight; why not swimming robots? Yes, they are as cool as flying robots; the only difference is that instead of flying, they can swim. These robots can take the form of insects, fish, or big slithering snakes.

Underwater robots often utilize ballast systems, which allow them to control their buoyancy, enabling vertical movement in the water column. Some can finely adjust their buoyancy to move between the surface and deeper water. 

One such unique robot is NASA’s SWIM (short for Sensing With Independent Micro-Swimmers). It’s a smartphone-sized robot capable of swimming through oceans and descending through the icy shell of a distant moon in search of extraterrestrial life. It can cover larger water regions compared to a singular probe.

Applications: Ocean exploration, inspection of underwater structures like pipelines and dams, and study of marine ecosystems, water quality, and pollution. 

More To Know

What are the most common uses of humanoid robots?

In addition to personal assistance and caregiving, human-like robots are used as research tools in various scientific fields, including biomechanics and cognitive science. They are used to develop complex prosthetics for people with disabilities and personalized healthcare aids for the elderly.

In the entertainment industry, humanoid robots have served as stunt doubles. Some robots have been specifically built to simulate real-world, dynamic movement.

At present, these robots can perform certain tasks only and are far from autonomous. Many practical applications are still unexplored.

In the future, such robots (integrated with AI technology) could be useful for space exploration missions — we don’t have to bring them back to Earth once the mission is accomplished.

Who developed the first autonomous robots?

In 1948, British neurophysiologist William Grey Walter developed the first electronic autonomous robot with complex behavior. He named it Elmer.

Due to its structure and slow rate of movement, it was often called a three-wheeled tortoise robot. It was capable of finding its own path to a charging station when it ran low on battery power.

What are some of the most famous robots?
  • Spot: An agile, mobile robot that can navigate the terrain with exceptional mobility.
  • Sophia: A humanoid robot that follows faces, makes eye contact, and recognizes individuals.
  • AIBO: A robotic dog that can recognize faces, respond to voice commands, and learn tricks via cloud computing.
  • Stretch: A commercial warehouse robot that can handle a variety of package types, sizes, and stacking configurations.
Robotics market size

According to a report published in Precedence Research, the global robotics technology market size will exceed $283.6 billion by 2032, growing at a CAGR of 12.3% from 2023 to 2030.

The major factor behind this growth includes the increasing demand for industrial robots that assist in material handling, manufacturing, welding, packaging and labeling, and security and inspection. Plus, the growing number of funding and investments in the field of robotics and machine learning is also driving this market across the globe.

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Written by
Varun Kumar

I am a professional technology and business research analyst with more than a decade of experience in the field. My main areas of expertise include software technologies, business strategies, competitive analysis, and staying up-to-date with market trends.

I hold a Master's degree in computer science from GGSIPU University. If you'd like to learn more about my latest projects and insights, please don't hesitate to reach out to me via email at [email protected].

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  • Kegesa Danvas Abdullah says:

    This is great. I am researching on the types of robots that are used in the motor vehicle manufacturing companies. Am I right to say that most of them are stationary robots?

  • kaden wiley says:

    this site is so helpful i used this a lot on my project for school if you look at the commets then i say i reccomend this to you it will help you so much with work and or school if you like doning robotics or you are a robo engenier

  • mike wiley says:


  • mr antON matijas says:

    dear sir im in market and looking for a robot who can put any sort of flat pack kit together . let me know when you programed one.