You are here: Robotics/Chapter 1/Robot Basics

What is a Robot?

For many people who think of robots and robotics, the first thing that would pop into their mind would be some sort of humanoid robot, such as Terminator, or androids in Star Wars.  Maybe you think of the robot Sunny in iRobot, or something along those lines.  Others may think of the show Robot Wars, where robots face off in a ring with the goal of destroying each other.  It is true that all of these that I’ve mentioned are robots.  But robots are much more than humanoids.  You may not realize how many robots applications there truly are, and how many robots are being used to the benefit of society (so far).  And if predictions are true, our robot overloads will all have us out of jobs in the next few decades, as they will be able to do anything better than humans – from flying aircraft, to making cars, to performing surgery.  In fact, these applications all exist today.  But in the present, robots are developing and arguably still a disruptive technology.  In many applications, they are almost certainly better than us humans.  Most applications are still be developed and perfected.  For instance, robotic surgery is currently a very small market.  Companies making surgical robots are only making them to perform routine and non-invasive surgeries.  But I wonder how long it will be until they can perform open heart surgery, with the speed and precision, of, well, a robot?  Even if the technology gets to that level, which it almost certainly would, would we be willing to put our lives in robotic hands?

The 3Ds: Dangerous, Dirty, and Dull

But although you may think of the more glamorous applications, many robots applications are based on three criteria: they do jobs that are dangerous, dirty, and dull.  These are known as the 3Ds.  Examples of these robots abound.  Dangerous jobs: a bomb diffusing robot would be a prime example. Dirty: this may be something like robotic welding in an auto factory.  Dull: a robot that moves boxes around in an Amazon warehouse.  Many jobs fit into more than one category.  You could argue that driving a vehicle is both dull and dangerous – a perfect task to hand off to robots (although this may fit better into the category of automation – discussed below).  Most robots, with the exception of robotic toys, fit into one of the 3Ds.  Maybe in the future when robots have perfected the 3D jobs, they will come for the rest of the jobs as well.

The Definition of ‘Robot’

This is a prime time to define exactly what a robot is.  Lets look at a couple of dictionary definitions, as that is usually a good place to start.

Merriam-Webster:

• a real or imaginary machine that is controlled by a computer and is often made to look like a human or animal
• a machine that can do the work of a person and that works automatically or is controlled by a computer

The first definition is what the general public would think of when thinking of robots.  This is a very narrow definition, and doesn’t really fit into the 3Ds.  In most cases, why would you bother making the robot look like a human or animal when the job is dangerous, dirty, or dull?  Unless the design of humans or animals is applicable to what you are doing.  For instance, Boston Dynamics often mimics animals such as dogs and cheetahs in their designs, and some of these robots would be used for transportation in war-zones, which definitely meets the dangerous criteria.  The second definition is much more along the lines of what a roboticist would think of when thinking of robots.  Wikipedia goes into even more depth:

• A mechanical or virtual artificial agent, usually an electro-mechanical machine that is guided by a computer program or electronic circuitry.

That is a decent definition, but it is a bit too specific for my taste, as it begins to discuss electro-mechanics, computer programming and electronic circuitry.  It is getting too far ahead and instead missing some of the basics.  Oxford Dictionaries says the following:

• A machine capable of carrying out a complex series of actions automatically, especially one programmable by a computer.

That is a good explanation, as it mentions the ‘carrying out a complex series of actions.’  What exactly do they mean by that statement though?  What counts as complex?  What counts as carrying out?  Another from the Robotic Institute of America (RIA):

• A reprogrammable, multifunctional manipulator designed to move material, parts, tools, or specialized devices through various programmed functions for the performance of a variety of tasks.

This hits some key points.  The only issue I have is with the use of the term manipulator, which may refer to a particular type of robot – the manipulator type, which is basically designed to resemble a human arm.  They may have been mentioning manipulator in a broad sense, but it is ambiguous nonetheless.  The best definition, in my mind, is probably either the RIA or Oxford definition, or some combination of the two.  You can see the definition is really quite broad!  And it is meant to be.  Anything that you program (and can be reprogrammed for different tasks), is a machine, and that is designed to carry out a series of tasks can be considered a robot.  A key part of the definition by RIA is that it is reprogrammable and multifunctional.  This forms the basics for the distinction between robotics and automation, which are not the same and can be easily confused.

Automation versus Robotics

The main difference is this: an automated process usually cannot be changed or reprogrammed to do a different job with relative ease.  If you wanted to switch up and automated process, you would likely need to do a major overhaul or build a separate machine altogether.  For instance, if you have an automated station that spray paints car parts – say just a bunch of spray nozzles attached at various locations with everything automated and timed correctly – it would be difficult to modify this device to instead weld car parts.  It isn’t set up for welding at all.  Some components may be reusable, but you would essentially have to rebuild the entire automation device to weld parts together instead.  But, if you had a robot manipulator – which resembles a human arm, but is usually faster, stronger, and more precise – you could have an attachment on it to spray paint car parts.  You would program the correct movements and timing so that it properly painted all of the parts.  If this robot is needed for welding instead, the company could switch out the end attachment to a welding device instead, and then reprogram in the correct movements and timing to correctly weld two parts together.  The robot is reprogrammable and multifunctional.  Just like a factory worker could be trained to both spray paint and weld, so could a robot manipulator.  An automated process could not.  It is difficult or impossible to reprogram an automated process to perform a different task.

Robots also often have sensory feedback, so that they can be trained to be more efficient and do their jobs better.  In this sense, robots are often aware of their environment, whereas automated processes are often not.  Robots can be reprogrammed to be made more efficient.  Often in the case of robotic manipulators, sensors are used heavily.  If something comes in the path of a robot, it will either sense the object with vision or proximity sensors, or stop moving once it impacts the object to prevent damage from occurring.  Automated processes do not have this level of feedback.  They will smash into whatever is in their path.  More advance robots may even be programmed to move around the obstacle in a safe way and continue on the assigned task.

Another difference between automation and robotics.  A robot would be able to use information from its sensors, collect information about the environment, and make intelligent decisions based on the surroundings.  This would be a form of Artificial Intelligence.  An automated process will not do this.  This is much too complex for an automated process, which are usually made to perform simple movements over and over again and will never learn from their environment or become more intelligent or more efficient.

The Origins of the Word ‘Robot’

This is something that is always mentioned, so I may as well mention it here as well.  Where did the word robot come from?  Robots are a fairly recent concept, so was it kicking around, say, in the middle ages?  No, robot is a recent word – in comes from a play called Rossum’s Universal Robots (R.U.R) first opened in Prague in January 1921.  The plot of the play?  A technologically advanced society dehumanizes humankind and eventually robots take over the world, with all humans killed.  It was enormously popular.  It is something that would probably still be relevant today, with concerns about AI in the future and robots stealing all of the jobs.  In the play, robots were not mechanical devices, but instead produced chemically out of synthetic organic matter.  The robots resembled humans – cyborgs, or clones even.  These robots can think for themselves, and though initially they co-exits with humans, eventually there is a violent rebellion.

Asimov’s Three Laws

The term Robotics did not actually come about from R.U.R but from Isaac Asimov, who was born in 1920 and died in 1992.  He was a Russian scientist (and writer) who lived in America.  He is well known for his science fiction works.  In his lifetime, he wrote or edited more than 500 books.  It is from Asimov that we have the term robotics, and his famous three laws, known as the Three Laws of Robotics or Asimov Laws, or simply the Three Laws.  This rules appeared in his short story Runaround, published in 1942.  I will replicate them here:

• A robot may not injure a human being or, through inaction, allow a human being to come to harm.
• A robot must obey the orders given it by human beings, except where orders would conflict with the First Law
• A robot must protect its own existence as long as protection does not conflict with the First or Second Laws.

You may recognize these laws.  While probably not used verbatim in most robots today, these laws have provided a great amount of influence.  A robot must, in general, be safe.  The Three Laws as written were imagined in a time when robots were though to be humanoid, cyborgs, capable of intelligent thought and interaction on a regular basis with society.  For a factory manipulator that welds all day long, these laws are not as relevant.  But these laws are classic in the world of robotics.  Every roboticist should know them.  Most of the general population knows them, in one form or another – or at least aware of their existence.  If you are interested in this topic, ethics of artificial intelligence, roboethics, and machine ethics would all be a good place to start.

Zeroth Law

The Three Laws above are the original laws as first published.  Asimov himself and other authors have altered and elaborated on these laws.  Mainly these laws were altered to further indicate how robots would interact with humans, and other robots as well.  Later on, Asimov added a fourth law that preceded the other three, termed the zeroth law:

• A robot may not harm humanity, or, by inaction, allow humanity to come to harm.

This zeroth law covers not only humans as individuals but as a species.  It is the robot’s ultimate job to defend humanity and preserve the human race.  It is interesting that although Asimov was praised for these laws that he created, he stated that they were obvious from the start, and that everyone was aware of them subliminally.  He just put the words on paper and organized them into a hierarchy.  He believed that the laws applied to other inventions, or tools, regardless of whether they were robotic or not.  For instance, a tool, such as a chainsaw, must first be safe for the user.  That is its primary law; if it is not safe, then it is not useful.  The second law would dictate that the chainsaw must perform it’s job efficiently and effectively, as long as it does not break the first law.  It must do the proper job within the confines of being safe to use.  The third law would describe that the chainsaw must be safe to use unless the destruction of it is required for the safety of the user.  This third law may be more difficult to define for a tool like a chainsaw.  An example could be that the chainsaw automatically stops if it becomes too hot or binds and becomes a danger to the user.  A better example would be a car or truck; they are designed to crumble and be destroyed in an accident in order to better protect the passengers.  In this way, it sacrifices it’s own purpose and usefulness in order to save the occupants, even though it means the destruction of its own existence.  You can see that these laws are widely applicable and really can be applied to anything that humans interact with and use as tools, not just robots.

Loopholes to Asimov’s Laws

Are there any loopholes to these laws?  Asimov himself raised doubts.  A fictional character in the Robot series written by Asimov called Elijah Baley (a homicide detective in NYC) pointed out in the Naked Sun that there is a problem with the laws.  A robot could unknowingly break any of the laws.  He suggested that the first law should be restated so that the a robot may do nothing to its knowledge that will harm a human being nor, through inaction, knowingly allow a human being to come to harm.  The issue with this is that the robots could be tricked into nefarious activity; a robot could cut the brakes on a car, not knowing that this would cause a person to be killed in a car wreck later on.  In later books, the robots became more advanced.  They had the ability to weigh consequences.  For example, a robot may seek to break as few laws as possible instead of inaction.  An example is with robotic surgery, which Asimov wrote about in the Bicentennial Man.  If during surgery, an emergency procedure was necessary to save the patients life, but it would also inflict harm on the patient?  Many surgeries require making incisions, which could technically be interpreted as harm to the human.  Or, take the simple example of doing CPR.  Often, the chest compressions will result in the cracking and breaking of ribs.  This is clearly a conflict with the first law, which states that a human cannot be harmed.  But inaction by the robot would result in further harm – death of the patient.  In this case, the robot would accept that some harm is necessary for a better outcome.

The zeroth law states that a robot may not harm humanity, or by inaction allow humanity to come to harm.  What if the robots become intelligent enough to understand and realize that humans are incapable of governing themselves?  What if robots today realized that the destruction of earth is inevitable due to global warming?  Would the ultimate goal of protecting the human race mean that robots take over, and stop any production or activities that result in further global warming?  This would essentially necessitate a hostile robotic coup to save humanity from itself.

A Multidisciplinary Field

Robotics is a perfect example of being multidisciplinary.  Robotics isn’t a core engineering field like Civil or Mechanical engineering.  It is a field composed of multiple disciplines.  The primary ones are mechanical engineering, electrical engineering and computer/software engineering.  You may have your hand in a few of these fields, or general knowledge of them, but usually if you go work in the robotics industry you will focus in one area.  It’s difficult to be an expert in all fields of robotics.

The following are the broad areas of knowledge necessary to construct a robot:

• Kinematics/Dynamics
• Solid Mechanics
• Power electronics
• Computer Programming
• Control Systems
• Hardware and computer interfacing

The mechanical aspect varies.  Typically, it involves solving the kinematics and dynamics of a robot.  These concepts will be discussed in greater depth, but basically this means solving for the motion of the robot.  We, as humans, take for granted the incredible complexity of performing basic movements, such as picking up a coffee cup, raising it to our mouth, tipping it in the exact correct way, and returning the cup to the table.  Your brain automatically solves for how much force is required, the angle of your elbow, shoulder and wrist joints, the location of your fingers, the strength of your grip.  But for a robot to do the same task, extensive physics and math is required.  The robot doesn’t natively know any of these things.  We need to tell it everything.  We need to tell it how to angle it’s joints to reach the cup, how much torque is required at each joint in order to hold the cup, and the correct path to bring the cup through the air and to the target object.  It is relatively easy to determine forces and torques required in a static (non-moving) problem.  It becomes much more difficult with movement, because the forces are constantly changing and other factors such as inertia come into play.  A mechanical engineer is responsible for determining how the robot moves, which is not an easy task.  A mechanical engineer might also be responsible for determining what materials to use in constructing the robot.  A robot that needs to lift heavy objects or that moves quickly and subjected to high forces may require steel or high strength parts.  Another robot might easily be made of plastic instead.  Solid mechanics to determine the forces and stresses on the different parts of the robot may be required.  For robots where high forces are involved, finite element analysis might be required to ensure that the robot will be strong enough, stiff enough, and to ensure that the robot will not fail due to cyclic loading.  You don’t want a robot to fail during the 100th surgery it performs due to fatigue issues.  Mechanical designers would be responsible for developing CAD for various components.

Electrical and computer engineers would be responsible for many aspects, including the computer programming, building actuators (providing the robot the ability to move), circuits, and control systems.  Controls is a huge aspect of robotics that will also be discussed in more depth later on.  A control system essentially controls the robot.  There are two major types of control systems – open loop and closed loop.  An open loop control system, the output of the system is based purely on inputs.  This is like working the accelerator in a car.  When you depress the pedal (input) the engine is provided with more fuel (output).  A closed loop system is more what we’re interested in as related to robotics.  A closed loop system also takes the output into consideration, and will make corrections.  The human body is full of closed loop control systems.  For example, trying to balance on one leg.  Your control system continuously analyzes whether you are balanced or not and makes slight adjustments to keep you upright.  That is why you wave your arms around when trying to balance – those are slight corrections based on your current position.  An open loop system would not be able to make these corrections.  The input would be the direction to stand on your leg, and the output would be standing on one leg.  But if you begin to lose your balance and tip over, there is nothing preventing that from happening since there is no feedback from the system.  Another classic example for closed loop control systems is cruise control on a vehicle.  You set the speed – say at 70 km/h.  The car provides enough fuel to get to that speed, and then examines the output (the actual speed of the car) to determine if it is correct.  If it is not, then the car will will make adjustments by either providing more or less fuel to reach the desired speed.  Your speed might slow due if you are climbing a hill, or if the surface of the road changes, or if a headwind develops.  Robots generally required closed loop control systems.  They will use information from various sensors, such as position sensors or accelerometers, to analyze their surroundings and their own position within it.  As necessary, the robot will be able to make corrections based on valuable feedback from sensors.  As mentioned, electrical/computer engineers would also be responsible for all the circuitry building, robot sensing, and providing the robot with power.

You can see that there are many disciplines and areas of knowledge required!  This is by no means an exhaustive list, just a taste of the complexity that goes into building a robot.  Other engineers or other disciplines entirely may be involved in developing a robot that is effective at whatever job it performs, as the purpose of building robots is to perform a job in a specific area.  For example, robotics engineers building a surgical robot probably wouldn’t know the first thing about the human body or performing a surgery.  They would need the assistance of biomedical or clinical engineers, and surgeons.  A robot intended to move items in a warehouse would likely need input from industrial engineers.  Engineers building robots for search and rescue would need input from search and rescue experts.  The human interaction aspect of building a robot could potentially be extremely important.  If you are designing a robot for diffusing bombs, you would want to consult and work closely with bomb disposal experts to make sure that the interface for controlling the robot is as good as it can be for them to perform their job.

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