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Introduction to Drones and Robotics Explained

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TECHNOLOGY EXPLAINER

Introduction to Drones and Robotics
— The shared skeleton of robots and drones: sense, think, act

Robots and drones look like quite different machines. Yet both are built from a combination of sensing (sensors), thinking (control and intelligence) and acting (actuators). As the entrance to the drones-and-robotics series, this article lays out in plain terms what robots and drones are, the degrees of autonomy, adoption statistics, and the trade-off between lift and battery.

In the second half, we look through a materials engineer’s eyes at how robot and drone performance rests on materials and parts: gear steel, motor magnets, fingertip rubber, lightweight materials and batteries.

Sources: official material from ISO, NIST, IFR, the FAA and Japan’s MLIT, a peer-reviewed paper (IEEE RA-L), and an arXiv survey. Numerical examples are our own calculation. Checked 25 October 2026

Concept image (AI-generated). A scene where a robot and a drone are examined on the same bench. It is not a real aircraft or facility.
Fig. 1. Concept illustration generated with ImageGen. Concept image (AI-generated). A scene where a robot and a drone are examined on the same bench. It is not a real aircraft or facility. Not an actual product, facility or measurement. Cutaways, colours and arrows explain the concept; proportions are illustrative.
Contents
  1. Short version / before you read / place in the series
  2. What is a robot?
  3. What is a drone?
  4. Sense, think, act
  5. A map of the kinds
  6. Degrees of autonomy
  7. Where robots stand (IFR statistics)
  8. Drone basics: thrust, weight, battery
  9. Through a materials engineer’s eyes
  10. Limits and summary
  11. How to read the yardsticks and standards
  12. Glossary
  13. References
  14. Claim-to-source audit
How to read the labels in this article

Sourced = stated in a published source (link given)
Our calculation = a value this article calculated from stated assumptions
Not yet confirmed = drafts, plans, targets and other items that are not settled
Our own readings for materials and design are marked as commentary. Inference is shown in bold. Every analogy comes with its limits.

How to read the numbers in this article

The flight times in Chapter 8 are examples from a simple model calculated under stated assumptions, not the performance of any real aircraft. IFR statistics are used as figures published by the federation itself; market estimates from research firms are not used. For ISO standards only the number, title, edition and stage were checked, not the paid text. This field moves quickly, so the state of standards and rules carries a check date (25 October 2026). No company, aircraft or country is ranked.

1. The short version / what to know first / where this fits in the series

  • Robots and drones are both a combination of “sense, think, act”. Sensors tell the machine about its surroundings, control and intelligence decide, and actuators (the parts that act as the robot’s muscles) move it. NIST also defines autonomy as sensing, perceiving, analyzing, planning, deciding and acting taken togetherSourced[Ref. 5]
  • “Autonomous” comes in steps. NIST splits it into four modes, from remote control by a person all the way to fully autonomous operationSourced[Ref. 5]. “Runs automatically” is not the same as “is autonomous”.
  • Much of the performance comes from parts and materials. On a simple model, a 1.0 kg aircraft hovers for about 22 minutes with a 0.5 kg battery, and only about 31 minutes with 2.0 kg, where the gain levels offOur calculation. A bigger battery makes the aircraft heavier.
What to know before reading

No prior knowledge is needed. It is enough to picture a machine that looks around, thinks, and moves its body. Each technical term is explained where it first appears and is collected in the glossary at the end (25 entries). This article is the entrance to the whole drones-and-robotics series: the words and analogies fixed here keep the same meaning in the other articles.

Where this sits in the series

The series can be read in five groups: (1) parts and materials (speed reducers and gears, joint actuators, robot hands and grasping, tactile sensors and electronic skin, soft robots, structural materials, power sources, permanent magnets, LiDAR and more); (2) intelligence and control (robot control, SLAM, vision, imitation and reinforcement learning, foundation models, simulation, teleoperation); (3) kinds of robots (industrial and collaborative, humanoid, legged, warehouse, surgical, underwater, micro, agricultural and construction); (4) drones (multicopters, fixed-wing and VTOL, communication and positioning, logistics, eVTOL); and (5) institutions and strategy (safety standards, regulation and airspace, national strategies). This article is the common base for all of them.

2. What is a robot? In the words of the international standard

“Robot” does not mean only a human-shaped machine. ISO 8373, the international standard for robotics vocabulary, defines a robot as a programmed actuated mechanism with a degree of autonomy that performs locomotion, manipulation or positioning. This is the definition the International Federation of Robotics (IFR) uses when it compiles statisticsSourced[Ref. 2, 1].

The “degree of autonomy” here means the ability to carry out an intended task from the current state and sensor input without human intervention. For service robots it ranges from partial autonomy, where a person helps, to full autonomySourced[Ref. 3].

CategoryKey point of the definitionFamiliar examples
Industrial robotAn automatically controlled, reprogrammable, multipurpose manipulator (arm) programmable in three or more axes, for factory automationSourced[Ref. 2]Arms for welding, painting, assembly
Service robotA robot in personal or professional use that performs useful tasks for humans or equipmentSourced[Ref. 3]Cleaning, delivery, guidance, inspection
Medical robotA robot intended for use as medical electrical equipment or systems; a third category next to industrial and service robots in the 2021 editionSourced[Ref. 3]Surgical robots (in another article)
Mobile robotA robot able to travel under its own control; it may also have a means of remote controlSourced[Ref. 2]Delivery vehicles, legged robots, humanoids

Source: IFR pages quoting ISO 8373. The definitions are paraphrased; the paid standard text was not checked.

Common misunderstanding: “a robot is a human-shaped machine” and “robot counts are all autonomous machines”

The facts: The definition above has no condition about a human shape. A factory arm is a robot. IFR itself explains that its service-robot statistics include systems with human-robot interaction and even fully teleoperated systemsSourced[Ref. 3]. When you read a robot count, check what was counted.

3. What is a drone? In the words of aviation

“Drone” is the everyday word. The rules call it an unmanned aircraft. The US federal rule (14 CFR § 107.3) defines an unmanned aircraft as an aircraft operated without the possibility of direct human intervention from within or on the aircraft, and a small unmanned aircraft as one weighing less than 55 pounds (about 25 kg) on takeoffSourced[Ref. 6]. That weight includes everything on board.

In Japan, every unmanned aircraft (drones and radio-controlled aircraft) of 100 g or more flown outdoors must be registered, carry its registration mark and have a remote ID function by lawSourced[Ref. 8]. ISO 21384-4:2025, the international vocabulary for uncrewed aircraft systems, was published in July 2025Sourced[Ref. 20].

In research, drones are also called “aerial robots”, and survey papers organize their types and issuesSourced[Ref. 11]. This series also treats robots and drones in one framework (sense, think, act). Whether a given aircraft counts as a “robot” under ISO 8373, however, was not checked, because the standard text is paid.

4. The skeleton they all share: sense, think, act

Start with an everyday example. When you pick up a bottle, your eyes check where it is (sense), you decide where to reach (think), and your arm muscles move (act). A robot replaces these three with machine parts.

Arms and drones repeatedly sense, decide, act and observe the result. AI can assist perception and action selection; power and safety systems remain essential.
Fig. 2. Concept illustration generated with ImageGen. Arms and drones repeatedly sense, decide, act and observe the result. AI can assist perception and action selection; power and safety systems remain essential. Not an actual product, facility or measurement. Cutaways, colours and arrows explain the concept; proportions are illustrative.
Original SVG, detailed explanation and sources
Robots and drones are both built on a “sense, think, act” loop 1. Sense sensors 2. Think control and intelligence 3. Act actuators Arm: joint angles, camera, force sensors Drone: tilt and rotation sensors, GPS, camera Arm: plans the path to the target Drone: keeps level and decides the route Arm: motors and reducers turn joints Drone: motors spin the propellers The environment (objects, wind, floor, air, people) forces, motion light, force, tilt * The loop repeats at high speed. Different robots share the same skeleton (our summary).

Original SVG reference: Concept diagram (vector drawing). Two example machines (a robot arm and a drone) are shown side by side. The contents differ, but the repeated cycle of sensing, thinking, acting, the environment changing and sensing again is the same. The parts are conceptual examples, not the build of any model.

(1) Sense: sensors

Sensors turn joint angle, tilt, force, distance and images into electrical signals. Cameras and LiDAR (a device that measures distance with laser light) are typical. LiDAR is covered in the LiDAR article of this series, and touch in the article on tactile sensors and electronic skin.

(2) Think: control and intelligence

This is the part that decides which joint to move, how much, and when. There is control, which repeats a fixed procedure accurately, and intelligence, which judges according to the situation. Estimating your own position while building a map of the surroundings is called SLAM (simultaneous localization and mapping).

(3) Act: actuators

An actuator turns energy such as electricity into force and motion; it is the robot’s muscle. Most are a motor combined with a speed reducer. A reducer slows the motor’s fast rotation to gain force, much like a bicycle gear (where the analogy stops: real reducers lose energy to friction and have play between the teeth; see the article on speed reducers and gears).

Where people get stuck 1: what are “degrees of freedom”?

Degrees of freedom (DOF) is the number of directions in which the joints can move. The human arm is often described as having seven (shoulder, elbow and wrist together; a textbook summary), which lets it grasp objects in any orientation. Six-axis arms are common in factories (commentary). IFR’s definition likewise requires an industrial robot to be programmable in three or more axesSourced[Ref. 2].

Drones need care too. An aircraft in the air has six motions: three of position and three of attitude. A common quadcopter, however, has only four independently controlled quantities (the speeds of its four propellers). The rest are achieved by combining them, for example tilting to move sideways (commentary).

Where people get stuck 2: what is “physical AI”?

Talk about robot intelligence often brings up “physical AI” and “robot foundation models”. In this article, read them as AI that has learned general ways of moving from the experience of many robots. Where the analogy stops: even when such AI looks general-purpose, it can be weak in situations it has not learned. See the articles on world models and embodied AI, and on robot foundation models and VLA.

5. A map of the kinds — tell them apart with three questions

A map of robot and drone types (this series) Robots (grouped by the ISO 8373 terms) Industrial robots Mostly multi-axis arms: welding, assembly, handling Service robots Personal or professional: cleaning, delivery, inspection Medical robots Robots used as medical equipment (third category, 2021) Mobile robots: robots that travel under their own control Delivery, legged and humanoid robots (cut across the groups) Drones (unmanned aircraft) Multicopters Several rotors; take off vertically and can hover Fixed-wing Wings give lift; far and fast, but need a runway or launch VTOL and hybrids Combine vertical take-off with wing-borne cruise In law: classes are set by weight US: under 55 lb; Japan: registration from 100 g Shared foundation: sense, think, act / power / communication / structural materials The rest of the series covers these parts and the machines that use them * The grouping is this series’ own. We did not check the paid ISO 8373 text on whether a given aircraft counts as a “robot”.
Fig. 3 Concept diagram (vector drawing). Robots are grouped by the ISO 8373 terms and drones by how they fly. “Mobile robots” is a view that cuts across the three robot categories. The grouping and examples are this series’ own summary, not the standard’s classification table.

When you meet a new machine, ask these three questions.

  1. Where does it work? (factory floor, warehouse, outdoor ground, air, water, inside the body)
  2. What does it do? (grasp, carry, look, measure, cut)
  3. Who decides? (a person operates all the time, a person supervises, the machine is trusted)

Once you have the three answers, you can roughly see which parts matter and which rules and standards apply. For “in the air, carrying parcels, flying itself”, for example, lightness, batteries and aviation rules are central.

6. Degrees of autonomy: remote control, semi-autonomous, fully autonomous

The word “autonomous” may bring to mind a machine that decides everything. In practice the split between person and machine has steps. The glossary compiled by NIST (ALFUS) divides the operation of unmanned systems into four modesSourced[Ref. 5].

There are steps between “piloted” and “autonomous” 1. Four operating modes (NIST ALFUS) Remote control A person watches and steers all the time; the machine takes no initiative Teleoperation A person uses sensor feedback to drive it or set small goals Semi-autonomous Shared planning; machine acts alone between human inputs Fully autonomous Finishes a defined mission alone, adapting to conditions Arrow (down): more machine decisions 2. Japan’s drone flight levels (line of sight and people below) Level 1 Piloted, in sight Level 2 Automatic, in sight Level 3 Out of sight, over unpopulated areas Level 4 Out of sight, over populated areas Level 4: flight out of sight, with no observers, over third parties ALFUS rates autonomy on three axes: human independence, mission complexity, environmental complexity “Runs automatically” is not enough: ask what it does, where, and without human help * The two scales are different (ALFUS covers unmanned systems in general; the levels are for drone operations in Japan).
Fig. 4 Concept diagram (vector drawing). Left: the four operating modes of NIST ALFUS, in brief. Right: Japan’s drone flight Levels 1 to 4 (MLIT and Cabinet Secretariat material). They are separate scales and are not meant to be matched one to one. The mode descriptions are paraphrases.

Japan’s drone flight levels depend on whether the flight is piloted or automatic, in sight or out of sight, and whether there are people below. Level 4 is out-of-sight flight with no observers over populated areas (over third parties); it became possible on 5 December 2022 once aircraft certification, pilot licensing and operating rules were in placeSourced[Ref. 7][Ref. 9].

ALFUS also offers a framework that rates autonomy on three axes: (1) human independence (how much human help is needed), (2) mission complexity and (3) environmental complexitySourced[Ref. 5]. Even among “automatic” machines, shuttling back and forth on a tidy factory floor and delivering a parcel outdoors in wind while dodging obstacles are quite different problems.

Common misunderstanding: “every humanoid video shows a robot acting on its own”

The facts: A video alone does not tell you whether the robot is autonomous or teleoperated. ALFUS formally separates teleoperation and remote control as operating modesSourced[Ref. 5]. When you watch a demonstration, check whether it was autonomous or teleoperated, how many units were tried for how long, what the task was, and whether a third party verified it. Treat a demonstration without these details as a company claim, not as proof of capability.

Where people get stuck 3: how do “automatic” and “autonomous” differ?

Automatic means following a procedure fixed in advance. Autonomous means sensing the situation, deciding for itself, and coping with the unexpected (commentary). A factory arm that follows the same path every time is automatic; a warehouse robot that dodges people and parcels and changes its destination is closer to autonomous. The boundary is blurry, and ALFUS treats it as steps.

7. Where robots stand: reading the IFR statistics

A good clue to how widely robots are used is the statistics that the International Federation of Robotics (IFR) publishes each year. According to IFR’s World Robotics 2025, 542,076 industrial robots were installed worldwide in 2024, the second highest ever after 2022 (552,946). At the end of 2024, 4,663,698 industrial robots were in operation (+9% on the year)Sourced[Ref. 4].

New industrial robot installations (IFR, 2025 edition) 1. Annual installations (world) 552,946 2022 541,302 2023 542,076 2024 Units. Operational stock in 2024: 4,663,698 (+9% on the year) 2. 2024 installations by customer industry (units) Electrical/electronics 128,899 Automotive 126,088 Metal and machinery 88,777 All others 77,752 Unspecified 73,277 Plastic and chemical 26,491 Food 20,792 Orange: plastic and chemical (about 5%, 26,491 units) “Unspecified” means the customer industry was not reported About 54% of world installations were in China (295,045); Japan 44,453; United States 34,164
Fig. 5 Concept diagram (vector drawing). The values are those published in IFR’s World Robotics 2025 (Executive Summary). “Installations” are units newly installed in the year; the “operational stock” is the total in use. The statistics cover industrial robots only, not drones or humanoids.
  • The largest customer was electrical/electronics (128,899 units, 24%), narrowly ahead of automotive (126,088). Metal and machinery took 88,777, plastic and chemical products 26,491 (about 5%), and food 20,792Sourced[Ref. 4].
  • By region, Asia took 401,665 units (74%) and China 295,045 (54%). Japan had 44,453 and the United States 34,164Sourced[Ref. 4].
  • Outlook: IFR expects 575,000 units in 2025 and more than 700,000 by 2028. These are IFR’s own forecasts, not settled numbersNot yet confirmed[Ref. 4].

A note on reading: this statistic counts industrial robots. “Counts” of service robots, humanoids and drones have different definitions and collection methods. This article does not use market-size estimates from research firms or figures reported only in the news.

8. Drone basics: thrust versus weight, and the battery trade-off

The condition for a drone to rise is simple: if thrust (the upward force the propellers get by pushing air down) is at least the weight (gravity), it lifts off. If thrust equals weight, the drone stays still in the air; this is called hovering.

The power needed to hover can be estimated with a basic theory called momentum theory. A multicopter study (Bauersfeld and Scaramuzza, 2022) gives the following formulaSourced[Ref. 10].

The formula for mechanical hover power

Ph = (m g)3/2 / ( ηP · √(2 ρ π Nr r2) )

In words: the heavier the aircraft (mass m, in kg), the more power it needs, rising with the 1.5th power of weight. More propellers (Nr) and larger radius r (a wider area of air pushed) need less power. ρ is air density (about 1.225 kg/m³), g is gravitational acceleration, and ηP is the propeller efficiency, called the figure of merit (0.5 to 0.7 is typical; 0.6 is used here)Sourced[Ref. 10].

Checking with numbers (Our calculation): an aircraft with 1.0 kg of non-battery mass and a 0.5 kg battery (1.5 kg in total), four propellers of 0.127 m radius (10-inch diameter), ηP = 0.6 and 80% motor efficiency. The weight is 1.5 x 9.81 = about 14.7 N. The formula gives about 133 W of mechanical power, or 133 / 0.8 = 167 W of electrical power. Assuming a battery of 150 Wh/kg and 80% usable, the usable energy is 0.5 x 150 x 0.8 = 60 Wh. 60 / 167 = 0.36 hours, or about 22 minutes.

Lift needs thrust at least equal to weight; a bigger battery also adds weight When hovering (staying still in the air) Aircraft 1.5 kg thrust thrust weight (gravity) 1.5 kg x 9.81 m/s² = about 14.7 N Four propellers must give 14.7 N in total Thrust > weight: climbs / thrust < weight: sinks Hover time as the battery grows (our calculation) 0 10 20 30 0 1 2 3 4 5 6 Battery mass (kg). The rest of the aircraft is fixed at 1.0 kg Flight time (min) Battery 0.5 kg: about 22 min Battery 2.0 kg: about 31 min (peak) Too much battery: time falls More weight needs more power, so the gain flattens out
Fig. 6 Drawing based on our own calculation (vector drawing). Left: the balance of forces. Right: hover time as the battery on a 1.0 kg (non-battery) aircraft is varied from 0 to 6 kg. Assumptions: four propellers (0.127 m radius), ηP = 0.6, 80% motor efficiency, 150 Wh/kg of which 80% is used. This is a simple model for the trend, not the performance of a real aircraft (structure and battery discharge behavior are ignored).

In the graph, doubling the battery from 0.5 kg to 1.0 kg lengthens the flight only from about 22 to about 28 minutes. The maximum of about 31 minutes comes near 2 kg, and adding more makes it shorterOur calculation. A bigger battery adds weight, and the power needed grows with the 1.5th power of weight.

The effect of going lighter (Our calculation): if the aircraft is 10% lighter, the power needed is 0.91.5 = about 0.85 times, a cut of about 15%. Conversely, 10% heavier needs 1.11.5 = about 1.15 times, about 15% more. This is why lightening the aircraft with better parts and materials helps both flight time and payload.

Common misunderstanding: “a bigger battery lets it fly as long as you like”

The facts: As the calculation shows, a bigger battery makes the aircraft heavier and the gain levels off. Real batteries also deliver less energy when drawn hard (the Peukert effect). Bauersfeld and Scaramuzza use a battery model that captures this, and in six example aircraft their estimated range and endurance were almost always within 10% of the manufacturers’ specificationsSourced[Ref. 10]. Real flight time varies with weight, wind, speed, temperature and battery condition.

Where people get stuck 4: how to read the figure

In the right-hand graph, the horizontal axis is battery mass and the vertical axis is flight time. Read it in order: (1) the left end has no battery, so no flight; (2) it climbs quickly (a little battery is enough to fly); (3) it flattens (the effect of weight starts to show); (4) it passes a peak and falls. The position of the peak (2 kg here) depends on aircraft weight and propeller size (a result of the assumed simple model).

9. Robots and drones through a materials engineer’s eyes

Let us look at the story so far through the eyes of materials and parts. The brain (software) of a robot or drone tends to get the attention, but what often sets the limits of motion, force, lifetime and weight are the parts and materials.

Steel gears, copper windings, composites, polymer covers and rubber mounts serve different mechanical, electrical, weight, radio and vibration-management roles.
Fig. 7. Concept illustration generated with ImageGen. Steel gears, copper windings, composites, polymer covers and rubber mounts serve different mechanical, electrical, weight, radio and vibration-management roles. Not an actual product, facility or measurement. Cutaways, colours and arrows explain the concept; proportions are illustrative.
Original SVG, detailed explanation and sources
Performance rests on parts and materials (concept diagram) Robot arm Joint: motor (magnet, copper) + reducer (steel) Links: aluminium, CFRP, polymer Fingertips and hand: rubber covering, tactile sensors Base and cables: bending life of cables Steel, magnets and rubber set force, life and dexterity Drone (multicopter) Propellers: polymer, CFRP (light and stiff) Motors: magnets, copper, bearings Battery: lithium-based (heavy part) Frame and boards: CFRP, polymer, heat-spreading Lightness, battery and magnets set flight time and payload * Layout and material names are generic examples, not the build of any specific model.

Original SVG reference: Concept diagram (vector drawing). Parts of a robot arm and a multicopter, and the materials that matter in each. Layout and material names are generic examples, not the build of a specific model. Each part is covered in more detail in the relevant article of this series.

A materials engineer’s view 1: lightness and strength mean different things in each part

A reducer gear in a joint, for example, needs fatigue strength to endure repeated loads and surface hardness to resist wear (the world of steel and heat treatment). A motor magnet needs strong magnetism that it keeps as the temperature rises (the world of rare earths). A drone propeller or frame needs lightness and stiffness. As Chapter 8 showed, a 10% lighter aircraft needs about 15% less power, so weight saving connects directly to flight time (Our calculation).

A materials engineer’s view 2: trade-offs among weight, strength, lifetime and cost, and heat

A robot joint produces large force in a small volume and moves millions of times. Here wear, fatigue and temperature rise decide the lifetime. A battery, too, becomes harder to manage thermally and against degradation as its energy per unit weight rises. Making something lighter lowers strength or lifetime, making it stronger makes it heavier, and being both raises the cost. Robot and drone design is a tug of war among these four (commentary). Heat is covered in the joint actuators article and batteries in the article on power sources.

Concept image (AI-generated). A scene of robot and drone parts laid out to be viewed as materials. It is not a real product or facility.
Fig. 8. Concept illustration generated with ImageGen. Concept image (AI-generated). A scene of robot and drone parts laid out to be viewed as materials. It is not a real product or facility. Not an actual product, facility or measurement. Cutaways, colours and arrows explain the concept; proportions are illustrative.
PartTypical materials (examples)What matters in the materialSeries article with details
Speed reducerAlloy steel, heat treatment, lubricantFatigue strength, surface hardness, wearSpeed reducers and gears
MotorNeodymium magnets, copper wire, electrical steelMagnetism, coercivity (heat resistance), lossesPermanent magnets and rare earths; joint actuators
Fingertip and skinSilicone and urethane rubber, conductive materialsFriction, softness, durability, sensitivityRobot hands and grasping; tactile sensors and electronic skin
Lightweight structureAluminium, CFRP, polymersSpecific strength, stiffness, fatigueStructural materials for robots and drones
BatteryLithium-based electrodes and electrolytesEnergy per weight, power, heatLithium-ion battery basics; thermal runaway and battery safety; power sources for robots and drones

Material names are general examples. This table is our own commentary; individual values are given with sources in each article.

10. Limits, what could not be confirmed, and a summary

  • The paid text of ISO 8373 was not checked. The robot definitions rely on the wording quoted on IFR’s pages. Whether a drone counts as a robot under ISO 8373 was not checked either.
  • No drone count or market statistics are used. Estimates by research firms are excluded, and no association-published statistic for the total number of drones was found.
  • Counts of humanoids and service robots are not covered. Only the IFR industrial robot statistics are used.
  • The calculation in Chapter 8 is a simple model. Structure, battery discharge behavior, wind, flight speed and motor variation are ignored. The numbers show a trend and are not the performance of a real aircraft.
  • Drone regulation outside the US and Japan (for example EASA in the EU) is not covered here. It is covered in the series article on drone regulation and airspace management.
Summary
  • Robots and drones both run on a sense-think-act loop. ISO 8373 defines a robot as a programmed actuated mechanism with a degree of autonomy that performs locomotion, manipulation or positioningSourced
  • Autonomy comes in steps. NIST has four modes and Japan has four drone flight levels. A demonstration video is a company claim until you confirm whether it was autonomous or teleoperatedSourced
  • 542,076 industrial robots were installed worldwide in 2024 and 4,663,698 were in operation (IFR). Plastic and chemical customers took about 5%Sourced
  • A drone lifts when thrust is at least its weight. Required power rises with the 1.5th power of weight, so a bigger battery gives diminishing returns (in a simple model, a 1.0 kg aircraft peaks at about 31 minutes near a 2 kg battery)Our calculation
  • Much of the performance is set by parts and materials. Gear steel, motor magnets, fingertip rubber, lightweight airframe materials and batteries underpin motion, force, lifetime and flight time (commentary)

11. How to read the yardsticks and standards

The “quality” of a robot or drone cannot be expressed by one number. For a robot we measure how accurately it can repeat a position (repeatability), how much load it can handle, and whether it is safe near people. For a drone the yardsticks are how many minutes it can fly, how much it can carry, and who may fly it in which airspace. What matters most is the conditions under which the number was measured: the same word, “accuracy”, gives different numbers under different test conditions. The table below organizes what could be confirmed (checked on 25 October 2026).

What is evaluatedTypical tests and benchmarks (name, source)Standards, rules and guidance (ISO, NIST, FAA and others)Reading notes
Terms and categories— (a vocabulary, not an evaluation)ISO 8373:2021 (published November 2021; stage 90.92 “to be revised”; successor ISO/DIS 8373 under development)[Ref. 1]Not yet confirmedThe basis for what counts as a “robot”. It is under revision, so a future edition may change the definition
Industrial robot accuracy and performanceTest methods for pose repeatability and similar (ISO 9283)ISO 9283:1998 “Manipulating industrial robots — Performance criteria and related test methods” (confirmed in 2021, now under review)[Ref. 16]SourcedCheck the test conditions (load, speed, posture) behind a catalog repeatability value. The test details were not checked (paid text)
Industrial robot safetyNot found (safety is shown by conformity to requirements, not by a performance number)ISO 10218-1:2025 (the robot itself) and ISO 10218-2:2025 (robot applications and cells), both published February 2025[Ref. 13, 14]SourcedA standard usually binds only when cited by law or contract (commentary). The requirements themselves were not checked
Safety of personal care robotsNot foundISO 13482:2014 (February 2014, confirmed in 2020; the page says it is expected to be replaced by ISO/FDIS 13482)[Ref. 15]SourcedNot yet confirmedCovers mobile servant, physical assistant and person-carrier robots (per the ISO page). The replacement is still at the planned stage
Service robot performanceTest methods for wheeled locomotion (Part 1), navigation (Part 2) and manipulation (Part 3)ISO 18646-1:2016 (confirmed), -2:2024 (January 2024) and -3:2021 (June 2021, under review)[Ref. 17, 18, 19]SourcedEach part has a different scope. Parts for legged robots and others show a development stage and are not covered here
Drone vocabulary— (a vocabulary)ISO 21384-4:2025 (published July 2025)[Ref. 20]SourcedThe words “drone”, “unmanned aircraft” and “UAS” differ between rules and sources
Drone rules and classes— (rules, not a benchmark)US 14 CFR § 107.3 (small unmanned aircraft: under 55 pounds)[Ref. 6]Sourced. Japan: registration and remote ID from 100 g, and the Level 4 system (started 5 December 2022)[Ref. 8, 7]SourcedRules differ by country and are amended. Weight classes differ by country (see the series article on drone regulation and airspace management)
Degree of autonomyNIST ALFUS: four operating modes and three axes (human independence, mission complexity, environmental complexity)[Ref. 5]SourcedNIST SP 1011-I-2.0 (October 2008): a terminology document, not a binding standard (commentary)Autonomy is not one number: ask what it does, where, and without human help
Flight time and rangeBauersfeld et al. model: in six example aircraft, estimates were almost always within about 10% of manufacturer specifications[Ref. 10]SourcedNot found (no unified international test standard for flight time was found in this survey)A catalog flight time depends on load, speed, temperature and battery state. Do not rank numbers measured under different conditions
Adoption statisticsIFR World Robotics 2025 (installations and operational stock of industrial robots)[Ref. 4]Sourced— (statistics, not a standard)Industrial robots only. The forecast is IFR’s own outlook, not settled

The table layout is our organization (Our calculation). Numbers, titles and stages were checked on each body’s official page (checked 25 October 2026). Standard texts are paid, so only titles and scope are given.

Reading notes (for materials engineers)

  • A demonstration, a benchmark and a real site are three different things. What you see at a trade show or in a video is a staged demonstration. A benchmark compares on a fixed task, while a real factory or outdoor site adds dirt, temperature swings and people moving about.
  • A manufacturer’s stated value and third-party verification are different. Catalog values are measured under conditions the maker chose. Do not compare numbers whose conditions are not stated.
  • Standards may be recommendations or requirements. An ISO standard generally binds only when cited by law or contract (commentary). National rules such as 14 CFR or the Japanese Aviation Act, in contrast, are legally binding.
  • A plan and an achievement are different. IFR’s forecast and drafts under revision such as ISO/DIS 8373 are not settled facts.

12. Glossary

Robot
Under ISO 8373, a programmed actuated mechanism with a degree of autonomy that performs locomotion, manipulation or positioning.
Industrial robot
An automatically controlled, reprogrammable, multipurpose manipulator (arm) programmable in three or more axes.
Service robot
A robot in personal or professional use that performs useful tasks for humans or equipment.
Mobile robot
A robot able to travel under its own control.
Sensor
A part that turns distance, angle, force or images into electrical signals. It handles “sense”.
Control
Computing commands to the actuators to follow a set procedure or target.
Actuator
A part that turns energy such as electricity into force and motion; the robot’s muscle.
Speed reducer
A part that slows the motor’s rotation to gain force; similar to a bicycle gear.
Degrees of freedom (DOF)
Degrees of freedom: the number of directions in which joints can move.
SLAM
Simultaneous localization and mapping: estimating your own position while building a map.
Physical AI / robot foundation model
AI that has learned general ways of moving from the experience of many robots; it can be weak in situations it has not learned.
Autonomy
The ability to perform intended tasks from the current state and sensing without human intervention.
Remote control / teleoperation
Operation by a person from a distance. In ALFUS they are separate operating modes.
ALFUS
Autonomy Levels for Unmanned Systems: terminology and a framework for autonomy compiled by NIST.
Unmanned aircraft / UAS
Unmanned aircraft system: an aircraft with no person on board together with its control and communication elements.
Multicopter
An aircraft with several rotors that can take off and land vertically and hover.
Fixed-wing
An aircraft that gets lift from wings; flies far and fast but needs a runway or launch.
VTOL
Vertical take-off and landing.
Thrust
The force a propeller gets by pushing air; equal to weight in a hover.
Hover
Staying still in the air.
Figure of merit (FM)
Propeller efficiency: ideal power divided by actual power. Typically 0.5 to 0.7.
Payload
The weight an aircraft can carry as load, including sensors and the like.
BVLOS
Beyond visual line of sight: flight outside what the pilot can see.
Installations / operational stock
In IFR statistics, units newly installed in the year / the total in use.
ISO/TC 299
The ISO technical committee responsible for robotics standards.

13. References (primary sources)

  1. ISO ISO 8373:2021 “Robotics — Vocabulary” (Edition 3, November 2021; ISO page; stage 90.92 “to be revised”, successor ISO/DIS 8373 under development) — iso.org/standard/75539.html
  2. IFR “Standardisation” (quotes the ISO 8373 robot definitions that IFR uses for its statistics) — ifr.org/standardisation
  3. IFR “Service Robots” (service-robot definition, degree of autonomy, medical robots as a third category) — ifr.org/service-robots/
  4. IFR “World Robotics 2025 – Industrial Robots”, Executive Summary (2025; statistics published by the federation itself) — ifr.org/img/worldrobotics/Executive_Summary_WR_2025_Industrial_Robots.pdf
  5. NIST Huang H.-M. (ed.) “Autonomy Levels for Unmanned Systems (ALFUS) Framework, Volume I: Terminology, Version 2.0”, NIST Special Publication 1011-I-2.0 (October 2008) — nist.gov/document/nistsp1011-i-2-0pdf
  6. U.S. Federal Aviation Administration / eCFR 14 CFR § 107.3 “Definitions” (small unmanned aircraft: less than 55 pounds on takeoff) — ecfr.gov/current/title-14/part-107/section-107.3
  7. Ministry of Land, Infrastructure, Transport and Tourism (MLIT) “Level 4 Flight Portal for Unmanned Aircraft” (in Japanese; definition of Level 4 flight, system started on 5 December 2022) — mlit.go.jp/koku/level4/
  8. MLIT “General Portal for Unmanned Aircraft” (in Japanese; registration of aircraft of 100 g or more, and other rules) — mlit.go.jp/koku/info/
  9. Cabinet Secretariat, Office for Small Unmanned Aerial Vehicles (Japan) “Realizing Level 4 flight and beyond”, March 2022 (in Japanese; diagram of drone flight Levels 1 to 4) — mlit.go.jp/common/001475188.pdf
  10. Bauersfeld L., Scaramuzza D. “Range, Endurance, and Optimal Speed Estimates for Multicopters”, IEEE Robotics and Automation Letters 7(2), 2953–2960 (2022), DOI 10.1109/LRA.2022.3145063 (arXiv:2109.04741) — arxiv.org/abs/2109.04741
  11. Liew C. F. et al. “Recent Developments in Aerial Robotics: A Survey and Prototypes Overview”, arXiv:1711.10085 (2017) — arxiv.org/abs/1711.10085
  12. Siciliano B., Khatib O. (eds.) Springer Handbook of Robotics, 2nd ed., Springer (2016), DOI 10.1007/978-3-319-32552-1 — doi.org/10.1007/978-3-319-32552-1
  13. ISO ISO 10218-1:2025 “Robotics — Safety requirements — Part 1: Industrial robots” (Edition 3, February 2025) — iso.org/standard/73933.html
  14. ISO ISO 10218-2:2025 “Robotics — Safety requirements — Part 2: Industrial robot applications and robot cells” (Edition 2, February 2025) — iso.org/standard/73934.html
  15. ISO ISO 13482:2014 “Robots and robotic devices — Safety requirements for personal care robots” (February 2014; confirmed in 2020; the page says it is expected to be replaced by ISO/FDIS 13482) — iso.org/standard/53820.html
  16. ISO ISO 9283:1998 “Manipulating industrial robots — Performance criteria and related test methods” (April 1998; confirmed in 2021; stage 90.60 “under review”) — iso.org/standard/22244.html
  17. ISO ISO 18646-1:2016 “Robotics — Performance criteria and related test methods for service robots — Part 1: Locomotion for wheeled robots” (September 2016, confirmed) — iso.org/standard/63127.html
  18. ISO ISO 18646-2:2024 “Robotics — Performance criteria and related test methods for service robots — Part 2: Navigation” (January 2024) — iso.org/standard/82643.html
  19. ISO ISO 18646-3:2021 “Robotics — Performance criteria and related test methods for service robots — Part 3: Manipulation” (June 2021; stage 90.60 “under review”) — iso.org/standard/73591.html
  20. ISO ISO 21384-4:2025 “Uncrewed aircraft systems — Part 4: Vocabulary” (July 2025) — iso.org/standard/85053.html

14. Claim-to-source audit

Claim in the textBasisType
ISO 8373 definitions of robot, industrial robot and mobile robot, and that IFR uses them for statisticsIFR standardisation page
Reference 2 https://ifr.org/standardisation
Sourced
Service robot and degree-of-autonomy definitions, medical robots as third category, and that IFR statistics include teleoperated systemsIFR service robots page
Reference 3 https://ifr.org/service-robots/
Sourced
Edition, date and stage (90.92) of ISO 8373:2021, and ISO/DIS 8373 under developmentISO page
Reference 1 https://www.iso.org/standard/75539.html
SourcedNot yet confirmed
Definition of autonomy (sensing, perceiving, analyzing, planning, deciding, acting), four operating modes, three axesNIST SP 1011-I-2.0
Reference 5 https://www.nist.gov/document/nistsp1011-i-2-0pdf
Sourced
Definitions of unmanned aircraft and small unmanned aircraft (under 55 pounds)14 CFR § 107.3
Reference 6 https://www.ecfr.gov/current/title-14/part-107/section-107.3
Sourced
Registration and remote ID from 100 g, definition and start of Level 4 (5 December 2022), diagram of Levels 1 to 4Two MLIT pages and a Cabinet Secretariat document
Reference 8 https://www.mlit.go.jp/koku/info/
Reference 7 https://www.mlit.go.jp/koku/level4/
Reference 9 https://www.mlit.go.jp/common/001475188.pdf
Sourced
Title and date of ISO 21384-4:2025 (July 2025)ISO page
Reference 20 https://www.iso.org/standard/85053.html
Sourced
Numbers, titles, editions and stages of ISO 10218-1/-2:2025, ISO 13482:2014 and ISO 9283:1998ISO pages
Reference 13 https://www.iso.org/standard/73933.html
Reference 14 https://www.iso.org/standard/73934.html
Reference 15 https://www.iso.org/standard/53820.html
Reference 16 https://www.iso.org/standard/22244.html
SourcedNot yet confirmed
Numbers, titles, editions and stages of ISO 18646-1:2016, -2:2024 and -3:2021ISO pages
Reference 17 https://www.iso.org/standard/63127.html
Reference 18 https://www.iso.org/standard/82643.html
Reference 19 https://www.iso.org/standard/73591.html
Sourced
2024 installations 542,076, 2022 552,946, 2023 541,302, stock 4,663,698, counts by industry and region, forecasts for 2025 and 2028IFR World Robotics 2025 Executive Summary
Reference 4 https://ifr.org/img/worldrobotics/Executive_Summary_WR_2025_Industrial_Robots.pdf
SourcedNot yet confirmed
The hover-power formula, propeller efficiency 0.5 to 0.7 (typical), the Peukert effect, and estimates within about 10% of manufacturer specifications for six aircraftBauersfeld and Scaramuzza (2022)
Reference 10 https://arxiv.org/abs/2109.04741
Sourced
Drones are also called aerial robots, and surveys of their types and issues existLiew et al. survey
Reference 11 https://arxiv.org/abs/1711.10085
Sourced
Battery mass versus hover time in Fig. 6 (about 22 min at 0.5 kg, about 28 min at 1.0 kg, about 31 min at 2.0 kg), power change of about 15% for a 10% change in mass, and the 167 W calculationOur calculation (Python; formula (5) of Bauersfeld et al.; assumptions: four propellers, 0.127 m radius, ηP 0.6, 80% motor efficiency, 150 Wh/kg, 80% usable). Not the performance of a real aircraftOur calculation
Seven degrees of freedom in the human arm, six-axis arms being common, automatic versus autonomous, four independent controls of a quadcopter, the materials engineer’s views, the physical-AI analogy, and the three questionsOur own commentary based on general textbook understanding; no source is attachedCommentary
The text of ISO 8373, whether drones count as ISO 8373 robots, drone count statistics, humanoid counts, rules of other countries such as the EU, and a unified flight-time test standardNot stated, because they could not be confirmed within this surveyCommentary

Last updated: 25 October 2026. Sources are limited to primary material (official ISO, NIST, IFR, FAA and MLIT documents, peer-reviewed papers, and an arXiv survey). Market estimates from research firms are not used. The numbers in Chapter 8 come from our simple model and are not the performance of a real aircraft. The text of ISO 8373, whether drones count as ISO 8373 robots, drone count statistics and the rules of other countries could not be confirmed and are not stated. Figures 1 and 8 are ImageGen-generated conceptual illustrations; the rest are explanatory concept diagrams or drawings that include our calculation.

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