DICTIONARY of ROBOTICS  (Robotics Dictionary)

by Robotpark Academy



Acceleration: (Robotic Mechanisms) The time rate of change of velocity of a body. It is  always produced by force acting on a body. Acceleration is measured as feet per second per second (ft/s2) or meters per second per second (m/s2).

Accuracy: The difference between the point that a robot is trying to achieve and the actual resultant position. Absolute accuracy is the difference between a point instructed by the robot control system and the point actually achieved by the manipulator arm, while repeatability is the cycle-to-cycle variation of the manipulator arm when aimed at the same point.

Air Muscles : Pneumatic artificial muscles, also known as air muscles, are special tubes that contract (typically up to 40%) when air is forced inside them. They have been used for some robot applications.

An·thro·po·mor·phism: Attribution of human motivation, characteristics, or behavior to inanimate objects, animals, or natural phenomena. The word anthropomorphism was first used in the mid-1700s. The word derives from the Greek ἄνθρωπος (ánthrōpos), “human”, and μορφή (morphē), “shape” or “form”. We commit anthropomorphism when we think of a computer or robot as human

Armature: ( Robot Electronics) The armature (or arm) is what spins in the motor and makes your rc helicopter move. It is made up of the commutator, laminations, shaft and winds. Electricity flows through the wires from the ESC to the end bell. It then travels through the brushes to the commutator, and into the windings on the arm. Since the windings are wrapped into a coil, they create a magnetic field when current is passed through them. This magnetic field is repelled and attracted to the magnets in the can causing the arm to turn.

Articulated Robot:  An articulated robot is one which uses rotary joints to access its work space. Usually the joints are arranged in a “chain”, so that one joint supports another further in the chain.


Brush: (Robot Electronics) Made of a silver, copper, or graphite compound and at the end of the shunt wire. They are what makes contact with the commutator and transfer the electric current to the commutator.


Crank: (Robotic Mechanisms) A side link that revolves relative to the frame.

Crank-Rocker Mechanism: (Robotic Mechanisms) A four-bar linkage characterized by the ability of the shorter side link to revolve through 360° while the opposing link rocks or oscillates.

Commutator: (Robot Electronics) Typically referred to as the Comm. The comm takes current from your brushes, which ride on this part of the arm, and sends it to the windings. The comm is not one solid piece, but is actually made up of 3 separate pieces. This allows the current to be switched to the different windings of the arm as it spins. Because it rubs against the brushes as the arm spins, the comm needs to be cleaned and shaped regularly.

Component Forces: (Robotic Mechanisms) The individual forces that are the equivalent of the resultant.

Concurrent Forces: (Robotic Mechanisms) Forces whose lines of action or directions pass through a common point or meet at a common point.

Continuous Path: A control scheme whereby the inputs or commands specify every point along a desired path of motion. The path is controlled by the coordinated motion of the manipulator joints.

Continuous / Burst Current: (Robot Electronics) Continuous current measures how much current a motor can handle continuously, for an extended period of time. Burst current measures how much current a motor can handle for a short amount of time, about a few seconds.

Couple: (Robotic Mechanisms) Two equal and opposite parallel forces that act at diametrically opposite points on a body to cause it to rotate around a point or an axis through its center.

Current Rating: (Robot Electronics) This is the maximum current that a given motor can handle, measured in amps.


Degrees Of Freedom (DOF): The number of independent motions in which the end effector can move, defined by the number of axes of motion of the manipulator.

Displacement:  Distance measured from a fixed reference point in a specified direction; it is a vector quantity; units are measured in inches, feet, miles, centimeters, meters, and kilometers.

Double-Crank Mechanism: A four-bar linkage characterized by the ability of both of its side links to oscillate while the shortest link (opposite the foundation link) can revolve through 360 °.

Dynamics: (Robotic Mechanisms)  The study of the forces that act on bodies not in equilibrium, both balanced and unbalanced; it accounts for the masses and accelerations of the parts as well as the external forces acting on the mechanisms. It is a combination of kinetics and kinematics.


Efficiency of Machines: (Robotic Mechanisms) The ratio of a machine’s output divided by its input is typically expressed as a percent. There are energy or power losses in all moving machinery caused primarily by friction. This causes inefficiency, so a machine’s output is always less than its input; both output and input must be expressed in the same units of power or energy. This ratio, always a fraction, is multiplied by 100 to obtain a percent. It can also be determined by dividing the machine’s mechanical advantage by its velocity ratio and multiplying that ratio by 100 to get a percent.

Elastic Nanotubes:  are a promising artificial muscle technology in early-stage experimental development. The absence of defects in carbon nanotubes enables these filaments to deform elastically by several percent, with energy storage levels of perhaps 10 J/cm3 for metal nanotubes. Human biceps could be replaced with an 8 mm diameter wire of this material. Such compact “muscle” might allow future robots to outrun and outjump humans.

Endbell: (Robot Electronics) The part of the motor that consists of the brush hoods and the tabs. The endbell holds the bearing that supports the short end of the shaft.

Energy: (Robotic Mechanisms)A physical quantity present in three-dimensional space in which forces can act on a body or particle to bring about physical change; it is the capacity for doing work. Energy can take many forms, including mechanical, electrical, electromagnetic, chemical, thermal, solar, and nuclear. Energy and work are related and measured in the same units: foot-pounds, ergs, or joules; it cannot be destroyed, but it can be wasted.

-Kinetic energy is the kind of energy a body has when it is in motion. Examples are a rolling soccer ball, a speeding automobile, or a flying airplane.

-Potential energy is the kind of energy that a body has because of its position or state. Examples are a concrete block poised at the edge of a building, a shipping container suspended above ground by a crane, or a roadside bomb.

Equilibrium: (Robotic Mechanisms) In mechanics, a condition of balance or static equilibrium between opposing forces. An example is when there are equal forces at both ends of a seesaw resting on a fulcrum.


Fil·a·ment : ˈfiləmənt/ : noun : 1 – (Robot Electronics) a conducting wire or thread with a high melting point, forming part of an electric bulb or vacuum tube and heated or made incandescent by an electric current 2- (3D Printing) A material made of ABS, PLA etc. in form of wire or thread with low melting point (200 C), used as 3d printing raw material, in 3d extrusion printing.

Force: (Robotic Mechanisms) Strength or energy acting on a body to push or pull it; it is required to produce acceleration. Except for gravitation, one body cannot exert a force on another body unless the two are in contact. The Earth exerts a force of attraction on bodies, whether they are in contact or not. Force is measured in poundals (lb-ft/s2) or newtons (kg-m/s2).

Fulcrum: (Robotic Mechanisms)A pivot point or edge about which objects are free to rotate.


Gripper: A device for grasping or holding, attached to the free end of the last manipulator link; also called the robot’s hand or end-effector.


Hex·a·pod     [hek-suh-pod]

1. a six-legged robot of the class Robots. Legs are usually controlled by servo motors
2. having six feet.
1660–70;  < Greek hexapod-  (stem of hexápous ) six-footed.


Ionoprinting: Researchers at NC State have developed a method called ‘ionoprinting’ with the capability to pattern and actuate hydrated gels in two and three dimensions by locally patterning ions using electric fields. The ability to pattern, structure, re-shape and actuate hydrogels is important for biomimetics, soft robotics, cell scaffolding and biomaterials.


Kinematic Chain: (Robotic Mechanisms) A combination of links and pairs without a fixed link.

Kinematics: (Robotic Mechanisms)The study of the motions of bodies without considering how the variables of force and mass influence the motion. It is described as the geometry of motion.

Kinetics: (Robotic Mechanisms)The study of the effects of external forces including gravity upon the motions of physical bodies.

Kv Rating: (Robot Electronics) The Kv number is the RPM per volt supplied to the motor. The KV number’s useful because it let’s you figure out how many volts you need to achieve a certain RPM, or vice versa. For example, a 1200 Kv motor, supplied with 3 volts, will run at a nominal 3600 rpm. The Kv rating always assumes no load on the motor, so the actual RPM that your achieve will be less than the one you calculate. Note that Kv is the voltage constant (capital-K, subscript v), not to be confused with the kilovolt, whose symbol is kV (lower-case k, capital V).


Laminations: (Robot Electronics -Electric Motors) The part of the armature the winds are wrapped around. These are usually about half a millimeter thick, and are stacked on top of each other. The laminations are sometimes shaped to provide a stronger field. They are usually made of iron ferrite.

Lever: (Robotic Mechanisms)A simple machine that uses opposing torque around a fulcrum to perform work.

Linear Motion: (Robotic Mechanisms)Motion in a straight line. An example is when a car is driving on a straight road.

Link: (Robotic Mechanisms)A rigid body with pins or fasteners at its ends to connect it to other rigid bodies so it can transmit a force or motion. All machines contain at least one link, either in a fixed position relative to the Earth or capable of moving the machine and the link during the motion; this link is the frame or fixed link of the machine.

Linkages: (Robotic Mechanisms) Mechanical assemblies consisting of two or more levers connected to produce a desired motion. They can also be mechanisms consisting of rigid bodies and lower pairs.


Machine: (Robotic Mechanisms) An assembly of mechanisms or parts or mechanisms capable of transmitting force, motion, and energy from a power source; the objective of a machine is to overcome some form of resistance to accomplish a desired result. There are two functions of machines:

(1) the transmission of relative motion and

(2) the transmission of force;

both require that the machine be strong and rigid. While both machines and mechanisms are combinations of rigid bodies capable of definite relative motions, machines transform energy, but mechanisms do not. A simple machine is an elementary mechanism. Examples are the lever, wheel and axle, pulley, inclined plane, wedge, and screw.

Machinery: (Robotic Mechanisms) A term generally meaning various combinations of machines and mechanisms.

Magnets: (Robot Electronics – electric motors) Provides the opposing force that the armature’s magnetic force pushes against.

Mass: (Robotic Mechanisms)The quantity of matter in a body indicating its inertia. Mass also initiates gravitational attraction. It is measured in ounces, pounds, tons, grams, and kilograms.

Maximum Speed: The compounded maximum speed of the tip of a robot moving at full extension with all joints moving simultaneously in complimentary directions. This speed is the theoretical maximum and should under no circumstances be used to estimate cycle time for a particular application. A better measure of real world speed is the standard twelve inch pick and place cycle time. For critical applications, the best indicator of achievable cycle time is a physical simulation.

Mechanical Advantage: (Robotic Mechanisms)The ratio of the load (or force W) divided by the effort (or force F) exerted by an operator. If friction is considered in determining mechanical advantage, or it has been determined by the actual testing, the ratio W/is the mechanical advantage MA. However, if the machine is assumed to operate without friction, the ratio W/is the theoretical mechanical advantage TA. Mechanical advantage and velocity ratio are related.

Mechanics: (Robotic Mechanisms) A branch of physics concerned with the motions of objects and their response to forces. Descriptions of mechanics begin with definitions of such quantities as acceleration, displacement, force, mass, time, and velocity.

Mechanism: (Robotic Mechanisms)In mechanics, it refers to two or more rigid or resistant bodies connected together by joints so they exhibit definite relative motions with respect to one another. Mechanisms are divided into two classes:

• Planar: Two-dimensional mechanisms whose relative motions are in one plane or parallel planes.

• Spatial: Three-dimensional mechanisms whose relative motions are not all in the same or parallel planes.

Moment of Force or Torque: (Robotic Mechanisms)The product of the force acting to produce a turning effect and the perpendicular distance of its line of action from the point or axis of rotation. The perpendicular distance is called the moment arm or the lever arm torque. It is measured in pound-inches (lb-in.), pound-feet (lb-ft), or newtonmeters (N-m).

Moment of Inertia: (Robotic Mechanisms)A physical quantity giving a measure of the rotational inertia of a body about a specified axis of rotation; it depends on the mass, size, and shape of the body.

Muscle Wire:, also known as Shape Memory Alloy, Nitinol or Flexinol Wire, is a material that contracts slightly (typically under 5%) when electricity runs through it. They have been used for some small robot applications. But muscle wire systems do not have enough power to handle high force applications.


Nonconcurrent Forces: (Robotic Mechanisms) Forces whose lines of action do not meet at a common point.

Noncoplanar Forces: (Robotic Mechanisms)Forces that do not act in the same plane.


Pair: (Robotic Mechanisms) A joint between the surfaces of two rigid bodies that keeps them in contact and relatively movable. It might be as simple as a pin, bolt, or hinge between two links or as complex as a universal joint between two links. There are two kinds of pairs in mechanisms classified by the type of contact between the two bodies of the pair: lower pairs and higher pairs.

• Lower pairs are surface-contact pairs classed either as revolute or prismatic. Examples: a hinged door is a revolute pair and a sash window is a prismatic pair.

• Higher pairs include point, line, or curve pairs. Examples: paired rollers, cams and followers, and meshing gear teeth.

Payload: The maximum payload is the amount of weight carried by the robot manipulator at reduced speed while maintaining rated precision. Nominal payload is measured at maximum speed while maintaining rated precision. These ratings are highly dependent on the size and shape of the payload.

Peristalsis Movement:/peri·stal·sis/ (-stahl´sis) 1-the wormlike movement by which the alimentary canal or other tubular organs having both longitudinal and circular muscle fibers propel their contents, consisting of a wave of contraction passing along the tube for variable distances.peristal´tic. 2- Peristalsis is a radially symmetrical contraction and relaxation of muscles which propagates in a wave down the muscular tube, in an anterograde fashion.

Pick And Place Cycle:  Pick and place Cycle is the time, in seconds, to execute the following motion sequence: Move down one inch, grasp a rated payload; move up one inch; move across twelve inches; move down one inch; ungrasp; move up one inch; and return to start location.

Power: (Robotic Mechanisms) The time rate of doing work. It is measured in foot-pounds per second (ft-lb/s), foot-pounds per minute (ft-lb/min), horsepower, watts, kilowatts, newton-meters/s, ergs/s, and joules/s.


Reach: The maximum horizontal distance from the center of the robot base to the end of its wrist.

Repeatability: See Figure. The ability of a system or mechanism to repeat the same motion or achieve the same points when presented with the same control signals. The cycle-to-cycle error of a system when trying to perform a specific task

Resolution: See Figure. The smallest increment of motion or distance that can be detected or controlled by the control system of a mechanism. The resolution of any joint is a function of encoder pulses per revolution and drive ratio, and dependent on the distance between the tool center point and the joint axis.

RPM: (Robot Electronics – Electric Motors) This is a measure of angular speed, or how fast something is rotating. A motor’s RPM is simply how fast it can rotate per minute.

Ro·bot  [roh-buht, -bot]
1.a machine that resembles a human and does mechanical, routine tasks on command.
2.a person who acts and responds in a mechanical, routine manner,
usually subject to another’s will automation.
3.any machine or mechanical device that operates automatically with humanlike skill.
4.operating automatically: a robot train operating between airline terminals.
< Czech,  coined by Karel Čapek in the play R.U.R.  (1920) from the base robot-, as in robota  compulsorylabor, robotník  peasant owing such labor

Ro·bot·ics  [roh-bot-iks]  

noun used with a singular verb  )
the use of computer-controlled robots to perform manual tasks, especially on an assembly line.
1941; robot + -ics; coined by Isaac Asimov

Robot Program: A robot communication program for IBM and compatible personal computers. Provides terminal emulation and utility functions. This program can record all of the user memory, and some of the system memory to disk files.


Servo Controlled: Controlled by a driving signal which is determined by the error between the mechanism’s present position and the desired output position.

Skeleton Outline: (Robotic Mechanisms)A simplified geometrical line drawing showing the fundamentals of a simple machine devoid of the actual details of its construction. It gives all of the geometrical information needed for determining the relative motions of the main links. The relative motions of these links might be complete circles, semicircles, or arcs, or even straight lines.

Statics: (Robotic Mechanisms) The study of bodies in equilibrium, either at rest or in uniform motion.


Torque: (Robotic Mechanisms)An alternative name for moment of force.


Oscillating Motion: (Robotic Mechanisms) Repetitive forward and backward circular motion such as that of a clock pendulum.


Velocity: (Robotic Mechanisms) The time rate of change with respect to distance. It is measured in feet per second (ft/s), feet per minute (ft/min), meters per second (m/s), or meters per minute (m/min).

Velocity Ratio: (Robotic Mechanisms) A ratio of the distance movement of the effort divided by the distance of movement of the load per second for a machine. This ratio has no units.

Via Point: A point through which the robot’s tool should pass without stopping; via points are programmed in order to move beyond obstacles or to bring the arm into a lower inertia posture for part of the motion.

Volt: (Robot Electronics) This measures electric potential, or how much “push” the electrons from a battery have. A greater voltage means that more energy is being applied to a given amount of charge.


Watt: (Robot Electronics) This is a measure of power, or how fast energy is used.

Weight: (Robotic Mechanisms) The force on a body due to the gravitational attraction of the Earth; weight _ mass _ acceleration due to the Earth’s gravity; mass of a body is constant but g, and therefore vary slightly over the Earth’s surface.

Work: (Robotic Mechanisms) The product of force and distance: the distance an object moves in the direction of force. Work is not done if the force exerted on a body fails to move that body. Work, like energy, is measured in units of ergs, joules, or foot-pounds.

Work Envelope: A three-dimensional shape that defines the boundaries that the robot manipulator can reach; also known as reach envelope.