Robotics glossary
Definitions of the component, specification and trade terms used across Sourcebotics product pages, comparisons and guides.
A
- Absolute encoder
A position sensor that reports a unique angle at power-up, so the joint knows its position without a homing move.
- Active degrees of freedom
Joints driven by their own actuator, as opposed to joints that move only through linkages or tendons coupled to another joint.
- AGV
An automated guided vehicle that follows fixed paths, markers or codes to move loads.
- AHRS
An attitude and heading reference system that fuses inertial and often magnetic data to estimate orientation.
- AMR
An autonomous mobile robot that navigates with onboard sensors and maps rather than fixed guide paths.
- Arcsecond
One sixtieth of an arcminute, a unit used for reducer backlash and accuracy.
B
- Back-drivability
How easily an external force can turn a joint's output when the motor is unpowered or in torque control.
- Backlash
The angular play at a reducer's output when the direction of rotation reverses.
- Ball screw
A screw and nut separated by recirculating balls that converts rotation into precise linear motion.
- Battery management system
Electronics that monitor and protect a battery pack's cells, including voltage, current and temperature limits.
C
- C-rate
Charge or discharge current expressed as a multiple of a battery's rated capacity.
- CAN bus
A two-wire serial bus widely used to connect motor drives and sensors with robust error handling.
- CAN FD
A CAN variant that allows larger data payloads at a faster data-phase bit rate.
- Capacitive sensing
Sensing in which pressure changes the gap between electrodes and therefore their capacitance.
- CE marking
The marking a manufacturer applies to show a product meets the applicable EU product legislation.
- Certificate of origin
A document stating the country where goods were manufactured, used for customs and preferential tariffs.
- Collaborative robot
A robot arm designed to work near people, with force or power limiting and safety functions.
- Commercial invoice
The final invoice issued for shipped goods, used by customs to assess duties.
- Cross-roller bearing
A bearing with cylindrical rollers set at alternating right angles, carrying radial, axial and moment loads in one compact element.
- Crosstalk
The error in one measuring axis caused by load applied on another axis, stated as a percentage of full scale.
- Cycloidal reducer
A gearbox in which an eccentric cam drives a lobed disc against pins, giving high ratio and high shock-load capacity.
D
- Datasheet
The manufacturer document that states a product's specifications, interfaces and operating conditions.
- DDP
Delivered Duty Paid: the seller delivers to the named destination with import duties and taxes paid.
- Decoupling matrix
The calibration matrix that converts a multi-axis sensor's raw channels into independent force and moment values.
- Degrees of freedom
The number of independent motions a mechanism can perform, counted as joints or axes.
- Dexterous hand
A multi-finger robotic hand with independently controlled joints for grasping and in-hand manipulation.
- Drag-chain cable
A cable built to flex repeatedly inside a cable carrier or robot dress pack.
- Dual-encoder joint
An actuator with one encoder on the motor shaft and one on the output, so output position is measured after the gearbox.
- Duty cycle
The pattern of load and rest over time that determines how much heat a joint must dissipate.
E
- Electric gripper
A motor-driven gripper with two or three jaws, specified by stroke, gripping force and repeatability.
- Encoder resolution
The number of distinct positions an encoder reports per revolution, usually stated in bits or counts.
- End effector
The device at the end of a robot arm that interacts with the work, such as a gripper, hand or tool.
- EtherCAT
An industrial Ethernet fieldbus that processes data on the fly in each device for deterministic, high-rate motion control.
- EXW
Ex Works: the buyer collects the goods at the seller's premises and bears the cost and risk from there.
F
- Factory acceptance test
Testing performed at the supplier's site against agreed criteria before shipment.
- Field of view
The angular region a camera or LiDAR can observe, usually stated horizontally and vertically.
- Field-oriented control
A motor control method that regulates current in the rotor's reference frame to produce smooth, efficient torque.
- Fingertip force
The force a finger can apply at its tip under the manufacturer's stated posture and conditions.
- FOB
Free On Board: the seller delivers goods loaded on the vessel at the named port of shipment; risk then passes to the buyer.
- Frameless torque motor
A motor supplied as a separate rotor and stator that the integrator builds directly into the joint housing.
- Full scale
The maximum value a sensor is specified to measure, used as the reference for percentage accuracy figures.
G
- Gear ratio
The ratio between input and output speed of a reducer, which also multiplies output torque before losses.
- Golden sample
An approved reference unit kept by buyer and supplier to judge whether production units match the agreed quality.
- Gyroscope bias stability
The drift of a gyroscope's zero-rate output over time, a key figure for heading accuracy.
H
- Harmonic reducer
A strain-wave gearbox in which a flexible spline meshes with a rigid circular spline to give a high ratio with low backlash in one stage.
- Holding brake
A spring-applied brake that locks a joint when power is removed so an arm does not fall.
- Hollow shaft
A reducer, motor or encoder with a central bore so cables or shafts can pass through the joint.
- HS code
The Harmonized System number used to classify goods for customs duties and trade statistics.
- Humanoid robot
A robot with a human-like body plan, typically two legs, two arms and a head, built to work in human environments.
- Hysteresis
The difference in a sensor's reading for the same load approached from increasing and from decreasing directions.
I
- IMU
An inertial measurement unit combining accelerometers and gyroscopes to measure linear acceleration and angular rate.
- Incoterms
International Chamber of Commerce rules that define which party pays for and bears the risk of each stage of delivery.
- Incremental encoder
A position sensor that counts pulses from a reference point and needs homing after power-up to know its absolute position.
- IP rating
An IEC 60529 code describing a housing's protection against solid particles and water.
J
- Joint module
An integrated robot joint that combines a motor, reducer, encoder and drive electronics in one housing.
L
- Lead time
The time between order confirmation and the goods being ready to ship or delivered, as agreed in the quotation.
- LiDAR
A sensor that measures distance by timing reflected laser pulses and builds a point cloud of its surroundings.
- Linear actuator
A device that produces straight-line motion, specified by stroke, thrust and speed.
- Linear guide
A rail and carriage system that supports and guides straight-line motion with low friction.
- Linkage-driven finger
A finger moved by rigid links from an actuator, giving a fixed coupling between joints.
- Lost motion
The output rotation measured as the load reverses within a small specified torque band, including backlash and elastic deflection.
M
- Modbus
A simple master-slave communication protocol often run over RS-485 or TCP/IP in grippers and sensors.
- MOQ
Minimum order quantity: the smallest order a supplier accepts for a product or configuration.
- Multi-turn encoder
An absolute encoder that also counts complete revolutions, either mechanically or with a battery-backed counter.
N
- Nonlinearity
The maximum deviation of a sensor's output from a straight line between zero and full scale.
O
- Outer-rotor motor
A motor whose rotor surrounds the stator, giving high torque at low speed in a flat package.
- Overload capacity
The load a sensor can withstand without permanent damage, beyond its measuring range.
P
- Payload
The mass a robot or end effector can carry under the manufacturer's stated conditions.
- Peak torque
The maximum output torque a joint or reducer can deliver for a short, specified duration.
- Piezoresistive sensing
Sensing in which a material's electrical resistance changes with applied pressure.
- Planetary reducer
A gearbox in which planet gears orbit a central sun gear inside a ring gear, sharing the load across several teeth.
- Planetary roller screw
A screw that transmits force through threaded rollers, used in compact high-force linear actuators.
- Point cloud
A set of measured 3D points describing the surfaces around a sensor.
- Proforma invoice
A preliminary invoice that states the goods, price and terms before shipment, often used to arrange payment.
Q
- Quadruped robot
A four-legged walking robot used for inspection, research and transport over uneven ground.
- Quasi-direct-drive actuator
A joint that pairs a high-torque motor with a low-ratio gearbox so it can be back-driven and estimate torque from motor current.
R
- Rated life
The operating time a reducer or bearing is expected to reach under the manufacturer's stated load and speed.
- Rated torque
The output torque a joint or reducer can deliver continuously under the manufacturer's stated speed, temperature and mounting conditions.
- Reach
The maximum distance from a robot arm's base axis to its tool flange.
- Repeatability
How closely a robot or mechanism returns to the same commanded position over repeated moves.
- RMA
Return merchandise authorization: the supplier's process for approving and handling returns and repairs.
- ROS 2
An open-source robotics middleware framework for messaging, drivers and tools across robot software components.
- RS-485
A differential serial interface used for multi-drop links to sensors, grippers and drives.
- RV reducer
A two-stage reducer combining a planetary input stage with a cycloidal output stage, common in industrial robot base and shoulder joints.
S
- SDK
A software development kit: libraries, documentation and examples for controlling a device from your own software.
- Six-axis force/torque sensor
A sensor that measures three forces and three moments at once, usually mounted between a robot flange and its tool.
- SLAM
Simultaneous localization and mapping: building a map of an environment while estimating the robot's position in it.
- Slip detection
Identifying the onset of an object sliding in a grasp, usually from rapid changes in tactile or force signals.
- Slip ring
A rotary electrical joint that passes power and signals across a continuously rotating interface.
- Solid-state LiDAR
A LiDAR that steers or spreads its beam without a spinning mechanical assembly.
- Spatial resolution
The smallest spacing at which a tactile sensor can distinguish two separate contacts.
- Stall torque
The torque a motor produces at zero speed, limited by current and heating.
- STEP file
A neutral 3D CAD format used to exchange mechanical models between design tools.
- Stereo depth camera
A depth camera that computes distance from the disparity between two offset images.
- Strain gauge
A resistive element bonded to a structure whose resistance changes as the structure deforms under load.
- Stroke
The usable travel distance of a linear actuator or the opening range of a gripper.
- Structured light camera
A depth camera that projects a known pattern and computes depth from how the pattern deforms on surfaces.
T
- Tactile sensor
A sensor that measures contact pressure, force or geometry on a robot's surface or fingertip.
- Taxel
A single sensing element of a tactile array, the tactile counterpart of a camera pixel.
- Teleoperation
Controlling a robot remotely in real time, often to collect demonstration data for learning.
- Tendon-driven finger
A finger moved by cables routed from actuators in the palm or forearm.
- Thermal derating
Reducing continuous torque or current to keep a motor or drive within its temperature limits.
- Time-of-flight camera
A depth camera that measures distance from the travel time or phase shift of emitted light for each pixel.
- Tool flange
The standardized mounting face at the end of a robot arm where grippers and sensors are attached.
- TOPS
Trillions of operations per second, a headline measure of AI accelerator throughput that depends on precision and workload.
- Torque constant
The ratio of motor torque to phase current, used to estimate output torque from measured current.
- Torque density
Output torque divided by actuator mass or volume, used to compare compact joints.
- Torsional stiffness
The torque needed to twist a reducer's output by a given angle, which affects positioning accuracy under load.
U
- UN 38.3
The UN test series that lithium batteries must pass before they can be shipped as dangerous goods.
- Underactuated hand
A hand with fewer actuators than joints, where linkages or tendons let fingers conform to an object.
V
- Vision-language-action model
A machine-learning model that maps camera images and language instructions to robot actions.
- Visuotactile sensor
A tactile sensor that uses a camera behind a deformable surface to measure contact shape and force.