Glossary of Robotic Terminology

In determining the appropriate products and models of robotic tooling that are required for an application, it is helpful for all parties to speak the same technical language. For that reason, we have compiled this brief glossary of robotic terms.

Robotic and Robot-Related Terms

Collision Sensor - Robotic end effector or device that can detect a crash before or during a collision of the robot or its tool. Collision sensors send a signal back to the robot controller before or during a collision to have the robot avoid the collision or stop before or during a collision. Robotic crash protection devices are collision sensors that detect the collision during the crash.  A collision sensor is also know as a robot safety joint, robot overload protection device, crash protection device, quickstop (trademark of Applied Robotics), robot safety mount, robotic clutch, and robotic collision protector.

Compensator - Remote Compliance Center Device from ATI using three to twelve elastomeric shear pads to aid in the insertion of peg-in-hole applications.

End-Effector - Any object attached to the robot flange (wrist) that serves a function. This would include robotic grippers, robotic tool changers, robotic crash protection, robotic rotary joint, robotic press tooling, compliance device, robotic paint gun, robotic deburring tool, robotic arc welding gun, robotic transgun, etc. End effector is also known as robotic peripheral, robotic accessory, robot or robotic tool, end of arm (EOA) tooling, or end-of-arm device. End effector may also be hyphenated as "end-effector."

Moment - (Mech.) (a) With respect to a point, the product of the intensity of the force into the perpendicular distance from the point to the line of direction of the force. (b) With respect to a line, the product of that component of the force which is perpendicular to the plane passing through the line and the point of application of the force, into the shortest distance between the line and this point. (c) With respect to a plane that is parallel to the force, the product of the force into the perpendicular distance of its point of application from the plane.

Remote Compliance Center (RCC) -  Any compliance structure has a center of compliance.   If you were to push at this center you would have a pure lateral motion (no rotation). If you were to rotate this center, you would have rotation with no lateral motion. A remote compliance center is a compliance center projected outward from the device. Remote compliance centers decouple lateral and angular motion. A RCC device can be used in assembly to ease the insertion force.  When a project compliance center is near the insertion point of a peg-in-hole type assembly, the peg translates into the hole when it strikes the outside lead-in chamfer without rotating. This translation without rotation prevents the jamming and galling seen from compliance devices that have a compliance center far away from the insertion point. The ATI Compensator is a RCC device.

Robot - Any multi-axes automated articulated arm that can be reprogrammed.

Robot Crash Protection Device (CPD) - See Collision Sensor.

Robotic Rotary Joint - Device used to keep electrical and pneumatic cables on robot stationary while cables for tool rotate with tool.  A Rotary Joint has two halves: a stationary half that is mounted on a robot arm, and a rotating half that mounts to the robot wrist and tool.  Slip ring technology is used to pass electrical signals. Also known as robotic rotary union, robot slip ring.

Robotic Deburring Tool - Deburring tool, air or electrically driven, with compliance and a method to mount to a robot wrist.  Deburring tools can also be mounted to a bench or fixture, with parts brought to the unit to be deburred.

Robotic Tool Changer or Robot Coupler - An end-effector with two mating parts normally called a Master Side and Tool Side that have been designed to lock or couple together automatically and are able to pass utilities such as electrical signals, pneumatic, water, etc. Most robot couplers use pneumatics to lock the Master and Tool side together. The robot tool changer provides flexibility for any automated process in order to change tools and pass various utilities. The Master Side of the tool changer mounts to a robot, CNC machine or other structure. The Tool Side of the tool changer mounts to tooling, such as grippers, welders, or deburring tools. A robotic tool changer is also known as an automatic tool changer (ATC), robot tool changer, robot coupler, robotic coupler, and robotic connector.

Shear Pads - Compliance pads that have layers of rubber metal stacked at heights from 0.5 to 1.5 inches.  The stacking of rubber metal layers provides soft lateral compliance and high axial compliance.  This high ratio of axial to lateral compliance provides the means to project a compliance center.

Sensor-related Terms:

Accuracy - See Measurement Uncertainty.

ActiveX Component - A reusable software component for the Windows applications.

Compound Loading - Any load that is not purely in one axis.

DAQ - Data Acquisition device.

F/T - Force and Torque.

Fxy - The resultant force vector comprised of components Fx and Fy.

Hysteresis - A source of measurement error caused by the residual effects of previously applied loads.

IFPS - InterFace/Power Supply box.    

IP60 - Ingress Protection Rating "60" designates protection against dust

IP65 - Ingress Protection Rating "65"  designates protection against water spray

IP68 - Ingress Protection Rating "68" designates submergibility in fresh water, in this case, to a depth of 10 meters

LabVIEW - A graphical programming environment created for data acquisition tasks by National Instruments.

Maximum Single-Axis Overload - The largest amount of pure load (not compound loading) that the transducer can withstand without damage.

MAP - Mounting AdaptorPlate. The MAP part of the transducer is attached to the fixed surface or robot arm.

Measurement Uncertainty - The maximum expected error in measurements, as specified on the calibration certificate.       

NI - National Instruments Corporation, the owner of the National Instruments and LabVIEW trademarks. (www.ni.com) Maker of Data Acquisition Cards used by ATI in force sensors.

Overload - The condition where more load is applied to the transducer than it can measure. This will result in saturation.

PCMCIA - A small computer card for use in most laptop computers.

Point of Origin - The point on the transducer from which all forces and torques are measured.

Quantization - The way the continuously variable transducer signal is converted into discreet digital values. Usually used when describing the change from one digital value to the next.

Resolution - The smallest change in load that can be measured. This is usually much smaller than accuracy.

Saturation - The condition where the transducer or data acquisition hardware has a load or signal outside of its sensing range.

Sensor System - The entire assembly consisting of parts from transducer to data acquisition card.

Six-axis Force/Torque Sensor- Transducer measuring and outputting forces and torques from all three Cartesian coordinates (x, y and z). A six-axis force/torque transducer is also known as multi-axis force/torque transducer, a multi-axis load cell, F/T sensor, six-axis load cell.

TAP - Tool AdaptorPlate. The TAP part of the transducer is attached to the load that is to be measured.

Tool Transformation - Mathematically changing the measurement coordinate system by translating the origin and/or rotating the axes.

Transducer - The component that converts the sensed load into electrical signals.

Txy - The resultant torque vector comprised of components Tx and Ty.

Visual Basic - A Microsoft programming environment for developing Windows-based applications.

Compensator-Related Terms:

Bottom Plate - Plate that interfaces customer tooling to compensator.

Center-of-Compliance (C-of-C) - The point in space at which a contact force will cause a translation with no rotation and a torque will cause a rotation with no translation.

Insertion Contact Point - Point at which the part being inserted contacts its mating part.  At this point, a contact force is created.

Lock Sensing - Proximity sensor mounted in a sensor fitting detects when compensator is locked.

Lock-Up - Pneumatically-powered locking mechanism that locks the compensator rigid for accelerated movements to reduce wear on shear pads.

Lock-Up Screw - Locking mechanism component that is pulled into the bottom plate by the lock-up to help securely lock the unit.

Lock-Up Screw Bushing - Wear bushing for the lock-up screw

Overload Pin - Component that limits the amount of compliance to prevent damage to the compensator when overloaded.

RCC - Remote Center-of-Compliance or Remote Compliance Center (same as C-of-C)

Sensor Ready - Compensator with a sensor fitting.  Customer supplies a proximity sensor for lock sensing.

Shear Pad - Component that provides compliance in the lateral, cocking, axial, and torsional directions.

Top Plate - Plate that interfaces the compensator with the robot or assembly machine