Robot Troubleshooting 331

5 Whys Technique

A troubleshooting process where operators ask a series of "why" questions, usually five, in order to isolate the root cause of a problem. The 5 Whys Technique is also a useful starting point for other troubleshooting methods.

5M + 1P

A method commonly known as 6M that is used during brainstorming to help identify the six major factors most likely to be the source of problems. The 5M + 1P categories are machinery, materials, methods, measurements, Mother Nature (process), and people (manpower).

6M

A method sometimes known as 5M + 1P that is used during brainstorming to help identify the six major factors most likely to be the source of problems. The 6M categories are machinery, materials, methods, measurements, Mother Nature (process), and people (manpower).

alphanumeric

Containing letters and numbers. Alphanumeric words are usually used as shorthand for issues explained in detail in accompanying manuals.

American National Standards Institute

ANSI. A private, non-profit organization that administers and coordinates voluntary standards and systems in the United States. The American National Standards Institute is one of several organizations that standardizes relevant safety codes for robot installation.

ANSI/RIA R15.06-2025

A publication produced by ANSI that provides guidelines for manufacturing, installing, and safeguarding robotic systems. ANSI/RIA R15.06-2025 includes information regarding risk assessment when using robots on a manufacturing site.

automation

The use of self-regulated equipment, processes, or systems that meet manufacturing requirements with limited human intervention. Automation, which includes both robotic and computer numerical control (CNC) functions, is an efficient means of performing manufacturing processes.

backlash

Unwanted motion caused by gaps between components that transmit motion, such as two gears or a leadscrew and a nut. Backlash occurs upon a reversal of motion, or if an excessive force is applied in the direction of motion that causes a snatching action.

ballscrews

A threaded device that rotates to provide precise linear motion. Ballscrews are often powered by servomotors and require proper lubrication and cleanliness to function properly.

bar charts

A chart that represents data with rectangular shapes whose heights or lengths are proportional to different values. Bar charts are common data visualization tools.

bearing

A friction-reducing device that allows one moving part to glide past another moving part. Bearings operate using a sliding or rolling mechanism.

belts

A band of flexible material that is looped around two or more pulleys to transmit motion. Belts are used to transfer the motion of the motor to the robot in order to perform a task.

cable testers

An electronic device that assesses the level of data flow, or signal strength, through a cable or from a wireless router. Cable testers are used to ensure that information is being properly exchanged between the robot and the machine interface.

catastrophic failure

The sudden and complete breakdown of a machine or part. Catastrophic failure can be hazardous to workers as it often involves flying debris and fast, unexpected machine movement.

check sheets

An information-gathering tool used to collect data in real time. On check sheets, tick marks are put into different cells of a table to create a graphical representation of numerical data, such as the number of times a robot halts unexpectedly in an hour.

class diagrams

A type of model that describes the structure of a system and the attributes, operations, and relationships of the system's classes. Class diagrams are a common type of information model.

cobots

A robot that can be programmed to learn a specific task in order to assist humans. A cobot, or collaborative robot, is designed to interact with humans in a shared workspace.

computerized maintenance management system

CMMS. A technology and software package that organizes and tracks data about a company's maintenance operations. Computerized maintenance management systems are an important tool for preventive and predictive maintenance.

computers

A processor-driven device for individual users and commercial software. A personal computer may be used as a programming device for a robot.

condensate traps

A device that removes the unwanted moisture that often occurs in pneumatic systems. Condensate traps are connected between the compressor and the inlet to the pneumatic system and often operate by draining automatically.

condense

Become concentrated. Water can condense in a humid environment and cause damage to mechanical components.

continuity testing

Assessing the presence and quality of current flow in a circuit. Continuity testing determines if there is an unwanted break or other malfunction in the circuit that prevents it from functioning properly.

continuous improvement

The belief that an organization must constantly measure the effectiveness of its processes and strive to meet more difficult objectives to satisfy customers. Continuous improvement is a guiding principle in lean manufacturing.

control program

A set of symbols and rules used to represent information and directions to a control device so that it can apply instructions. Control programs for robots or control systems are created in all forms of robot programming, though usually through the use of a tool such as a teach pendant or simulator.

control systems

A network of control loops used to manage dynamic processes by adjusting or maintaining physical variables. Control systems allow for more precise and repeatable processes.

corrective action

A solution implemented to resolve a manufacturing or robotic issue. Corrective actions include repairing a broken part, renewing a worn part, cleaning a sensor, cleaning the robot, adjusting the computer programming for a machine, or checking the quality of the incoming parts.

couplings

A component that connects two objects in a fluid system. Couplings are prone to leaking because they create breaks in a uniform shaft or tube.

current

The amount of electricity flowing in a circuit. Current is measured in amperes.

dashboards

A data visualization tool that contains current and updated information related to performance and operations throughout a supply chain. Dashboards are used in smart factories to fully utilize data.

data

Factual information that is used for analysis and problem solving. Data is often in the form of values or numbers.

data visualization

The graphical representation of information collected from a system or process. Data visualization uses tools like graphs and interactive maps to help personnel understand operational data collected in smart manufacturing.

debugging

Testing programs to identify and fix errors. Debugging ensures that robot programs and operations are safe and work as intended.

defective

Damaged or not up to specifications. Defective parts must be discarded or reworked and represent a loss to the manufacturing operation.

dehumidifier

A device that removes excess moisture from the air. Dehumidifiers can be used to keep a work area dry and prevent water-related damage to machine components.

delta robot

A special type of robot that has three sets of connected arms that work in conjunction to move one end effector. Delta robots are most commonly used in packaging or assembly processes.

division charts

An organizational tool that breaks down a mechanical component into small, discrete components. Division charts for robotic grippers might include servomotors, sensors, and the actual grippers or mechanical fingers.

electric motor

A device that uses electrical power to create rotary motion. Electric motors for robots are typically servomotors or stepper motors.

encoders

A device that translates rotary or linear motion into a digital signal. Encoders can become loose or get dirty, leading to malfunctions that cause machine positioning issues.

end effectors

The end component of a robotic arm that enables the robot to perform work. End effectors give robots their distinct functional characteristics, and include grippers, welding torches, and other tooling.

engineers

A person who is responsible for ensuring a manufacturing machine or process runs efficiently and safely. Engineers are generally in charge of any troubleshooting and repair operations.

error codes

An alphanumeric character that references a specific cause of malfunction. Error codes appear on the robot machine interface and are cross-referenced in the manual.

exploded views

A diagram that shows all the components of an assembly by picturing them all separately in the order they fit together. An exploded view of an assembly helps operators see where various components in a part are supposed to go.

feedback

A return signal that confirms the position of the robot. Feedback devices include proximity sensors and encoders.

finger

A gripper appendage with its own set of flexible joints. Fingers on a robot can move with accuracy and dexterity similar to a human finger.

firmware

The software that allows hardware to operate and programs to be completed. Firmware must be kept updated to protect industrial robot equipment from security threats.

fishbone diagrams

A visual cause and effect chart used to identify and isolate potential causes of a problem or effect. Fishbone diagrams have the primary process in the center with possible causes branching off on separate lines.

flow chart

An organizational tool that diagrams a specific process step by step with branches depending on the particular issues that arise. Flow charts ask "yes" or "no" questions in order to guide an operator to the probable solution for a problem.

fluid hoses

A hollow tube, which may be rigid or flexible, that is used to convey fluid in a fluid system. Fluid hoses, particularly flexible ones, may wear over time and leak, often around the connection joint or where scuffing takes place, causing the fluid system to malfunction.

fluid systems

A power transmission system that uses the energy of flowing liquids and gases to transmit power. Fluid system robots have additional components that can malfunction, such as hoses and valves.

fork vehicle

A mobile robot that uses a set of prongs that slide under a load in order to lift and transport it. Fork vehicles usually move pallets from one area of a work space to another.

friction

A force that resists motion between two components that are moving while in contact with each other. Excessive friction generates excessive heat and can lead to premature wear and other damage of machine components.

fuse

A safety device that detects excessive electrical current in a system. Fuses often have components that melt in the presence of excess current to open a circuit.

gear

A circular, toothed machine component that engages, rotates, and transmits power to another circular, toothed machine component when rotated. Gears are usually used in pairs to transmit energy and motion.

gimbal lock

A robot programming issue in which two axes become parallel, causing the loss of one degree of freedom in a three-dimensional rotation system. Gimbal lock results in an inability to rotate the object independently around a specific axis.

grid

A bounded area. A grid in robotics can refer to a narrow area of movement or performance around a set baseline or home position.

grid shift

A positioning error that leads a robot to move in a predictably incorrect fashion or create parts that will be predictably out of tolerance. Grid shift occurs when a robot jumps to a new and unwanted baseline home position but then functions normally.

gripper

A dexterous material-handling component that resembles and performs similarly to a human hand. Robotic grippers allow robots to perform tasks such as handling small parts or assembling components.

hard data

Quantifiable information about manufacturing processes, which can be measured and analyzed for troubleshooting and process management. Hard data includes machine performance, production output, and material usage.

home position

The central point from which a mechanism begins an operation. The home position, or machine zero point, has a value of zero in the programming language of the mechanism.

home switch

A component that provides a reference point for encoders. Without a home switch, encoders are unable to assess how they have moved in relation to a set point.

humid

An atmosphere containing a large amount of moisture. A humid work environment can cause issues if electrical components become too damp.

hydraulic

Power created by the controlled motion of a liquid. Hydraulic systems are often used with robots that must lift heavy loads.

industrial robots

A reprogrammable machine sometimes used in place of a person in a manufacturing setting. Industrial robots perform dangerous or repetitive tasks with a high degree of accuracy and repeatability.

information flow diagrams

An organizational tool that charts a specific process step by step throughout a system or supply chain. Information flow diagrams are information models that help find the origins of data.

information modeling

Representing concepts, relationships, grouping, constraints, and rules of data to specify how data is organized for a chosen application. Information modeling helps improve data management and system security.

input device

A device that allows a human being to communicate with and program a robot. Input devices include keyboards and teach pendants.

Integrated Development Environments

Software that allows programmers to write, debug, and test program code. Integrated Development Environment software combines multiple types of software and processes into one platform.

joint

A connecting component on a robot that can rotate and move linearly. The joint, or movable axis, mimics the movement of human joints, such as the elbow joint but might also include a rotational axis perpendicular to the centerline of the arm.

lasers

A device that generates a coherent and narrow beam of light that can be precisely aimed and controlled. Lasers can be used to assess component alignment.

lights-out manufacturing

A facility being fully automated and operating without any employees on-site. Lights-out manufacturing allows for processes to operate overnight and during the weekend.

line graphs

A type of chart that uses one or more lines to show information that changes over time. Line graphs are common data visualization tools.

lockout/tagout

A method of protecting employees by preventing accidental machine startup through proper locking and labeling of machines during maintenance. Lockout/tagout is the common term for OSHA's Control of Hazardous Energy Standard.

logic errors

Incorrect calculations or deviation from the rules of a program. Logic errors generally produce an action, but not with the correct result or location.

lubrication

A substance that reduces friction in moving machine components. Adding lubrication is a common preventive maintenance task that prevents issues such as premature component wear or one-off pulses.

machine zero point

The central point from which a mechanism begins an operation. The machine zero point, or home position, has a value of zero in the programming language of the mechanism.

maintenance personnel

A person who is responsible for repairing a machine and performing scheduled upkeep procedures, such as adding lubrication. Maintenance personnel generally help implement the corrective action decided on by the engineer.

material handling

The process of loading, unloading, placing, or manipulating material. Material handling operations often require highly repetitive tasks that are ideal for robotic work.

mobile robot

A robot that is able to move through space. Mobile robots often use tracks or a set of independent wheels to move.

movable axis

A connecting component on a robot that can rotate and move linearly. The movable axis, or joint, mimics the movement of human joints, such as the elbow joint but might also include a rotational axis perpendicular to the centerline of the arm.

multimeters

A device that is used to assess the quality and functionality of electrical connections. Multimeters combine the functions of an ammeter, voltmeter, and ohmmeter.

one-off pulse

A robot motion error where the robot occasionally moves incorrectly or occasionally creates parts out of tolerance before returning to normal motion. One-off pulses generally occur as the result of an intermittent mechanical issue, such as inconsistent lubrication.

operators

A person responsible for running a manufacturing machine or process. Operators are responsible for running their assigned tasks correctly, safely, and efficiently and must alert engineers if problems or inefficiencies arise.

oscilloscope

A device that displays a visual representation of a waveform. Oscilloscopes can be used to display vibration and electrical changes.

out-of-tolerance

A deviation from a desired dimension that no longer meets specifications. Out-of-tolerance parts may be a result of improper robot motion.

overshoot

To exceed a set value. Overshoot in robots refers to a robot always moving past a desired location.

peak efficiency

The maximum level of productivity possible for an operation or machine. Peak efficiency is rare to achieve in real-world conditions but serves as a good benchmark for gauging the effectiveness of an operation or machine.

peripheral devices

A physical device connected to a wired or wireless network that performs an auxiliary function. Peripheral devices communicate with a controller.

permanent solutions

A corrective action used to resolve a root cause and symptoms for the foreseeable future. Permanent solutions, such as fully replacing parts, are always preferred since temporary solutions may lead to additional mechanical issues or safety concerns.

personal protective equipment

PPE. Any clothing or device worn to minimize exposure to hazards and prevent injury. Personal protective equipment may include eye and ear protection, safety footwear, gloves, and other devices.

pie charts

A circular chart that is divided into wedge-shaped sections that are proportional to the values of different data types that make up a whole dataset. Pie charts are common data visualization tools.

pinhole leaks

The loss of hydraulic or pneumatic fluid through a small hole in the fluid system. Pinhole leaks, particularly those in pneumatic systems, may require the use of specialized equipment, such as an ultrasonic leak detector, to detect them.

pneumatic

Power created by the controlled motion of gas, usually air, under pressure. Pneumatic systems are often used to power robotic grippers, simple pick-and-place devices, and robots in which electric motors might pose a hazard.

position sensors

A device that senses the location of a component. Position sensors may be used with industrial robots to aid automation.

predictive maintenance

A maintenance approach that involves collecting data in order to anticipate and correct potential issues before they arise. A predictive maintenance approach involves performing maintenance before failures occur to prevent unscheduled downtime and reduce the labor, cost, and time needed for repairs.

preventive maintenance

PM. A type of maintenance performed while a component is in working order to keep it from breaking down. Preventive maintenance may include lubricating, tightening, and replacing worn parts.

production rates

The speed at which a manufacturing operation produces products. Production rates can slow due to worn, dirty, broken, or malfunctioning machines or processes.

programming parameters

A set of rules, limits, or physical properties that determine the characteristics and allowable actions and movements of a machine. Programming parameters for robots include speed of movement, positional coordinates (linear, angular, and spatial), and sensor interfaces, which all become part of the program that controls the robot functions.

protocols

The standards and rules used by network devices to interact with each other. Essentially, protocols are the language that networked devices use to communicate.

proximity sensors

A device that uses a sensing field to detect the presence of an object. Proximity sensors can be used in conjunction with robots to help position the robot in space relative to other objects.

pulse train

A repetitive series of pulses. Pulse trains can be used to calculate pulse frequency and average power of a stepper motor.

recalibration

The process of resetting or reconfiguring in order to more accurately measure a quantifiable subject, such as motion. Feedback devices need recalibration if they begin to measure movement or numbers incorrectly.

referencing

To set a consistent baseline point to measure against. Operators need to reference some encoders to a home switch for them to be able to accurately measure their motion.

reworked

Subjected to further manufacturing procedures, such as rewelding, remachining, or reassembly. Some defective parts can be reworked to save material and reduce the cost of scrapping.

robotics

A field of science that is focused on programmable mechanical devices. Robotics enable the work of a person to be done by a robot with a higher degree of accuracy.

root cause

The underlying cause of a problem. It is important to identify the root cause of a problem before taking corrective action.

safety fences

A type of physical barrier used to deter accidental entry into a robot's workcell. Safety fences should have signs warning of the hazards within their boundaries.

scatterplots

A data visualization tool that uses the clustering of plotted data points. Scatterplots are used to determine if the increase or decrease of one variable is related to an increase or decrease in another variable.

scrapped

Discarded, recycled, or otherwise destroyed. Parts must be scrapped if they do not meet official part specifications.

seals

A device used to contain pressure and prevent leakage in a fluid system. Seals include mechanical devices and rubber and polymeric rings, as well as other configurations of material that can be applied to a fluid system connection.

sensors

A device that detects the presence or absence of an object, certain properties of an object, environmental changes, or the internal state of a robot and provides feedback. Sensors allow robots to have an awareness of their environment.

servomotor

A small electric motor used in robots to allow for precise movement. Servomotors are often used in several places in a robotic arm, including the elbow joint and the gripper.

signal strength

The data power output from a network connection cable or a wireless router. Signal strength can be measured using a cable tester.

simulation

A computer program that generates three-dimensional models of a robot, its parts, and its manufacturing environment. Simulation software also records the desired robot movements, creating control programs that can be uploaded to the robot's machine interface.

singularity

Multiple joint axes on a robot aligning in a way that causes a loss of degrees of freedom, leading to unpredictable or uncontrollable movement. Singularity, also called gimbal lock, essentially makes the robot unable to move in the desired direction.

smart manufacturing

A method of manufacturing designed to improve product design and other processes through the integration of digital technology throughout the supply chain. Smart manufacturing increases connectivity across all areas of product development.

software

A set of digitized programs and operating procedures. Software determines the actions or performance of a computer or machine.

spring

A flexible device made of coiled material that yields under force and returns to its original shape once the force is removed. Springs are used to connect the arms of delta robots.

step lists

An organizational tool where operators list every possible step in a manufacturing process. Step lists help operators assess what specific parts of the manufacturing process they must monitor to determine the root cause.

stepper

A type of electrical device that creates mechanical movement in small, precise increments. Stepper motors are often used in open loop systems.

syntax

The format or order each word in a program follows. Syntax errors can cause serious problems within a part program.

teach pendants

A hand-held device that can be used to program a robot or control its movements. Teach pendants are used in online programming.

temperature sensors

A type of sensor that measures thermal values. Temperature sensors monitor both internal robot and ambient temperatures.

temporary solution

A corrective action used as a stopgap until a more permanent and complete corrective action can be implemented. Temporary solutions, such as adding lubrication to a joint rather than replacing a worn coolant line, are not optimal because they reduce both robot and production efficiency and potentially compromise operator safety.

time-based

Service performed on equipment according to an established inspection schedule. Time-based preventive maintenance schedules can be tracked manually or with computerized maintenance management systems.

tolerance

An acceptable deviation from a desired dimension that meets specifications. Parts outside of a required tolerance must be discarded or reworked.

troubleshooting

A systematic, standardized approach to solving problems quickly and efficiently. Troubleshooting focuses on identifying the root cause of a problem and eliminating that cause to create a permanent solution.

troubleshooting manual

A document that outlines common issues that arise in manufacturing operations along with corrective actions. Troubleshooting manuals streamline the troubleshooting process and are sometimes provided by the equipment manufacturer.

undershoot

To fall short of or below a set value. Undershoot in a robot refers to a robot consistently and repeatedly not moving far enough to reach a desired location.

usage-based

Service based on product utilization and performance. Usage-based preventive maintenance can be scheduled according to length of time in use, number of product cycles, or other types of measured performance.

vision sensors

A type of sensor that uses a camera to detect the presence, orientation, and features of an object. Vision sensors provide guidance to robots.

wear

The gradual removal or decay of material caused by contact, corrosion, and friction. Wear can occur on many parts of the robot, such as the sensors, gears, and end effectors, and cause the robot to malfunction.

weld pool

The pool of molten metal created by the heat of the welding. Weld pool characteristics vary depending on the metal being welded.

welding

A joining process that uses heat, friction, or a combination of methods to fuse two materials together permanently. Welding is used in a variety of industries from auto manufacturing to aerospace engineering and can be performed by industrial robots.

welding arc

The area in which electricity transfers from the wire electrode to the workpiece. The heat generated by the arc melts the base metals and filler metal during welding.

welding torches

A welding instrument that holds an electrode and generates an arc or releases gases to produce a flame used to melt and join materials. A welding torch may be used as an end effector for robotic welding.

welds

A mixture of metals that joins at least two separate parts. Welds can be produced by applying heat, pressure, or a combination of these.

wire

A thin, flexible, elongated piece of metal. Wire in welding refers to the consumable metal fed through the welding machine to create the mass of the actual weld.

wire feeder

The device connected to or built on the welding machine that dispenses the welding filler metal. Wire feeders should be cleaned of dust regularly to prevent malfunctions.

wiring diagrams

An illustrated version of an electrical circuit. Wiring diagrams indicate the connections of the components in electrical or electronic circuits.

workcells

The area composed of a robot and any external devices or equipment that interact with the robot, including additional robots. Robotic workcells can include multiple robots controlled by a single interface.

workholding devices

A component used to support, locate, and hold a workpiece. Workholding devices include clamps, vises, and collets.

working backward

A troubleshooting process where operators reverse a manufacturing process to assess each step for potential root causes. Working backward helps organize the troubleshooting process and ensures operators check each possible root cause.

wrist joint

The joint that connects the gripper or other end effector of the robot to the robot arm. Wrist joints have a number of components to allow full rotational movement for the gripper or other end effector.