ROBOTICS Robotics Safety 2 Previous Accidents From OSHA

ROBOTICS

Robotics Safety 2

Previous Accidents (From OSHA Web Site) 3

What Can Go Wrong? • On July 21, 1984, a thirty-four-year-old male operator of an automated die-cast system went into cardiorespiratory arrest and died after being pinned between the back end of an industrial robot and a steel safety pole. The hydraulic robot had been installed in an existing production line to remove die-cast parts from a die-cast machine and to transfer these parts to a trimmer. The victim had fifteen years' experience in die-casting and had completed a one-week training course in robotics three weeks before the fatal incident. • The victim entered the working range of the operating robot presumably to clean up scrap metal that had accumulated on the floor. Despite training in the robotics course, instructions on the job, and warnings by fellow workers to avoid this dangerous practice, the victim apparently climbed over, through, or around a safety rail which surrounded two sides of the robot's work envelope. The entry point in the safety rail was interlocked. No other presence-sensing devices were operative in the system. 4

Configurations 5

Robots Work Envelope 6

Robotics Characteristics • Programmable • Multi-Functional o Transfer/Motions programmed path • ANSI-RIA R 15. 06 -2012 7

Definitions • Maximum Space o Space that can be swept by the moving parts of the robot as defined by the manufacturer plus the space which can be swept by the end-effector and the workpiece • Restricted Space o Portion of the maximum space restricted by limiting devices that establish limits which will not be exceeded 8

Definitions (cont. ) • Operating Space o Portion of the restricted space that is actually used while performing all motions commanded by the task program • Safeguarded Space o Space defined by the perimeter safeguarding 9

Limiting Device • A device that restricts the maximum space by stopping or causing to stop all robot motion and is independent of the control program and the task programs. 10

Operating Modes • Program/Teaching • Normal Operations • Maintenance 11

Accidents included the following: • Robot’s arm functioned erratically during programming and struck the operator. • Operator entered the work envelope during operations and was pinned between the back end of the robot and a pole. • A fellow employee accidentally tripped the power switch while a maintenance worker was servicing a robot. The robot arm struck the maintenance worker. 12

Types of Accidents Include: • Impact or Collision Accidents – Unpredicted movements, malfunctions, peripheral equipment. • Crushing or Trapping Accidents • Mechanical Part Accidents – Breakdown, release of energy, failure of endeffectors • Other – Ruptured hydraulic lines, arc flash, metal spatter, dust, tripping hazards. 13

Loss Sources • Human Factor • Control Error • Mechanical • Environmental • Component Failure • Unexpected Energy Release 14

Applicable Standards • 1910. 212(a)(1) • 1910. 212(a)(2) • 1910. 212(a)(3)(ii) • 1910. 212(b) • 1910. 147 • 1910. 331 -. 335 • Section 5(a)(1) 15

Safeguarding Stages 1. Risk Assessment 2. Safeguarding Devices (limiting devices, presence-sensing, fixed barriers, interlocked barrier guards) 3. Awareness Devices 4. Safeguard the Teacher 5. Operator Safeguards 6. Attended Continuous Operation 7. Maintenance and Repair 8. Safety Training 9. General Requirements 16

Robot Safeguarding Devices • Mechanical limiting devices • Non-mechanical limiting devices • Presence-sensing safeguarding devices • Fixed barriers • Interlocked barrier guards 17

NIOSH Recommendations (Publication 85 -103) • Include physical barriers that incorporate gates equipped with electrical interlocks so that operation of the robot stops when the gate is opened. • Include, as a backup to electrical interlocks, o motion sensors, light curtains, or floor sensors that stop the robot whenever a worker crosses the barrier. • Provide barriers, as may be appropriate, between robotic equipment and any freestanding objects such as o posts limiting robot arm movement so that workers cannot get between any part of the robot and the "pinch points. " • Provide adequate clearance distances around all moving components of the robotic system. 18

NIOSH Recommendations (continued) • Include remote "diagnostic" instrumentation as much as possible so that the maximum amount of troubleshooting of the system can be done from areas outside the operating range of the robot. • Provide adequate illumination in the control and operational areas of the robotic system so that written instructions, as well as buttons, levers, etc. , are clearly visible. • Include on floors or working surfaces clearly visible marks that indicate the zones of movement of the robot. 19

Hierarchy of Controls (In Order of Priority) 1. Elimination or Substitution 2. Engineering Controls 3. Awareness Means 4. Training and Procedures – Administrative 5. Personal Protective Equipment 20

Elimination or Substitution • Eliminate human interaction in envelope • Eliminate pinch points • Automated material handling 21

Engineering Controls • Mechanical hard stops • Barriers • Interlocks • Presence sensing devices • Two hand controls 22

Awareness Means • Lights, beacons, strobes • Computer warnings • Signs • Restricted space painted on floor • Beepers • Horns • Labels 23

Training and Procedures • Safe job procedures • Safety equipment inspections • Training • Lockout/tagout 24

Personal Protective Equipment • Safety Glasses • Ear Plugs • Face Shields • Gloves 25

Teaching Protection • Slow Moving • Emergency Stops • Under Control 26

Maintenance • Lock-Out and Tag-out • Slow Moving Mode 27

Robot Safety Standards • Current National Standards o ANSI/RIA R 15. 06 -2012 o CSA Z 434 -14 (Canadian) • Current International Standards o ISO 10218 -1: 2011 Industrial robots o ISO 10218 -2: 2011 Industrial robot systems and integration • Technical Reports o RIA TR R 15. 306 -2014 – Task-based risk assessment o RIA TR R 15. 406 -2014 – Safeguarding o RIA TR R 15. 506 -2014 – Existing Applications 28

Definitions • Industrial robot (Must answer yes to all 5 bullet points) o Automatically controlled o Reprogrammable multipurpose manipulator o Programmable in 3 or more axes o Can be either fixed in place or mobile o For use in industrial automation applications • If not yes to all 5, not industrial robot and R 15. 06 not required • For example, warehouse retrieval systems are not industrial robots because they don’t have a multipurpose manipulator 29

Definitions • Industrial robot system – System comprising: o Industrial robot o End-effector(s) o Any machinery, equipment, devices, external auxiliary axes or sensors supporting the robot performing its task. • Industrial robot cell o One or more robot systems including associated machinery and equipment and the associated safeguarded space and protective measures 30

Risk Assessment • Give particular consideration to: o Intended operations of the robot including teaching, maintenance, setting, and cleaning o Unexpected start-up o Access by personnel from all directions o Reasonably foreseeable misuse o Effect of failure in the control system o Hazards associated with the specific robot application 31

Risk Assessment – Hierarchy of Controls • Risks eliminated or reduced first by design or substitution, then by safeguarding and other complementary measures. • Residual risks then reduced by other measures o warnings, o signs, o training 32

Design requirements and protective measures • Robot designed in accordance with principles for relevant hazards • Power transmission components guarded o Fixed guards attached o Moveable guards interlocked • Loss or variation of power not result in a hazard o Re-initiation of power not lead to motion (2 -step process) • Components designed so hazards of breaking, loosening, or releasing stored energy are minimized 33

Functional Safety • Single fault in any of these parts does not lead to the loss of safety function • Single fault detected at or before the next demand upon the safety function whenever possible • When single fault occurs, safety function is always performed and safe state maintained until the detected fault is corrected • All reasonably foreseeable faults shall be detected 34

Functional Safety Continued • Comprehensive risk assessment performed on the robot and its intended application may determine an alternate performance is warranted • Selection of other performance criteria specifically identified and appropriate limitations and cautions included in the information for use provided with the affected equipment 35

Single point of control • When robot placed under local control, initiation of motion or change of local control selection from any other source is prevented o Manual control using the pendant o Other teaching devices o Pendant is in charge • Pendant Controls must have 3 -position enabling device o Continuously held in center to permit motion o Release or fully-depressing stops motion o Must be fully released before re-initiation of motion 36

Risk Assessment Needed • Integrator perform a risk assessment to determine the risk reduction measures required to adequately reduce the risks presented by the integrated application • Risk assessment enables systematic analysis and evaluation of the risks associated with the robot system over its whole lifecycle • Risk assessment included o o Determination of the limits of the robot system Hazard identification Risk estimation Risk evaluation • The user shall be consulted to ensure that all reasonably foreseeable hazardous situations are identified 37

Safeguarding • Required when design does not remove hazards or adequately reduce risks • Guards and protective devices can (See RIA TR R 15. 406): o o o Prevent access to the hazard(s) Cause hazard(s) to cease before access Prevent unintended operation Contain parts and tooling Limit other process hazards • Guards or sensitive protective devices used for perimeter safeguarding • Selection take into account all the hazards within the safeguarded space 38

Requirements for Guards • Only removable by the use of a tool • Perimeter safeguarding not installed closer to the hazard than the restricted space • Openings in any fixed guard shall not allow a person to reach over, under, around or through any opening or gap and access a hazard o Max opening at bottom 7 inches o Minimum height at top 55 inches • Moveable guards shall open laterally or away from the hazard, and not into the safeguarded space and bring any hazards to a safe state before an operator can gain access 39

Task Based Risk Assessment Methodology • RIA TR R 15. 306 – 2014 • Information and guidance only. Not only method of doing. • Integrates hierarchy of control methodology 40

Barrier Protected Area 41

Example of Barrier Protection 42

Barrier Protection 43

Resources • RIA, www. roboticsonline. com • www. osha. gov/SLTC/robotics/index. html • STD 01 -12 -002 – Guidelines for Robotics Safetywww. osha. gov • OSHA Technical Manual – Industrial Robots and Robot System Safety https: //www. osha. gov/dts/osta/otm_iv/otm_iv_4. html • Preventing Injury of Workers by Robots – NIOSH Publication 85 -103 - https: //www. cdc. gov/niosh/docs/85 -103/ 44

Questions? 45