5.1 Robot Safety Basics
At each stage of design and installation of a robot and robotic system, a hazard identification and risk assessment, including personnel safeguarding requirements, must be performed. The risk assessment must then be sent to OHS. The appropriate level of safeguarding, determined by the hazard identification and risk assessment, must be applied prior to operation.
Lab Managers are required to verify robot users are trained about the specific hazards and safety requirements associated with the specific type(s) of robot(s) they will be working with and must ensure that robot users follow required safety procedures.
Robot Users and/or Managers must prepare a job hazard analysis with operators for each new robot or new robot-related task to identify and control hazards. Use the robot manufacturer’s safety instructions to establish the risk zone for the specific machine, attachment, and task. After the Risk Assessment and Risk Assessment Form are complete, the Risk Assessment Form must be submitted to OHS for review and approval prior to starting work.
Always stay outside the risk zone when the machine is in operation, and do not enter until the machine is put into emergency stop mode or is de-energized. Consider using a proximity warning system or other similar safeguard, such as those based on radio frequency identification (RFID), to maintain a safe worker-to-machine distance when practical.
Train operators to manage power cables and to continually monitor the process for hazards and redefine the risk zone as needed.
Ensure operators always read and follow manufacturer’s provided safety instructions and consider using a spotter to assist the operator when appropriate.
5.2 Safeguards
When design does not either remove the hazards or adequately reduce the risks, and the risk assessment indicates a need, safeguarding must be applied to limit access to hazardous areas of the robot and robotic systems.
Methods of safeguarding include, but are not limited to:
Limiting robot motion
Use of a key, plug, or actuating device which is not easily duplicated or tamper-resistant
Ensure that keys which disable safeguards are not left in robot unattended
Barriers that cannot be defeated intentionally without the use of tools
Perimeter safeguarding
Installation that cannot be placed in automatic operation until the associated safeguard is active.
Installation that will result in a shutdown of operations if the safeguard is removed while the hazard is present.
Ensuring installation of the safeguard will not result in an automatic re-start of operation.
Must be capable of being easily unlocked from the inside of the safeguarded space with or without power when the possibility of full body access exists.
5.3 Protective Devices
When protective devices such as pressure sensitive equipment (mats), light curtains, and laser scanners are required based on the Risk Assessment, they must comply with the following requirements:
Barrier guards need to be free of sharp edges and be able to be securely attached.
Mechanical devices need a physical link between the energy source of a hazard and the locking mechanism to allow removal of the key (for key-interlocked devices) only when the hazard has been controlled. They must also provide a mechanical lock for the guard at the point of access that can only be unlocked by the key.
Electrical devices, such as safety switches, must provide a method to unlock the device in the event of power failure and provide a method to monitor the state of the locking mechanism.
Safety light curtains must be marked with their maximum response time, maximum angle of divergence, minimum object sensitivity, and protected height. They need to visibly indicate a fixed blanked area; if not, the user will verify that blanking is being used, including the number, size, and location of the blanked beams.
RF/capacitance devices need to have a sensitivity adjustment to allow for authorized adjustment of the field and must not be adversely affected by external fields such as those created by welding.
Safety mats must have a minimum object sensitivity that detects a 30-kg (66-lb) weight on an 80-mm (3.125-in.) diameter circular disk placed anywhere on the mat sensing surface. Mats need to be securely mounted to prevent inadvertent movement or removal and installed to minimize tripping hazards, typically achieved by use of ramped edging. Maximum response time should be less than 100 m/sec, measured over the system operating-temperature range.
5.4 Emergency Stop
Every robot system, pendant, or cell must have a protective stop function and an independent emergency stop function. These stops must stop all robot motion and other hazardous functions in the cell or at the interface between cells and other areas of the workplace.
5.5 Suspension of Safeguards
Tasks that require the suspension of installed safeguards must have a dedicated mode of operation that automatically selects the appropriate alternate safeguards, as determined by the risk assessment, or other approved safeguarding methods must be used.
5.6 Lockout/Tagout Procedures
When entering a robot cell for any maintenance/servicing, un-jamming, or housekeeping, lockout/tagout procedures are required per the Control of Hazardous Energy Program.
5.7 Initial Start-up Procedure Plan
An initial start-up procedure plan for a new robot or robotic system must be established that includes mechanical, electrical, and operational tests, with and without power being applied.
Non-Collaborative
| Non-Collaborative Robots are robots which are not designed to operate with human interaction. These robots must be protected and guarded by a wall or barrier to prevent contact during operation.
|
Collaborative
| Collaborative Robots, or “Cobots,” are designed for robot/human interaction during tasks. These often include robots designed for assembly operations and must have safeguards in place to slow down or stop operation when a person is detected within its operating cell or work area.
|
Autonomous
Mobile Robots
| Autonomous Mobile Robots drive and operate themselves within the parameters of their programming, without direct human guidance. Industrial autonomous mobile robots include robots used for warehousing operations and inventory management, as well as some self-driving vehicles.
Robot travel path must be kept clear of hazards during operation
Steps must be taken to ensure robot will not stop in front of or otherwise block emergency exits, fire alarms, fire extinguishers, or emergency equipment.
For robots with consistent travel areas, such as lawnmower robots or vacuum robots, travel area must be defined with a visible boundary and signage alerting people in the area of the robot’s presence and operating path.
|
Service Robot
| Service Robots perform useful tasks for humans or equipment outside of an industrial setting, such as an office or building lobby. These include lawnmower robots, vacuum robots, personal caretaker robots, and most robots which have conversational software to facilitate verbal communication.
Robot travel path must be kept clear of hazards during operation
Steps must be taken to ensure robot will not stop in front of or otherwise block emergency exits, fire alarms, fire extinguishers, or emergency equipment.
For robots with consistent travel areas, such as lawnmower robots or vacuum robots, travel area must be defined with a visible boundary and signage alerting people in the area of the robot’s presence and operating path.
Mobile Service Robots without a defined travel path must be escorted or monitored by a robot user with direct line of sight while the robot is in operation
|
Prototypes
| Prototype robot refers to any robot or robot system currently under development.
|
