È stata pubblicata la specifica tecnica ISO/TS 15066:2016 “Robots and robotic devices – Collaborative robots”.
Per robot collaborativo si intende un robot che opera condividendo lo spazio di lavoro con un operatore umano.
Questo documento definisce i criteri per la valutazione dei rischi generati dall’utilizzo di robot collaborativi e le misure di protezione che devono essere adottate.
Pur non essendo una norma, e quindi non potendo essere armonizzata ai sensi della direttiva macchine, la specifica tecnica ISO/TS 15066 definisce lo stato dell’arte attuale per la progettazione e realizzazione di sistemi robotici collaborativi.
Scope
This Technical Specification specifies safety requirements for collaborative industrial robot systems and the work environment, and supplements the requirements and guidance on collaborative industrial robot operation given in ISO 10218-1 and ISO 10218-2.
This Technical Specification applies to industrial robot systems as described in ISO 10218-1 and ISO 10218-2. It does not apply to non-industrial robots, although the safety principles presented can be useful to other areas of robotics.
Terms and definitions
Collaborative operation – state in which a purposely designed robot system and an operator work within a collaborative workspace.
Collaborative workspace – space within the operating space where the robot system (including the workpiece) and a human can perform tasks concurrently during production operation.
Collaborative operations
Collaborative operations may include one or more of the following methods:
a) safety-rated monitored stop;
b) hand guiding;
c) speed and separation monitoring;
d) power and force limiting.
5.5.2 Safety-rated monitored stop
In this method, the safety-rated monitored stop robot feature is used to cease robot motion in the collaborative workspace before an operator enters the collaborative workspace to interact with the robot system and complete a task (e.g. loading a part onto the end-effector).
If there is no operator in the collaborative workspace, the robot may operate non-collaboratively. When the robot system is in the collaborative workspace, the safety-rated monitored function is active and robot motion is stopped, the operator is permitted to enter the collaborative workspace. Robot system motion can resume without any additional intervention only after the operator has exited the collaborative workspace.
5.5.3 Hand guiding
In this method of operation, an operator uses a hand-operated device to transmit motion commands to the robot system.
Before the operator is permitted to enter the collaborative workspace and conduct the hand-guiding task, the robot achieves a safety-rated monitored stop (see 5.5.2).
The task is carried out by manually actuating guiding devices located at or near the robot end-effector.
Robot systems used for hand guiding can be equipped with additional features, such as force amplification, virtual safety zones or tracking technologies.
If the requirements of 5.5.5 are fulfilled in a hand guiding task, then the requirements of 5.5.3 do not apply.
5.5.4 Speed and separation monitoring
In this method of operation, the robot system and operator may move concurrently in the collaborative workspace.
Risk reduction is achieved by maintaining at least the protective separation distance between operator and robot at all times.
During robot motion, the robot system never gets closer to the operator than the protective separation distance.
When the separation distance decreases to a value below the protective separation distance, the robot system stops.
When the operator moves away from the robot system, the robot system can resume motion automatically according to the requirements of this clause while maintaining at least the protective separation distance.
When the robot system reduces its speed, the protective separation distance decreases correspondingly.
5.5.5 Power and force limiting
In this method of operation, physical contact between the robot system (including the workpiece) and an operator can occur either intentionally or unintentionally.
Power and force limited collaborative operation requires robot systems specifically designed for this particular type of operation.
Risk reduction is achieved, either through inherently safe means in the robot or through a safety-related control system, by keeping hazards associated with the robot system below threshold limit values that are determined during the risk assessment.
A means to establish the threshold limits values is outlined in Annex A.
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