With the advent of the Industry 4.0 era, robots are increasingly used to replace traditional labor and become an important way to increase production efficiency and improve product quality.

Imagine an automated factory, robots waving their arms, quickly welding, spraying, assembly and other processes, and staff shuttling among them, a busy scene…… Are you confident about the safety of the robot?

IC697MDL750E The difference between industrial robots and ordinary machinery

The biggest difference between industrial robots and ordinary machinery is the following:
• The robot is capable of high energy movement over very large areas
• The starting motion point of the robot and its motion trajectory are difficult to predict, especially after switching the robot program
• The operating space of the robot is likely to overlap with other robots and other machines and equipment, and if the robot moves incorrectly, it is likely to cause human injury or damage other equipment
• The operator is required to enter the robot area under live conditions due to the need for commissioning

It is precisely because of the difference between robots and traditional mechanical equipment that the risk assessment and safety measures taken for robots also need to be different. For robots and robot system integration, the state promulgated the mandatory national standards GB 11291.1 and GB 11291.2 for robot safety, which will be implemented from November 1, 2014 at the latest. Mandatory national standards are a necessary basis for judging whether robots in factories are compliant.

The choice of security protection mode

According to the definition in the risk assessment form, the IC697MDL750E risk reduction index number is determined, and the performance of the safety protection device and the minimum performance requirements of the safety control system are determined from Table 1 below.

Table 1 Safety protection device performance selection array table
1. Index number R4- This type is the lowest level of safety protection and risks should be reduced by administrative means, including audible/visual warning measures and training.
2. Index R3- Security protection shall rely, at a minimum, on non-interlocking barriers, spacing from hazard sources, safety procedures, personnel protection equipment to reduce risks, and security protection measures adopted by index R4.
3. Index number R2- Safety protection shall be achieved by measures to prevent the entry of hazards or to cut off hazards, and the use of safety protection in terms of R3 and R4 to reduce risks.
(4) Index R1- The reduction of risk shall be accomplished by the elimination of the hazard or by substitutions which do not really create an equivalent or greater hazard. Where elimination of hazards or substitution is not possible, all provisions of R2 and safety protections of R3 and R4 shall be applied to reduce the risk.

Corresponding to the performance IC697MDL750E of the safety protection device, the safety control system also needs to achieve the control performance shown in Table 1. Security control performance is mainly divided into the following categories:

1. Simple safety control system performance

A simple safety control system should be designed and constructed with a single channel circuit and be programmable. Note: This typical circuit should only be used for signaling and alarm.

2. Single channel security control system performance

Single-channel safety control system should be based on hardware, or use limit IC697MDL750E devices to restrict the operation of the robot to form a limited space, such as: mechanical stop, limit switch, light screen, laser scanning device, etc. These parts should be verified to be safe and used in accordance with the manufacturer’s recommendations. The circuit design used should be proven to be safe (e.g., a single-channel electro-mechanical reverse brake that signals a stop in the open state).

3. Single channel security system performance with monitoring function

A single channel safety control system with a monitoring function should include the requirements for a single channel safety control system, should be verified to be safe, and should be inspected at appropriate intervals (if possible, automatically identify faults).

a) The safety function can be checked at the start of the robot and its systems and at each state change during operation.

b) If no fault is detected during inspection, the operation is allowed to proceed; A stop signal should be generated if a fault is detected; If the danger persists after the movement has stopped, a warning should be issued.

c) No new dangerous state will be caused during inspection.

d) Fault tracking and detection should be kept in a safe state until the fault is cleared.

4. Control the performance of reliable safety control system

A reliable safety control system should be designed and constructed so as not to prevent the robot from stopping in the event of failure of any single component.

Such safety control system shall consist of hardware, or on this basis, use software and a firmware-based controller, and include automatic monitoring devices at the system level.

If…

– You have questions about whether the robots in the factory are compliant

– You want to know the mandatory national standard of the robot

– Your company, as a robotic system integrator, urgently needs to understand the requirements of robotic system standards

You can contact Pilmagnetic, we can provide safety services including risk assessment, safety training and safety modification to meet your needs, so that your robot equipment fully meets the requirements of the national mandatory standards.