Introduction to Safety Functions#

The GCR series robots are equipped with a variety of built-in safety functions as well as safety I/O, digital and analog control signals for emergency electrical interfaces for connecting other robots and additional protective devices. According to ISO 13849-1:2023 section 3.1.43, all the safety functions are high demand mode.

Once one of the safety functions is triggered, a pop-up window will show in the teach pendant with correspondent error code. The mean of the error code can refer to <GCRseries Cobot Maintenance Manual>

Caution

  • The use and configuration of safety functions and interfaces must follow the risk assessment procedure for each robot application.

  • If the robot detects a malfunction or violation in the safety system (e.g. A line is cut in the emergency stop circuit or a safety limit violation occurs), a Class 0 stop will be initiated.

  • Stop times should be considered as part of the application risk assessment.

Warning

  • The use of safety configuration parameters that differ from those identified in the risk assessment can lead to hazards that cannot reasonably be eliminated or risks that cannot be adequately reduced.

  • Ensure that the TCP and gripper are connected correctly to avoid hazards in the situation of a power interruption.

  • The function of end-effector is not protected by the GCR safety system. The connecting cable of the end-effector is not monitored.

Table 3‑1 and Table 3‑2 below list all the safety functions of the GCR series robots. Robot safety features are used to reduce the risk to the robot system as determined by a risk assessment.

Table 3‑1 Safety Functions List#

Safety Function

Function Name

Description

STO

SBC

Safe Torque Off

Safe Brake Control

This function executes Safe Torque Off, Safe Brake Control at the same time. Cut off the power of robot arm immediately. The robot will stop immediately. The motion will deviate the trajectory expected.

SS1-t (STOP1)

Emergency Stop

Safe Stop Category 1

This function executes Safe Stop Category 1. The robot will stop with the maximum deceleration. The motion will deviate the trajectory expected but controlled by joint. Delay 500ms, cut off the power of robot arm.

SS2-t (STOP2)

Safe Stop Category 2

This function executes Safe Stop Category 2. The robot will stop with the setting deceleration. The motion will follow the trajectory expected.

SOS

Safe Operation Stop

This function monitoring the unexpected motion after Safe Stop Category 2. Once the robot the SS2 function executes completed, SOS function will be activated. If one of the joints moves more than 3 degrees, the STO will be triggered.

Reduce

Reduce mode switch

Once the related safety input is triggered, the robot switches to Reduce mode, then all the safety parameters threshold change to Reduce mode value.

SHP

Safe Home Position

If all the joints reach to home position defined, the related safety output will be triggered.

SLP

Safe Limiting Position

Monitoring the joint position, once the joint’s position exceeds the safe limit, a related safe stop will be triggered.

SLS

Safe Limiting Speed

Monitoring the joint speed, once the joint’s speed exceeds the safe limit, a related safe stop will be triggered.

TPL

TCP/Elbow Position Limiting

Monitoring the TCP and the elbow space position, once the TCP/elbow position exceeds the safe limit, a related safe stop will be triggered.

TSL

TCP/Elbow Speed Limiting

Monitoring the TCP and the elbow space speed, once the TCP/elbow speed exceeds the safe limit, a related safe stop will be triggered.

SLT

Safe Limiting Torque

Monitoring the joint torque, once the joint’s torque exceeds the safe limit, a related safe stop will be triggered.

SPL

Safe Power Limiting

Monitoring the robot mechanical power. The mechanical power is the summary of all the joints mechanical power. The joint mechanical power is the product of joint torque and joint speed. Once the robot mechanical power exceeds the safe limit, a related safe stop will be triggered.

CD

Collision Detect

Monitoring the difference between theoretical and actual joint torque. Once the difference exceeds the safe limit, a related safe stop will be triggered.

SI

Safety Input

Received safety input signal.

SO

Safety Output

Output safety output signal.

TOM

TCP Orientation Monitoring

Monitoring the angle between TCP’s “Rz” axis and the reference direct. Once the angle exceeds the safe limit, a related safe stop will be triggered.

The test for all safety functions is triggered every 10ms after system startup.

Table 3‑2 Safety Functions Detail

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