Safety#
Abstract#
This section describes important safety and risk assessments that you need to be aware when installing, applying, and maintaining on robot and its components. The user must read and fully understand this information before the robot is powered on for the first time.
Before performing any operations, be sure to read all operating instructions provided with the equipment, in particular, instructions that may endanger personal safety and equipment safety, such as hazards, warnings, and cautions, to minimize the chance of an accident. When this document differs from the documentation shipped with the device, the documentation shipped with the device shall prevail.
The technicians responsible for installing and maintaining the equipment must be a trained person who has proper methods of operation and all safety precautions. Only trained and qualified technicians are able to perform equipment installation and maintenance.
Limitation of Liability#
This information neither includes how to design, install and operate a complete robot system, nor any peripherals that affect the overall system. In order to protect personal safety, an outstanding system must be designed and installed in accordance with the safety requirements stipulated in the standards and regulations of the country where the robot is installed.
The robot integrator is responsible for ensuring that the robot system complies with the applicable safety laws and regulations of the country or region where the robot is located and that the necessary safety equipment for the protection of the robot system operator is properly designed and correctly installed.
Specifically including but not limited to the following:
Ensure that the robot system meets all basic requirements；
Perform a risk assessment of the complete system；
Ensure the design and installation of the entire system is accurate；
Make appropriate security settings in the software and ensure that it will not be modified by the user；
Develop detailed operating instructions；
Issue a declaration of conformity；
Collect all information in technical documents；
Label the integrator’s logo and contact information on the installed robotic system.
SIASUN Co., Ltd. is committed to providing reliable safety information and will not be liable unless there is intentional or gross negligence by SIASUN Co., Ltd. in providing reliable safety information. It is important to declare that even if all operations are carried out in a safe manner, there is no guarantee that the robot system will not cause personal and property damage to the user.
SIASUN Co., Ltd. will not be liable for the loss of users caused by the following reasons:
Force Majeure events (e.g., natural disasters, fires, wars, etc.);
Natural damage or wear of the robot system;
The site operating environment (e.g., voltage, temperature, humidity, etc.) or external factors (e.g., external interference, etc.) cannot meet the environmental requirements for normal operation as indicated;
The robot system is not installed correctly (including not reinstalled correctly after relocation);
due to the willful or negligence of the user or a third party, improper use (including the user’s failure to use in accordance with this User’s Manual and/or other requirements of SIASUN Co., Ltd.) or willful sabotage.
Unless otherwise agreed, SIASUN Co., Ltd. will not be liable for the indirect, special and incidental losses caused by the use of the robot system, including but not limited to the loss of revenue, actual or expected revenue, business loss, opportunity loss, goodwill loss, reputation loss, data loss, damage or leakage, etc.
Risk Assessment#
Risk assessment is one of the most important tasks that integrators must accomplish. The robot itself is a partially completed machine, and the safety of the robot installation depends on how the robot is integrated (e.g. tools, obstacles and other machineries).
It is recommended that integrators perform risk assessment in accordance with ISO12100 (GB 15706) and ISO10218-2 (GB 11291.2). Alternatively, technical specification ISO/T 15066 (GB/T 36008）may be selected as additional guidance. Integrators performing a risk assessment should consider all procedures during the entire lifespan of the robot, including but not limited to:
Teach robots when developing robots；
Fault diagnosis and maintenance；
General operation of robot installation.
Risk assessment must be performed before the robot arm is powered on for the first time. Part of the risk assessment performed by the integrator is the necessity to identify the correct security configuration settings, emergency stop buttons and additional protections for specific robot applications.
The following list identifies the significant risks that integrators must consider. Please note that there may be other significant hazards from certain robotic devices.
Finger is clamped between joint 4 and joint 5;
Sharp edges and sharp spots on the tool or the tool connector may cause damage to human skin;
The obstacles sharp edges and sharp spots, which is closed by the robot track, may be dangerous to human skin;
Sprains or fractures due to impact between the robot payload and a solid surface;
Consequences due to loosening of bolts used to secure robot or tools;
Items fall off the tool. For example, due to insufficient clamping or accidentally power down;
Operating error due to different emergency stop button allocation and types.
If the robot is installed in a non-cooperative application (e.g. using dangerous tools) where the risk cannot be adequately eliminated by using its internal safety functions, the system integrator must install other protective devices based on the risk assessment (e.g. Installing a safety enclosure that can provide protection to the integrator during installation and programming).
Safety Operations#
Emergency Stop#
Emergency stop takes precedence over all the other robot control operations. Pressing emergency stop will cause all controlled hazards to stop, removing the motor power from the robot drive. It will remain in effect until reset manually.
Activate emergency stop to immediately stop the robot from any motion. The user must perform a restoration procedure, resetting the emergency stop button and pressing the “Power On” button on demonstrator, to resume normal operation. Emergency stop shall not be used as a risk reduction measure, but as a secondary protective device.
Emergency stop must not be used for normal program stop; constantly pressing may result in additional unnecessary wear on the robot.
Safety-related Functions and Interfaces#
Introduction#
Siasun GCR series are equipped with a range of built-in safety functions as well as safety I/O, digital and analog control signals to connect to other machines and additional protective devices.
The use and configuration of safety functions and interfaces must follow the risk assessment procedures for each robot application
If the robot discovers a fault or violation in the safety system (e.g. if one of the wires in the Emergency Stop circuit is cut or a safety limit is violated) then a Stop Category 0 is initiated
The stopping time should be taken into account as part of the application risk assessment.
The use of safety configuration parameters different from those determines by the risk assessment can result in hazards that are not reasonably eliminated or risks that are not sufficiently reduced.
Ensure tools and grippers are connected appropriately so if there is an interruption of power, no hazards occur.
The end effector is not protected by the GCR safety system. The end effector and / or connection cable is not monitored.
Stop Categories#
Depending on the circumstances, the robot can initiate three types of stop categories defined according to IEC 60204-1. These categories are defined in the following table.
Stop Category |
Description |
|---|---|
0(SS0) |
Stop the robot by immediate removal the power |
1(SS1) |
Reduce joints acceleration to 0 as soon as possible. Once each joint stopped, brake applied and power removed |
2(SS2) |
Stop the robot with power available to the drives, while maintaining the trajectory. Drive power is maintained after robot is stopped; no brake applied. |
Swap between each stop categories:
The timer runs as soon as any stop category 1 occurs. At 500ms, if the robot is still running over speed, the stop category will be automatically swapped to category 0.
Safety functions#
The GCR robot safety functions, are meant to control the robot system, such as the robot with its attached tool/ end effector. The robot safety functions are used to reduce robot system risks determined by the risk assessment. Positions and speeds are relative to the base of the robot.
The control unit safety functions are listed as follow:
Safety Function |
Description |
|---|---|
Emergency stop (ES) |
Perform SS1 |
Protective stop |
Perform SS2 |
Safe Operating Stop (SOS) |
After SS2 is executed, SOS monitoring will be triggered to monitor the current position deviation of the robot. If it is violated, SS0 will be triggered |
Joint Safe limited position (SLP) |
According to the threshold setting, SS2 is triggered when the joint position reaches the threshold. If the trigger joint is limited, SS0 is fired directly |
Joint Safe limited speed (SLS) |
According to the threshold setting, SS2 is triggered when the joint velocity reaches the threshold. If the joint speed limit is triggered, SS0 is fired directly |
TCP position limit |
The safe plane can be set to limit the operating area of the robot, which is set according to the threshold value. When the threshold value is reached, SS2 is triggered. If the safety plane is triggered, the safety controller directly triggers SS0. Up to 6 security planes and 3 TCP coordinate systems are allowed |
Tcp speed limit |
According to the threshold setting, SS2 is triggered when the threshold is reached. If the TCP speed limit is triggered, the safety controller directly triggers SS0 |
elbow pos limit |
According to the threshold setting, SS2 is triggered when the threshold is reached. If the Elbow position limit is triggered, the safety controller fires SS0 directly |
elbow speed limit |
According to the threshold setting, SS2 is triggered when the threshold is reached. If the Elbow speed limit is triggered, the safety controller fires SS0 directly |
joint force limit |
According to the threshold setting, SS2 is triggered when the threshold is reached. If joint torque limits are triggered, the safety controller directly triggers SS0 |
tcp force limit |
According to the threshold setting, SS2 is triggered when the threshold is reached. If the end force limit is triggered, the safety controller directly triggers SS0 |
elbow force limit |
According to the threshold setting, SS2 is triggered when the threshold is reached. If the Elbow force limit is triggered, the safety controller fires SS0 directly |
power limit |
According to the threshold setting, SS2 is triggered when the threshold is reached. If power limits are triggered, the safety controller directly triggers SS0 |
mode switch input |
You can optionally enable this input , you can toggle through the UI; But not both. SS2 is triggered when the mode is switched. If the script is currently running, the script is paused and can continue to run later. |
enable device input |
You can optionally enable this input. This input is valid only in manual mode, not in automatic mode. Violation triggers SS2. |
protective stop input |
Valid in all modes, triggering SS2. If the reset input is not activated, after the signal disappears, it will reset automatically. Otherwise, it can reset only when the reset input is triggered. |
protective stop reset input |
You can optionally reset the signal input. If the safety protection reset is activated, when the trigger safety protection stops and the trigger signal disappears, the channel signal input is required before the movement. The rising edge is effective and the high level needs to be maintained at 500ms |
automatic protective stop input |
Only valid in automatic mode, triggering SS2. After the signal disappears, the safe mode resumes Normal |
automatic protective stop reset input |
Similar to the Protective Stop Reset Input, only valid for protective stops triggered by Automatic Protective Stop Input. |
system emergency stop output |
This signal will be output only when the system is triggered by an emergency stop |
protective stop output |
Protective Stop output. This signal is emitted when the Protective Stop Input is triggered |
automatic protective stop output |
Automatic mode protective stops output, only when the protective stops triggered in automatic mode, the signal will be output. |
reduce mode |
Trigger the reduction mode, using the parameters associated with the reduction mode. |
reduce mode output |
Globally, the signal can be output. |
recovery mode |
When the joint limit, or TCP limit, is exceeded, a reboot is required to enter recovery mode. Recovery mode to limit speed not more than 30 deg/s, the end of the speed of less than 250 mm/s |
The Risk of Collision#
There is still a collision detection blind zone during the actual operation of the robot. Users must pay attention to the risk of collision detection failure under special working conditions. Typical three types of operating conditions are as follows.
Scenario 1: When the robot tool flange is outside the range A from the center of the robot base, if the robot moves along the direction of the red arrow in Figure 1 and Figure 2, the robot is less sensitive to external forces in the moving direction. The risk of pinching is more likely to occur; when the robot moves along the direction of the green arrow in Figure 1 and Figure2, if the robot collides with the external environment, the external force generated by the collision is more sensitive.
Model |
Range A mm |
|---|---|
GCR3-618 |
500 |
GCR5-910 |
750 |
GCR7-910 |
750 |
GCR10-1300 |
1000 |
GCR10-2000 |
1500 |
GCR12-1300 |
1000 |
GCR14-1400 |
1000 |
GCR16-960 |
750 |
GCR20-1100 |
900 |
GCR25-1800 |
1300 |
Figure 1 Scenario 1: robot front view
Figure 2 Scenario 1: robot top view
Scenario 2: Centering on the Z-direction of the robot base coordinate system, the radius is shown in Figure 3. If the contact point is within this range B, and the contact force direction is perpendicular to the plane of the joints of the joints 2 and joint 3, the collision detection function is difficult to detect collisions between the robot and the outside world. As the red arrow shown in Figure 3 in Figure 4; if the force direction between the robot and the outside is consistent with the Z direction of the robot base, the robot is more sensitive to the external force generated by the collision, as the green arrow shown in Figure 3.
Model |
Range B mm |
|---|---|
GCR3-618 |
150 |
GCR5-910 |
200 |
GCR7-910 |
200 |
GCR10-1300 |
350 |
GCR10-2000 |
500 |
GCR12-1300 |
350 |
GCR14-1400 |
500 |
GCR16-960 |
350 |
GCR20-1100 |
500 |
GCR25-1800 |
600 |
Figure 3 Scenario 2: robot front view
Figure 4 Scenario 2: robot front view
Scenario 3: When the robot collides with the outside world, and if the collision point is located in the spherical range with a radius C on the robot base, the robot is more difficult to detect the collision regardless of the pose and state of the robot. It is more prone to the risk of pinching, as the arrow shown in Figure 5 and in Figure 6; when the collision point is outside the range, and does not meet the conditions of the collision detection zone described in scenario 1 and scenario 2. At the time, the robot is more likely to detect collisions with the outside world, as the green arrow shown in Figure 5 and in Figure 6.
Model |
Range C mm |
|---|---|
GCR3-618 |
150 |
GCR5-910 |
200 |
GCR7-910 |
200 |
GCR10-1300 |
350 |
GCR10-2000 |
500 |
GCR12-1300 |
350 |
GCR14-1400 |
500 |
GCR16-960 |
350 |
GCR20-1100 |
500 |
GCR25-1800 |
600 |
Figure 5 Scenario 3: robot side view
Range C
Figure 6 Scenario 3: robot front view
For all above-described scenarios, if the robot moves in a direction that is insensitive to external collision detection, considering the limitation of the cooperation between the robot and the outside world, the running speed at this time should be reduced as much as possible.
Risk of Stall at Robot Singularity#
When the robot performs motion planning (straight line, arc, etc., excluding joint motion) near the singularity point, it will automatically reduce speed. When teaching, avoid the singularity point or pass the singularity point with joint motion. For the GCR series configuration, there are shoulder singularities, elbow singularities and wrist singularities.
Shoulder Singularity#
When the wrist joint center O6 is on a joint axis J1, the shoulder singularity is caused at this time, resulting in no solution for joint 1. When O6 is located very close to J1, it will also be affected strangely. At this time, moving the end may cause joint 1 to overspeed. Refer to the picture below for the singular pose near the shoulder.
Figure 7 Shoulder singularity pose reference pose
Elbow singularity#
When the axes of the two, three, and four joints J2, J3, and J4 are coplanar, at this time, the two joints have no solution. Simply, when joint 3 is near 0 degrees in a near singularity, moving the end may cause 2 joints, 3 joints, and 4 joints to overspeed. Refer to the figure below near the elbow singularity:
Figure 8 Elbow Singularity Pose Reference
Wrist singularity#
When the joint 5 is 0 degrees, the joint 6 has no solution at this time, causing the wrist to be singular. When joint 5 is close to 0 degrees, it is a strange posture near the wrist. At this time, moving the end may cause 4 joints, 5 joints, and 6 joints to overspeed. Refer to the following figure:
Figure 9 Wrist Singularity Reference
When the robot reaches or approaches the singularity, the planned movement based on Cartesian coordinates cannot be correctly reversed to the joint motion of each axis, and the movement planning cannot be performed correctly. The off motion or move j motion instruction can be used.
Avoid using commands such as straight lines, arcs, and moving the ends in the directions of X, Y, Z, RX, RY, and RZ near the singularity points. The robot is at risk of stalling.
For trajectories with singular risks, they must be fully evaluated before running.