Ask the Experts

I agree with Jeff's response. It may be used for guarding applications. If there is a possibility of a part, parts, scrap, or other potential impact to the guard, then it must be designed to contain these objects and still function properly. For example, shattering would be inappropriate and subject personnel to added hazards. The operational forces may be chemical in nature, such that the "cage" is subjected to fumes or other sources that may degrade the performance of the "cage".

Over the past few years, there have been studies about the use of polycarbonate type materials and their effective life. Increasingly machine providers / integrators are requiring inspection of such guards & their replacement if there is any damage. They also require replacement within X (differs) years, regardless of any visible damage.

If you select the guard and its materials, you are responsible to check, test, and ensure that the selection will work as anticipated throughout it lifecycle.

The safety standard is ANSI RIA R15.06 - 1999. Although a revision will be starting soon, the existing standard contains details and useful information. If you need further assistance regarding safety requirements or in understanding safety standards, please feel free to contact Pilz Automation Safety, L.P. (www.Pilz.us) 734-354-0272, select technical support.

There is a short answer and a long answer. However please be assured that some of these new features can be used now. However there are capabilities that will not be addressed until ISO 10218-2 is completed, & rolled into R15.06.

SHORT: There is a technical report that will help with this: ANSI RIA TR R15.206. This document addresses using robots that meet ISO 10218-1 and complying with R15.06. ISO 10218-1 includes such new technology and the guide helps to make use of this new and optional robot technology.

LONG: The R15.06 committee is very active now. First we are addressing (and providing input to) ISO 10218-2 Integration of Robot Systems. Once ISO 10218-2 is adopted, the R15.06 committee will be taking both part 1 and part 2 of ISO 1018, to turn it all into the new R15.06. There are formatting issues, packaging issues, and even the possibility of providing a guide. These open issues will be addressed by the committee.

Emergency Stopping is meant for emergencies. So if it is an emergency, YES "hit the e-stop".

Machine damage is not tracked by the safety standard committee, and technically, it is not a safety issue. However there are safety implications of machinery damage. (1) if personnel think that an action will harm the machine, they may hesitate when the action is needed, thereby increasing the risk to personnel. (2) damage to the equipment may not be visible, and such damage may affect the machine's ability to respond as expected when needed for safety issues.

I suggest that you contact Fanuc, as they will be able to give you specific information and guidance about appropriate use of the robot.

There is information that coorelates a dimension of 20" or 1/2 meter as needed to prevent crushing. CSA Z434 uses 20" (1/2 meter) for clearance. It is expected that the ISO 10218-2 will also state 20" (1/2 meter) when clearance is required.

The only run-away situations that I know are quite old, dating to the hydraulic robot days. However this does not mean that it has not happened, only that I do not know of any such instance.

Roberta Nelson Shea Pilz Automation Safety , L.P.

The ANSI/ISO 10218-1 defined the requirements for safety-rated software defined axes limits. The recent RIA TR15.206 technical report allows the use of this new technology for limiting motion and defining the restricted space. To be considered safety-rated, this function must have a third party certification to category 3. The ABB EPS carries this certification. Therefore, you may use it in place of hard stops.

The real advantage is that it can be used on any of the six axes and in logical combinations. The system may also be used in place of 1st axis zone switched in muting applications.

First of all you need to decide which of the three functional safety standards best fit your product. In this case, since you have a complex electronic device, you should use IEC 62061 or IEC61508. From this analysis, you can then certify your product to a SIL. Then you can use this data to rate your device in ISO 13849-1 Performance Level.

You have three requirements you must meet.

1, Prove you hardware meets the architecture, reliability MTTFd and diagnostic coverage DC. 2. The you must write your code with adequate diagnostic techniques to fulfill the requirments of the SIL you wish to achieve. 3. Finally, you must demonstrate that your design process is managed to minimize systematic failures CCF

Please contact me if you have further questions and if you feel I can be of assistance at this preliminary phase.

Take care.

One method to determine the stopping time is to use a camera to record the actuation of the safeguarding device (light curtain) and the robot motion. Count the frames, starting with and including both the first frame in which the light curtain indicator displays the interruption and the final frame after which there is no longer any apparent robot motion. The standard frame rate of a digital camera is 30 frames per second or 33.3 ms per frame. If you then add the response time of the light curtain from the manufacturer's data sheet you will have determined the stopping time of the robot. The 33 ms resolution of this method provides a 2.1 inch resolution for the safe distance calculation at an approach speed of 63 inches per second. 1. The light curtain should be triggered at the point of the highest speed of the robot. 2. Use multiple measurements and average the result. 3. If higher resolution is desired, there are high speed cameras available.

I am not aware of and have been unable to find standards that address this topic. The approaches suggested by Mr. Anderson are valid in addressing the hazards. The speed, energy, shape, and hardness of the moving hazard all contribute to the severity of the potential injury as does the point of impact on the body. Even compliant projectiles that leave no physical sign of injury are known to cause death in certain instances when impacting the chest. Impact injuries to the head that may seem insignificant at the time frequently have severe consequences as well. The robot standard addresses robot motion hazards by the application of safeguards and the reduction of speed to a maximum of 250 mm/s. Reduction of speed and energy, elimination of corners and edges, and the application of safeguards should all be considered and applied when practicable.