Topic Title: Robotic arm design, development and installation
Created On: 06 February 2013 02:22 PM
Status: Post and Reply
|Linear : Threading : Single : Branch|
06 February 2013 02:22 PM
Joined: 18 October 2002
I am currently investigating the feasibility of using a robot arm for packing products. The products are cylndical in shape and about 150mm long. They are packed into a box which needs to be replaced by an operator when full (no conveyor system here I'm afraid). As such I need recomendations on guarding as the operator need access.
Any ideas, documentation, regulations, thoughts, video, etc ? All help is gratefully appreciated.
Davie Orr CEng FIET
06 February 2013 03:21 PM
Joined: 04 July 2002
A good place to start is HSE Guidance Document HSG 43. This is old (2000) and you would need to contact HSE Books to see if still available.
I have some basic scans I can send you if you send me your email address (to email@example.com)
You should refer to ISO 10218 - part 1 and ISO 10218 - part 2. They are both available through British Standards Online. Part 2 still has the draft for comment status so is incomplete.
BS EN ISO 10218-1:2008
Robots for industrial environments. Safety requirements. Robot
BS EN ISO 10218-2. Robots for industrial environments. Safety requirements. Part 2. Robot system and integration
· Status: Current, Draft for public comment
May be of interest...
BS EN ISO 9946:1999
Manipulating industrial robots. Presentation of characteristics
· Status: Current
BS EN ISO 11161:2007+A1:2010
Safety of machinery. Integrated manufacturing systems. Basic requirements
For a designer of a robotic cell, the top level requirement is to comply with The Supply of Machinery (Safety) Regulations. This is the UK implementation of the Machinery Directive. It applies even if you are building & self supplying machinery.
In general, the design considerations necessary will include;
Guarding - Prevention of people coming into contact with the equipment. Prevention of ejection of material from equipment. Normally 2 meter high.
Maintenance - Safe access / egress. Safe systems of work. Often provided with key interlocked access door. Robot control system will only allow operation in manual (slow) operating mode from teach pendant whilst engineer inside cell.
Extraction - May be needed to remove dust & / or fume.
Operation - Often interchange station for loading of work parts outside cell while robot performs operations inside cell. Sometimes have rise/fall door, sometimes turntable. Frequently loading area protected by light curtains and reset functions outside of robot reach.
Manual Handling - may have to access under regulations.
Under the directive you have to comply with a set of Essential Health & Safety Requirements (EHSR) before you can apply a CE mark. To be able to do comply with the EHSR, the machine will need to be designed in accordance with a number of relevant European Normalised (EN) Standards, national guidance and any other applicable legislation / regulations.
CE marking is designed to allow for freedom of trade of equipment within the European Economic Area. Marking of equipment with the CE mark indicates that the design meets the requirements of all the relevant directives.
For Robotics automation this will be a combination of three or possibly four directives;
The Machinery Directive 2006/42/EC
The Low Voltage Directive 2006/95/EEC
The EMC Directive 89/336/EEC
It could also include,
The Pressure Equipment Directive 97/23/EC
It is illegal to affix the CE mark to a machine unless it complies with all applicable directives.
The key part of the directives are the Essential Health & Safety Requirements (EHSR).
In order to comply and be able to legally affix the CE mark we have to;
Demonstrate compliance with the Essential Health & Safety Requirements (EHSR).
Carry out the appropriate conformity assessment procedure - the Technical Construction File.
Draw up & issue a Declaration of Conformity or Incorporation.
Apply the CE mark. (where a Declaration of Conformity is being issued).
Make sure that it is safe.
(4) EN Standards
A Type - Apply to all machines
B Type - Promote safety & split into B1 & B2 sub types
C Type - Apply to a specific type of machine
Listed below are some of the most common standards for this type of equipment. NOTE: This should not be considered to be an exhaustive list.
C Type (Specific) robot safety standards
ISO 10218-1 2008 Robots for Industrial Environments - Safety Requirements. Part 1: Robots
(This is the main safety standard for manufacture of robotic systems. There is a second part that has not yet been released concerning Robot Systems & integration).
EN 775:1992 / BS7228-6: 1992 Industrial robots - Recommendations for Safety
(This pair of standards are linked together. EN775 was the initial embodiment of ISO 10218 into the EU and BS 7228 the British Standard. However, they are basically the same as ISO 10218 which considered the parent standard).
Health & Safety Executive guidance notes HSG 43
B1 / B2 Standards (Promoting Safety)
Any particular robot cell may utilise a large range of standards. Common examples might be;
BS EN ISO 13849-1:2008 Safety of machinery - Safety related parts of control systems. Part 1 - General Principles for Design or
BS EN 62061:2005 Safety of machinery - Functional safety of safety-related electrical, electronic and programmable electronic control systems or
EN 954-1:1997 Safety of machinery - Safety related parts of control systems. Part 1 - General Principles for Design
(All above relate to safety of control systems - can use any of these although do have some particular circumstances in which one is more suitable than another).
BS EN ISO 13857:2008 Safety of machinery - Safety distances to prevent hazard zones being reached by the upper and lower limbs.
BS EN 349:1993 +A1:2008 Safety of machinery - Minimum gaps to avoid crushing parts of the human body.
BS EN ISO 13850:2008 Safety of machinery - Emergency stop - Principles for design.
BS EN 953:1997 +A1:2008 Safety of machinery - General requirements for the design and construction of guards (fixed, movable).
BS EN 1037:1995 +A1:2008 Safety of machinery - Prevention of unexpected start-up.
BS EN 1088:1995 +A2:2008 Safety of machinery - Interlocking devices with and without guard locking; general principles and provisions for design.
A Type Standards (General)
BS EN ISO 14121-1:2007 Safety of machinery - Principles for risk assessment.
BS EN ISO 12100-1:2003 +A1:2009 Safety of machinery Basic concepts, general principles of design Part 1: Basic terminology
BS EN ISO 12100-2:2003 +A1:2009 Safety of machinery Basic concepts, general principles of design Part 2: Technical Principles and specifications
A supplier of equipment is governed by the Supply of Machinery (Safety) Regulations, which is also known as The Machinery Directive.
A customer receiving equipment is governed by The provision & Use of Work Equipment Regulations (PUWER).
(6) Useful Links
Sam Wane CEng, MEng, MPhil, MIET, PgC
Senior Lecturer in Robotics, Staffordshire University
Committee Member, IET Robotics and Mechatronics Network
09 February 2013 04:16 PM
Joined: 11 January 2006
safety dept at Milton Keynes
They will supply all the gear to you and to code
Keep up with the antics of the UK,s most humoured electrical company
23 February 2013 07:36 PM
Joined: 23 February 2013
I dont have any info on what you need but just a question to you do you believe we will eventually be able to use this kind of equipment for people who have lost there limbs, I have a friend who lost there arm and really hope someone can come up with this development soon what are your thoughts on this.
05 April 2013 09:44 AM
Joined: 26 April 2006
Almost any supplier (Staubli, Omron, etc) will be more than happy to provide help and advice. Personally I would also recommend Pilz for their safety systems (the PNOZmulti relay works like a PLC and simplifies the wireing of the safety circuit.
There are a number of ways to handle the guarding. The easiest is a lockable cage with the access gate having a safety switch only allowing robot operation when the cage is locked. This is simple to operate but possibly causing delays to the process. More complex you could use light curtains, safety keys, and / or two handed safey switch operation (forcing the operator to be at the operating position before the robot can operate.
I would always include sufficient E-stop buttons inside and outside the area to allow the system to be stop in case somebody tries to operate the system with someone inside the working area - you can't design out human stupidity, but you can make it easier to react to it!
Other factors to consider:
Positioning accuracy for the items to be picked and the destinationm box. The simplest is some form of mechanicla positioning so that the items are always accurately positioned, more complex methods could use vision control.
Recovery when things do go pear-shaped, how to move the robot back into it's start position.
Gripper design - how do you actually grip the item and detecting when it's open, closed or holding an item.
09 April 2013 11:45 AM
Joined: 09 July 2006
Think about who/what is going to have priority.
If you want a person to be able to access the box at all times then you need to make the robot stop mid load then, when safe, carry on.
If the robot is going to have priority you'll have to make the person wait till it's finished loading.
Basically this leads to light-curtain or guard respectively. Now having made a design decision, look at implementing the chosen function.
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