Design-for-maintenance and enhanced remote diagnostics are just two of the latest trends in robot service and support, as Steed Webzell discovers.
Robots work hard: it’s one of the main reasons they’re deployed, after all. As a result, alongside the critical nature of the operations they perform, maintenance and service factors are creeping higher up the OEM priority list. This is long overdue in a sector where many end users are more concerned with meeting production schedules than looking at preventative maintenance to increase the life expectancy of robots and reduce downtime.
A case in point can be seen at the commercial vehicle plant of Vauxhall, in Luton, UK. One of the deciding factors when selecting Fanuc robots to help build the 2014 Vivaro there was ease of service. The design advantage of having the electronic and transmission components located on the outside of the robot, where they can be accessed easily for repair or maintenance, reduces downtime. Vauxhall reports that a harness change, which took eight hours on its previous robots, will take just one hour on a Fanuc.
“From an automotive perspective, down-time is lost revenue and profit, so it is fundamental to include service and maintenance factors in an OEM business plan,” says Sean J Murphy, regional sales manager at Fanuc Robotics UK. “Windows of opportunity for planned preventative maintenance are small, so minimal servicing is a key factor in robot selection.”
A typical Fanuc robot requires only one service per year. Fanuc provides support packages through which access to a qualified service is available around the clock via a variety of communication methods: on-site, telephone and internet. The provider also offers reliability and maintainability studies to assist customers in identifying, validating, documenting and prioritising solutions to root causes of production downtime. The goal is to help achieve return on investment and identify recommendations to increase equipment reliability and durability. The studies are produced following on-site research of each production shift for a mutually defined period of time.
“Customer maintenance training also forms a vital part of our support,” says Murphy. “This allows a service engineer the ability to communicate with a customer on a problem in a way that a resolution is found quickly. The training permits us to help the customer to help themselves and keep the robots in operation.”
Despite massive globalisation over the past two decades, local support is of course hugely beneficial to robot users, albeit that the internet has now made support feel ‘local’. As a company, Fanuc Robotics makes remote diagnostics available to each of its service engineers, such that no matter where the robot is, if it has internet connectivity, ‘local’ support is available anywhere in the world. Local availability of support and service is also a priority at Comau, especially in countries that have not historically been able to deploy these types of solutions.
“Our business has been built around solutions, not just products,” says Arturo Baroncelli, robotics proposal manager at Comau. “This means that we approach every client and every project in a hands-on manner, which by its very nature includes local support and services. We offer both standard and ad-hoc service packages depending upon the customer’s needs.” “Ease of maintenance is important and even though the reliability of our robots is extremely high, customer training is essential,” he continues. “Comau training courses are designed for programmers, maintenance experts and robot operators.”
If required, Comau can also offer online support through remote diagnostics and remote aids enabled by the connection capacity of its new C5G robot control unit. Further services include on-site consignment of spare parts, support at the start-up phase, repairs and re-conditioning of equipment as needed, and training at either a Comau training centre or the customer’s site.
The presence of in-depth maintenance knowledge on site is clearly negated using effective remote diagnostics capability. ABB AnyWhere, for example, is a software package designed to remotely connect robot production cells with the local ABB customer support desk and allow data reading from the cell. An ABB technical support engineer then has access to log files, I/O, the robot teach pendant and current program status. After diagnosis, the engineer guides the operator through the actions to be performed to restart production. ABB AnyWhere functions include robotic maintenance (file manager, back-up restore, back-up management, parameter management, robot I/O display); teach pendant real-time display for each connected robot; direct ‘main processor’ access; integrated process system access; PC file manager and remote access; BaseWare installation; operator communication – chat or voice (optional); and PLC management.
Kuka also has an offer in this area in the form of Kuka Teleservice. Accessed via the internet using remote control software or an integrated http server, Kuka Teleservice can inform a service technician about robot status at the touch of a key. Kuka personnel can inspect and reprogram robots to clear up malfunctions anywhere in the world without the need to travel.
This point is similarly promoted by Cloos for users of its Remote Service Manager (RSM). RSM permits the use of remote diagnostics and maintenance as a tool to avoid downtime and unnecessary service costs, no matter where the robot is located.
The central point for use of the Cloos RSM is the PC, which is linked to Cloos Romat robot controllers. The software contains all the necessary support functions, no matter whether it is a software update for the robot controller, diagnostics of system status and maintenance cycles, or remote service measures.
Arguably the most common maintenance/repair task is recalibration. This is required in the event of a robot ‘bump’ or crash, after changing the motor or in the case of end-effector replacement. Sometimes it is possible to ‘manipulate’ the robot program manually to compensate for subsequent inaccuracies but this is poor industry practice. Instead, full recovery to original factory performance is preferable. When the need for recalibration arises, the tool centre point (TCP) and joint mastering must be maintained to very strict tolerances. Fortunately there are companies that specialise in the provision of robot calibration services and among their number is Dynalog. Here, solutions such as DynaCal are said to offer accurate recovery of the entire robot, TCP and fixture alignment, which is performed off-line, while AutoCal is an automated, ‘in-line’ recovery system.
Dynalog reports that it has just been chosen by a major automotive seating/interior manufacturer to provide DynaCal robot calibration system for all its plants worldwide. The firm will be deployed to calibrate the robots for initial robot cell accuracy as well as for recovery. In the latter’s case, the cell will be recovered to the robot’s level of repeatability, thus eliminating manual touch-up of robot programs altogether.