Case Studies Of Industrial Robots

Preserving resources by minimizing their environmental impact, improving energy efficiency, reducing waste, and adopting new environmental friendly technology will be the trends in the future for robot manufacturers. On the other hand, robots take part in producing environmental friendly products.

Wittmann, Austria - IFR-Partner

The new EcoMode helps getting energy efficient robots

When considering a robot's energy consumption, many parallels can be drawn with the conditions associated with automobiles. A road vehicle's fuel consumption is known to depend on the employed engine?s technology and performance, the vehicle's weight and, not least of all, the driving style. A robot is not much different. Here too, a basic combination of ideal drive technology, consistent weight reduction (by means of lightweight construction) and energy-optimized movement control is indispensable for a convincing outcome.


Motors

At WITTMANN, the robust asynchronous servo drives of the 1980s and 1990s have now given way almost entirely to high-quality synchronous servo motors with rare-earth magnets. The motors now used by WITTMANN unfailingly achieve efficiencies in excess of 90%. This by far exceeds the requirements of even the strictest energy efficiency class IE4 (Super Premium Efficiency) of the IEC 60034-30:2008 standard which defines current efficiency classes for electric motors.


Recycling of brake energy

A robot's advantage over an automobile is a consistent use of electric drives. The employed motors act as generators during braking. They return the brake energy to the power output stage which can relay the energy directly to motors for other axes. Alternatively, the returned energy can be stored in intermediate-circuit capacitors and made available for the next acceleration phase.


The EcoMode

WITTMANN introduced an EcoMode with its W8 robot series. If viewed in terms of an automobile's operation, the EcoMode corresponds to a reserved and anticipatory driving style, as opposed to a racing-car driver's tactic of speeding and braking. However, it would be a mistake to think that the EcoMode slows down a robot. This mode does not reduce the robot's maximum achievable dynamics. Furthermore, the EcoMode utilizes the full dynamic range only if it is truly needed. Throughout the remaining period, the robot operates in a measured manner which not only reduces energy consumption, but also conserves mechanical components and increases the robot's life expectancy.

Conclusion

The energy consumption of WITTMANN's robots would be admirably low even without the newly introduced Eco-Mode. The energy consumed by lighter robot models from the W801 onward - including that needed by the control unit, colour display and three servo-axes - is lower than the
energy requirement of a standard personal computer. Even a robot in the UHS (ultra high speed) class, such as the W832 UHS, performs very impressively in consumption tests.

 

W823 Robot

Example 1: W823
The energy consumption of a W823, even when operating at the limits of its performance, is about 0.5 kW. This value can be significantly reduced by activating the EcoMode. The larger the reserve of cycle time, the greater the energy savings.

 

W832 UHS

 

Example 2: W832 UHS
The W832 UHS is one of WITTMANN's fastest robots. Its energy consumption remains at a level of about 2 kW even at the performance limit. The effect of the EcoMode is impressive: While the robot operates below its performance limit, an active EcoMode soon achieves energy-cost savings of more than 40%!