Member of the management of B & R Industrie-Elektronik GmbH, Eggelsberg / A
"The response from Bernecker and Rainer to the challenges of the tool manufacturer to integrate all automation components in a system."
In addition to energy efficiency, system integration, scalability, space savings and increased productivity coupled with higher performance and precision are the requirements of the machine tool manufacturer's requirements for drive technology. B + R Bernecker and Rainer particularly focus on the integration of all automation components. Development Scout talked to Markus Sandhöfner about the development status of drive technology for the industry, the trends and the forthcoming EMO trade fair appearance of the company.
development scout: What is the current state of development of your drives for machine tools?
Sandhöfner: B & R offers the complete range of machine tool drives from 50 W to 500 kW. The high scalability in the power range and the ability to use different technologies allow the machine builder to choose exactly the drive that is needed for the job. The concept of our automation technology is characterized by integration and consistency. The special feature of this is the possibility of being able to operate the main and secondary axes side by side centrally in the control cabinet or decentrally on the machine in a high degree of protection on the ultra-fast Powerlink. 'Generic Motion Control' stands on the software side for the fact that different drive technologies can be operated in the CNC network with identical machine software. This saves the customer money, installation space and configuration times. At the same time, he gains flexibility in the implementation of the machine until shortly before delivery.
development scout: What are the biggest challenges your customers in the machine tool industry have to your company?
Sandhöfner: Machine tool builders are always on the lookout for ways to increase the productivity of their machines while minimizing the effort required to configure the machine. B & R's answer to these challenges is the integration of all automation components into one system. So far, there have been system boundaries between CNC and PLC, robotics and process, functional control and fail-safe control and drive technology. By eliminating them, our automation solution now makes it easy to implement functions that previously seemed impossible. Here is a very concrete example: at the Euroblech at the end of last year in Hanover, the world's fastest bending cell was presented by the machine tool builder Trumpf. A B & R CPU controls the complete bending cell, consisting of an electric bending machine and two robots. As a result of the transparency of the data within the control, it is possible to carry out balancing operations on the backgauge of the bending machine by the robot "on the fly". The result can be stopped with the clock: in less than 300 milliseconds, the balancing process is already completed in most cases. Our solution is that the machine control now also takes control of the robots up to complex safety functions such as 'safe limited speed' at the tool center point of the robot. Previously, there were separate, self-contained robot controls used that could not perform this Ausregelvorgang so.
development scout: How much potential is energy efficiency still available for the drive technology of machine tools?
Sandhöfner: That depends on which energy-saving technologies are already being used in the machine tool. Many investments in energy efficiency pay off immediately or pay for themselves within a short time. Looking at the lifecycle costs of a drive, it consumes a lot more energy costs over its lifetime than it itself is worth.
We have a whole bundle of efficiency measures ready for the machine tool. This starts with fully integrated frequency converters, which always operate a simple asynchronous motor at the optimum operating point. This saves an average of 40 percent of energy compared to operating the motor directly on the grid.
For hydraulics, we offer solutions that save up to 70 percent of drive energy. Direct-line vane pumps are replaced by simple gear pumps driven by servo or frequency converters. The drive is controlled in such a way that pressure and volume are only made available by the controlled drive when they are actually needed. In partial load operation, the drive runs quieter up to 70 decibels. By using the regulated drive, savings can be made in the pump, piping and radiator, so that the amortization often
already achieved on the first day of operation.
In the servo area we have with
our 'Acopos Multi' series is one of the first providers to set accents in energy efficiency. By using the energy-saving technologies Regeneration into the grid, DC link coupling and cold plate assembly in the control cabinet, up to 80 percent of the total drive energy of a machine can be saved. The power factor correction provides a resource saving of over 50 percent in power supply technology to the drive. Optimally software-designed drive trains and function modules integrated into the drive for en gEnergy and power measurement enable energy-efficient design of the machine and the drive process.
development scout: What accuracies are required today for milling, turning and grinding machines and what does this mean for your drive technologies?
Sandhöfner: Assuming a stiff powertrain, high resolution feedback, and optimal control loop set-up, PID controller cascades provide very good accuracy results. Unfortunately, these conditions are rarely met everywhere. This is exactly where B & R comes in: In the intelligent Acopos Servodrive, it is possible to use the connections of forces, speed, position and mass inertia as standard functionality. Due to the pre-control of the mass inertia, even mechanically very soft drives can be moved with maximum dynamics. Instead of determining the drive torque from the following error, in the Acopos the required drive torque can be calculated from the respective acceleration and mass moment of inertia, fully synchronously with the position control loop. In concrete applications, we were able to improve the precision of main axes in milling machines by a factor of two. The required setting values are simply determined automatically via a comprehensive 'autotuning' functionality with the drive stationary. Additional control structures can be realized on the drive through the 'Smart Process Technology' (SPT) functions of the Acopos drive.
Not negligible for the accuracy of the drives is the setpoint specification. Here, we offer a fully synchronized automation system in which PLC and CNC tasks are synchronized microsecond precisely with the Powerlink communication and the position control loop of the Acopos drive. With all these possibilities our customers achieve new dimensions in the accuracy of their machines.
development scout: What influence does the advent of generative manufacturing have on drive technology in new areas of application such as mechanical engineering and tool and die making?
Sandhöfner: First of all, the elimination of high process forces in machining simplifies the complexity of the drive control system. The masses to be moved become smaller. This increases the dynamics of the drives as well as the precision and speed of the setpoint specification more weight. Our drives are characterized by their high bandwidth of technologies and their high scalability.
development scout: What trends do you see in the development of the powertrain for machine tools?
Sandhöfner: There is a further differentiation of the drive types. Every drive is tested for value in the process and the drive technology is selected according to requirements. B & R makes the choice easier for the machine manufacturer, as all drive technologies are seamlessly integrated into the 'Automation Studio' configuration tool and can be operated with identical machine software.
Thus, the stepper motor with feedback at lower power offers a low-cost alternative to the servo. Pneumatics and hydraulics are increasingly being replaced by electric drives for reasons of energy efficiency. The servo drive itself is becoming more and more differentiated by the fact that different feedback systems, different mass inertias, linear and rotary direct drive technology can be used optionally.
Safety technology is playing an increasingly central role in drive technology. 'Open Safety' in conjunction with Powerlink offers the possibility of stopping the drive with a hundredfold shorter stopping distance compared to conventional safety controllers thanks to microsecond fault detection. This results in higher safe speeds, which can drastically increase productivity in the setup process. The smaller distance of the housing leads to a reduced footprint of the machine and at the same time to a higher flexibility in the operation of the machine.
development scout: Which innovations will you present at the EMO and what features are behind it?
Sandhöfner: With Generic Motion Control, B & R offers an automation solution that sets standards in CNC machining. The worlds of robotics, CNC, coupled axis movements and single axis positioning merge into a homogeneous system. The findings of the complex path planning for robots are also taken over for tool and production machines. The control of articulated arm robots is just as possible as complex CNC machining in 3D.
The seamless integration of the Generic Motion Control components into the real-time operating system offers additional advantages for the simple realization of automation processes through the integration of I / O nodes and the direct link to PLC functions. The machine builder saves time and costs during the entire product life cycle from design through to commissioning, commissioning, series production and service of the machine.
The cornerstones of Generic Motion Control are the full synchronism of PLC, CNC, drive control loop and communication. The flexible GMC interpreter and the fusion of PLC and CNC control on one core simplify programming and shorten development time. Existing NC programs adopted for another platform can continue to be used. The deterministic real-time Ethernet Powerlink enables decentralized automation structures and helps minimize cabinet volumes. The fully scalable hardware offers a variety of options for any machine and machining configuration and saves costs by tailoring to the needs of the machine needs.
EMO Hall 25 stand B14
Interview by Editor in Chief Angela Scheufler.