Intelligent sensors are on board

Bang manufactures process and tool transport cranes for loads up to 500 tons for the automotive, steel and energy industries. When customers demand the highest levels of reliability, positioning accuracy and freedom from interference from their semi or fully automated handling and intralogistics systems, the crane specialist relies on sensor systems from Balluff.

Automated tool transport crane from Bang in the press shop at Volkswagen in Zwickau.

Picture: Bang Kransysteme GmbH & Co. KG 

Successful company stories usually begin in a garage: In 1989 Werner Bang founded a 160 square foot service workshop for the repair of hoists and crane systems in Adorf, Vogtland. In the turbulent post-reunification period, it was by no means foreseeable that this would result in an internationally active specialist for planning, production, assembly and service of process, automatic cranes and winch systems in just 30 years. The garage workshop has now become a company with around 200,000 square feet of production space on a modern crane campus with an integrated training and administration center. At the new company location in the Oelsnitz industrial area with the auspicious name ‘An der Neuen Welt’, 160 predominantly highly specialized workers are currently employed. Bang crane systems apply in the steel, automotive, paper and energy industry as innovative and flexible. The company offers an above-average vertical range of manufacture; cranes from Bang stand for reliability, economy and safety. The two sons Christoph and Marcus Bang have been running the company since 2009.

Crane systems operate semi or fully automatically

Bang test crane with high-precision long distance positioning system from Balluff. Inside the red circles: position encoder. 

Picture: Bang Kransysteme GmbH & Co. KG

Traditionally, gantry cranes are still controlled manually in many areas; only a few control, service and safety devices support the operator. The control of the desired positions, the handling of different objects with various load handling devices and the necessary skills are mainly in the hands of the crane operator. But the increasing amount of automated processes, digital change and the increased demands on cycle times and process efficiency are having an effect: crane systems of the future will operate semi-automatically or fully automatically!

Modern control technology has already made cranes more efficient in recent years: In the automotive industry, 80 ton tool transport cranes move to their positions automatically and with millimeter precision. There, the operator is no longer responsible, but an electronic control system for accelerating, braking and carefully setting down workpieces. Electronic sway control and damping systems ensure that loads hang vibration-free on hooks, grippers or magnets. Fully automatic process cranes communicate based on the application at hand and in real time with the higher-level control technology and production management. With their efficient handling of tools and the optimal interlinking with production systems, automated crane systems have the potential to save manufacturers money.

Bang crane systems thinks ahead of the operational requirements of their customers: “We translate customer requests into optimal crane solutions that guarantee a fast, efficient and safe material flow as well as maximum reliability. Customers like to refer to our process cranes as agile large-capacity robots that achieve competitive advantages in everyday use,” emphasizes Christoph Bang, one of the two managing directors. Although there are also many non-negotiable standards in crane construction, the challenges lie in the details. David Böttiger, Head of Automation, when asked how Bang Kransysteme was able to establish itself on the market and write full order books even in economically difficult times: “Our customers appreciate the fact that we respond to their wishes with dedication and competence.

Innovations in test operation

Image: BANG Kransysteme GmbH & Co. KG

In order to test new ideas or unusual customer requests, Bang operates a specially designed test crane. In the field of sensors, controls and safety, Bang Kransysteme works exclusively with competent partners who share the company’s innovative approach. The automation specialist Balluff has been represented at Bang with sensor and position measuring systems for over ten years. In the near future, an innovative condition monitoring system is to be used in cranes from Bang, which provides early warning of any signs of damage to moving parts and axles. Condition monitoring sensors from Balluff (BCM) are used for flexible condition monitoring in the smallest of spaces. “You can record several physical quantities such as vibration, temperature, humidity and ambient pressure. Then you can process that information and send the data to the higher-level control system through the bidirectional IO-Link interface, ”says Balluff Sales Engineer Erik Geigenmüller, describing the functionality of the sensors. These are attached either to the drive motors or to the crane rollers. The control system recognizes abnormalities immediately, the operator can intervene before massive damage occurs and the system is shut down for hours. The sensors are IP69K so they are unaffected by the effects of dirt and water.

From test operation to market readiness

After extensive tests, for the first time ever Bang installed the Balluff condition monitoring sensors on a tool crane that will be used in the branch of a large German automobile manufacturer in China. “This user has recognized that he can practically rule out unplanned and expensive downtimes. From a cost-benefit perspective, this is a standard that we will recommend to our customers as practically indispensable in the future,” says Michael Schmidt, Head of Electrical Design.

With cranes in intralogistics in particular, the operator or the control system always needs to know the exact position of the crane. This is all the more true when two or more cranes are on the way on a runway. Laser sensors are preferably used to meet common performance requirements under normal ambient conditions for position determination and to avoid collisions. If there is too much pollution inside or if the cranes are used outdoors, laser-based systems cannot be used.

Always in the right position

Bang test crane with the Balluff SmartLight (top center): Green = crane ready for operation! 

Picture: Bang Kransysteme GmbH & Co. KG

Wherever maximum precision is required for position and speed measurement, Balluff offers an absolute measuring position measuring system that can determine positions over several hundred meters with a repeat accuracy of 0.5mm. The Long Distance Positioning System works wear-free and maintenance-free. It is also robust enough to stand up to a high shock environments with lots of vibration or contamination. Bang Kransysteme has put the system through its paces: “The approximately four-meter-long distance measuring system recognizes the position sensors that are attached along the travel path according to a specified scheme and calculates the absolute crane position from them. If knowing this position is critical, even under harsh conditions, the Balluff Long Distance Positioning System is ideal.”

The BML magnetically encoded position measuring system from Balluff offers high-level precision and reliability in crane applications: “The precise, robust and fast-working magnetically encoded sensors are used for exact positioning in dynamic applications. They are suitable for both linear and rotary applications,” says Erik Geigenmüller, briefly describing the system. It is true that the indirect measuring system located at the drive of the cable drum communicates how much the cable is extended. However, this is too uncertain for demanding customer requirements. The solution: With the BML magnetically coded position measuring system from Balluff, the crane receives a second, direct measuring system via a coded magnetic tape that is also attached to the cable drum. This means that the position of the hook is determined redundantly and reliably.

A close eye on operating conditions

In order to demonstrate to crane operators how they can easily display different operating states, status and warning displays, Bang tested the versatile SmartLight from Balluff. With the operating modes Stacklight, Level, Runlight and Flexible mode, it can visually transmit an immense range of messages. Each individual segment can be controlled separately, colors and zones are freely programmable.

In addition to common issues such as ‘crane ready for operation’ (green, steady light) or ‘fault’ (red, flashing). The SmartLight can use a programmable run light color to signal that the lifting or transport process is currently taking place and much more. “SmartLight offers a wealth of user-specific expression options. The advantage is that when changes or additions are made, the light can be reprogrammed rather than a stacklight that would need to be dismantled or removed to provide additional segments,” explains Michael Schmidt.

In September last year, Bang Kransysteme celebrated its 30th anniversary. The company started a new decade with the aim of further automating processes and integrating the crane as a ‘co-bot’ into intralogistics processes. The distinctive spirit of innovation and the close cooperation with selected project partners should guarantee that the large-capacity robots from Bang will continue to be modern crane solutions of the highest quality in the future and that customers will remain closely connected to the company with follow-up orders.