Benefits to the power of three – outstanding productivity, all-encompassing safety technology and optimized energy efficiency

The more flexible, speedy and precise they are, the greater the competitive edge they deliver: Storage and retrieval machines are a core component of conveyor, logistics and stock movement systems. They offer enormous potential for saving time and money. Furthermore, they play a substantial role in reducing energy consumption. Operator protection is another core issue – the relevant requirements for storage and retrieval machines are clearly defined in the C standard EN 528. As a complete provider of components and systems, Siemens can supply the solutions to all these challenges.

Throughput increased by up to 15 %

Siemens has developed the right solutions for raising the performance of storage and retrieval machines. These are designed to maximize acceleration potential while minimizing wear. They also use sway control to reduce mast vibrations, helping to deliver material savings.

Performance boost thanks to intelligent all-wheel drive

With two powered wheels on the chassis, the drive torque can be distributed in such a way as to maximize acceleration and prevent the drive wheels from spinning. Siemens can supply a specially developed application that allows the drive torque to be statically and dynamically distributed between both drive wheels.

Integral sway control in drive increases throughput

Fast acceleration rates inevitably lead to mast vibration. With the assistance of the SINAMICS technology extension VIBX (Vibration Extinction), this vibration can be prevented without restricting the dynamic performance of the machine. With VIBX, the acceleration/deceleration of the travel axes is unable to excite the natural frequency of the storage and retrieval machine. The frequency can be adapted as a function of the cargo load and the position of the load handling device while the machine is in operation. There is no need to install a sensor to detect mast vibration. The sway control function is proven to shorten the time that it takes a mast to reach a sufficiently still position to allow load handling devices to move into a rack, pick up goods and move out again so that the storage and retrieval machine can travel to the handover station. This boosts throughput by up to 10 % and also increases warehouse capacity. Thanks to the reduction in wear and tear on the machine, less expensive materials can be used in the machine construction. Energy consumption can be reduced as a result of the lower masses.

By combining sway control (VIBX) with an intelligent all-wheel drive, it is possible to boost performance by up to 15 %.

100 % compliance with DIN / EN 528 – standards-compliant safety concepts

A comprehensive, but flexible safety concept is needed in order to protect operator and machine and to optimize the entire plant. Using the safety modules supplied free of charge by Siemens, it is possible to implement safety concepts in accordance with the storage and retrieval machine standard DIN EN 528. These modules are certified by TUV (German Technical Inspectorate) and are therefore a "plug&play" solution. They are based on Integrated Drive Systems. The optimum interaction between the Safety Integrated functions of SIMATIC S7-F controllers and SINAMICS S120 drives allows customers to develop their own safety concepts. Siemens is offering concepts for warehouses with reduced or without buffer area, safety strategies for systems subject to slip and monitoring devices for typical storage and retrieval machine applications (e.g. slack rope or overload detection).

Up to 80 % reduction in grid power input – by use of self-generated energy

Drives often need to brake heavy weights in hoisting applications. Frequency converters with energy recovery capability help significantly reduce energy requirements. By using Line Modules capable of regenerative feedback, energy can be recovered and used to supply other loads. No braking resistors are required which means that a smaller control cabinet and a simpler cooling system can be used. Energy consumption is balanced via the common DC link of the SINAMICS S120, so minimizing the overall losses in the system. Furthermore, Siemens has used ultracapacitors to implement a strategy for storing energy in the DC link. In addition to reducing power input by up to 80 % ¹⁾, electrical braking remains possible even during power failures. Wear to brakes and wheels is also minimized and the availability of the storage and retrieval machine is increased.

¹⁾ Applies to electromechanical systems with an overall efficiency of 90 %. With an efficiency of 80 %, the power input is reduced by 64 %.