Warehouse using robot pickers

Gaining Speed in Intralogistics With the Right Drives

June 26, 2023
High-performance micromotors are needed to ensure warehouses are running around the clock and processing thousands of orders every day to keep up with the competition.

Functional transportation equipment in intralogistics is a prerequisite in any industry in order to be able to withstand competitive pressures. An increasing number of steps involved in storing, retrieving, and preparing items for dispatch in warehouses are being taken over by automatic storage and retrieval system (AS/RS), driverless transport systems, and intelligent logistics robots.

In order to speed up these processes, flexible systems that can work around the clock are needed. Such logistics solutions are often driven by high-performance micromotors.

The demands that modern intralogistics place on used drives are high: In many instances, they must be capable of releasing tremendous forces under extremely confined conditions, work reliably in continuous or stop-and-go operations, and oftentimes must also perform highly precise positioning tasks. Speed also plays an important role as many thousands of orders need to be processed every day in large warehouses.

Powerful Handling With Finesse

Autonomously driving and self-contained logistics robots are a critical component of "Intralogistics 4.0". They are used both for storage as well as removal and dispatch preparation. They optimize material flow, relieve employees and replace, e.g., conventional lift trucks or pallet trucks. Autonomous picking robots that allow individual objects to be precisely accessed are one example.

A typical picking robot comprises a lifting column and gripper. As a drive unit, it contains, e.g., BX4 series brushless DC-servomotors with an integrated motion controller and planetary gearhead. When used in the gripper, this combination ensures precise positioning during storage or retrieval—all during continuous operation with constant load changes.

Yet the complete drive unit weighs only about 300 grams (0.6 lb). This means that no counterweight is needed even when the gripper is fully extended. With a diameter of only 1 in. and a length of 3 in. (32 and 85.4 mm), the brushless DC-servomotors are also very compact. This makes it possible to design the gripper very flat, allowing it to also pick up packages that are stored just above ground. Thanks to the brushless commutation system, the motors are long-lasting and reliable, delivering high torques and balanced rotors, and are quiet running. With the integrated current control, the torque demands are limited and the drive is protected against overload.

Compact Drives for Rapid Start/Stop Operation

Graphite-commutated DC micromotors of the CXR series combined with matched gearheads have also proven themselves in handling tasks. Their commutation system is very robust and is especially well suited for dynamic, high-performance applications with fast start/stop operation as is required in many handling systems as well as with automatic sorting, e.g., in cases where switches are used to change routes on transport paths.

Thanks to their linear characteristics, DC motors are easy to control. Combined with high-resolution encoders, they're ideal for precise positioning tasks. High-quality neodymium magnets ensure a high power density in a compact design, letting them be installed directly in the handling elements. In spite of their small size, they can lift considerable weights there.

Flexible Through Production

Automated guided vehicles (AGV) are the means of choice when it comes to flexible transportation in production processes. Among the most important requirements for the used drives with in-house material transport systems are availability, speed, flexibility, and low space requirements. The current consumption also plays a role in ensuring that the battery of the vehicles is as long-lasting as possible.

For example, brushless DC-servomotors of the BP4 series are suitable to drive the wheels, whereby the motor power can be transferred to the wheels via planetary gearheads and drive belts. The motors operate with high efficiency: their winding technology allows for high copper content and keeps losses to a minimum thanks to high winding symmetry.

Encoders of the IE3-1024 series are built right onto the servomotors for precise position detection. The magnetic incremental encoders, which are available with different resolutions, feature an indexing channel for referencing a revolution of the drive shaft as well as a standardized, electronic encoder interface. The resolution, direction of rotation, index width, and index position can be flexibly adapted to the application. A motion controller controls the servomotors. Such drive systems are also used for mobile robot platforms, which move about completely autonomously in industrial halls without a preinstalled guidance system. Above all, their high power density is particularly evident in the wheel modules.

A Lot of Power in a Very Small Space

If there is limited installation space for wheel drives in the axial direction, the high-torque flat motors of the BXT series are often an option. Thanks to an optimized design, the motors are just 0.5, 0.6, and 0.8 in. (14, 16, and 21 mm) in length but deliver torques up to 134 mNm, within a diameter of 0.9, 1, and 1.5 in. (22, 32, and 42 mm) respectively.

For precise speed control or in the case of high requirements on positioning accuracy, diameter-compliant magnetic encoders or speed controllers are now fully integrated into the housed motor variants, whereby the drive is increased by just 0.2 in. (6.2 mm). Speed control is performed by the digital Hall sensors integrated into the motors giving them a wide speed range from 200 rpm to 10,000 min -1 is available. The compact drive combination is ideal for space-critical applications and simplifies installation and commissioning. The matching metal planetary gearheads of the GPT series too are characterized by a short design, high torque, and extremely fine graduations of the numerous reduction ratios.