Bespoke drives for Automatic Guided Vehicles

Thanks to her many years of experience in the field of drive technology, ELSTO Drives is able to provide “made to measure” components that are a 100% match with the design goals of the end-user. In cooperation with robot manufacturers our experienced engineers use the latest technological advances in both drive and production technology to create flawlessly operating AGV drives that will make a difference.

ELSTO uses multi-module systems for her AGV drive applications. This means that the modules of these systems can also be used in other applications. Using modular system solutions saves time, and reduces the development costs in comparison with starting each time from scratch.
The five functional modules for a drive system are:
 Energy Supply, Energy Management, Controls, Motor and Gearbox.
 

Optimum energy flow

For the energy management it is important the electric motor and the battery of the AGV are perfectly matched. By multiplying the required power with the desired autonomy time, the necessary battery capacity is calculated. That efficient and well matched motor-reducer combinations allow for smaller and more compact battery packs is self-evident

Motor-reducer combination

Due to the increasing market demand ELSTO develops compact motor-reducer combinations for AGVs on a regular basis. Usually the motor-reducers are combined with rims fitted with pneumatic tyres that get the power to the workshop floor. The motors can each be controlled individually enabling wheel specific power delivery.  

The relative position of the AGV is determined by means of location sensors such as cameras, lasers or antenna/transponder systems. If for a brief period the location information is not available, the AGV can calculate its position on the basis of the number of motor revolutions it has travelled from the last known position. When the location information is available again the position is updated with information from the position sensors. 
Doing so the encoders serve a dual purpose:

• Accurate speed control and monitoring.
• Measurement of the distance travelled

Pancake motors

Pancake DC servo motors offer high dynamics, excellent controllability and a rapid start-stop capability. In other words they are ideal for low torque, low speed and low inertia applications. These special motors have a long service life and are exceptionally suitable for direct drive applications such as driving an AGV.

The temperature inside the motor can be quite high due to rapidly changing load- and environmental conditions. To protect the motor from these high temperatures, the windings are insulated. Insulation class F material is used to provide thermal security up to 155°C.

All in one drive

For some time now, ELSTO supplies the Smartris system. This is a complete drive package for AGVs that consists of a servo motor, a Cyclo gearbox and a servo controller. This new integrated drive offers several advantages. This smart wheel drive for AGVs offers high precision and high reliability. The servo motor and its control system offer not only accurate positioning, but do so in a very energy efficient, dynamic an flexible manner. Integration of a drive system in an AGV demands the most compact construction method. Since the gear train is situated in the wheel, the Smartris is one of the shortest drives on the market. 
This means an even lower building height for the AGV, and a more effective use of the interior space of the AGV.

Watch this video as an example of Automated Guided Vehicles

Safety Torque Off

The Smartris is available in ECO and PRO versions with a maximum radial load per driven wheel between 1.500 and 16.500 N. The maximum mass of a loaded AGV varies between 900 kg for the lightest version, and 3600 kg for the heaviest version with two driven wheels.

Speed is an important factor for an AGV drive. A maximum speed of 2 m/s is available with an acceleration of 1,0 m/s2. Thanks to the innovative Cyclo transmission, the drive is capable of absorbing substantial shock loads and vibrations. This provides an extra security against overloading the drive. The housing is leakproof, and  Safety Torque Off is integrated as standard. The drive communicates via CanOpen (DS402), ModBus (RS485) or serial (RS232).

This article was featured in the April 2023 “Aandrijftechniek” magazine: Aandrijftechniek intralogistiek april 2023