Compet­i­tive­ness and sustain­ability both have one thing in common – effi­ciency – after all, effi­cient produc­tion and logis­tics are fast and conserve resources. Robotics and automa­tion are there­fore partic­u­larly impor­tant in high-wage coun­tries such as Germany and in general in times of staff short­ages and the ergon­o­miza­tion of the working world, as they can play a key role in increasing effi­ciency. This also applies to auto­mated guided vehi­cles (AGVs).

The company emm! solu­tions, commis­sioned by ebm-papst, devel­oped the Eddy (an AGV that exploits the poten­tial for increased effi­ciency due to time and space savings, in partic­ular thanks to the ArgoDrive installed in it) espe­cially for the new fan produc­tion line in Mulfingen. The omni­di­rec­tional drive solu­tion from ebm-papst ensures the solu­tion can be maneu­vered fully in all direc­tions from a stationary posi­tion and can cope better with inclines and higher weights than other drives on the market.

Agile runabout for Mulfingen

The new produc­tion line in Mulfingen produces various size 90 motor vari­ants for fans and produc­tion is almost fully auto­matic. This is only possible in this form thanks to the Eddy. For example, in the case of two islands, each with three balancing stations, the AGVs are clocked so that they always bring and collect compo­nents at the right time to enable them to switch between the indi­vidual stations quickly and without any waiting times. This is achieved by auto­mat­i­cally prior­i­tizing the balancing machines to be started using the EPOS soft­ware from ebm-papst. The Eddys are also compat­ible with this soft­ware.

In order to ensure the indi­vidual work­sta­tion types are optimal in terms of ergonomics, they have different work heights depending on the task. In addi­tion, assem­bled work­piece carriers are replaced with empty ones at two different heights at one station. The Eddy has a scissor lift with the ECI63 K5 motor from ebm-papst, which precisely lifts and lowers the loading area to match the different stations in order to perform this range of tasks.

The ECI63 K4 and K5 drives in the Eddy control the scissor lift, which can be precisely adjusted to the different stations. (Photo | ebm-papst/­To­bias Gerber, Fotogloria)

The ECI63 motors, which control the scissor lifts with and without conveyor belts, are char­ac­ter­ized by a wide speed control range as well as various inter­faces and oper­ating modes, among other things. (Photo | ebm-papst/­To­bias Gerber, Fotogloria)

Among other things, it features an inte­grated CAN inter­face, allowing the vehicle control system to directly control it and read out its process data. It also has a variety of digital inputs and outputs, enabling it to control the drive for the Eddy conveyor belt – an ECI63 K4. The AGVs trans­port the prod­ucts from level to level and also take care of return trans­port. When the Eddys pick up the final prod­ucts from finishing, they then go directly to the attached ware­house – ship­ping and the incoming ware­house are also in the imme­diate vicinity.

Steffen Ley, who is respon­sible for digi­tal­iza­tion processes in produc­tion, explains how the Eddys use ebm-papst soft­ware to react intel­li­gently to the rele­vant require­ments and tasks during the entire process: “Using this soft­ware enables ebm-papst to take full advan­tage of all of the bene­fits of matrix produc­tion. This compen­sates for fluc­tu­a­tions within the product fami­lies, which increases the degree of utiliza­tion and machine perfor­mance.”

The dream team – drive and soft­ware

The Eddy devel­oper team has drawn upon the outstanding perfor­mance offered by the ArgoDrive from ebm-papst for the drive system. The unit consists of motors, a special trans­mis­sion, sensors, and all the neces­sary connec­tions, and allows for omni­di­rec­tional navi­ga­tion. In other words, a key advan­tage of this drive tech­nology is its ability to move in all direc­tions, which can be achieved with two drives per AGV which are arranged diag­o­nally.

(Photo | ebm-papst/­To­bias Gerber, Fotogloria)

For example, this also enables the Eddys to approach or leave the stations for wheel bolting, balancing, or work­piece carrier return at an angle, meaning the time for the next AGV is reduced, as it does not have to wait for the AGV before it to perform a parking or turning maneuver. This mobility advan­tage compared to normal AGVs not only opti­mizes trans­port and transfer times between different produc­tion stations, but also means that signif­i­cantly less space is required.

The hall­mark of the ArgoDrive is that it combines two motors that are respon­sible for both driving and steering. The inte­grated motors and super­po­si­tion gear enable precise control and adjust­ment of motor powers to ensure optimum AGV maneu­ver­ability and effi­ciency.

The Eddys in Mulfingen can carry up to 50 kilo­grams of weight using the scissor lift – only limited by the load capacity of the lifting table. In general, the payload can be varied via the ArgoDrive, as 500 kilo­grams can be carried per wheel, depending on the type of drive solu­tion (Light, Stan­dard, and Heavy). This means that a total weight of up to two tons can be carried with four Heavy versions.

The soft­ware in the Eddy devel­oped by emm! solu­tions inde­pen­dently detects obsta­cles and brakes the AGV in good time – meaning that even complex routes are no problem for the AGVs. To ensure that all this works seam­lessly, the user creates virtual plans for the surrounding area first by guiding the vehicle through the manu­fac­turing facility with a joystick. The vehicle uses laser scan­ners – a process also known as SLAM navi­ga­tion or free laser navi­ga­tion – to record a virtual map of the surrounding area. This is then inte­grated into the master controller, which means it can be quickly trans­ferred to other vehi­cles later.

This map will enable the vehicle to guide itself later using trian­gu­la­tion by measuring the distance to various machines and spatial struc­tures. V-shaped sheet metal plates support precise posi­tioning at docking stations, as they enable the vehicle to deter­mine its posi­tion in the room and to know when it is in a specific loca­tion such as a return or assembly station.

(Video | ebm-papst/­To­bias Gerber, Fotogloria)

This method of navi­ga­tion and loca­tion finding enables the vehicle to move flex­ibly and effi­ciently within the produc­tion surround­ings without the need for phys­ical guide­lines such as strips on the floor or reflec­tors. The system also offers the user the option of updating or extending the virtual map by allowing new stations or routes to be “trained” directly by the vehicle.

Outstanding fleet concept

The Eddys in use in produc­tion are connected with one another via the ebm-papst soft­ware so that they are in the right place at all times and no station has to be kept waiting for an Eddy. This coop­er­a­tive use of the units is essen­tial, as 30 AGVs will be in constant use when the system is fully completed. Of these, 23 will be active, 5 will be charging, and 2 will be used as backup.

They will be controlled via a central control center which uses infor­ma­tion such as the battery condi­tion of the vehi­cles, their precise posi­tion, and whether they currently have a trans­port task or are ready for new orders. Based on this, the control center decides which vehicle is best suited to a partic­ular trans­port task, taking into account the different capa­bil­i­ties and capac­i­ties of the vehi­cles. These capa­bil­i­ties in combi­na­tion with prior­i­tizing tasks and inde­pen­dently stop­ping in the event of obsta­cles all signif­i­cantly reduce the need for manual inter­ven­tion.

Devel­oping this soft­ware was a major chal­lenge, but produc­tion in Mulfingen clearly demon­strates how an effi­cient, highly mobile, and state-of-the-art system signif­i­cantly increases effi­ciency, explains Steffen Ley: “Thanks to the Eddy fleet, we can opti­mally operate fixed routes and vari­able processes without any delays or waiting times, which has signif­i­cantly increased the number of cycles we have.”

The devel­op­ment has already been rewarded with the Industry 4.0 Award in the Winner cate­gory for the successful overall concept of the factory building which consists of automa­tion, matrix produc­tion, and highly effi­cient produc­tion with a batch size of 1.