EASYBOTS: a tiny great solution

by Products on 2012-08-15 02:46:49

The internal Logistics world is in continuous evolution at the set rhythm by the technology.

ASTI has been offering internal logistics solutions for 30 years and the concept about how to optimize the internal transport processes has not changed much from the beginning, what has changed is the way to do it.

From its three business areas: .01 Conveying and materials handling systems, .02 AGV systems and .03 IT systems, they continue studying the concrete problem to solve in order to develop as a team the best solution for each customer.

This, basically has not changed, what has changed is the way to carry out its projects, they count with multiple progresses, from design software to pre view the 3D solution, to improved materials, more sophisticated mechanisms, or new technologies…

But without a doubt, what has changed is the importance of automation in the logistics. For years all the efforts have been focused on improving the productive processes. Just a few years ago the logistic has started to get the attention that deserves as an important source of costs and in most of the cases unnecessary ones that can be significantly reduced by using new technologies.

As a consequence of the economic environment and the European market evolution, it is observed a great development of the logistic sector as the answer to the market needs. The market is facing an increment of the imports and so it needs to increase its competiveness level to improve the product attractiveness.

The market is analysing its processes, identifying those that provide value to get them systematized as much as possible. Those processes that do not provide any value (cost) will be identified as well to be reduced; therefore the remaining ones will get automatized.

ASTI observed the urgent need to look for a solution to tasks such as transportation among working stations or assembly processes that do not provide added value to the product but on the contrary they represent a significant cost.

ASTI as an expert on producing AGVs (Automated Guided Vehicles), identified the potential that this technology has in the industrial world.

Until the Easybot development, ASTI’s AGV were conceived as vehicles which had a conventional truck as mechanical base used to transport palletized loads among determined loading and unloading points.

The specialization in this kind of solutions arise a question: Why not using them to transport other kind of loads, designing a made to measure chassis? And if they were used on assembly processes as a tool to link different productive procedures.

That was the moment when ASTI’s grey matter started to work.

One of the set objectives was: maximum cost reduction as the tasks that they were conceived to carry out did not require great sophistication and it was not necessary to employ high cost technology to guarantee maximum accuracy.

The first step was to identify the elements that form part of an AGV. Five basic modules were identified:

- Mechanic module: This module is the one that determines the vehicle appeal and its mechanical properties such as loading capacity or maximum speed. Considering the way to transport the load we determine three types: towing, integrated towing and carrying.

Towing easybots are those vehicles that by means of carts transport the load by pulling; on the other hand the integrated towing easybots are those vehicles that adapt their chassis to transport a specified tool that at the end is other part of the final vehicle.
Carrying easybots are characterized for transporting the load on the vehicle itself.

- Guiding module: this module determines how the AGV is going to follow the prefixed route. Here we find several guiding methods even though all of them are characterized by the simplicity that we mentioned from the beginning:

Optic band: this system implies to install a band on the floor to set the route to follow and a band identifier installed on the vehicle to make possible the vehicle to follow this route.

Magnetic band: this system consists on the installation of a magnetic band on the floor to set the route and a reader on the vehicle. This way, the reader detects the band following it up automatically.

Painted band: as in the other two methods, it is marked a route on the floor, this time just by painting it. The AGV has installed a camera to detect the band to follow along the route.

In this module we also include other kind of technologies that let us establish the key points in a route such as stops or changes in the vehicle behaviour. We are referring to tags and magnetic spots that buried in determined points along the route make the vehicle stop, change speed or vary the load transportation height as a sample.

- Safety module: as every AGV, a fundamental part of the vehicle is to guarantee a safe coexistence with people, other vehicles and in general with the environment where it has to work.

The AGV apart from having emergency stop buttons; it can be implemented with elements such as bumpers and laser scanners. The first ones are mechanical measures to stop the vehicle and imply direct contact with the obstacles to activate the stop; the second ones detect the obstacle making the vehicle reduce the speed to finally stop it when reaching a determined and configurable distance, without any direct contact with the obstacle. The speed to develop by the AGV will be one of the determining variables to choose among these systems, when speed is too high, the bumper will not be good enough to guarantee safety.

- Power supply module: the AGVs get the necessary power to move from a battery system. These batteries can be: gel or acid lead batteries. The decision to install one or other type will depend on variables such as maintenance or the installation characteristics. Once again we face an important issue as the battery recharging can be carried out in two different ways: by replacing manually the battery or by hot recharging. In the first option, the consumed batteries have to be interchanged with recharged ones and placed them in a charger in order to get them recharged. In the hot recharging, the AGV uses the non-working periods to get to the recharging points and recharges its battery. This way the vehicle never stops working.

- Auxiliary systems module: this module includes several systems that provide higher functionalities to the vehicles.

This module includes the possibility to define routes that can be really helpful in plants with more than one route to differentiate the right route to be followed by each AGV.

Other included functionality is synchronization with production lines to keep the AGV movements in time with the lines and so avoid waiting time.

In addition, the AGVs can be implemented with the capacity to communicate with the elements in plant. This way apart of collecting the production data from the productive centre, they are able to further automatize the operations, as a received signal from a machine will be enough to make the vehicle start a preprogramed operation.

Other of the components that can be included is related with maintenance. The warning service by sms messages makes that in case of failure, the company maintenance team will receive a sms with the information about the AGV stop. Related with this, remark the added property to diagnose the stop cause in remote and so give an immediate response to solve the problem.

The offer and posterior sale of a system based on easybots to a company from the automotive sector was the starting point used by ASTI as pilot experience for development and performance. The project included up to 37 vehicles to automate the assembly lines of bumpers, boilers and cockpits.

The Easybot Ivecoe concrete needs of the company were studied in order to design the most suitable system to obtain the highest benefits.

From the conveying and materials handling system it was designed a small enough chassis to let it move freely around the plant, but big enough to room all electronic and mechanic components required to carry out the tasks it was conceived for, taking into account that it had to be adapted to the tool used by the company in the assembly process.

The AGV area itself got in charge to give them the capacity to work in automatic mode. As result ASTI installed 37 integrated towing AGV with the load transport tool that had optic guiding system and that moved from one station to another along the assembly lines to manufacture cockpits, bumpers and boilers. These three lines communicated with a principal truck assemble line, synchronizing the parts production with the final product assembly line.

Its performance is very simple, an easybot conveys the base part where it is added different components along the different work sites, promoting the work division and the specialization in simple and concrete tasks.

This way, the product to ensemble moves toward the worker instead of making the worker moves to the product,   improving significantly the ergonomics for the work force.

The project was a completely success as it automated these three lines, getting more efficiency in the process and so higher productivity rates.  

Loyal to its philosophy, which states that every customer needs its own solution, all these vehicles that are equal in concept, are different and unique as the total configuration of the elements let them get adapted easily to every customer needs giving as result a new vehicle with every project.

ASTI whose mission is to increase its customers competitiveness, has found in the easybots the perfect tool to go on fulfilling its duty.

www.asti.es