Sensors and systems for intralogistics

In intralogistics, sensors optimised to the relevant requirements are needed for the respective applications. In many respects, modern shuttle systems reflect the future challenges of the industry. Potentially they are an answer to the key trends toward greater throughput, agility and flexibility, as well as more efficient utilisation of space, more sustainable use of resources and so on. At the same time, they embody the growing requirements on sensor systems and automation components in the form of smaller and smaller - yet ever more powerful - devices networked in line with the principles of Industry 4.0. Leuze electronic offers high-end sensors with application know-how in all areas of intralogistics from a single source.

E-commerce is making great advances in retail and is increasingly determining consumer behaviour. The extremely dynamic nature of online retail throws up new challenges for the logistics industry. This is true for the CEP (courier, express and parcel) sector, with the processing of shipments and returns, as well as for internal logistics (intralogistics). At the turn of the millennium, German B2C online retailing amounted to just two billion euros; this figure now stands at well over 40 billion euros, corresponding to roughly 12 per cent of total retail sales. And throughout the sector, the fastest possible product availability determines competitiveness. This is, of course, just one aspect, albeit a significant one, of the dynamic trends influencing intralogistics.

One mega trend that is also attributable not least to the rapidly developing e-commerce sector is the volatility of markets and competitive conditions. On the one hand, there are the increasing volumes of parcels that need to be shipped ( ie the amount of order picking to be processed). On the other hand, smaller orders cause growing uncertainty for the manufacturer with respect to planning. As a result, procurement, production and distribution become considerably more complex. This also makes innovation topics such as Industry 4.0 ever more important for intralogistics. Whereas seamless networking is only just beginning to emerge in many business sectors, systems that are designed according to the principles of Industry 4.0 can already be found in intralogistics. Seamless networking is therefore frequently described as the backbone of the fourth industrial revolution. To continuously improve speed, precision, flexibility and availability, transparency at every process step as well as networking between the operative retail outlet and the warehouse are necessary. Here, innovative shuttle systems in both conveying and storage systems, for example, increasingly provide appropriate concepts.

Wolfgang Peisker, Head of Industry Sales Intralogistics at Leuze electronic, explains: "Regardless of whether shuttles are implemented on conveyor lines or in high-bay warehouses, or whether conventional high-bay storage devices, continuous conveyors, telpher lines, cranes or driverless transportation systems are used - up to the point of order picking, the applications are very similar with regard to the functions that sensors are required to perform." In other words, system parts as well as products must be positioned and often also identified, the presence of goods or system parts (eg columns and bars in high-bay warehouses) must be detected, compartment occupation checks or clearance monitoring must be carried out, volumes, fill levels, stack heights or overhangs must be detected, and also various types of working areas and transportation paths must be safeguarded. Last but not least, data must be transferred.

High-end sensors for shuttles

Peisker states: "The growing demands that all intralogistics applications place on sensors are particularly evident in modern shuttle solutions." Shuttles are extremely flexible, dynamic and, not least, also resource-friendly with regard to the space utilisation and energy consumption. They can be used in various areas of material flow or storage systems and can handle different loads. At the same time, they are able to perform an extremely high number of storage and retrieval operations within a short period of time. For fast and highly flexible shuttles, very reliable, space-saving and safe sensors are needed for fine positioning, the detection of free spaces, presence monitoring and for collision prevention. For all of these tasks, Leuze electronic offers suitable sensors that ensure availability and can be easily and quickly mounted and commissioned.

Examples of smart sensors that meet the demands with regard to dynamics, precision and, above all, high flexibility, but also with regard to compact design and simple handling are the 10 series optical distance sensors from Leuze electronic. Their high tolerance to colour, material, surface and detection angle makes the measuring (ODS 10) and switching (HT 10) distance sensors exceptionally reliable and precise. Almost irrespective of the material and surface finish, the new ODS 10 and HT 10 achieve a consistent switching point. They function reliably even with changing environmental conditions or materials, as well as with various detection angles with objects that are not aligned exactly orthogonal or that are being rapidly transported. As a result, detection errors are avoided and the need for complicated readjustment is eliminated.

The working range of these distance sensors spans from 50mm to 8m; when used against a reflective tape, it is even possible to achieve scanning ranges of up to 25m. The accuracy with which the ODS 10 and HT 10 detect objects with a diffuse reflectance of 6 to 90 per cent lies at a consistency of up to 4mm. Thanks to their compact form with easy-to-mount design, they allow space-saving installation in confined spaces. Large operating and teach buttons as well as the OLED display with the ODS 10 facilitate step-by-step commissioning and diagnosis of the sensors at the press of a button. The highly visible status displays on the top and front make it easy to check the status, even from a distance or in restricted installation situations. Even with respect to the electrical connections and the number of I/O, the ODS 10 and HT 10 can be adapted extremely flexibly to the individual requirements. Both device models also provide an IO-Link interface ready for Industry 4.0. In this way, diagnostic data can be transferred so that, by means of constant monitoring of the received signal level, the user can be alerted in good time to an impending failure due to, for example, excessive dirt build-up or misalignment.

Apart from the ODS 10 and HT 10 measuring distance sensors that are used in shuttles primarily for compartment occupation checks, collision protection or positioning applications, miniaturised sensors are popular due to the limited space available. Such sensors include, for example, the 2 and 3B series photoelectric sensors and diffuse sensors from Leuze electronic. As a result, overhang controls very close to the outer edge can be implemented simply but very effectively using LSR 2 throughbeam photoelectric sensors or PRK 2 retro-reflective photoelectric sensors. Both devices have large operating ranges from 0-2m (LSR 2) and 0.07-4m (PRK 2), as well as high function reserves. Measuring just 23.1x12x8mm, these tiny sensors are much smaller than a matchbox and are said to be unbeatable when it comes to installation in confined spaces. They are suitable for the reliable detection of, for example, small parts or, in the case of the PRK 2 polarised retro-reflective photoelectric sensors, detecting objects with shiny surfaces.

Also with a compact design, the 3B series sensors have a range of innovative features and are claimed to have the largest selection of functions that any device currently available on the market in this performance segment has to offer. Moreover, they impress with high operating ranges and improved function reserves for reliable object detection, even in dusty environments or with high mounting tolerances. Technologies such as A2LS active extraneous and active ambient light suppression, brightVision for simple handling and fast commissioning are characteristic for this sensor series. In shuttles, PRK 3B retro-reflective photoelectric sensors or HRT 3B diffuse sensors are used, for example, at the end of aisles or for reference runs in order to detect the reference points with maximum precision using scanning or reflective technology. The 3B series sensors are an excellent choice for these applications owing to their low minimum distance, their increased switching frequency and their compact design. These features make the HRTL 3B diffuse sensor suitable for applications such as compartment fine positioning.

Sensors for implementing Industry 4.0

In addition to the sizes and sensor types already mentioned, Leuze electronic also offers an extensive range of products with countless functions for every application field in intralogistics. These also include automation components such as bar code readers, bar code positioning systems or data transmission photoelectric sensors. Bar code readers such as the BCL 648i are characterised by high resolution and simple handling. They use blue laser light and therefore provide for a 50 per cent greater depth of field compared with conventional scanners with red laser light. This makes them less sensitive to variations in distance to the object to be detected. Furthermore, manual focus adjustment is often unnecessary in applications with varying distances.

Bar code positioning systems such as the BPS 348i are also said to set new standards both in performance parameters and in handling. They enable continuous positioning with millimetre precision over distances of up to 10km. Moreover, with their large operating range of +/-60mm they are tolerant to mechanical variations.

Optical data transmission photoelectric sensors can be the right choice for any application where data needs to be transmitted over long distances without cables and without interference. Devices such as the DDLS 500i enable contact-free and wear-free optical communication wherever mechanical systems are pushed to their technical limitations. With optical real-time 100Mbit/s, all common data protocols can be transmitted without time delay over a distance of up to 200m.

Peisker comments: "Communication is also a buzzword for Industry 4.0 topics which are becoming increasingly relevant in the area of intralogistics." What he is referring to here is what the 'sensor people' from Owen/Teck describe as 'integratedconnectivity' or 'availabilitycontrol.' These are functions that enable,in particular, the named bar code systems as well as the data transmission photoelectric sensors but also other switching or measuring sensors such as the series 10 models, to take a leading role. For several years now, Leuze electronic has been equipping many of its sensors with industrial interfaces such as Profibus, Profinet, Ethernet IP and IO-Link. They not only allow process information to be transferred. They also provide elegant configuration possibilities and deliver diagnostic data. This data, in turn, enables, for example, prefailure messages to be issued to enable weak points in the system or device (dirt build-up, misalignment, code readability, etc) to be detected early. As a result, systems can be maintained more efficiently and in a more targeted manner, and unscheduled downtime can be avoided. "These functions make the sensor system outwardly more transparent and thereby support intralogistics applications on their way to the fourth industrial revolution", concludes Peisker.

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