In order to increase productivity and make processes more intelligent, companies in the manufacturing industry are looking to create complete networking, from the systems that control production to the individual sensors and actuators that control the plant. Connectivity is one aspect of the big picture. Another essential part of achieving the desired benefits of a 'connected enterprise' is increasing flexibility within production. It enables those responsible to quickly adapt production to changing circumstances - regardless of whether this is through the individualization of the goods produced or whether it involves holistic production adjustments due to changing demand. For manufacturers, the quest for flexibility has sparked great interest in mechanical engineering innovations that promise greater agility in production.
One of the innovations that meets these objectives is Independent Cart Technology (ICT). It can be seen as the basis for new intelligent conveyor systems that represent an alternative to conventional conveyor and positioning systems. A new type of control system makes it possible to implement decentralized, scalable architectures that manage a large number of individual carts via a network of linear motors.

In traditional systems based on conveyor belts, product specifications are subject to a standard procedure and a constant production rhythm, which is limited by the linear movement of the conveyor carriage. ICT, on the other hand, uses a combination of sensors, control software and magnet-based drives to achieve the independent movement of individual conveyor trolleys in a multi-dimensional production environment. For the plant operator , this means that he can simultaneously manage several product specifications in an agile production environment, each of which can fulfill different weight and speed variables.
But why are OEMs still hesitant when it comes to using and implementing ICT in an industrial environment?

Optimal use of space and time

To answer this question, it is first necessary to understand exactly which factors need to be considered when designing a production facility. Two factors in particular are decisive for the management of such a process: the space used and the time required for production. The time component is primarily optimized by enabling production to process the largest possible number of individual components in the shortest possible time. Closely related to this is the space used. If the available space is used as effectively as possible, optimization can lead to a higher throughput, as products of different sizes can also be produced within the system without major modification measures.

With conventional conveyor systems, however, the possible increase in total throughput is limited due to the rigid production conditions. The fact that the production speed must follow certain machine specifications, distances must be maintained between individual products and presettings for production are often rigidly designed means that the maximum throughput that can be achieved within any given period is capped. If, in addition, the general conditions of production need to be adapted - for example, by changing the product size - the operator must also accept a high time expenditure for the production changeover and reconfiguration.

Both production dimensions can be optimized using ICT. This is made possible by using magnetism to drive the individual conveyor trolleys. If one of the trolleys moves within the conveyor system, it can be tracked constantly and precisely using sensors that measure the magnetic fields. In this way, several lanes and conveyor sections can be operated without the risk of individual trolleys colliding with each other. For machine operators, this means increased user-friendliness, additional flexibility and far-reaching scalability. Format changes can be achieved more quickly thanks to simple software adjustments and do not require manual adjustment by the operating personnel.

Safety has top priority

With the iTRAK drive system, the transport carriages move independently of each other on a fixed path. This means that distances and speeds can be flexibly adapted to the production process.

© Rockwell Automation

While the technology of ICT and conventional conveyor systems is fundamentally different, the same safety requirements and regulations apply to both systems. As the functionality of ICT is much more complex than that of conventional systems, the approaches to complying with the relevant standards and guidelines are fundamentally different. The challenge for plant managers and operators when switching to ICT is that they have to maintain the usual level of occupational safety that was guaranteed by tried-and-tested legacy systems.

With conventional conveyor belt systems, it is common for workers to intervene manually in the process flow. For example, maintenance staff can stand next to the conveyor belt and make adjustments to production while it is running at a safely reduced speed. Interaction with the system itself is possible via control panels, for example, as well as adjusting sensors or carrying out minor maintenance work that does not necessarily require production to be stopped. If the production line is blocked, operators can safely stop production for a short time directly at the control panel in order to make the necessary adjustments.

With ICT systems, the basic interaction between worker and machine is different. Due to the flexible movement of the conveyor trolleys, ICT can result in unforeseen movements for the operator, which can lead to a brief moment of surprise for employees at first. Operators should therefore act with caution when handling ICT; after all, the magnetic fields within the system transport goods of different sizes at variable speeds. If work needs to be carried out on ICT systems, which otherwise function largely without external intervention, it is advisable to only carry out this work in STO (Safe Torque Off) mode for the safety of employees. This minimizes the risk of trapped fingers or dangerous evasive manoeuvres by oncoming trolleys. In addition, employees with pacemakers should keep their distance due to the magnetic fields - depending on the type and performance of the ICT system.

Important safety aspects are already fundamentally implemented in conventional systems due to the rotary drives used. Thanks to the encoders integrated into the rotary actuators, the operator or the control system itself is able to safely monitor the respective speed, position and direction and perform emergency stops or emergency shutdowns if necessary. This function is not available in ICT systems. It may therefore be difficult for the operator to implement the necessary controls, such as safe speed limits, in the system in the event of a risk occurring.

It is essential for operations managers to address this safety gap within ICT systems. It also represents a regulatory challenge. For example, the Ordinance on Industrial Safety and Health at federal level stipulates that machine operators are obliged to promote the safe use of machines by means of a risk assessment, protective measures and associated inspections. In addition, Directive 2006/42/EC of the European Parliament stipulates that machine manufacturers must produce safe machines and implement accident prevention measures. Failure to comply with these laws and machinery directives can have serious consequences for both OEMs and their customers.
The DIN EN ISO 12100 standard applies to the design of safe machines and emphasizes that management should keep risks as low as possible on the factory floor. The standard also stipulates that the mass and/or speed of moving elements in the production environment must be limited if necessary in order to comply with it. However, modern ICT systems do not yet provide the comprehensive requirements to meet this standard on their own. As a result, machine manufacturers are obliged to take additional precautions to ensure compliance with these standards and directives.