Compact cable guidance for innovative robot for unloading tyres from lorries

• What was needed: e-spool® energy chain, chainflex® cable
• Requirements: A space-saving cable routing was needed to supply the robot. As it rubs against the concrete floor, it also had to be wear-resistant.
• Industry: Robotics, tyre industry
• Success for the customer: With the e-spool® including spring return, all cables are rolled up compactly. No special solution had to be designed and the project budget could be adhered to.

This 7-axis robot arm was mounted on a mobile crawler platform and is used in lorries in the tyre industry. Thanks to a sophisticated gripper, a vision system and artificial intelligence developed by the Michelin Study and Research Centre in Ladoux, the robot arm identifies and grips the tyres and places them on a conveyor belt under the robot, which transports the tyre to its processing area.
In manual mode (radio-controlled), the platform can travel with the robot in all directions, with the destination being the loading/unloading dock. Once at the dock, it switches to autonomous mode. However, when working in the narrow trailer of the truck, the robot can only move forwards and backwards to a limited extent and can only turn slightly to re-centre itself. This posed a space problem, especially for guiding the numerous power, control and pneumatic lines from outside into the trailer where the robot works. Alternatives such as a battery for the power supply or a motor were out of the question due to the robot's size and weight restrictions.
Instead, the choice fell on an energy chain system, which is pulled horizontally behind the robot over concrete and the wooden or plastic formwork of the lorry trailer at a minimum travel of 14 m, a speed of 12 m/min. and acceleration of 1 m/s2. The small height difference between the dock and trailer also posed a challenge and required a cable routing that was as wear-free as possible. As the chain would be slightly off-centre from the track of the mobile platform, it had to be able to accept twisting/deformation.

In order to fulfil the special requirements of the cable routing, we worked closely with the customer to find the best technical solution.
In the end, the choice fell on an e-spool® with spring return, which today enables the engineers to guide all power and data cables as well as pneumatic hoses safely to the robot platform.
To ensure that the uncoiled energy chain could also move in the Y direction, the e-spool® was mounted on a turntable with the 1400 series energy chain. Another specification concerned the last sliders of the chain, which were mounted in reverse so that the cable routing is lower above the floor when the e-spool® is unrolled.
Additional sensors were also installed on the energy chain to stop the mobile platform before the chain runs out. The e-spool® made it possible to wind up the cable in a confined space. Thanks to the integrated spring return system, the engineers were able to dispense with a motorised system for winding up the chain.
Unlike a battery- or motor-operated system, the robot could thus be kept as light and slim as possible. In addition, e-spool® was also able to meet the project team's budget for the cable routing. In addition to the energy chain, we also sourced the cables and hoses used in it. These were primarily chainflex® motor cable, chainflex® control cable and a pneumatic hose.