HRC-capable robots require peripherals that are reliably and safely designed for collaboration. One does not work without the other. This is precisely where Schunk comes in with the Co-act EGL-C gripper and presented an intelligent robot tool for collaborative applications at the Hannover Messe. On the one hand, it complies with the biomechanical limits of ISO/TS 15066 and, on the other, opens up a previously inaccessible weight class for users. A world first, says the manufacturer Schunk, because for the first time it will be possible with the gripper to fully exploit the load-bearing potential of conventional cobots and provide users with effective ergonomic relief with the robot.

Intelligent force and displacement measurement
The key lies in integrated force and displacement measurement as well as a specially developed and patent-pending safety intelligence system that is integrated directly into the gripper and divides the gripping process into individual phases: As long as there is a risk of human hands or fingers being trapped, the integrated logic limits the gripping force to a harmless 30 Newtons. Only from a workpiece distance of less than four millimetres, i.e. when jamming is no longer possible, do the gripper fingers move with the freely definable gripping force of a maximum of 450 Newtons. If the system detects yielding during this closing phase, for example if a workpiece is gripped that is too small and the operator is about to remove it by hand, this movement also stops automatically.

The same applies if the expected workpiece dimensions are exceeded by two millimetres, for example because no part is present. The distance of two millimetres corresponds to the tolerance field of human skin and the underlying tissue, which prevents injury. Finally, in the third phase, the gripper detects whether the workpiece is securely gripped and activates the integrated gripping force maintenance by applying the brake.

Schunk thus kills two birds with one stone: the gripper meets the requirements for safe human-robot collaboration and ensures that the gripped part, which weighs up to 2.25 kilograms, is not lost even in an emergency stop situation and the associated emergency braking. All in all, the Co-act EGL-C guarantees safe gripping with over six safety functions in one package - more than any other catalog gripper on the market. These are: integrated safe travel measurement, safe position detection of the gripper fingers, safe shutdown (STO, Safe Torque Off), safe brake control (SBC, Safe Brake Control), safe operating system architecture (SOS, Safe Operation System) and safe movement and speed control (SLS, Safety Limited Speed).

Numerous interfaces
Markus Glück, Head of Development at Schunk, sees great potential for users, especially from an ergonomic point of view: "There are countless assembly applications in which components with a higher weight are manually fed, held and assembled with great motor sensitivity." In this higher load range in particular, little technical support has been offered on assembly lines to date, even though the physical strain is high in the long term. If the cobot carries the load, the workers can concentrate much better on the quality-critical core tasks.

When designing the system, the manufacturer also focused on improving flexibility of use. The powerful end-of-arm tool for collaborative operation with interfaces for HRC robots from Kuka, Yaskawa, Fanuc, Universal Robots and Nachi, among others, will be launched in series production by the end of 2019. Communication is possible via Profinet, Ethercat, EtherNet/IP, Modbus/TCP or TCP/IP. The industrial Ethernet interfaces pave the way for intelligent, highly flexible processes and the effective use of robots in the smart factories of tomorrow.

Assistant robotics for production
"We are currently experiencing a turning point in robotics," emphasizes Glück. "A branch of classic industrial robotics is evolving into modern assistance robotics for use in production. In many areas, we will soon see robots that actively support people in their tasks. This will primarily involve medium payloads, such as those covered by the Co-act EGL-C." Assembly applications in the automotive industry are just as much a part of this as the loading of work containers and machines, for example to support workers when operating multiple machines. Thanks to the operating voltage of 24 volts, application scenarios on mobile robot platforms are possible. The 24-volt standard opens up further combination possibilities, for example in end effector design and tool use. Schunk had already laid the foundations for this with the Co-act JL1 technology carrier. Since then, gripping strategies and hardware have been continuously refined. pb

Focus on DGUV certification
As with the Co-act EGP-C collaborative small parts gripper, Schunk also attaches great importance to continuous monitoring of the product development process and HRC certification by the DGUV for the Co-act EGL-C. "Our aim is to provide robot manufacturers, integrators and system builders with mature and independently tested components with which they can implement and certify collaborative scenarios comparatively quickly," emphasizes Markus Glück. The Co-act team provides users with early and comprehensive support in the design, evaluation and certification of HRC applications, as well as in the selection of suitable fields of application. The specialists work closely with the relevant robot manufacturers and the employers' liability insurance association and help with the development and analysis of HRC scenarios and risk assessment. They also ensure fast and targeted technical implementation - regardless of the robots or handling systems used.