The special MRK gripper enables safe working without a safety fence. © MOT - ICM

In addition to the sensors, the "mobile HRC robot" demonstrator mainly consists of a collaborative robot CR-7iaL from Fanuc, a track-guided autonomous driverless transport system Beldrive AGV and an HRC gripper HRC-04-072810 from the Zimmer Group. The mobile HRC robot carries out the sub-processes of transporting and handling perforated plates and filling a vibratory bowl feeder at SchAz. The HRC gripper picks up the empty perforated plates, transports them to the robot, picks up the loaded perforated plates and transports them to the manual workstation. A worker then carries out the final assembly of the assembled perforated panels in a collaborative process with the robot.

Human-robot collaboration in practice

In robotics, the term human-robot collaboration (HRC) refers to cooperation on a component between humans and robots at a shared workstation without separating protective devices. With a view to safety aspects, the SchAz application center examines the various stages of interaction between humans and robots using practical processes - from the classic robot cell to pure collaboration.

The demonstrator here is a system that ICM e.V. has largely designed and assembled itself. A Stäubli robot type TX2-90L with a tactile sensor skin from Airskin, which has a maximum load capacity of 20 kilograms, was placed on the base frame. The sensor skin acts as a kind of air cushion in which the internal pressure is permanently monitored. If the pressure changes, for example in the event of a collision, the system reacts and stops safely. Safety is also a top priority for the gripper. For example, the Zimmer Group's HRC03-072844 electric gripper, specially designed for HRC applications, has no sharp edges and is constructed in such a way that its rounded shape on all sides practically prevents it from accidentally getting caught. This feature, combined with mechanical self-locking of the gripper jaws - the gripper does not lose the workpiece even in the event of an emergency stop or power failure - offers maximum safety in every application. All Zimmer Group HRC grippers meet the high requirements of the safety principles in accordance with ISO/TS 15066 (HRC standard) and are BG/DGUV-certified.

The ICM e.V. HRC system is intended to illustrate the collaborative assembly of a 2-meter measuring tape consisting of three parts (tape, actuator, shell). Two components are pre-assembled by a worker on a mobile work table. Once the assembly has been transferred to the robot, it is visually inspected by the robot using a Balluff camera system. The third component is then inserted into the fixture by the worker. The final collaborative joining process and function test is then carried out by the robot or HRC gripper.

The fact that the Chemnitz training and application center is a resounding success is reflected in the many interested companies and, above all, in the numerous external supporters: "In addition to modern, well-equipped training rooms for developing creative ideas, our application center offers a wide range of automation technologies for researching and experimenting with new solutions. Without the support of technology leaders such as the Zimmer Group from Rheinau, these innovative solutions would not be so impressive," says Marcel Ott, software developer and technical contact for the application center.

Gregor Neumann, Zimmer Group / dsc