New Ultrasonic Sensor Makes Robots Safe

The requirements for safe workpiece and tool protection are high. The force and the pressure on a person who touches the mandrel of a gripper or cordless screwdriver are above the permissible limit value of the ISO / TS 15066 standard. The protection of the screwdriver must therefore be contactless. At the same time, the automated work process must not be impaired.

Transducer arranged decentrally on the robot

The joint solution from Mayser and KUKA is based on the use of ultrasonic sensors. The new sensor development, Ultrasound Safety, recognizes both people and non-conductive objects, without contact and unaffected by dirt, external noise, air currents and moisture.

The special feature of Mayser ultrasonic sensors are the two very small ultrasonic transducers, which are positioned flexibly and geometrically independently of the electronics. They can be placed directly on the robot or gripper and monitor their surroundings flatly and safely. The converters can also be arranged decentrally.

The sensors measure in an elliptical sound field and detect even small objects. In addition, a teach-in function enables the entire measuring environment to be taught in as a standard environment. This means that the system only reacts to deviations from the target state.

Personal protection through safe ultrasound

The safe ultrasonic sensor is a new development worldwide, as it is also approved for personal protection due to its two channels. For KUKA, this was crucial for the tool protection of a KUKA LBR Iiwa in order to get involved in the joint advance development with the medium-sized company Mayser.

The two transducers of the ultrasound safety set up two protective fields around the robot. The larger protective field allows the tool arm to move quickly. The smaller protective field is activated when the screwdriver approaches a workpiece. The robot slows its movement so that a person is recognized in time and contact with the tool is excluded. Cooperation between robots and humans is possible without risk.

Employees benefit from better ergonomics

The solution from Mayser and KUKA for the KUKA LBR Iiwa offers a complete system for securing HRC workplaces and therefore better ergonomics for employees. These can be supported efficiently during heavy work. At the same time, higher robot speeds and cycle times are possible.

Thanks to the certification of the fail-safe, two-channel ultrasound safety according to ISO 13849-1: 2015 category 3 PL d, the world first is approved for personal protection from February 2017. (jv)