PDC Sensor for Machine Safety - Ultrasonic Safety-Rated Sensing for Human-Robot Collaboration and Industrial Machinery Protection
This in-depth technical article examines the application of PDC sensors for machine safety, covering the ultrasonic safety-rated sensing principles, the EN ISO 13849 category 3 PL d certification, the flexible ultrasonic sensor system for proximity sensing in human-robot collaboration, and the integration with industrial machinery control systems for personnel protection and collision avoidance.
Ultrasonic machine safety sensors provide safety-rated proximity sensing for human-robot collaboration and industrial machinery protection. The USi-safety ultrasonic sensor system is a certified sensor technology used to safeguard hazard areas on mobile machines such as robots, industrial trucks, machines, and plants according to EN ISO 13849-1 category 3 PL d. The system protects people and objects from potential dangers and collisions, taking its place in the range of electro-sensitive protective devices. The sensor achieves an accuracy of 3 mm over a detection range of 510 mm in flexible ultrasonic sensor systems for safety control during human-robot collaboration. The safety function is provided with only one sensor unit, without requiring redundancy, and the sensor units are extremely small and can be freely positioned, meaning they can be detached from the control interface for flexible positioning in the extremely narrow space of fork arms. The elliptical sound field of the ultrasonic transducer has an opening angle of ±17° and ±5°, optimized for monitoring a three-dimensional range.
PDC Sensor
The EN ISO 13849 category 3 PL d certification ensures the sensor meets the highest safety standards for industrial applications. The USi-safety is the only safe ultrasonic sensor system according to this standard. The safety approval means the benefits of ultrasonic technology over optical systems can now be utilized for safety applications, allowing objects made of different materials to be reliably detected. The control interface offers two safe OSSD outputs per channel for the adjustable protection field and one PNP switching output for the warning field. The reaction time is typically 99 ms, ensuring rapid response to detected obstacles. The sensor units comply with IP69K degree of protection, while the control interface complies with IP65. The sensing range is up to 2,500 mm, providing adequate coverage for most industrial safety applications. The sensor is resistant to environmental influences such as dirt, air currents, humidity, and similar factors.
The flexible ultrasonic sensor system for proximity sensing enhances safety controls during human-robot collaboration (HRC). The sensor achieves an accuracy of 3 mm over a detection range of 510 mm, providing precise proximity detection to prevent collisions between robots and environmental objects. Proximity sensing emerges as a critical technology to prevent collision between the robot and its environmental objects. The safety sensor must have long proximity range and fast response in order to secure enough response time before colliding with ambient objects. The sensor's ability to reliably detect moving and stationary objects with any shape, color, or surface in an elliptical, three-dimensional sound field ensures comprehensive protection in complex industrial environments. Dirt, temperature, air flow, and humidity have no impact on the function of the sensor, making it an excellent choice for almost all applications in the industry and outdoors.
The integration with industrial machinery control systems uses the sensor's safety outputs to stop or slow machinery when a person or object enters the protection field. The sensor provides two short-circuit and cross-circuit-monitored OSSD safety outputs for the adjustable protection field, ensuring fail-safe operation. The teach-in function for teaching in the complete detection area as a standard environment increases operational safety, with the function suppressing vehicle contours that cause disturbance, for example. The sensor system is set up using convenient parameterization software, enabling easy configuration and adaptation to different applications. The integration with the machine's control system enables automatic machine stopping or speed reduction when a person enters the danger zone, preventing accidents and injuries. The sensor's resistance to environmental influences ensures reliable operation in demanding industrial environments, including those with dust, dirt, and humidity.
The future of ultrasonic machine safety is moving toward enhanced accuracy and integration with advanced control systems. The development of extreme-edge TCN-based low-latency collision-avoidance safety systems using ultrasound sensing and temporal convolutional networks is enabling functional safety solutions for industrial machinery. The use of compliant ultrasound proximity sensors with fast response and tactile sensing capability is being developed for safe operation of human-friendly robots. The integration of ultrasonic sensors with other safety systems, such as light curtains and radar, is providing redundant protection for critical safety applications. The ongoing advancement in ultrasonic transducer technology and signal processing is improving the accuracy, range, and reliability of machine safety sensors. The ultrasonic machine safety sensor continues to evolve, providing the safety-rated sensing required for human-robot collaboration and industrial machinery protection.
