Functional model
Safety Sensor Demonstrator
for safe distance measurement

The trade show demonstrator attracts visitors' attention with over 3,000 installed LEDs and illustrates the operating principle of safe distance measurement using a doubly implemented radar measurement path. Pre-programmed games and mechanically adjustable sensors invite you to discover the advantages of radar technology interactively.

For safe distance measurement, two sensor pairs each consisting of two opposite radar sensors form a self-monitoring measurement system. When the two lower sensors move in parallel they provide matching and thus valid distance values. If the difference between the measured values is too large, an alarm is automatically triggered and the system is immediately brought to a safe state.

The LPR®-1DHP-291 sensors from SYMEO are used in demanding industrial environments where high robustness and reliability are critical, for example with dust, dirt and extreme weather conditions.

One example is use in shipyards. Mounted on the crane bridge, the sensors precisely detect and monitor the crane position during loading of container ships and ensure the safety of people and equipment under extreme conditions.

To lighten the atmosphere at the trade show booth, two interactive games and an Easter Egg were programmed into the functional model:

In the first game, inspired by “Beer Pong,” the player must use a sensor movement to throw a virtual ball into a “cup” made of markers - fingertip precision required!

In the second game, “Space Egg,” the player controls a hen (sensor marker) and must position it over an egg (color stripe) to incubate it. The first to hatch their chick (stripe color change from red to green) wins.

The Easter Egg reveals a beautiful rainbow running light that flows like falling drops of color from top to bottom. It is activated when the sensors are moved against each other for several seconds.

To ensure smooth production of the trade show model, the entire model was designed in detail in 3D.

The construction of the LED tube posed a particular challenge: an aluminum tube that simultaneously serves as the LED carrier, a ventilated heat sink and a cable channel gives the column the required stability. In addition, two acrylic tubes acting as diffusers were integrated to gently spread the LED light. This combination had to meet both functional and aesthetic demands.

The perfect interplay of microelectronics and custom-made mechanics.

Hidden in the base of the functional model is the powerful control electronics that processes sensor signals and controls the LED tubes. At its heart is an ESP32 dual-core 32-bit microcontroller that is programmed in C++ and produces impressive LED effects at up to 120 FPS. The radar sensors are connected via Ethernet through a CISCO switch.

An Igus plain bearing enables smooth movement of the sensor in the Z direction and reliably prevents rotation about its own axis.

The well-designed combination of two tension springs holds the sensor precisely in the center position. One spring carries almost the entire self-weight of the sensor, while the second spring absorbs the remaining weight force only beyond the center position due to its preload. In this way, an exactly defined central rest position is achieved despite bearing friction and manufacturing tolerances.

A total of 3,000 LEDs of the WS2812 ECO type were installed in the functional model’s two acrylic tubes to display measurements and light effects. The energy-efficient LEDs are connected in series in a daisy chain, which allows all RGB LEDs to be driven in groups with only a few data lines from a single ESP32 microcontroller.

A cooling system with high-quality Noctua PC fans creates a constant airflow inside the tubes and the base. This reliably cools the power supplies and LEDs, ensuring long-lasting performance.

All components with complex geometries were manufactured on a Bambu Lab X1E 3D printer. The carbon-fiber-reinforced filament used, PAHT-CF (high-temperature resistant nylon), is particularly durable and withstands high loads.

To ensure the highest fit accuracy and minimize post-processing effort, all required wooden parts of the functional model were CNC-manufactured and could be mounted precisely as-is.

A transport box specially designed for the functional model ensures quick assembly and disassembly and provides optimal protection during transport of the valuable trade show object.

Behind the scenes, work was carried out with passion and creativity. The development and construction of the functional model were a perfect combination of software, electronics, and hardware. From precise CAD design through manufacturing by CNC and 3D printing to programming in C++, I was able to contribute everything that makes my engineer's heart beat faster. Especially the programming of the LED effects left plenty of room for creativity and made the project a real highlight.

Already during manufacturing and especially after completion, the functional model offered an excellent opportunity to fully indulge my passion for photography and videography. The individual steps of the production process as well as the impressive lighting effects made the project a fascinating subject for the camera.

... for the SYMEO team at the trade show booth.

Many thanks to the trade fair team of Symeo GmbH from Munich for the trusting and appreciative collaboration. Especially the friendly and warm personal contact and the creative freedom granted during implementation made this project a thoroughly enriching experience. A valuable collaboration that was positive in every respect.

At the SPS trade fair in Nuremberg, the functional model attracts attention. With fascinating LED lighting effects and interactive games, it invites trade fair visitors to explore the world of radar technology in a playful way.