Pioneering sensor technology - experience innovative safety solutions in action

Functionally safe sensors are the main business of TWK-ELEKTRONIK GmbH in Düsseldorf since years. To expand the customer base, TWK is exhibiting at several trade fairs this year.

These include MODEX 2024 in Atlanta, Georgia (USA) from 11 to 14 March (stand A13611) and LogiMAT 2024 in Stuttgart (Germany) from 19 to 21 March (stand 3F30). The American exhibition MODEX in particular will be a debut for the safety encoder specialist from the Rhineland.

In the logistics sector, the sensors used must offer a high degree of functional safety in a particularly small and lightweight design. The mobile vehicles used drive independently from A to B, picking up and putting down objects and reacting to unforeseen obstacles. They are also small and manoeuvrable and are not allowed to expose people and their surroundings to danger at any time. This is why all eyes are on the wide range of certified sensors that TWK manufactures almost exclusively in its own development and production facilities: Rotary encoders, inclination and vibration sensors. The term 'safety' covers a range of different properties.

In addition to the functionally safe sensors with SIL2 / SIL3 and PLd / PLe levels according to IEC 61508 and ISO 13849-1, there are also devices with EX protection Zone 1 and 2 according to ATEX / IECEx or with UL^® approval according to UL 61010-1. Not forgetting the ASIL-D compliant devices according to ISO 26262 and those with E1 approval from the German Federal Motor Transport Authority.

With a diameter of just 38 mm for single-turn encoders and 42 mm for multi-turn encoders, these safety sensors are extremely compact and lightweight. They are available with all the common industrial interfaces used in the safety sector: PROFIsafe via PROFINET, Failsafe over EtherCAT (FSoE), CANopen Safety and - brand new - incremental. Other interfaces can be implemented and offered on request – such as J1939 Safety, BISS Safety or LoRaWAN.

The SIL / PL certified or fully redundant encoders can process speeds of up to 15,000 rpm and offer a typical position resolution of 16 bits / 360° as well as a speed signal of 16 bits with degrees of protection up to IP69K. A typical application is the steering angle and speed detection of a drive system. The miniature encoders can be placed directly on the wheels of automated guided vehicles, for example, or on the motor with a reduction gearbox. For the latter, a special SIL2 slewing ring function is available for multiturn encoders if required. The housing material aluminium, stainless steel 1.4404 or magnetically shielded stainless steel ensures maximum environmental resistance and operational safety.

The newly designed, cost-effective TKN55 Safety SIL2-KIT encoder without shaft bearing with CANopen safety interface and electronic multiturn detection has a housing depth of just 20 mm and is ideal for integration into existing systems - e.g. on motors. The position magnet is fixed on the moving application side and placed opposite the encoder housing without any mechanical connection. The speed signal is configurable. The ASIL-D-compliant TxSN42 rotary encoder with SIL3 certification and CANopen safety interface, which is available as a singleturn or multiturn, offers an even higher level of safety. A wide range of flange, shaft, plug and cable connections make this compact unit easy to implement.

Draw-wire sensors with an attached rotary encoder are also available for measuring a fork or boom stroke. They convert the linear stroke into a rotary movement and, depending on the model, can measure lengths of up to 30 metres. And to prevent a vehicle from tilting, SIL2 / PLd-certified inclination sensors are available for detecting vehicle inclination.

Equipped with a gyroscope, they provide the dynamically corrected tilt angle as well as a speed signal and the raw values of 6 axes via PROFIsafe or CANopen Safety. The raw signals, especially those from the accelerometer, can be used simultaneously for condition monitoring of the vehicle (oscillations and vibrations) and for control purposes. Some of the devices can be equipped with safety switching contacts for safe limit value monitoring and guarantee safe driving at all times.

www.twk.com

  Ask For More Information…