SICK is presenting the world’s first certified safe laser scanner system for outdoor use, the OS2000, at the Hanover Trade Fair 2008.
It combines the hardware and software of the LMS Outdoor Laser Measurement System – proven in thousands of applications and specially designed for outdoor use – with the safety level of the UE4470 safe programmable logic controller, which is certified as a safety component within the sense of the Machine Directive.
Typical application examples of the system solution, which received approval from TÜV Rhineland in late 2007, include door and gate protection, cranes, manned and unmanned vehicles, waterway structures such as bascule bridges or locks, and rail or conveyor systems.
In the OS2000 system, the monitoring and test signals of up to three LMS units are evaluated by the UE4470 safety network controller.
The controller, certified as Safety Category 4 (EN 954-1) and SIL 3 (IEC 61508), handles the machine-side connection, evaluation of the output signals of up to three LMS units, control of the LMS units, evaluation of their output signals, and control of the cyclical testing of the sensors on the basis of fixed test targets.
The OS2000 safe laser scanner system thus fulfils the demands of Performance Level ”d” according to EN ISO 13849-1 and SIL2 in compliance with EN IEC 62061.
Proven outdoor sensor technology
The system’s sensor – the LMS – has already been proven in several thousand outdoor applications worldwide, e.g. for collision prevention or building security.
The OS2000 profits from this experience: it can be used wherever a hazardous area requires monitoring outdoors.
Depending on the task, IP67-protected laser scanners with scanning angles of 100° or 180° are available and can be used in environmental temperatures between -30°C and +50°C.
Neither snow, rain or dampness (fog); the incidence of bright light in the form of interfering reflections from snow or rain; dampness on the front screen: or the extreme incidence of light from a low-lying sun can impair the sensors.
The protective fields can be parameterised and evaluated as desired within the safety-oriented range of 20 m.
Safety-oriented evaluation, testing and connection
The UE4470 safe programmable logic controller from SICK gives the laser scanners, and the entire OS2000 solution, the necessary safety level.
Whereby the most important aspects here are the control of cyclical testing of the sensors on the basis of external test targets (as proof of the detection capability of the LMS); evaluation of protective fields parallel to the test cycle; regular inspection of scanner signals for error-free function; and automatic monitoring of the cable for breakages and short-circuits, cross-circuits, short-circuits to ground or voltage problems.
The working chain of sensor – output signals – controller is thus comprehensively monitored. The UE4470 can also carry out additional safety functions (e.g. emergency stop) and process the signals from the automation system of a machine or vehicle. Safe integration in a fieldbus system is also possible.