Protective device Self-adjusting access and access protection

Related Vendors

Taiwan Machine Tool & Accessory Builders' Association (TMBA)

Wuxi InfiMotion Technology Co., Ltd.

SIMTOS (Seoul International Machine Tool Show)

The new safety system solution Safe Adaptive Access (SAA) from Sick monitors entry and exit routes at machines with hazardous movements.

Two special features characterize the non-contact protective device SAA for material flow systems: firstly, the dynamic and automatic adjustment of the protective fields to the height, width, and position of the conveyed goods, such as cartons, and secondly, the safety function to differentiate between humans and materials without external signals and sensors. This provides the SAA with the highest flexibility in implementing demanding, flexible, and worker-friendly protective measures in automated conveyor systems.

Protection of people at machines and installations

In automated material handling technology, non-contact protective devices (BWS) ensure the protection of people around machines and systems where there is a risk of injury. Triggered by a safety-directed detection of a person or body part, the BWS places the relevant machine or system in a safe state before a person is endangered. Unlike protective fences, BWS provide the ergonomic and process-related advantage of unhindered access to the machine, allowing operation or maintenance.

People in the vicinity of storage and conveyor systems are part of everyday intralogistics. When transporting materials into or out of storage or production areas, there is always a requirement to protect them from accident hazards posed by machines using BWS—safely distinguishing between materials and people. This differentiation should allow materials to be conveyed in or out unhindered. Unauthorized access by people, however, must be detected and result in the timely stoppage of all dangerous machine movements before they can be reached by a person.

Distinguish people from material

Often, conveyed goods are moved with varying dimensions and the positions and orientations of these goods on the transport device can differ. This results in the challenge of safely detecting and distinguishing people even with variable dimensions and orientations of conveyed goods, in order to stop dangerous movements in time. Automatic protective field adjustment and human-material differentiation: the SAA solves these two requirements in a single system solution.

The task of the SAA is to enable the unhindered transport of conveyed goods into or out of a danger zone without disturbance, while detecting unauthorized access of people into the danger zone. The vertical securing of the passage area is achieved by two side-mounted microScan3 safety laser scanners, whose measurements are processed for distance measurement in a SIM1200 interface. The Flexi Soft safety controller processes these sensor signals, switches between the corresponding monitoring cases according to the recognized object sizes, and issues the stop command when unauthorized access is detected. A key switch for retraction of the system after the safety device is triggered and a command device for resetting the protective devices and restarting the conveyor technology complete the SAA system scope.

Deviation triggers safety function

The two safety laser scanners of the SAA measure the conveyed goods in the passage area to a machine and report the measurement data to the controller. If the measurement data is within the allowed range, the logic of the SAA switches to the monitoring case corresponding to the measurement data. If there is a change in the width or height of the conveyed goods, the protective field is dynamically adjusted to the newly detected dimensions. A deviation from the parameters allowed for the passage of the conveyed goods triggers the safety function, as does the intrusion of a person into the protective field. In this case, the safety laser scanners recognize the spatially and temporally fundamentally different human movement patterns, so the SAA, in accordance with its protective function, stops the machine or its dangerous movement. With Type 4 / SIL3 / PL d, the SAA meets the highest requirements of functional safety.