Monitoring of Natural Hazards With the ImpactSentinel Alarming System An Intelligent Solution ImpactSentinel Natural Hazard Sensors und Systems hazard signalization in protection fences overstress, shock and tipping detection redundant radio technology offer extremely short reaction time compact, robust and reliable sensors lifetime operation without battery change false alarm proof easy to install
IPS INGLAS, Bermatingen 2003/2015
Rockfall in Protection Nets Benefit of Electronic Monitoring Steel wire mesh and netting are used to protect traffic infrastructure or settlements against rockfall, slope and avalanches. However some hazardous events will outbid these barriers to their limit or overstress them. Then the protection impends to fail or in the end fails. The electronic sensor system ImpactSentinel will in time warn reliable against imminent hazard to stop trains or to evacuate settlements. Before any hazard will occur, cumulative smaller rockfall events or slopes will be electronically recognized. Any trend towards an overstress situation will be recorded. The system reacts by optical or acoustic alarming and warns responsible authorities via LAN, SMS or alternative data transmission. The economic system can easily be installed even on existing barriers and so improves their protective outcome.
Components of an ImpactSentinel System ImpactSentinel sensors permanently monitor the functional elements of protection nets like branches, posts and brakes against rockfall, slopes or avalanches. The alarming system collects the data of many wireless sensors associated with the base station. It computes the alarming state and transmits it to the control center. The ImpactSentinel wireless sensors form a redundant network, which allows a supervision of the protection net. A fault of a single sensor will not lead to a loss of functionality. For bigger systems extra data relays and receivers can be added. By intelligent evaluation of the sensor data fault alarms caused by animals or vandalism distinguished from real alarm situations. The intensity of events and the service status of the rockfall nets can be determined by measuring the shock acceleration, the drawing of pullout bolts and the dumping of the sensors. Sensor data transmission is started when a defined (adjustable) limit of acceleration (vibration) in the protection net is exceeded. The data will be transmitted wireless to the base station. Data from all associated sensors are computed in the stations data logger. A configurable data filter allows the generation of individual alarms. The base station operates by using mains supply or a battery which will be charged by a solar panel. This allows any installation even in unexplored areas. A distance of a few hundred meters form the sensors is possible, depending on radio spread. Extra data relays are available to increase distances. The forwarding of the alarms to the control center by the base station can be accomplished in different ways. LAN, 3G, any radio transmission or optical wave guide transmission are possible on demand.
Sensor Installation The wireless sensors use universal brackets for mounting on respective positions in a protection net: directly on a wire rope or on top of a post. On its base plate the sensor will be screwed directly on top of a post which holds a mounting plate. Alternatively a special adapter is available for clamp mounting. For mounting on a wire rope the integrated clamps can be used. Ropes with diameters from 11 to 28 mm will fit. Two pullout studs are the main functional elements of every sensor. Every stud can be tied to one or more 2 mm steel wires which should be arranged across the critical zones of the protection net. The studs are fixed with two screws and a sheet, which breaks at a pull out force of about 500 N. On a pull out event the sensor triggers an alarm, for every stud an alarm of its own. A considered placement of the sensors in the protection net allows the monitoring of the complete structure, the net itself, the brakes and posts. Steel wires fixed to the studs should be spanned across the net to detect overload. Redundancy and safe alarming are achieved by using a crossing of the two ropes of two neighboring sensors. The pull-out stud will be drawn when the brakes are stressed to a defined degree. Then an alarm is triggered. Especially side and hillside bracings of the protection net are well suited for that. A typical arrangement is shown in the drawing below. Steel wires are plotted in red. The sensors accelerometer element detects the maximum intensity of vibrations due to rockfall within consequent time segments after the first shock. The intensity trend from segment to segment is evidence for the magnitude of the event. Additionally the sensors orientation and with it the posts orientation can be calculated by determining the static gravity acceleration in every spatial direction. Changes give a measure for the deflection of the protection net by slopes or avalanches. Even very slow dumpings can be detected.
Alarm Data Processing SAM is the operating system which receives and stores the broadcasts of all sensors, calculates the alarm status and forwards relevant information to the operational centers. Simultaneously housekeeping data will be processed and additional functions as camera operation become activated. All system relevant information is represented on the graphical user interface. The systems configuration file enables an individual modification of SAM software parameters like alarming type and alarming threshold for the demands of the customer. In an extra file all sensor ID s are listed. Only sensors listed there become active. For post-processing services every day logfiles are permanently actualized. Every input is marked by a timestamp. So an analysis of events can be performed and the reaction of the SAM software can be analyzed. These data are also useful for judicial and insurance issues. A main function element is the computers remote access function which allows online status control and updates via internet.
Add-ons Data relays Extended systems comprising many protection nets can be connected via data relays. These relays direct all data coming from sensors or other relays to the base station. A selforganizing firmware allows redundant crosslinking of the relays, so an uninterrupted transmission is guaranteed even if one system fails. Usually data relays use loadable batteries and solar panels for operation. Cameras For visual control of critical periphery video cameras can be activated remotely or by automatic alarm recognition. Following hazardous events photos of observed area allow a quick evaluation. This is a meaningful accessory to arrange a quick response of the intervention team. Customer Sensors Often an integration of customer sensors would be helpful. Universal wireless modules can integrate their functionality into the ImpactSentinel system. Then the sensors can be remotely read and controlled.
IPS INGLAS GmbH & Co. KG IPS INGLAS GmbH & Co. KG Muschelweg 19 88697 Bermatingen Germany www.impact-sentinel.de info@impact-sentinel.de T. +49 7544 90492 90 F. +49 7544 90492 95