Energy autonomous wireless sensors: InterSync Project FIMA Autumn Conference 2011, Nov 23 rd, 2011, Tampere Vesa Pentikäinen VTT
2 Contents Introduction to the InterSync project, facts & figures Design challenges of wireless sensor systems Reconfigurable Sensor Node Platform Energy management and harvesting Wireless condition monitoring sensor with ultra low power consumption
3 InterSync -project facts & figures Project schedule: 06/2009 03/2014 Funding scheme: FIMECC EFFIMA programme Total budget: 6.2 M Work effort: 41 person years, companies 50 % Project partners: ABB Marine, DA-Design, Kone, Konecranes, Metso Automation, University of Oulu, Tampere University of Technology, VTT
4 InterSync vision From manual raw data collection towards energy autonomous distributed intelligence in condition monitoring of industrial machinery
5 Design challenges of wireless sensor systems Wireless sensor networks are taking place in industrial condition monitoring and control applications The benefits of wireless technology are well known but there is still substantial issues to be solved 1. Performance of the embedded electronics should be high enough still keeping it configurable easily 2. Life-time of the power source for the certain device should be several years or even maintenance free 3. The usage of radio spectrum should be optimized better for commercial applications to prevent overload on the bands used
6 Design dilemma Performance Compromise? Energy efficiency Flexibility
7 Reconfigurable Sensor Node Platform High performance and energy efficient wireless digital signal processing platform for distributed condition monitoring and control purposes. Enables new way of thinking based on distributed intelligence where raw sensor data will be analyzed close to the source of origin. This reduces the amount of data transferred and stored as well as offers redundancy to the process compared to fragile centralized analysis systems. Current status: First pilot applications deployed in late 2011.
8 Data processing architecture overview The architecture is based on dual core layout combining energy efficient microcontroller and configurable flash based FPGA circuit Microcontroller takes care of operational logic of the architecture and is able to switch power on and off from all other components separately FPGA could be programmed to provide high capacity parallel signal prosessing pipelines or even high performance processor core mode Prototype of the node
9 Architecture Power AVR Radio Dataflash 16/24 bit 4ch ADC DAC, PWM Outputs Inputs FPGA RT clock Radio Filter Opamp 3D Acc sensor SRAM USB, UART SPI, DIGIO Digital IO
10 Options for the FPGA Tool Chain Synphony Model Compiler Simulink Simulation and Verification Fast model creation Optimization, Exploration and Verification from a single model Transport Triggered Architecture (TTA) Processor is composed of Function Units, Register Files and Interconnection network Scalable and flexible Efficient especially for parallel processing applications
11 Advanced methods and tools for measurement data analysis Signal analysis tools for industrial applications: Methods for detecting rope defects for condition monitoring developed Methods for bearing fault diagnostics analyzed Algorithms for the energy efficient sensor node (VTT node) implemented Ongoing development: A signal analysis toolbox for energy efficient sensor nodes Implemented algorithm blocks using the Matlab/Simulink tool chain Implemented energy optimized algorithms using the TTA processor tool chain Energy efficiency analysis of design tool chains on the VTT node Demonstrate energy efficient signal processing on the VTT node in the bearing fault diagnostics case
12 Communication interfaces The communication modules are placed on the external boards to provide possibility to choose optimal transceiver for each application Available modules until now are based on NanoLOC 2.4GHz and Radiocrafts 868MHz transceivers In the future there will be high interest to implement UWB (ultra wide band) communication to the node to provide broadband communication channel for high frequency measurements Prototype of the comm board
13 Energy management and harvesting The main purpose of energy management architecture is to guarantee constant energy delivery to the payload during critical processes Several types of energy sources can be connected parallel to the management system to provide best energy delivery available in current conditions (thermoelectric energy harvesting, electromechanical energy harvesting, electromagnetic energy harvesting, photovoltaic energy harvesting, wireless energy transfer) Operational logic to control sensor node activity is placed in the microcontroller which will take care of active and sleeping periods as well as active components in the different activity profiles
14 Energy management principle Energy converter Energy converter Energy converter Energy management HW ENERGY HARVESTER Monitor & control Intermediate energy storages Data processing HW Energy management SW Sensor data processing SW Operating system SW including HW platform control & power management Ambient energy - light - thermal - mechanical - electromagnetic Communication SW Sensor driver SW User interface SW APPLICATION PAYLOAD Communication HW Sensing HW Optional local user interface
15 Energy management system tasks Optimizes energy acquisition from the energy converters Makes voltage conversion between the energy converter and application payload Provides energy availability monitoring interface for the application payload Controls charging and discharging of the intermediate energy storages that are needed because of intermittent operation of the energy converters and supply current peaks of the application payload
16 Wide band vibration energy harvester Vibration powered sensors Vibration Rotation Electric energy Easy installation. Easy re-configuration in temporary installations. No cabling costs: Cables, cabling work and accessories. No need to replace or recharge batteries.
17 Ultra Low Power Wireless Condition Monitoring Sensor Condition monitoring solutions based on acoustic emission (AE) sensor. Listens to the high pitched noise of a leaking valve. Low power wireless wake-up radio architecture @ 2.45 GHz. Measurement time slots not predefined sensor node can be activated when needed. Range ~10 m. Current consumption <7 µa in listening mode. 10 year battery life time realistic with one measurement per day. Contact person Pekka Pursula, pekka.pursula@vtt.fi Wireless sensor node - on lab table - on a valve Base station
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