Extreme Sensing - IPSN 2007

To sense or not to sense...that was the question at the Extreme Sensing competition held during IPSN 2007 a few weeks ago. Crossbow was a sponsor of the International Conference on Information Processing in Sensor Networks and co-chaired the session on Sensor Platforms, Tools and Design Methods (SPOTS). The Extreme Sensing competition presented attendees with a live deployment that showcased the ability of wireless sensor networks to capture real-time data quickly and accurately. The challenge was for each team to build a sensor system using five sensors or less that could count people walking through a 10ft x 10ft arena. Each phase consisted of a different challenge. In Phase 1, the arena was placed in a high traffic area and teams were to sense normal foot traffic from conference attendees for the duration of 10 minutes. In Phase 2, each team was to try and "walk" through the arena 10 times without being detected by the opponent's sensors to increase their own score while decreasing the scores of their opponents.

The rules were simple - each team would need to build a sensing system that counted the number of people exiting the arena while also leaving two sides and the center unobstructed for people to walk. The teams were allowed to use unobtrusive sensors such as floor sensors, passive infrared motion sensors, ultrasound, doppler radar, lasers, etc. The restrictions stipulated that no system could have wires more than 12 inches in length, and no system could use more than five pixels in total (i.e. cameras or sensors). Each system was to immediately and automatically report scores to the scoring server with no human intervention.

It was the "Pixelators" from MIT who took home the gold! They were able to count 203 out of 204 people with their RSSI based, single-pixel radio sensor! During Phase 1 all teams performed equally. However, it was during Phase 2 and the use of adversarial strategies that the Pixelators shone improving their scores while the remaining teams fell away. The video below features the conference attendees at IPSN participating in the Extreme Sensing competition and the opposing teams hopping, crawling and doing little less than a conga line to take home the coveted grand prize.

Substation Monitoring

There are so many situations in my life that could be avoided or handled more effectively if I knew what was going on before the situation got out of hand. For instance, this past week my utility bill indicated that my water consumption was way up from the last bill. I didn't think I had done that much more laundry, had bubble baths every day or filled up my non-existent swimming pool! After investigating further, I eventually discovered that I had a leak! If I had known earlier, I could have fixed the leak right away instead of paying more in my utility bill! It is for scenarios like this that a wireless sensor network is vital and can provide important data that can be used for predictive maintenance. Crossbow's wireless sensor network products have been used in many solutions to provide maintenance data for various applications. 

All over the country, electric utilities are trying to extend the lives of expensive transmission and distribution systems through effective maintenance programs. Utility PNM is partnering with its sister subsidiary Avistar Inc. to find innovative ways to do just that.

One project deals specifically with circuit breakers, but more generally it covers monitoring all the gear that a substation uses to get power to customers. Many of the circuit breakers on PNM's T&D system use sulfur hexafluoride (SF6) gas as an insulator to prevent arcing. It works well for this purpose, but has two drawbacks: 1) It's very expensive and, 2) According to the EPA, one pound has the same global warming impact as 11 tons of CO2. So, if a breaker is leaking SF6, nobody's happy!

Avistar has devised a sensor system to detect SF6 leaks and transmit that information back to a central location so that a utility engineer can check out leak and trend data for multiple substations from a single web page. Crossbow's MICA2 Motes, which Avistar built into the sensor enclosures, and the XMesh protocol, available in MoteWorks, form the data backbone within the substation while a Stargate gateway aggregates and serves the data. Compared to installed costs for wired systems, while according to EPRI can range to $1,000/ft., the wireless aspect alone saves thousands of dollars per installation.

Beyond circuit breakers, wireless data transmission and easy Web-based monitoring of that data are becoming their own important solution for monitoring other equipment at a substation. This capability will help utilities optimize maintenance practices, extend equipment life and more quickly determine when a given piece of equipment should be replaced. Anything that contributes to efficiency results in at least some environmental benefit. Avistar's system will be the subject of a national-level EPRI research project in the near term!

The Real Issue...

The following post is taken from DataWeek TechNews and written by a project manager at National Instruments. The article addresses the adoption of wireless sensor networks into mainstream and provides some thoughtful insight into current issues.

While wireless sensors have become a hot topic in recent years, many experts note that they remain underused commercially. Some cite confusion with the numerous proprietary and standard communication protocols as the cause, while others talk about lack of security. Companies such as Crossbow, are beginning to offer wireless sensor hardware that addresses some of those concerns, but one issue still frustrates potential users of this technology - software.Companies that provide hardware solutions typically offer network configuration and monitoring software, but the problem of allowing users to program multiple nodes at once with the same functionality has yet to be well addressed. In addition, the existing software may make sharing data among the nodes in the wireless sensor network simple, but challenges arise when users try to share that data on the rest of the network or publish it to the Web. This article discusses these and other software challenges that wireless sensor network users still face and offers potential solutions to these problems.

The current state of wireless sensor software

The software packages provided by today's wireless sensor vendors include the basics for performing wireless measurements - node configuration and management and data logging and display.

* Node configuration and management: nearly every wireless sensor vendor's software package provides some level of node configuration. For example, with Agile-Link software, a user can add a node to the system, manually put it to sleep or wake it up, and configure how fast it will stream data. Other ssoftware packages, such as Mote-View (Figure 1) from Crossbow Technology, also represent visually where the node is located on a floor plan of your facility. Most software packages also offer information on the state of each node, indicating whether the node is connected to the network and actively transmitting data.

* Data logging and display: all software packages display realtime wireless sensor data on a graph for monitoring purposes, but some such as Agile-Link also provide an interface for the user to set up basic datalogging. The user can then export data to Microsoft Excel or other spreadsheet packages for offline analysis.While these node management software tools are fairly intuitive even for beginners, they typically have fixed capabilities and lack several features that many users view as necessary for wireless sensor networks to be truly useful.

What is still missing

Wireless sensor technology has certainly come a long way in the past decade, but the software for programming and managing these nodes is still missing many of the fundamental pieces that would make it beneficial to real users, not just those experimenting with the technology. These boil down to three high-level features - node intelligence and automation, node aggregation, and integration with the rest of the enterprise.

* Node intelligence and automation: while the software packages mentioned above and others contain some basic features for configuring a node, none of them offer an intuitive method for users to customize their hardware nodes with additional intelligence, such as local analysis. Local analysis facilitates scenarios where higher-power gateway nodes aggregate and process data from several lower-power end nodes and pass minimal information, such as the result of a limit test, back to a central location. Another form of an intelligent node is one that can acquire data very fast (on the order of several kilosamples per second) and store it locally, passing back only parametric data. For example, a node might be embedded in a large machine to monitor its vibration levels. While it may be acquiring a large amount of raw data, it may only need to send a pass or fail indicator to the host indicating whether the machine is within required limits.

Crossbow has addressed this issue with the new Imote2  platform. This platform is a high performance node with local intelligence. It is built around the low power PXA271 XScale processor and integrates an 802.15.4 radio (CC2420) with a built-in 2.4GHz antenna, and it provides an extension board interfaces. The Imote2 delivers the next generation high-performance, high-capacity processor/radio platform that breaks computational and memory limitations of current platforms by orders of magnitude. It provides a high performance platform for advanced, compute intensive wireless sensor network applications such as digital imaging and industrial vibration monitoring.    

Most wireless sensor nodes today are still passive nodes that simply pass back the data they are hard-coded to provide. Very few have built-in intelligence for data analysis or automated power management. Those nodes that do have a way to incorporate additional intelligence use programming interfaces that are not nearly as simple as the node management interface described above, and users must often resort to low-level text-based programming. This is a less than ideal situation for engineers and scientists who may be experts in their fields but who are not embedded programmers.

* Node aggregation: the current node management software may work well for networks of 20 to 30 nodes, but when a government organisation or large corporation wants to implement a network of hundreds or thousands of nodes, the setup becomes extremely time-consuming. At this point, it becomes difficult to program each node individually, so software packages for programming and configuring nodes need to be able to aggregate them into groups and program an entire group at a time with the same function. For instance, an oil company may want to monitor the flow in its pipeline at many points. Since all nodes will essentially perform the same task, monitor flow and log or pass data back to a central location, the company could save time and money if they could program all nodes at once. This node aggregation capability creates a simple interface for developing redundant systems and speeds the configuration of very large networks. Wireless sensor technology cannot scale beyond research and small applications without this feature.

* Integration with the enterprise: before fully adopting wireless sensor technologies, most companies will demand the ability to easily integrate their sensor networks with the rest of the enterprise. This means not just providing a method for datalogging and offline analysis, but also offering a way to pass data directly between a hybrid network of wireless sensors and office systems that use different networking protocols (Figure 2 - Currently, most wireless sensor node data can only be logged to a spreadsheet, and no automated method exists for getting the data to the rest of the enterprise). This, in turn, requires online analysis capabilities. Being able to aggregate this data and provide access to it via a Web server is an optional but often important feature for companies whose employees are spread out across the globe or who want to give multiple internal consumers of the data easy access to it.

Crossbow has successfully demonstrated our ability to provide our customers with the ability to do enterprise integration. Our award winning  deployment with BP (British Petroleum) to do Wireless Sensor Networking for Condition Monitoring of Rotating Equipment on Oil Tankers highlighted the use of motes to tie sensors into a wireless network, which then could pass data to back-end systems. For this particular application, Crossbow provided this enterprise integration with Rockwell Enshare. The project's predictive maintenance system monitored the pumps and motors in the ship's starboard engine room. Nearly 150 accelerometers attached to the machinery provided vibration data to evaluate operating conditions, and wireless motes and gateways delivered the wireless communications used to send alerts when wear and tear was detected. 

A potential solution to much of the problem

Wireless sensor networks may seem to have a long way to go before their software can meet the majority of user needs, but a solution to some of these shortcomings actually exists today. Though it does not yet have the capability to program multiple nodes at once, a currently available software tool offers a way to program nodes, add intelligence, and integrate wireless sensor data with the rest of the enterprise. That tool is National Instruments' LabVIEW, an industry-standard graphical development environment for measurement and automation in the wired world.

* Node intelligence and automation: with the recently-released NI LabVIEW Embedded Development Module, users can program any 32-bit processor and, therefore, any wireless sensor based on a 32-bit processor. Using this tool, wireless sensor vendors can develop drivers for their wireless nodes so end users can program the nodes with LabVIEW. As a result, wireless sensor users can add custom intelligence to their nodes without complex register-level or text-based programming.

* Integration with the enterprise: NI LabVIEW and its toolkits offer compatibility with numerous networking protocols, such as TCP/IP and Bluetooth, and databases, such as Microsoft Access, SQL Server, and Oracle. As a result, a host computer can run a LabVIEW program to aggregate data from multiple wireless sensor nodes and automatically send it to other machines on the network or store it to a database. In addition, LabVIEW Full Development Systems and higher include a built-in Web server, so a host computer can aggregate data from the nodes and serve up the data in realtime to a website that clients of the data can access and even control through their web browser. (Figure 3 - LabVIEW provides database connectivity and a built-in Web server so that wireless sensor node data can easily integrate with the rest of the enterprise.) Even though LabVIEW cannot yet program multiple nodes at once, a user can build a standard configuration, save it, and download it to each node in turn.

Several top universities and many corporations already place heavy emphasis on wireless sensor technology research. As the buzz around wireless sensors continues to grow and hardware platforms and protocols proliferate, the software must scale to meet the needs of users who could most benefit from implementing them. By providing LabVIEW drivers for wireless sensors, manufacturers can open the door to a whole new set of users who require node intelligence and integration with the rest of their enterprises."

Crossbow has worked closely with National Instruments to provide the necessary tools customers need to successfully deploy wireless sensor networks quickly and easily. National Instruments (NI) provides free LABVIEW drivers for Crossbow wireless sensor networks, giving developers working with these devices the ability to fully integrate their wireless sensors into the LabVIEW graphical development environment. This free driver software works with several of the Crossbow sensor boards and includes communication functions and example programs compatible with these sensors. With the help of these drivers,  developers can start reading from their sensors within a matter of minutes, saving them time and resources because they do not have to write custom interfaces themselves. 

Motes in water!

Only in Boston, where the most resilient survive - whether they are running marathons in dangerous weather or having a tea party at sea, the city of Boston has inspired many. At University of Massachusetts, Boston a center has been established to bring together university researchers, business and industry leaders as well as state and federal decision makers to provide an integrated framework for developing environmental sensor networks in coastal areas.

CESN is unique in its development of "smart" underwater networks ranging from ecological to military to recreational. With several deployments at their doorstep in the Boston Harbor, CESN has truly crossed the land-water barrier! Taking advantage of their unique surroundings, CESN has deployments operating in the 900MHz frequency range using Crossbow's MICA2 motes, MDA Mote data acquisition boards coupled with salt marsh moisture sensors, temp, light, sound, humidity, smart cameras, etc...to gather data previously unobtainable in low cost marine data buoys. This testbed of Crossbow Mote based Micro Buoys showcases the ability to integrate sensor modalities and deployment packages into marine environments.

Coastal environmental sensing networks will provide the ability to support environmental decision-making processes - this includes the ability to observe the complex interactions of coastal systems of "hotspots and hot moments" where the nodes can focus on objects and events of interest. Using Crossbow's Stargate platform, researchers have been able to work cooperatively with the USGS to provide visual monitoring of current river stages and dam status. The integration is accomplished using a DSL service with existing USGS phone lines. This allows for high bandwidth data haul to UMASS and the Stargate uplink to receive data from the mesh network environment.CESN is targeting the set-up of a multi-cluster mesh network based on Crossbow's mote and sensor architecture. The possibilities are endless. Where there is a mote...there is a way!

Honey, I've lost the kids!

When I was younger, I remember my mom telling me not to wander too far and to stay close. As I grew older this changed to her asking "Where do you think you're going?" or "Where have you been?" Of course I was always where I was supposed to be...studying hard and not doing anything to warrant her asking those questions! I suppose these questions are typical of a parent wanting to make sure their kids are safe and doing what they are supposed to be doing. But now, it seems like the days of questioning are over! Parents will soon be able to track their children's whereabouts remotely whenever they want to. 

Crossbow's Japan office is working with a customer to develop a system based on Crossbow's MICAz Mote to demonstrate how wireless sensor network products can be used to ensure safety for children and others using ubiquitous networking technologies. The initial system was featured on the news and can be seen in the video below. The Motes were used on school children who had a MICAz Mote attached. The school property was outfitted with MICAz Motes fixed in various locations to provide location data on the child based on the signal strength from their attached Mote. This setup also allowed the teachers to monitor whether a child left the school premises. The perimeter was equipped with MICAz Motes so that if a child left the school property and their signal was detected to have moved in a direction away from the school, the gateway would detect the activity and automatically send an email or text alert to the parent/teacher informing them that their child had exited the school. This was also tested by a group of children on a school field trip. If any student moved out of range from the teacher, there would be a display or sound alert so that the teacher was notified instantly.

So, I guess this means by the time I have kids, I won't be asking the questions - I will be waiting at the door ready to ground them because I would already know about their hiatus that day!

Cover Story - The Economist

It appears the wireless sensor network revolution is continuing to become more and more mainstream. This technology always gets lots of coverage but the image covering the current issue of  The Economist captures the vision Crossbow has for its future. I was over at my parent's house this past weekend and my brother showed me the cover story entitled "When Everything Connects". The article lists how Crossbow is applying the innovations in wireless sensor networks to our existing technologies and moving towards a world where sensors can keep a remote eye on almost anything! 

The article describes the various solutions that wireless sensor networks can provide whether it is for civilian use or military use. The idea of smart sensors scattered throughout a battlefield to warn of danger and provide tactical information, or the ability to use the products as security systems or for environmental/ industrial/ building automation solutions. The applications continue to be endless. With the continued innovations coming from universities/research groups worldwide and the increasing adoption by companies globally, the push to live in a world where everything connects is moving closer and closer to reality.