Description:
The future of manufacturing will include highly adaptive, reconfigurable, and mobile machinery that can interact with and collaborate with humans safely, reconfigure quickly and cost-effectively depending factory needs, and anticipate the situational environment. Mobile robotic work agents will have the ability to move between work cells, reconfigure, and perform tasks within that work-cell. The control systems that operate such factories will require communication technologies for command and control of machines with rapidity, reliability, and timeliness. Wireless protocols such as IEEE 802.11 currently address these requirements singularly but not all of them simultaneously. For example, existing protocols can provide low latency for steaming video at the cost of reliability. Other protocols can provide high reliability using low density parity check codes for forward error correction, but they sacrifice latency. Still others such as IEEE 802.15.4-based protocols offer reliability while sacrificing latency and throughput. New protocols are needed to address reliability (data transaction error rate < 1e-9) and latency (closed-loop sense-to-actuation time < 1ms) simultaneously within a factory work cell with at least ten (10) sensing/actuation devices such as proximity sensors, scanners, and switches. Such a system would address all aspects of the communications system including RF band selection, antenna selection, radio diversity, forward error correction, bandwidth, and interference mitigation. Ideally, the solution would build upon existing physical layer specifications.
This project addresses the wireless requirements of the future factory by developing a solution using existing physical layer technologies such as IEEE 802.11. The project will produce models and simulations of the proposed wireless communications system within a discrete manufacturing work-cell. The proposed communications system will include all aspects of the channel including the antenna system, radio front-ends, baseband processing, and error coding. Study of the proposed solution will include the co-simulation of the wireless communications model with a model of a factory process. Coexistence of the proposed solution with other competing data sources within the factory will be addressed.
Phase I expected results:
Produce a model of the end-to-end communications system with particularly detailed attention placed on the focal point of the model such as the antenna system that addresses the communications reliability requirement (data transaction error rate < 1e-9) while maintaining latency constraints (closed-loop sense-to-actuation time < 1ms).
Phase II expected results:
Produce a working system prototype of the wireless communications system. The hardware prototypes will include all aspects of the system modeled during Phase I. The prototype will include an Ethernet-based port for injecting/extracting sensor/actuator data. The prototype will also include common analog inputs and outputs such as on/off and pulse-width modulation interfaces. The prototypes will be demonstrated within a testbed that emulates the harsh radio frequency environment of the future factory, and may be used to demonstrate a wireless protocol standardization candidate. The prototype design shall demonstrate the commercialization potential of the wireless solution.
The NIST Engineering Lab has conducted several RF measurements campaigns to assess the characteristics of RF propagation within the factory environment. The results of these measurement campaigns which are publically available (http://doi.org/10.18434/T44S3N) include channel impulse responses (magnitude and phase) and can be used to develop novel approaches for wireless communications that are highly reliable and have low latency. In addition, NIST industrial wireless project staff may be available to collaborate with the incumbent as an advisor, provide manufacturing use case examples, and offer test-bed resources including the use of a wireless channel emulator.
