Abstract :
Intelligent wireless sensor-based controls have drawn industry attention on account of reduced costs, better power management, ease in maintenance, and effortless deployment in remote and hard-to-reach areas. They have been successfully deployed in many industrial applications such as maintenance, monitoring, control, security, etc. This presentation focuses on research that addresses the issues faced by instrumentation systems and predictive maintenance industrial applications and presents a design solution to cater to the issues faced by these applications. Instrumentation systems are either open or closed loop control systems formed using sensors and actuators with the objective of controlling certain parameters, or state of the system. The system elements are always in communication with each other, typically, requiring real-time performance and built-in fault-tolerance for communication/node failure-to return to a safe-state in a deterministic amount of time. Predictive-maintenance involves tracking physical state of equipment or machine, and to take action, if an acceptable or allowed state(s) is violated. Predictive-maintenance applications are not active all the time in Order to conserve energy. The sensors are either periodic or event-based; they wake up, check status and go back to sleep. In case of any violation, they raise an alarm or record the digression. They are very useful in keeping machine downtimes low and help locate the problem before the machine breaks down. Typical systems employ different types of sensors (e.g., position, accelerometers, gyros, etc.) and actuators (e.g., motors) often deployed within the same network, having different capabilities, interfaces, and supporting different protocols for data and communications. Formation of systems from such diverse distributed sensor elements entails versatile control modules, which understand different sensor protocols and utilize them. In addition, the operational challenges are exacerbated wh- en different RF links have to be used to satisfy the requirements of bandwidth, payload, delay, jitter, range, noise immunity and others (including cost) for communication. The Smart Sensor Platform discussed in this presentation is an attempt to develop a generic platform with a "plug-and-play" capability to support hardware interface, payload and communications needs of multiple inertial and position sensors, and actuators/motors used in instrumentation systems and predictive maintenance applications. Communication is carried out using a RF link (Wi-Fi, Bluetooth, Mote or RFID), in a point-to-point topology. The design also provides means to update operating and monitoring parameters, and thresholds as well as sensor and RF link specific firmware modules "over-the-air". It is composed of two main components - a sensor-wireless hardware interface and system integration framework, which facilitates the defining of interaction between sensors/actuators based on process needs. The intelligence necessary to process the sensor signals, monitor the functions against defined operational templates, and enable swapping of sensor and RF link re! sides on the micro controller of the hardware interface. A variety of industrial motion sensors like gyroscopes, Inertial Measurement Units (IMU), linear position sensors, absolute and incremental encoders and Brush less DC motors, have been interfaced and successfully tested with the platform.
