Sensors and Actuators Integration in Embedded Systems

Sensors and actuators are critical components of several embedded systems (ES) and can trigger the incidence of catastrophic events [1-3]. Sensor and actuator faults detection is difficult [2, 3] and impacts critically the system performance. While integrating sensors and actuators with the rest of (sub) system, there is a need to identify all failure modes and rectify them. Several researchers have addressed software integration issues [6, 7]; however sensors and actuators integration issues were not addressed so far. This paper focuses on the problem of integration testing of sensors and actuators in ES. A fault model, applicable to both sensors and actuators is proposed based on embedded system model in [12] and some of the observed faults are described. They are similar to the control flow and data flow faults [10]. The integration testing of sensor / actuator within ES is the problem of diagnosing faulty machine in a sequence of two CFSM [11]. For solving the diagnostic methodology [13] is used. The integration testing of sensors / actuators is a subset of general diagnostic problem. The sensor/actuator integration method is described with an example and shows that solution exists for the case of integration. Manifestation of faults in real interfaces is described from integration point of view.