Online Built-In Self-Test Architecture for Automated Testing of a Solar Tracking Equipment

This paper presents an Online Built-In Self-Test (OBIST) architecture which is tailored towards the detection of hardware faults found in solar tracking systems. The goal of the proposed OBIST is two-folded: first, we identify the idle states of the electrical equipment that orients the payload of a dual-axis solar tracker to the maximum sun exposure with the support of an idle state detector which requires minimum hardware overhead; secondly, when the solar tracking device is in idle state, we disconnect its Circuits Under Test (CUTs) consisting of one Optocoupler, one Arduino UNO and two L298N motor drivers from the main data flow stream (initially connected directly to the solar panel) and attach the proposed OBIST equipment via dedicated switches in order to inject test vectors and collect their output signals in a signature-based response manner. The experimental results based on our hardware implementation and software simulation achieve an average of 93.93% coverage for single bit-flip errors (last 8 bits, mutant), 100% coverage for single stuck-at-faults (8, 12 and 16 random bits) as well as 96.96% for all targeted faults, showing that the proposed OBIST architecture is efficient with regard to test coverage and cost points of view.