As the use of small satellites for advanced space missions continues to grow, the importance of low mass and cost three-axis attitude stabilization systems increases as well, with these systems requiring high accuracy attitude knowledge. Star trackers provide the most accurate attitude knowledge of any type of attitude sensor, but the high cost, size, and weight of commercial star trackers can be prohibitive to small satellite missions. Many simple star trackers have been developed using commercial off-the-shelf camera sensors and processing hardware, but the challenge remains in testing and characterizing these devices. A common solution is night sky tests, in which the star tracker is held up to the night sky to image the star field and perform attitude determination. Commercial star trackers, on the other hand, are regularly tested with manufacturer provided star field images that attach directly to the sensor. These methods, however, severely limit the sky conditions that can be used in testing. Night sky tests depend on weather and can only image regions of the sky the user has access to, while lab-based testing uses the few provided still images. This thesis presents a hardware-in-the-loop star tracker test bed developed for comprehensive ground-based testing of both in-house and commercial star trackers. The system consists of a small screen to display a star field, a simple in-house camera star tracker, and a microprocessor. This test bed allows any star field image to be simulated. The system is set up for use on a stationary tabletop, but its small size lends itself for use with a spacecraft dynamics platform, which can facilitate testing of control algorithms using real star tracker output.

Integration testing in software refers to a type of tests where system components are tested as a group for the purpose of verifying their interfaces. It is an important phase in system testing which aims at verifying the compliance of the system with specified functional requirements and the elimination of errors in the interaction of system components. Often integration testing is performed on complex systems with additional requirements for the testing approaches wherein the hardware limitations and time delays need to be taken into account. The testing of such systems is commonly performed through hardware-in-the-loop (HIL) tests. Despite the advances in both integration testing and HIL testing, combining the two for complex systems is still a challenging issue requiring a new set of potential solutions. In this thesis work we propose a new solution approach for HIL integration testing of Supervisory Control and Data Acquisition (SCADA) systems which does not require any simulation of the system under test. The solution presented in this thesis is based on the utilization of probes which are deployed to select component interfaces and through which real-time, inter-component communication can be observed without interference. The feasibility of the proposed approach is evaluated by applying it to a proof-of-concept test of the SCADA control system for a wave-energy converter in development by the thesis host company CorPower Ocean. In the results chapter we further discuss the architectural solution of the probing-based approach and provide further implementation details. Our conclusion is that the proposed approach corresponds to a promising, light-weight, and modular testing solution that can be used to perform live software integration tests of a fully connected system with little to no interference on its operation. / Inom mjukvarubranschen är integrationstester en typ av testning där grupper av systemkomponenter testas tillsammans för att säkerställa funktionaliteten av deras gränssnitt. Det är en viktig fas inom systemtestning som försäkrar att systemet som helhet uppfyller designkraven samt som minimerar felrisken i interaktioner mellan delkomponenter. Integrationstester utförs ofta på komplexa system där testningen i sig har ytterligare krav som inskränker metodvalet, till exempel då hänsyn behöver tas till hårdvarubegränsningar eller timing. Ofta genomförs testningen av sådana system med så kallade hardware-in-the-loop-tester (HIL). Trots modern utveckling inom både integrations- och HIL-testning är det fortfarande mycket utmanande att kombinera båda metoderna för komplexa system och nya lösningar behöver utvecklas och utvärderas. I denna avhandling föreslås en ny sådan lösning för HIL-testning av Supervisory Control and Data Acquisition (SCADA) -kontrollsystem som inte kräver att någon del av systemet simuleras under testernas utförande. Lösningen är baseras på användandet av mjukvarusonder som sätts in vid utvalda komponentgränssnitt och som i realtid kan observera interkomponentkommunikation utan störningspåverkan på komponenterna i sig. Den beskrivna lösningen utvärderades genom att utföra en praktisk konceptvalidering mot SCADAkontrollsystemet för avhandlingens värdbolag CorPower Oceans vågenergigenerator. I avhandlingen beskrivs även den arkitekturella lösning som krävdes för att genomföra sonderingsbaserad testning på ett reellt system samt implementationsdetaljer för konceptvalideringen. Slutsatsen är att den föreslagna lösningen beskriver en lovande och modulär testningsmetodik som kan användas för att genomföra mjukvaruintegrationstester av komplexa, sammankopplade system i realtid, utan simuleringar och utan betydande störningspåverkan på systemets operation