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At Epiroc’s drill rigs a safe system is installed to make sure the vehicle is driven in a safe manner. In the development both machine tests and hardware-in-the-loop (HIL) tests have been performed but when changes are made the firmware in the safe modules has to be updated. To speed up the process a digital twin would be beneficial. This enables testing of parameters and formulation of criteria detecting faults. The purpose of the work is to develop a digital twin for steering and braking safe functions and evaluate the performance using data from machines as well as data from a HIL-rig. Also, the impact of the hydraulic model used in the HIL-rig is investigated. When the model is built two test cases are used to investigate how well the model replicates the behaviour of the real system and how sensitive it is to what input data is used. The biggest difference in the data is the sampling time, machine logs have 80 ms interval while logs from the rig are logged every 5 ms. It is discovered that some of the fault detection functions work very well no matter what data is used while others must have the better resolution to be trusted. The complexity of the hydraulic model used impacts the pressures but seem to have little effect on which fault codes are activated. With this the main purpose is partly achieved and further investigation is needed before the model can be used for all fault codes.

In this paper, the architecture and implementation of an embedded controller for a steering based semi-autonomous collision avoidance system on a 1/10th scale model is presented. In addition, the development of a 2D hardware-in-the-loop simulator with vehicle dynamics based on the bicycle model is described. The semi-autonomous collision avoidance software is fully contained onboard a single-board computer running embedded GNU/Linux. To eliminate any wired tethers that limit the system’s abilities, the driver operates the vehicle at a user-control-station through a wireless Bluetooth interface. The user-control-station is outfitted with a game-controller that provides standard steering wheel and pedal controls along with a television monitor equipped with a wireless video receiver in order to provide a real-time driver’s perspective video feed. The hardware-in-the-loop simulator was developed in order to aid in the evaluation and further development of the semi-autonomous collision avoidance algorithms. In addition, a post analysis tool was created to numerically and visually inspect the controller’s responses. The ultimate goal of this project was to create a wireless 1/10th scale collision avoidance research platform to facilitate human studies surrounding driver assistance and active safety systems in automobiles. This thesis is a continuation of work done by numerous Cal Poly undergraduate and graduate students.

The automatic creation of test cases has been a well-researched area in recent years. Indeed, the industry’s testing procedure still uses the traditional way of manual practices. However, investigations are continued to deliver new methods, but research results have not been fully adopted. In this paper, the investigated method applies the model-based testing (MBT) method to evaluate the ability to automate the creation of hardware-in-the-loop (HIL) test cases, where generated tests are created using MBT tools. The tools’ properties were compared to each other through a literature study, with the result of selecting tools to be used in a case study, and the tools selected were GraphWalker and MoMuT. The generated test cases perform similarly to their manual counterparts regarding how the test cases achieved full requirements coverage. When comparing the effort needed for applying the methods, a comparable effort is required for creating the first iteration, while with every subsequent update, MBT will require less effort compared to the manual process. Both methods achieve 100% requirements coverage, and since manual testing is created and executed by humans, some requirements are favoured over others due to company demands, while MBT tests will be generated randomly.In addition, a comparison between the used tools showcased the differences in the models’ design and their test case generation. The comparison showed that GraphWalker has a more straightforward design method and is better suited for smaller systems, while’s MoMuT can handle more complex systems but has a more involved design method.The results of the thesis showed that using MBT tools proved helpful as it covers the system requirements, can be executed in HIL and helps discover faults within the requirements and HIL system. These facts satisfy the companies’ demands. This thesis shows a promising improvement in automating the test process within the vehicular domain.

This thesis aimed to develop a rendezvous and proximity operation simulation to be tested with physical sensors and hardware, in order to assess the fidelity and performance of low-cost off-the-shelf systems for a hardware-in-the-loop testbed. With the push towards complex autonomous rendezvous missions, a low barrier to entry spacecraft simulator platform allows researchers to test and validate robotics systems, sensors, and algorithms for space applications, without investing in multimillion dollar equipment. This thesis conducted drone flights that followed a representative rendezvous trajectory while collecting lidar data of a target spacecraft model with a lidar sensor affixed to the drone. A relative orbital motion simulation tool was developed to create trajectories of varying orbits and initial conditions, and a representative trajectory was selected for use in drone flights. Two 3D tracking systems, OptiTrack and Vive, were assessed during these flights. OptiTrack is a high-cost state-of-the-art motion capture system that performs pose estimation by tracking reflective markers on a target in the tracking area. Vive is a lower-cost tracking system whose base stations emit lasers for its tracker to detect. Data collection by two lidar types was also assessed during these flights: real lidar data from a physical sensor, and virtual lidar data from a virtual sensor in a virtual environment. Drone flights were therefore performed in these four configurations of tracking system and lidar type, to directly compare the performance of higher-cost configurations with lower-cost configurations. The errors between the tracked drone position time history and the target position time history were analyzed, and the low-cost Vive and real lidar configuration was demonstrated to provide comparable error to the OptiTrack and real lidar configuration because of the dominance of the drone controller error over the tracking system error. In addition, lidar data of a target satellite model was collected by real and virtual lidar sensors during these flights, and point clouds were successfully generated. The resulting point clouds were compared by visualizing the data and noting the characteristics of real lidar data and its error, and how it compared to idealized virtual lidar data of a virtual target satellite model. The resulting real-world data characteristics were found to be modellable which can then be used for more robust simulation development within virtual reality. These results demonstrated that low-cost and open-source hardware and software provide satisfactory results for simulating this kind of spacecraft mission and capturing useful and usable data. / Master of Science / As space missions become more complex, there is a need for lower-cost, more accessible spacecraft simulation platforms that can test and validate hardware and software on the ground for a space-based mission. In this thesis, two position tracking systems and two lidar data collection types were assessed to see if the performance of a low-cost tracking system was comparable to a high-cost tracking system for a space-based simulation. The tracking systems tested were the high-cost state-of-the-art OptiTrack system and the low-cost Vive system. The two types of lidar data collected were real lidar from a physical sensor and virtual lidar from a virtual sensor. These assessments were performed in four configurations, to test each configuration of tracking system and lidar type. First, a simulation tool was developed to simulate the orbital dynamics of a spacecraft that operates in proximity to another spacecraft. After choosing an orbit and initial conditions that represent one such potential mission, the resulting trajectory was uploaded to a drone which acted as a surrogate for a spacecraft, and it flew the uploaded route around a model satellite, collecting lidar data in the process with a lidar sensor affixed to the drone. The tracking systems provided the drone with its position data, and the lidar sensor on the drone collected lidar data of a model satellite as it flew. The data revealed that the low-cost tracking system performance was comparable to the high-cost tracking system because the drone's controller error dominated over the tracking system errors. Additionally, the low-cost drone and physical lidar sensor generated high quality point cloud data that captured the geometry of the target satellite and illustrated the characteristics of real-world lidar data and its errors. These results demonstrated that low-cost and open-source hardware and software provide satisfactory results for simulating this kind of spacecraft mission and capturing useful and usable data.

This thesis explores the application of the Virtual Test Bed (VTB) and its real-time extension, VTB-RT, for protective relay modeling, simulation, and testing. An instantaneous overcurrent relay model was developed in VTB for a transmission line protection. The same relay model was built in Matlab/Simulink for validation purposes. Both models were tested for various fault conditions on a radial power system and results were compared. Moreover, a low cost real-time Hardware-In-the-Loop (HIL) simulation platform was implemented for relay model testing using VTB-RT and public domain software packages such as Real-Time Application Interface (RTAI), Comedi, and Comedilib, and notebook computer hardware. The applicability of VTB-RT was verified through an open-loop simulation and a HIL simulation of a simple dynamic system using dSPACE as the control hardware and NI DAQCard-6062E as the input/output interface. Simulation results are presented showing the effectiveness of the VTB-RT platform for model testing.

A shipboard power system (SPS) should be stable and reliable in order to ensure that the ship has better fight-through capability and increased fault invulnerability. The protection system is designed to minimize the effects of faults in the SPS, which presents challenges, such as increased fault vulnerability and lack of an electrical ground in the system. If protection devices are not updated after power system reconfiguration, they may not protect the power system appropriately. Therefore the development of elaborate digital protection devices for the SPS is required. This thesis focuses on the model-based methodology for designing a protection scheme for SPS based on instantaneous overcurrent digital relays. To achieve this, an instantaneous overcurrent relay model is first developed in MATLAB/Simulink. Then, the Simulink model is downloaded to the DSP-based platform dSPACE, which runs the Simulink model in real-time, to perform hardware-in-the-loop testing (HIL). Thus, through the dSPACE hardware, the proposed relay model is tested for various fault conditions in three HIL platforms. Different electromagnetic transient real-time digital simulators are used to simulate the SPS, to which protection is provided through the relay modeled in dSPACE. Simulation results from these three HIL platforms demonstrate that the proposed overcurrent relay model was successfully modeled, simulated and tested using various tools for model-based design. Testing results show that the developed model can work with different real-time platforms, and that in contrast to a commercial relay, the developed relay model has increased flexibility because settings such as reclose delay and pickup value can be changed online. This feature can be used to develop an advanced relay model with a dynamic pickup value. An advanced relay model will be useful for the SPS, because such system is subject to topological changes and reconfiguration that are not as prevalent in other types of power systems.

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