Since forward collision is one of the most common and dangerous types of traffic accidents, many studies and researches have been conducted to develop forward collision avoidance system. To facilitate the tradeoff between comfort and safety for forward collision avoidance, the driver's state needs to be monitored and estimated. Such support is necessary for Forward Collision Warning (FCW) system given human-involved control. Due to the advances of Driver Monitoring System (DMS), the demand for camera-based driver's state estimation has increased. This master thesis project, conducted at Zenuity AB, investigates a method to estimate driver's awareness based on DMS. The estimation of a driver's awareness is expected to help adapt FCW system based on visual attention when facing the unpredictable braking of the leading vehicle. The project consists of three tasks: gaze estimation, Gaze-to-Object Mapping (GTOM), and awareness estimation. A combined Kalman Filter was developed in gaze estimation for compensation of missing data and outliers and reducing the difference to “ground truth” data. The uncertainty matrix from gaze estimation was utilized to extract a gaze-to-object probability signal in GTOM, while the corresponding fixation duration was also obtained in GTOM. The two extracted new features were used in awareness estimation with two methods: Logistic Regression and two-Hidden Markov Model. The comparison between the two methods reveals whether a complex method is preferred or not. Based on the results of this project, Logistic Regression seems to perform better in driver's state estimation, with 92.0% accuracy and 76.3% True Negative rate. However, further research and improvements on the two-Hidden Markov Model are needed to reach a more comprehensive conclusion. The main contribution of this project is an investigation of an end-to-end method for driver's awareness estimation and thereby an identification of challenges for further studies. / Frontkollision (forward collision) är en av de vanligaste och farligaste typerna av trafikolyckor. Många studier och undersökningar har genomförts för att utveckla system för att undvika kollisioner. För att underlätta avvägningar mellan komfort och säkerhet för att undvika Frontkollision måste förarens tillstånd övervakas och skattas. Ett sådant stöd är nödvändigt för Forward Collision Warning (FCW) systemet, som involverar interaktion med människor. Efterfrågan på kamerabaserad uppskattning för föraren har ökat på grund av framsteg Driver Monitoring System (DMS). Det här examensarbete genomfördes på Zenuity AB och undersökte en metod för att skatta förarens medvetenhet baserad på Driver Monitoring System. Uppskattningen av förarens medvetenhet förväntas bidra till att anpassa FCW-systemet. Detta FCW-system är baserat på visuell uppmärksamhet om när oförutsägbar bromsning av det framförvarande fordonet sker. Examensarbetet består av tre uppgifter: blickuppskattning, Gaze-to-Object Mapping (GTOM), och medventenhetsuppskattning. Ett kombinerat Kalman-filter har utvecklats i gaze uppskattning för att kompensera saknade data och outliers samt reducera skillnaden till “ground truth” data. Osäkerhetesmatrisen från gaze uppskattningen användes för att extrahera en gaze-to-object sannolikhetssignal i GTOM. Den motsvarande fixeringsvaraktigheten erhålls också i GTOM. De två extraherade nya egenskaperna användes i medvetenhetsanalys med hjälp av två metoder: logistic regression och two-Hidden Markov Model. Jämförelsen mellan de två metoderna avslöjar om en komplex metod är att föredra eller inte. Resultatet av detta examensarbet visar att logistic regression fungerar bättre i förarens statusuppskattning med 92% noggrannhet och 76.3% True Negative rate. Vidare forskning och förbättringar av den two-hidden Markov modell behövs för att dra en mer omfattande slutsats. Det huvudsakliga bidraget av examensarbetet är en utforskning av en end-to-end metod för att uppskatta förarens medvetenhet och därmed kunna identifiera utmaningar för framtid studie.

During monitoring of rear-mounted equipment, frequent rearward turning of tractor drivers in awkward postures can cause musculoskeletal disorders related to the back, neck, and shoulders. A camera-based monitoring system, consisting of one or more cameras placed on the implement and a monitor placed inside the tractor cab, has potential ergonomic benefits compared with traditional implement monitoring strategies by reducing the rearward turning and twisting movements of tractor drivers. A camera-based monitoring system was compared with two traditional monitoring strategies (direct looking and using rear-view mirrors) in a lab environment using a Tractor Air-Seeder Driving Simulator. The operator’s reaction time and response errors, head/neck movement (acceleration), and neck muscle temperature were compared for the three monitoring strategies. The camera-based monitoring system yielded significantly (α=0.05) better outcomes in terms of acceleration and muscle temperature values. No significant difference was observed for response errors.

During monitoring of rear-mounted equipment, frequent rearward turning of tractor drivers in awkward postures can cause musculoskeletal disorders related to the back, neck, and shoulders. A camera-based monitoring system, consisting of one or more cameras placed on the implement and a monitor placed inside the tractor cab, has potential ergonomic benefits compared with traditional implement monitoring strategies by reducing the rearward turning and twisting movements of tractor drivers. A camera-based monitoring system was compared with two traditional monitoring strategies (direct looking and using rear-view mirrors) in a lab environment using a Tractor Air-Seeder Driving Simulator. The operator’s reaction time and response errors, head/neck movement (acceleration), and neck muscle temperature were compared for the three monitoring strategies. The camera-based monitoring system yielded significantly (α=0.05) better outcomes in terms of acceleration and muscle temperature values. No significant difference was observed for response errors.

Blind source separation (BSS) aims at separating useful signal content from distortions. In the contactless acquisition of vital signs by means of the camera-based photoplethysmogram (cbPPG), BSS has evolved the most widely used approach to extract the cardiac pulse. Despite its frequent application, there is no consensus about the optimal usage of BSS and its general benefit. This contribution investigates the performance of BSS to enhance the cardiac pulse from cbPPGs in dependency to varying input data characteristics. The BSS input conditions are controlled by an automated spatial preselection routine of regions of interest. Input data of different characteristics (wavelength, dominant frequency, and signal quality) from 18 postoperative cardiovascular patients are processed with standard BSS techniques, namely principal component analysis (PCA) and independent component analysis (ICA). The effect of BSS is assessed by the spectral signal-tonoise ratio (SNR) of the cardiac pulse. The preselection of cbPPGs, appears beneficial providing higher SNR compared to standard cbPPGs. Both, PCA and ICA yielded better outcomes by using monochrome inputs (green wavelength) instead of inputs of different wavelengths. PCA outperforms ICA for more homogeneous input signals. Moreover, for high input SNR, the application of ICA using standard contrast is likely to decrease the SNR.