Modelling cyclists’ comfort zones from obstacle avoidance manoeuvres

This paper introduces a framework for modelling the cyclist’s comfort zone. Unlike the driver’s comfort zone, little is known about the cyclist’s. The framework draws on existing literature in cognitive science about driver behaviour to explain experimental results from cycling field trials, and the modelling of these results. We modelled braking and steering manoeuvres from field data of cyclists’ obstacle avoidance within their comfort zone. Results show that when cyclists avoided obstacles by braking, they kept a constant deceleration; as speed increased, they started to brake earlier, farther from the obstacle, maintaining an almost constant time to collision. When cyclists avoided obstacles by steering, they maintained a constant distance from the object, independent of speed. Overall, the higher the speed, the more the steering manoeuvres were temporally delayed compared to braking manoeuvres. We discuss these results and other similarities between cyclist and driver behaviour during obstacle avoidance. Implications for the design of acceptable active safety and infrastructure design are also addressed

Development of an ADAS function for combined adaptive cruise control and lane keeping assist up to highway speeds

Due to the need of higher control strategies for the viability of autonomous vehicles on an ever changing environment, this thesis will cover the development of an autonomous vehicle simulation considering longitudinal control from an Adaptive Cruise Controller (ACC) and lateral control from a Lane Keeping Assist (LKA) controller. The implementation of the control model and code will be made in Simulink and Matlab and simulated using the virtual testing software IPG CarMaker. The vehicle simulated is a Volkswagen Beetle equipped with two sensors. For the ACC, a radar sensor is placed at the front bumper providing relevant information about the preceding traffic object, in particular, the presence of an object and the relative distance and velocity. On the other hand, a line sensor is placed behind the windshield rear-view mirror to monitor the lane bounds and provide the relative position of the lane with respect to the sensor. A line sensor, essentially, emulates a camera sensor with some image processing layers capable of reliably detect lines. To enable longitudinal control, the Intelligent Driver Model calculates the desired acceleration by comparing the desired ego car speed with the actual value. Also, it compares the actual relative distance to a desired distance calculated by considering a standstill gap, a desired time gap at a certain speed and the relative velocity with a preceding vehicle. This model though does not precisely track the relative distance when approaching the desired speed. To address this issue, an algorithm that enables this functionality is implemented monitoring the relative velocity beyond the speed limit to avoid undesired driving conditions. On the other hand, lateral control is achieved by considering both degrees of freedom of a four wheeled vehicle, yaw angle and lateral deviation from the lane centreline. For this, Catmull-Rom curves are fitted in the lane centre to measure both magnitudes and compare them to their ego vehicle’s respective values. Then, both errors are fed to their respective PID controllers and combined into one signal to command the steering angle of the vehicle. Combining both functionalities results in loss of acceleration control for approaching curves and, thus, a method for such task is developed. The algorithm consists in monitoring the curvature of a moving point on the fitted curves and modify the desired speed inversely proportional to it. Finally, a safety measure is implemented for instances where a preceding vehicle disappears from the radar sensor scope. By monitoring the intersection of the path with the sensor cone, the ego vehicle expects a vehicle to enter the radar scope through that point and adapts the acceleration accordingly. To evaluate the performance of the controller, several test cases are executed both assessing the ACC and LKA capabilities by its own, and the combined implementation. For this, synthetic and real life scenarios are tested with and without traffi

Integration of Autonomous UAVs into Multi-agent Simulation

In recent years, Unmanned Aerial Vehicles (UAVs) have attracted much attention both in the research field and in the field of commercial deployment. Researchers recently started to study problems and opportunities connected with the usage, deployment and operation of teams of multiple autonomous UAVs. These multi-UAV scenarios are by their nature well suited to be modelled and simulated as multi-agent systems. In this paper we present solutions to the problems that we had to deal with in the process of integrating two hardware UAVs into an existing multi-agent simulation system with additional virtual UAVs, resulting in a mixed reality system where hardware UAVs and virtual UAVs can co-exist, coordinate their flight and cooperate on common tasks. Hardware UAVs are capable of on-board planning and reasoning, and can cooperate and coordinate their movement with one another, and also with virtual UAVs

Report on the Workshop held at the University of Leeds on 6 November organised on behalf of the Transport Sub-Committee of the Environment Committee of the Science and Engineering Research Council

The meeting was the second in a series of three; called to review the prospects for future development of the Special Programme in the Application of Information Technology to Transport set up by the Transport Sub-committee of the Science and Engineering Research Council (SERC). The other seminars were: at University College London on Traffic Engineering Applications; held in July 1986; and at the University of Newcastle up Tyne, on Public Transport Information Systems, held in December 1986. The objectives of the workshop were to (i) review current perceptions of and future prospects for the role of expert systems in transport; and (ii) provide such feed-back to the SERC Transport Sub-committee as would assist it in forming a view about future work in this area. (Continues..

Report on the Workshop held at the University of Leeds on 6 November organised on behalf of the Transport Sub-Committee of the Environment Committee of the Science and Engineering Research Council

The meeting was the second in a series of three; called to review the prospects for future development of the Special Programme in the Application of Information Technology to Transport set up by the Transport Sub-committee of the Science and Engineering Research Council (SERC). The other seminars were: at University College London on Traffic Engineering Applications; held in July 1986; and at the University of Newcastle up Tyne, on Public Transport Information Systems, held in December 1986. The objectives of the workshop were to (i) review current perceptions of and future prospects for the role of expert systems in transport; and (ii) provide such feed-back to the SERC Transport Sub-committee as would assist it in forming a view about future work in this area. (Continues..

Full Automation of Air Traffic Management in High Complexity Airspace

The thesis is that automation of en-route Air Traffic Management in high complexity airspace can be achieved with a combination of automated tactic planning in a look-ahead time horizon of up to two hours complemented with automated tactic conflict resolution functions. The literature review reveals that no significant results have yet been obtained and that full automation could be approached with a complementary integration of automated tactic resolutions AND planning. The focus shifts to ‘planning for capacity’ and ‘planning for resolution’ and also – but not only – for ‘resolution’. The work encompasses a theoretical part on planning, and several small scale studies of empirical, mathematical or simulated nature. The theoretical part of the thesis on planning under uncertainties attempts to conceive a theoretical model which abstracts specificities of planning in Air Traffic Management into a generic planning model. The resulting abstract model treats entities like the planner, the strategy, the plan and the actions, always considering the impact of uncertainties. The work innovates in specifying many links from the theory to the application in planning of air traffic management, and especially the new fields of tactical capacity management. The second main part of the thesis comprises smaller self-containing works on different aspects of the concept grouped into a section on complexity, another on tactic planning actions, and the last on planners. The produced studies are about empirical measures of conflicts and conflict densities to get a better understanding of the complexity of air traffic; studies on traffic organisation using tactical manoeuvres like speed control, lateral offset and tactical direct using fast time simulation; and studies on airspace design like sector optimisation, dynamic sectorisation and its optimisation using optimisation techniques. In conclusion it is believed that this work will contribute to further automation attempts especially by its innovative focus which is on planning, base on a theory of planning, and its findings already influence newer developments

A study on vehicle Noise Emission Modelling: correlation with air pollutant emissions, impact of kinematic variables and critical hotspots

This work proposes a methodology suitable for analysing the sound power levels (Lw), and carbon dioxide (CO2) and nitrogen oxides (NOx) emissions along a travel, and consequentially assessing the related critical hotspots. The estimation of noise and pollutant emissions from six vehicles driven along three different routes (one National Road and two highways) was conducted, in combined way, through seven Noise Emissions Models (NEMs) and Vehicle Specific Power (VSP) methodology, respectively. The inputs required by the models (namely, vehicle speed and acceleration and road grade) were extrapolated from On-Board Diagnostic (OBD) system and Global Positioning System (GPS) data recorded during monitoring campaigns. The specificities of each model were analysed, and the role played by the kinematic variables in noise and exhaust emissions assessment was highlighted. Results show that all the tested NEMs estimated higher noise levels on the highways, while VSP predicted higher emissions on the National Road. This happens because speed is the main input variable in NEMs, while acceleration has an impact on noise estimation in the low-speed range (below 50 km/h). For pollutant emissions evaluation, acceleration plays a fundamental role also at high-speed range, where a transition from a cruising condition to an acceleration phase leads to significant variations in terms of VSP values. Lw values, estimated with NEMs that use acceleration correction terms, present positive moderate-to-high correlation with VSP ones. Moreover, the models that neglect acceleration in noise estimation fail to recognize traffic control treatments as critical hotspots.A. Pascale acknowledges the support of FCT for the Scholarship 2020.05106.BD.publishe