Rollover prevention system dedicated to ATVs on natural ground

In this paper, an algorithm dedicated to light ATVs, which estimates and anticipates the rollover, is proposed. It is based on the on-line estimation of the Lateral Load Transfer (LLT), allowing the evaluation of dynamic instabilities. The LLT is computed thanks to a dynamical model split into two 2D projections. Relying on this representation and a low cost perception system, an observer is proposed to estimate on-line the terrain properties (grip conditions and slope), then allowing to deduce accurately the risk of instability. Associated to a predictive control algorithm, based on the extrapolation of riders action, the risk can be anticipated, enabling to warn the pilot and to consider the implementation of active actions

리스크 필드 접근법을 활용한 고속도로의 일반화된 주행위험 평가기법 개발

학위논문(박사) -- 서울대학교대학원 : 공과대학 건설환경공학부, 2023. 2. 김동규.This study provides a generalized method, which visually captures multiple conflicts in various scenarios, for assessing the driving risk encountered by on-road vehicles for driver support and automation systems. To this end, this study employs risk field theory. The risk field approach defines any obstacle to a vehicle as a finite scalar field using the predictive position of the obstacle. This study proposes a modified risk field called the conflict field that captures the drivers subjective risk perception to quantify the level of conflict. The proposed conflict field provides a visually intuitive basis to assess the extent of the conflict and proactively quantifies the risk of the situation in real-time This study compares the proposed method with existing conflict measures for three driving situations (i.e., car-following, yielding, and lane changing) using highway naturalistic driving data. As a result, the proposed method imposes a higher risk for multiple risky interactions than for a single risky interaction and is generally consistent with post-encroachment time (PET). Lastly, a sensitivity analysis investigates the parameters assumption and the predictive positions bias and variance. The major innovative aspect of this study is to simultaneously assess the various types of multiple conflicts with adjacent vehicles and provide their potential conflict locations. Therefore, the proposed driving risk assessment method can provide robust and stable safety criteria for the autonomous vehicle system in a generalized way.본 연구는 운전자 지원 및 자율주행 시스템에서 차량이 직면하는 주행상황의 위험을 평가하기 위해 고속도로에서 발생할 수 있는 시나리오에서 여러 차량과의 충돌을 시각적으로 포착하는 일반화된 방법을 제공한다. 이를 위해, 본 연구는 장이론 기반의 접근법을 활용한다. 리스크 필드 접근법은 장애물의 예측 위치를 사용하여 장애물이 발산하는 위험감을 나타내는 장을 스칼라 필드(리스크 필드)로 정의한다. 물체들에서 발생되는 리스크 필드의 중첩에 의해 발생하는 상충의 강도을 정량화하기 위해 운전자의 주관적 위험 인식을 포착하는 상충 필드라는 수정된 위험 필드를 제안한다. 제안된 상충 필드는 충돌의 정도를 평가할 수 있는 시각적으로 직관적인 근거를 제공하고 실시간으로 주행상황의 위험을 선제적으로 정량화할 수 있다. 제안된 방법론을 검증하기 위해 고속도로 주행 데이터를 사용하여 세 가지 주행 상황(즉, 차량 추종, 양보 및 차선 변경)에 대한 기존 안전성 평가방법론과 비교했다. 결과적으로 제안된 방법은 단일 위험 상호 작용보다 여러 위험 상호 작용에 더 높은 위험을 가지는 것으로 평가하며 일반적으로 PET와 일관된 결과를 도출한다. 마지막으로, 민감도 분석을 통해 주요 모수의 가정과 예측 모형에서 발생한 편향과 분산에의 영향을 평가하였다. 본 연구의 주된 학술적인 기여는 인접 차량과의 다양한 유형의 다중 충돌 상황을 동시에 평가하고 잠재적 충돌 위치를 제공하는 것이다. 또한 제안된 운전 위험 평가 방법은 통합되고 일반화된 방식으로 자율주행차 시스템에 효과적이고 안정적인 안전 기준을 제공함으로서 자율주행 산업에 있어서 기여할 수 있을 것으로 기대된다.Chapter 1. Introduction １ 1.1. Background １ 1.2. Study goals and objectives ６ Chapter 2. Literature Review ８ 2.1. Surrogate safety of measures (SSM) ８ 2.2. Field theory-based risk assessment １９ Chapter 3. Method ３０ 3.1. Risk field concept ３０ 3.2. Risk field design ３３ 3.3. RSCF and Approximation ４２ 3.4. Prediction model ４４ Chapter 3. Data ５１ 3.1. Data Acquisition and Preprocessing ５１ 3.2. Test scenario choice ５２ Chapter 4. Results ５８ 4.1. Overview of test scenarios ５８ 4.2. Comparison with SSMs ６１ 4.3. Risk homeostasis ６８ 4.3. Sensitivity Analysis ７４ Chapter 5. Conclusions and Future research ８２ 6.1. Conclusion ８２ 6.2. Future research ８４ Reference ８５ 초록 ９３ Acknowledgement ９５박

A QFD framework for quality, innovation and high-tech product development dynamics

The customer mostly chooses a product on the base of its quality, which therefore arises as the main cause of its commercial success. In a nearly axiomatic drawing, it follows that the effect of innovation is the improvement of quality, which itself becomes the aim of innovation. Even though the previous statement relates quality and innovation, it still does not explain their dynamics. To stress them, the ‘quality' concept must be analyzed in more detail. In fact, in addition to the ‘perceived quality', the quality ensured through `design, manufacturing and marketing' combined domains should be dealt with. This paper enhances this issue taking advantage of principles and models made available by control theory schemes coupled with quality function development (QFD) and best practice software modeling based on unified modeling language (UML

On-line estimation of a stability metric including grip conditions and slope: Application to rollover prevention for all-terrain vehicles

International audienceRollover is the principal cause of serious accidents for All-Terrain Vehicles (ATV), especially for light vehicles (e.g.quad bikes). In order to reduce this risk, the development of active devices, contributes a promising solution. With this aim, this paper proposes an algorithm allowing to predict the rollover risk, by means of an on-line estimation of a stability criterion. Among several rollover indicators, the Lateral Load Transfer (LLT) has been chosen because its estimation needs only low cost sensing equipment compared to the price of a light ATV. An adapted backstepping observer associated to a bicycle model is first developed, allowing the estimation of the grip conditions. In addition, the lateral slope is estimated thanks to a classical Kalman filter relying on measured acceleration and roll rate. Then, an expression of the LLT is derived from a roll model taking into account the grip conditions and the slope. Finally, the LLT value is anticipated by means of a prediction algorithm. The capabilities of this system are investigated thanks to full scale experiments with a quad bike

Development of multi-functional streetscape green infrastructure using a performance index approach

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.This paper presents a performance evaluation framework for streetscape vegetation. A performance index (PI) is conceived using the following seven traits, specific to the street environments – Pollution Flux Potential (PFP), Carbon Sequestration Potential (CSP), Thermal Comfort Potential (TCP), Noise Attenuation Potential (NAP), Biomass Energy Potential (BEP), Environmental Stress Tolerance (EST) and Crown Projection Factor (CPF). Its application is demonstrated through a case study using fifteen street vegetation species from the UK, utilising a combination of direct field measurements and inventoried literature data. Our results indicate greater preference to small-to-medium size trees and evergreen shrubs over larger trees for streetscaping. The proposed PI approach can be potentially applied two-fold: one, for evaluation of the performance of the existing street vegetation, facilitating the prospects for further improving them through management strategies and better species selection; two, for planning new streetscapes and multi-functional biomass as part of extending the green urban infrastructure

Climate change adaptation in industry and business

This report delivers a best practice framework to integrate financial risk assessment, governance and disclosure with existing governance principles around climate change adaptation.AbstractThe Australian business community has long been aware of the risks and opportunities associated with greenhouse gas mitigation and climate change policies. Some businesses have taken initial steps to adapt to the expected effects of climate change; however, most enterprises are only vaguely aware of the breadth of adaptation that may be required. Associated with strategic adaptation are the principles of financial/operational risk management and governance, as well as financial impact disclosure to investors and regulators. We develop a consolidated framework in which boards and executive managers can develop a robust approach to climate change adaptation governance, climate change risk assessment and financial disclosure. The project outlines a matrix of disclosures required for investors to enable them to evaluate corporate exposure to climate change risk.The project initially comprised a set of workshops with members of the Australian business community, industry representatives, regulatory authorities and academics with expertise in business risk and disclosure effects. Each workshop focused on a separate theme that built upon the work of previous workshops. A set of follow-up discussions was held with some of the key members who contributed to the project, including the Australian Stock Exchange (ASX) Investor Group on Climate Change (IGCC), the Australian Accounting Standards Board (AASB) and the Australian Institute of Company Directors. This discussion permitted each body to comment on the final report, advise on the mechanics of the costing, reporting and disclosure approaches of climate change adaptation, and lend their expertise to the formulation of an appropriate framework.The scope of the research is constrained to firm behaviour and the requirements for investor disclosure and governance of adaptation activities. The project therefore focuses on financial analyses – including real options – undertaken by firms with regard to investing in climate change adaptation activities and projects. While the economic costs and benefits are important to organisational adaptation activities, they represent a secondary level of analysis that may need to be carried out on either an independent or cumulative scale by governments or other bodies to measure the wider effects.As the degree of sophistication in climate change adaptation activities, modelling and cost estimation increases, along with the anticipated growth in interest of both company boards and managers, it is expected that accounting standards, ASX listing rules and disclosures required under the Corporations Act would need to explicitly reflect these corporate actions. The asset allocation of banks, mutual funds, superannuation funds and other investments is also likely to adapt as companies quantify their exposure to climate change. The makeup of assets in investment portfolios may therefore markedly shift, and thus indirectly adjust to the climate change adaptation activities of companies in the broader market

Simulation verification techniques study

Results are summarized of the simulation verification techniques study which consisted of two tasks: to develop techniques for simulator hardware checkout and to develop techniques for simulation performance verification (validation). The hardware verification task involved definition of simulation hardware (hardware units and integrated simulator configurations), survey of current hardware self-test techniques, and definition of hardware and software techniques for checkout of simulator subsystems. The performance verification task included definition of simulation performance parameters (and critical performance parameters), definition of methods for establishing standards of performance (sources of reference data or validation), and definition of methods for validating performance. Both major tasks included definition of verification software and assessment of verification data base impact. An annotated bibliography of all documents generated during this study is provided