An adaptive attitude controller is designed based on Barrier Lyapunov Function (BLF) to meet the state constraints caused by side window detection. Firstly, the attitude controller is designed based ...on the BLF, but the stabilization function is complex and its time derivative will cause “differential explosion”. Therefore, Finite-time-convergent Differentiator (FD) is used to estimate the first derivative of the stabilization function. If the tracking error is outside the BLF's convergence domain, BLF controller cannot guarantee the error global convergence. Sliding mode controller (SMC) is used to make the system's error converge to set domain, and then the BLF controller could be used to ensure that the output constraint is not violated. Uncertainties and unknown time-varying disturbances usually make the control precision worse and Nonlinear Disturbance Observer (NDO) is designed for estimation and compensation uncertainties and disturbances. The pseudo rate modulator (PSR) is used to shape the continuous control command to pulse or on-off signals to meet the requirements of the thruster. Numerical simulations show that the proposed method can achieve state constraints, pseudo-linear operation, and high accuracy.
Automated driving (AD) has been widely recognised as the future of transportation, especially the level-4 AD defined by SAE J3016 with its promising mass-production potential, drawing great attention ...across industry and the academia. However, high-level AD has been long criticised for its high development cost, high technical uncertainties, and the lack of industrial-accepted processes to assure safety and product quality. This paper presents the work of developing a systems engineering framework and an open platform for facilitating the development of AD features from an industrial perspective. The systems engineering framework is an extension and adjustment of the traditional V-model process to fit for the AD development purposes. Starting from a business need, the development work is arranged in a top-down manner, with techniques of requirements engineering, testing planning, and safety considerations. In order to accommodate the uncertain nature of AD development, agile methods are added and integrated with the proposed framework. With this framework, an open platform was developed and some of the key parts of this platform including hardware, software, communication network, and verification and validation work are presented. An AD feature based on this platform providing the basic AD function was demonstrated. The results show the effectiveness of the proposed methodology and the open platform concept for facilitating AD development in an industrial environment. The work laid groundworks for clearing the way for the industrialisation of AD technologies with the future evolution of the proposed methodology and the platform.
Autonomous driving presents an exciting new development in vehicle technology. It poses a new challenge in driver-automation collaboration particularly during handover transitions between human and ...machine. In order to deal with this problem, this paper proposes a novel control framework for the haptic take-over system. The high-level framework of the haptic take-over control system, which takes driver cognitive workload, neuromuscular dynamics and optimal trajectory planning into consideration, is developed. Under the proposed framework, the determination approach of the optimal input sequence is introduced. The model of the allowed driver take-over authority, which is associated with driver's cognitive workload, as well as muscle readiness during take- over, is investigated and developed. The haptic feedback torque controller is then designed so as to minimize the deviation between the allowed control authority and driver's current degree of participation. A handover process, along with the proposed take-over control method, is also simulated. The simulation results validate the feasibility and effectiveness of the proposed approach.
In order to develop an advanced haptic take-over system for highly automated vehicles, research into the driver's neuromuscular dynamics is needed. In this paper a dynamic model of drivers' ...neuromuscular interaction with a steering wheel is firstly established. The transfer function and the natural frequency of the systems are analysed. In order to identify the key parameters of the driver-steering-wheel coupled system and investigate the system properties under different situations, experiments with drive-in-the-loop are carried out. For each test subject, two steering tasks, namely the passive and active steering tasks, are instructed to be completed. Furthermore, during the experiments, subjects manipulated the steering wheel with two distinct postures and three different hand positions. Based on the test results, key parameters of the transfer function and system properties are identified and investigated. The data and characteristics of the driver neuromuscular system are discussed and compared with respect to different steering tasks, hand positions and driver postures. These test results identified system properties that provide a good foundation for the development of a haptic take-over control system for automated vehicles.
The control algorithms based on TTR threshold were researched using a 3DOF simplify model in order to establish an effective way of alert and control for heavy duty vehicle. The control method based ...on PID controller was established via PID principle and TTR threshold methodology. The vehicle was verified using fishhook condition simulation. The conclusion showed that every observed parameter is convergent, it testify that the algorithm is simple and effective, it can be apply to early warning and control for commercial vehicle rollover.
The molecular compositions and stable carbon and hydrogen isotopic compositions of natural gas from the Xinchang gas field in the Sichuan Basin were investigated to determine the genetic types. The ...natural gas is mainly composed of methane （88.99%-98.01%）, and the dryness coefficient varies between 0.908 and 0.997. The gas generally displays positive alkane carbon and hydrogen isotopic series. The geochemical characteristics and gas-source correlation indicate that the gases stored in the 5th member of the Upper Triassic Xujiahe Formation are coal-type gases which are derived from source rocks in the stratum itself. The gases reservoired in the 4th member of the Xujiahe Formation and Jurassic strata in the Xinchang gas field are also coal-type gases that are derived from source rocks in the 3rd and 4th members of the Xujiahe Formation. The gases reservoired in the 2nd member of the Upper Triassic Xujiahe Formation are mainly coal-type gases with small amounts of oil-type gas that is derived from source rocks in the stratum itself. This is accompanied by a small amount of contribution brought by source rocks in the Upper Triassic Ma＇antang and Xiaotangzi formations. The gases reservoired in the 4th member of the Middle Triassic Leikoupo Formation are oil-type gases and are believed to be derived from the secondary cracking of oil which is most likely to be generated from the Upper Permian source rocks.
Restricted pagetoid reticulosis, also known as Woringer-Kolopp disease, represents a rare cutaneous lymphoproliferative disorder categorized as an isolated variant of mycosis fungoides. This report ...presents a case involving limited pagetoid reticulosis affecting the right upper extremity in a 25-year-old female. The patient had been experiencing plaques on the right upper extremity for a decade. Dermatologic examination revealed well-defined scaly plaques on the right forearm, surrounded by hyperpigmented patches. Skin histopathology demonstrated atypical mononuclear cell infiltration in the lower part of the epidermis, forming nests. Immunohistochemistry indicated CD3+, CD4+, CD5+, CD7+, CD8+, CD30+, and Ki-67-positive staining. Additionally, CD20, CD79α, and PD-1 were negative. Monoclonal rearrangement of T-cells was identified in TCR β and TCR γ through clonality assessment. The diagnosis of limited paget-like reticulocyte hyperplasia was established, leading to surgical resection. A review of the literature affirmed the variable immunophenotype of pagetoid reticulosis, with atypical cells exhibiting four types: (1) CD3+, CD4+, CD8+-type; (2) CD3+, CD4-, CD8+-type; (3) CD3+, CD4-, CD8-type; and (4) CD3+, CD4+, CD8+-type-relatively uncommon in the restrictive type. This case report details the clinical features, histologic and morphologic characteristics, immunohistochemical phenotype, diagnosis, and differential diagnosis of a rare CD3+, CD4+, CD8+ limited pagetoid reticulosis. The lesion was surgically resected, and the patient underwent a 3-year follow-up to observe its prognosis.
This paper investigates multi-objective optimization of electric vehicle (EV) based on features extracted from three driving styles, aiming at coordinating dynamic performance, ride comfort and ...energy efficiency. First, an unsupervised learning approach is used to clusters real-world driving data, obtaining three different driving styles. Then, the preferred performances under distinct driving styles are analyzed, and driving-style-oriented are determined. A model predictive controller is developed so as to handle the formulated multi-objective optimization problem. Simulations are carried out under with the developed controller and system models. Simulation results showed that the proposed controller could well coordinate the dynamic performance, ride comfort and energy efficiency of the 4IWDEV, validating the feasibility and effectiveness of the developed methodology and algorithms.
In this paper an adaptive dynamic surface attitude controller is designed to meet the requirement of fast, accurate and robust for kinetic kill vehicle (KKV) attitude control under the constraints of ...side window detection. Firstly, the influence of different target detection methods on attitude is analyzed and the desired attitude angle is derived. Secondly, the mathematical mode of KKV is established which considered about interaction between three channels and control torque. Then, an adaptive dynamic surface attitude controller is designed and nonlinear disturbance observer (NDO) is adopted for the uncertainties estimation and compensation to improve the control precision. The pulse-width pulse-frequency (PWPF) modulator is utilized to shape the continuous control command to pulse or on-off signals to meet the requirements of the reaction thruster. Numerical simulations demonstrate that the proposed method can achieve good control performance such as pseudo-linear operation, high accuracy, and fast enough tracking speed.
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