This paper is concerned with controller design of net- worked controlsystems (NCSs) with both network-induced delay and arbitrary packet dropout. By using a packet-loss-dependent Lyapunov function, sufficient condi...
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This paper is concerned with controller design of net- worked controlsystems (NCSs) with both network-induced delay and arbitrary packet dropout. By using a packet-loss-dependent Lyapunov function, sufficient conditions for state/output feedback stabilization and corresponding control laws are derived via a switched system approach. Different from the existing results, the proposed stabilizing controllers design is dependent on the packet loss occurring in the last two transmission intervals due to the network-induced delay. The cone complementary lineara- tion (CCL) methodology is used to solve the non-convex feasibility problem by formulating it into an optimization problem subject to linear matrix inequality (LMI) constraints. Numerical examples and simulations are worked out to demonstrate the effectiveness and validity of the proposed techniques.
The advantage of vehicle platoons is reflected in their tighter inter-vehicle ***,under the non-ideal communication environment,communication outage occurs which may cause the distance between adjacent vehicles too cl...
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ISBN:
(数字)9789887581536
ISBN:
(纸本)9781665482561
The advantage of vehicle platoons is reflected in their tighter inter-vehicle ***,under the non-ideal communication environment,communication outage occurs which may cause the distance between adjacent vehicles too close to result in a collision *** the communication outage with predecessor following between vehicles in a platoon,and applying the constant time headway policy,firstly,this paper quantifies the relationship among headway time,control parameter and communication reliability probability while satisfying plant stability and string ***,given a communication reliability probability,the parameter space method is used to obtain the range of the control parameter,so as to ensure platoon ***,we optimize the transmission power of vehicles to minimize the worst outage probability by some transformation and the adoption of the Perron-Frobenius *** this way,an iterative update rule is presented to obtain the optimal transmission ***,the simulation results demonstrate the effectiveness of the proposed control parameter adjustment method and power optimization scheme.
This paper j ointly designs the communication and control schemes for vehicle platoons by taking into consideration of the limited communication and computing resources of *** at achieving the stable tracking of the m...
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ISBN:
(数字)9789887581536
ISBN:
(纸本)9781665482561
This paper j ointly designs the communication and control schemes for vehicle platoons by taking into consideration of the limited communication and computing resources of *** at achieving the stable tracking of the member vehicles at a desired inter-vehicle distance and the same velocity,while improving the communication and computation efficiency,we propose a bandwidth-aware transmission scheduling(BATS) mechanism and an event-triggered distributed model predictive control(ET-DMPC) scheme for the longitudinal control of a vehicle ***,by introducing bandwidth-aware parameters,the triggering threshold for the event-triggered BATS mechanism is dynamically adjusted according to vehicle and bandwidth ***,an output-based ET-DMPC scheme is designed to ensure that the platoon tracks a reference velocity and maintains the desired inter-vehicle ***,extensive simulations are carried out and the results demonstrate the effectiveness of the proposed BATS mechanism and ET-DMPC scheme in terms of adaptive communication scheduling and low computational burden.
In urban driving scenarios,owing to the presence of multiple static obstacles such as parked cars and roadblocks,planning a collision-free and smooth path remains a challenging *** addition,the path-planning problem i...
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In urban driving scenarios,owing to the presence of multiple static obstacles such as parked cars and roadblocks,planning a collision-free and smooth path remains a challenging *** addition,the path-planning problem is mostly non-convex,and contains multiple local ***,a method for combining a sampling-based method and an optimization-based method is proposed in this paper to generate a collision-free path with kinematic constraints for urban *** sampling-based method constructs a search graph to search for a seeding path for exploring a safe driving corridor,and the optimization-based method constructs a quadratic programming problem considering the desired state constraints,continuity constraints,driving corridor constraints,and kinematic constraints to perform path *** experimental results show that the proposed method is able to plan a collision-free and smooth path in real time when managing typical urban scenarios.
This paper proposes a dependency-enhanced pre-reordering method for Chinese-English statistical machine translation(SMT).Firstly,two kinds of dependency structure-based rules are extracted based on the source-side dep...
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ISBN:
(纸本)9781509009107
This paper proposes a dependency-enhanced pre-reordering method for Chinese-English statistical machine translation(SMT).Firstly,two kinds of dependency structure-based rules are extracted based on the source-side dependency tree and corresponding word alignments between the source-side and the target-side *** a maximum entropy classifier is used to calculate the orientation probability in terms of swap or monotone between two *** a result,a reordering rule set is *** different ways are proposed to filter out the rule ***,the dependency parsing trees of the training data,development set and the test set are traversed,and if the syntactic sub-tree structure matches the rules in the rule set,the word orders will be ***,a reordered source-side sentence is generated and then fed into an SMT system for *** conducted on NIST Chinese-English MT data sets show that the proposed method significantly improves translation performance by 0.46 BLEU compared to the baseline system.
Path following refers to traveling along the desired path with automatic steering control,which is a crucial technology for automatic driving *** in private areas are highly irregular,resulting in a large curvature va...
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Path following refers to traveling along the desired path with automatic steering control,which is a crucial technology for automatic driving *** in private areas are highly irregular,resulting in a large curvature variation,which reduces the control accuracy of the path following.A curvature adaptive control(CAC)based path-following method was proposed to solve the problem mentioned ***,CAC takes advantage of the complementary characteristics in response to the path curvature fluctuation of pure pursuit and front-wheel feedback and by combining the two methods further enhances the immunity of the control accuracy in response to a curvature *** CAC,the quantitative indices of the path curvature fluctuation and control accuracy were *** model between the path curvature fluctuation and a dynamic parameter was identified using the quantitative index of the control accuracy as the optimization *** experimental results of a real vehicle indicate that the control accuracy of path following is further enhanced by its immunity in response to curvature fluctuation improved by the *** addition,CAC is easy to deploy and requires low demand for hardware resources.
Nonlinear system identification is one of the most important topics all over the word. Until now, there are many of off-line identification methods which exhibit well performance. The online approach with non-Gaussian...
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ISBN:
(纸本)9781467374439
Nonlinear system identification is one of the most important topics all over the word. Until now, there are many of off-line identification methods which exhibit well performance. The online approach with non-Gaussian noise, however, is still a challenge. For a class of nonlinear systems where all of the candidate parameters are contained in a definite parameter set, an online parameters and sates estimation method is proposed based on particle filter and Bayes theorem as the following steps. Firstly, regarding all of the candidates, the states are estimated by particle filter(PF) algorithm. Secondly the posterior probabilities of all of candidates are calculated according to the Bayes theorem;then the weights of all of the candidates are obtained through normalization. Lastly, the parameters and sates are estimated ultimately according to the weighted sum of all of the candidates and states. Numerical illustrations are presented to exhibit the application of the method proposed herein, and the performance of the method is examined.
Tractor-trailer vehicles,which are composed of a car-like tractor towing a passive trailer,have been widely deployed in the transportation industry,and trajectory planning is a critical step in enabling such a system ...
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Tractor-trailer vehicles,which are composed of a car-like tractor towing a passive trailer,have been widely deployed in the transportation industry,and trajectory planning is a critical step in enabling such a system to drive *** to the properties of being highly nonlinear and nonholonomic with complex dynamics,the tractor-trailer system poses great challenges to the development of motion-planning *** this study,an indirect trajectory planning framework for a tractor-trailer vehicle under on-road driving is presented to deal with the problem that the traditional planning framework cannot consider the feasibility and quality simultaneously in real-time trajectory generation of the tractor-trailer *** indirect planning framework can easily handle complicated tractor-trailer dynamics and generate high-quality,obstacle-free trajectory using quintic polynomial spline,speed profile optimization,forward simulation,and properly designed cost *** under different driving scenarios and trajectories with different driving requirements are conducted to validate the performance of the proposed framework.
作者:
SU YiminWANG LinDepartment of Automation
Key Laboratory of System Control and Information Processing of Ministry of EducationShanghai Jiao Tong UniversityShanghai 200240China
Autonomous vehicles must pass effective standard tests to verify their reliability and ***-ingly,it is very important to establish a complete scientific test and evaluation system for autonomous vehicles.A comprehensi...
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Autonomous vehicles must pass effective standard tests to verify their reliability and ***-ingly,it is very important to establish a complete scientific test and evaluation system for autonomous vehicles.A comprehensive framework incorporating the design of test scenarios,selection of evaluation indexes,and estab-lishment of an evaluation system is proposed in this *** aims of the system are to obtain an objective and quantitative score regarding the intelligence of autonomous vehicles,and to form an automated process in the future *** proposed framework is built on a simulation platform to ensure the feasibility of the design and implementation of the test *** design principle for the test scenarios is also *** reduce subjective influences,the proposed framework selects objective indexes from four aspects:safety,comfort,driving performance,and standard *** order relation analysis method is adopted to formulate the index weights,and fuzzy comprehensive evaluation is used to quantify the ***,a numerical example is provided to visually demonstrate the evaluation results for the autonomous vehicles scored by the proposed framework.
In this paper, a method for a sort of nonlinear system identification with stochastic time-varying parameter is investigated. This kind of nonlinear systems is referring to the system where probability density functio...
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ISBN:
(纸本)9781509009107
In this paper, a method for a sort of nonlinear system identification with stochastic time-varying parameter is investigated. This kind of nonlinear systems is referring to the system where probability density functions(PDFs) of the parameters are known. This parameter identification and states estimation method is realized based on expectation maximization(EM) algorithm and particle filter. Firstly, parameter particles are generated randomly according to the PDF of parameter. Secondly, the particle filter is employed to estimate system states corresponding to each group of the parameters, and the weight of each group parameters is calculated according to the Bayesian theory. Then the new iteration of parameter is obtained by adopting the expectation maximization algorithm. Lastly, the real parameters are obtained along with system operation. Numerical illustrations are presented to exhibit the effectiveness of the method proposed herein, and the performance of the method is examined.
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