Driving Velocity Tracking Error Analysis of Different Broadcast Methods Under Green Light Optimal Speed Advisory System

Purpose This paper aims to discuss the precise altitude and velocity tracking control of a hypersonic vehicle, a global adaptive neural backstepping controller was studied based on a disturbance observer (DOB). Design/methodology/approach The DOB combined with a radial basis function (RBF) neural network (NN) was used to estimate the disturbance terms that are generated by the flexible modes of the hypersonic vehicle system. A global adaptive neural method was introduced to approximate the unknown system dynamics, with robust control terms pulling the system transient states back into the neural approximation domain externally. Findings The globally uniformly ultimately bounded for all signals of a closed-loop system can be guaranteed by the proposed control algorithm. Additionally, the command filtered backstepping methods can avoid the explosion of the complexity problem caused by the backstepping design process. In addition, the effectiveness of the proposed controller can be verified by the simulation used in this study. Research limitations/implications Normally lateral dynamics issue should be discussed in the process of control system designed, the lateral dynamics are not included in the nonlinear dynamic model of hypersonic vehicle used in this paper, merely the longitudinal flight dynamics are discussed in this paper. Originality/value The flexible states in rigid modes are considered as the disturbance of the system, which is estimated by structuring DOB with NN approximations. The compensating tracking error and prediction error are used in the update law of RBF NN weight. The differential explosions complexity derived from the backstepping procedure is dealt with by using command filters.

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A New Approach for Real Time Train Energy Efficiency Optimization

Energies ◽

10.3390/en11102660 ◽

2018 ◽

Vol 11 (10) ◽

pp. 2660 ◽

Cited By ~ 7

Author(s):

Agostinho Rocha ◽

Armando Araújo ◽

Adriano Carvalho ◽

João Sepulveda

Keyword(s):

Energy Efficiency ◽

Simulated Annealing ◽

Energy Consumption ◽

Real Time ◽

Optimization Algorithm ◽

Normal Operation ◽

Speed Profile ◽

Railway Systems ◽

Optimal Speed ◽

Advisory System

Efficient use of energy is currently a very important issue. As conventional energy resources are limited, improving energy efficiency is, nowadays, present in any government policy. Railway systems consume a huge amount of energy, during normal operation, some routes working near maximum energy capacity. Therefore, maximizing energy efficiency in railway systems has, recently, received attention from railway operators, leading to research for new solutions that are able to reduce energy consumption without timetable constraints. In line with these goals, this paper proposes a Simulated Annealing optimization algorithm that minimizes train traction energy, constrained to existing timetable. For computational effort minimization, re-annealing is not used, the maximum number of iterations is one hundred, and generation of cruising and braking velocities is carefully made. A Matlab implementation of the Simulated Annealing optimization algorithm determines the best solution for the optimal speed profile between stations. It uses a dynamic model of the train for energy consumption calculations. Searching for optimal speed profile, as well as scheduling constraints, also uses line shape and velocity limits. As results are obtained in seconds, this new algorithm can be used as a real-time driver advisory system for energy saving and railway capacity increase. For now, a standalone version, with line data previously loaded, was developed. Comparison between algorithm results and real data, acquired in a railway line, proves its success. An implementation of the developed work as a connected driver advisory system, enabling scheduling and speed constraint updates in real time, is currently under development.

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Design optimisation for optically tracked pointers

International Journal Sustainable Construction & Design ◽

10.21825/scad.v8i1.6805 ◽

2017 ◽

Vol 8 (1) ◽

pp. 10

Author(s):

Bert De Coninck ◽

Jan Victor ◽

Patrick De Baets ◽

Stijn Herregodts ◽

Matthias Verstraete

Keyword(s):

Error Analysis ◽

Tracking Error ◽

Rigid Bodies ◽

Optical Tracking ◽

Target Point ◽

Tracking Systems ◽

Design Optimisation ◽

Final Design ◽

Normally Distributed

The use of mechanical pointers in optical tracking systems is needed to aid registration processes of unlocated rigid bodies. Error on the target point of a pointer can cause wrong positioning of vital objects and as such these errors have to be avoided. In this paper, the different errors that originate during this process are described, after which this error analysis is used for the optimisation of an improved pointer design. The final design contains six coplanar fiducials, favored by its robustness and low error. This configuration of fiducials is then analysed theoretically as well as practically to understand how it is performing. The error on tracking the target point of the pointer is found with simulation to be around 0.7 times the error of measuring one fiducial in space. However, practically this error is about equal to the fiducial tracking error, due to the non-normally distributed errors on each separate fiducial.

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