scholarly journals Ecological control strategy for cooperative autonomous vehicle in mixed traffic considering linear stability

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Chaoru Lu ◽  
Chenhui Liu
Keyword(s):  
Fuel Consumption ◽  
Linear Stability ◽  
Control Method ◽  
Control Strategies ◽  
Autonomous Vehicle ◽  
Emission Model ◽  
Mixed Traffic ◽  
Cruise Control ◽  
Content Type ◽  
The Impact

Purpose This paper aims to present a cooperative adaptive cruise control, called stable smart driving model (SSDM), for connected and autonomous vehicles (CAVs) in mixed traffic streams with human-driven vehicles. Design/methodology/approach Considering the linear stability, SSDM is able to provide smooth deceleration and acceleration in the vehicle platoons with or without cut-in. Besides, the calibrated Virginia tech microscopic energy and emission model is applied in this study to investigate the impact of CAVs on the fuel consumption of the vehicle platoon and traffic flows. Under the cut-in condition, the SSDM outperforms ecological SDM and SDM in terms of stability considering different desired time headways. Moreover, single-lane vehicle dynamics are simulated for human-driven vehicles and CAVs. Findings The result shows that CAVs can reduce platoon-level fuel consumption. SSDM can save the platoon-level fuel consumption up to 15%, outperforming other existing control strategies. Considering the single-lane highway with merging, the higher market penetration of SSDM-equipped CAVs leads to less fuel consumption. Originality/value The proposed rule-based control method considered linear stability to generate smoother deceleration and acceleration curves. The research results can help to develop environmental-friendly control strategies and lay the foundation for the new methods.

scholarly journals Impact motion control of a flexible dual-arm space robot for capturing a spinning object

2019 ◽  
Vol 16 (3) ◽  
pp. 172988141985753
Author(s):  
Xiali Li ◽  
Licheng Wu
Keyword(s):  
Motion Control ◽  
Control Method ◽  
Initial Conditions ◽  
Autonomous Vehicle ◽  
Stable State ◽  
Momentum Conservation ◽  
Space Robot ◽  
Dynamics Response ◽  
The Impact ◽  
Dual Arm

As an autonomous vehicle that moves on the space orbit, a space robot needs to be carefully treated on the motion planning and control method. In this article, the optimal impact and postimpact motion control of a flexible dual-arm space robot capturing a spinning object are considered. Firstly, the dynamic model of the robot systems is built by using Lagrangian formulation. The flexible links are modeled as Euler–Bernoulli beams of two bending modes. Through simulating the system’s postimpact dynamics response, the initial conditions are obtained from the impact model. Next, the initial velocities of base and joint are adjusted to minimize the velocity of the base after the capture according to generalized momentum conservation. After the capture, a proportional–derivative controller is designed to keep the robot system’s stabilization. The simulation results show that joint angles of base and manipulators reach stable state quickly, and motions of the space robots also induce vibrating motions of the flexible manipulators.

The impact of biomass consumption on CO2 emissions

2015 ◽  
Vol 7 (3) ◽  
pp. 348-358 ◽  
Author(s):  
Salih Turan Katircioglu
Keyword(s):  
Error Correction ◽  
Fuel Consumption ◽  
Fossil Fuel ◽  
Annual Data ◽  
Total Biomass ◽  
Content Type ◽  
Fossil Fuel Consumption ◽  
Equilibrium Relationship ◽  
The Impact

Purpose – The purpose of this study is to investigate the long-term equilibrium relationship between carbon dioxide (CO2) emissions and total biomass consumption (BC) in Turkey, which has a rich diversity of ecological conditions prevailing throughout its regions. Design/methodology/approach – Bounds tests and conditional error correction models under the autoregressive distributed lag approach have been applied to annual data that cover the 1980-2010 period. Findings – Results suggest that CO2 emissions are in a long-term equilibrium relationship with total BC in Turkey. BC has a negative effect on CO2 emissions; 1 per cent increase in total BC would lead to 0.029 per cent reduction in CO2 emissions. Long-term coefficient of fossil fuel consumption for CO2 emissions is positive and elastic, 1.247. Finally, conditional error correction model of the present study reveals that CO2 emission in Turkey converges to its economic long-term equilibrium very quickly by 93.7 per cent speed of adjustment through the channel of BC and fossil fuel consumption. Originality/value – Although there have been a considerable number of studies investigating the link between total energy consumption and CO2 emissions in the literature, searching the contribution of components of energy to CO2 emissions deserves attention. Therefore, this study contributes to the literature by investigating the effect of BC on CO2 emissions in the case of Turkey.

Minimization of aircraft fuel consumption subjected to arrival time constraint

2020 ◽  
Vol 92 (7) ◽  
pp. 1063-1072
Author(s):  
Muhaned Gilani ◽  
Durmuş Sinan Körpe
Keyword(s):  
Fuel Consumption ◽  
Operating Cost ◽  
Time Constraints ◽  
Programming Algorithm ◽  
Time Of Arrival ◽  
Content Type ◽  
Design Variables ◽  
Aircraft Fuel ◽  
Optimum Speed ◽  
The Impact

Purpose This paper aims to minimize aircraft fuel consumption during the cruise phase when the flight is subjected to a specific time of arrival for different weights and distances. Design/methodology/approach The approach adopted herein uses sequential quadratic programming algorithm from MATLAB optimization toolbox, which includes a mathematical model of a jet airliner based on the Base of Aircraft Data as a function evaluator, to find out the impact of meet-time of arrival constraints on fuel consumption. The cruising speeds at predefined segments and the altitude are defined as the design variables. Findings The algorithm determines the optimum cruise altitudes and speeds for minimum fuel consumption in the case of no time constraints, also, for different time constraints where the flight time shall be reduced by increasing speed and lowering the altitude in most of the investigated cases. Practical implications The algorithm computes the optimum speed and the altitude according to different flight scenarios with the meet-time of arrival constraints for minimum fuel consumption which affects the direct operating cost of the flight. The algorithm might greatly help in decision-making for the meet-time of arrival operations. Originality/value Developing an algorithm to optimize the speed and the altitude of an aircraft based on weight and range for minimization of fuel consumption. It is a pioneer study in the literature that deals with the effect of meet-time constraints on fuel consumption.

scholarly journals LPV robust servo control of aircraft active side-sticks

2020 ◽  
Vol 92 (4) ◽  
pp. 599-609
Author(s):  
Guang Rui Zhou ◽  
Shi Qian Liu ◽  
Yuan Jun Sang ◽  
Xu Dong Wang ◽  
Xiao Peng Jia ◽  
...  
Keyword(s):  
Control Method ◽  
Linear Time ◽  
External Disturbance ◽  
Servo System ◽  
Slip Angle ◽  
Content Type ◽  
Civil Aircraft ◽  
Non Linear ◽  
Lpv Control ◽  
The Impact

Purpose This paper aims to focus on the variable stick force-displacement (SFD) gradience in the active side stick (ASS) servo system for the civil aircraft. Design/methodology/approach The problem of variable SFD gradience was introduced first, followed by the analysis of its impact on the ASS servo system. To solve this problem, a linear-parameter-varying (LPV) control approach was suggested to process the variable gradience of the SFD. A H∞ robust control method was proposed to deal with the external disturbance. Findings To validate the algorithm performance, a linear time-variant system was calculated to be used to worst cases and the SFD gradience was set to linear and non-linear variation to test the algorithm, and some typical examples of pitch angle and side-slip angle tracking control for a large civil aircraft were also used to verify the algorithm. The results showed that the LPV control method had less settling time and less steady tracking errors than H∞ control, even in the variable SFD case. Practical implications This paper presented an ASS servo system using the LPV control method to solve the problem caused by the variable SFD gradience. The motor torque command was calculated by pressure and position feedback without additional hardware support. It was more useful for the electronic hydraulic servo actuator. Originality/value This was the research paper that analyzed the impact of the variable SFD gradience in the ASS servo system and presented an LPV control method to solve it. It was applicable for the SFD gradience changing in the linear and non-linear cases.

Robot compliant catching by Maxwell model based Cartesian admittance control

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Le Fu ◽  
Jie Zhao
Keyword(s):  
Control Method ◽  
Maxwell Model ◽  
Admittance Control ◽  
End Effector ◽  
Content Type ◽  
Model Based ◽  
Time Optimal ◽  
Voigt Model ◽  
Optimal Movement ◽  
The Impact

Purpose Admittance control is a typical complaint control methodology. Traditionally, admittance control systems are based on a dynamical relationship described by Voigt model. By contrast, after changing connection of spring and damper, Maxwell model produces different dynamics and has shown better impact absorption performance. This paper aims to design a novel compliant control method based on Maxwell model and implement it in a robot catching scenario. Design/methodology/approach To achieve this goal, this paper proposed a Maxwell model based admittance control scheme. Considering several motion stages involved in one catching attempt, the following approaches are adopted. First, Kalman filter is used to process the position data stream acquired from motion capture system and predict the subsequent object flying trajectory. Then, a linear segments with parabolic blends reaching motion is generated to achieve time-optimal movement under kinematic and joint inherent constraints. After robot reached the desired catching point, the proposed Maxwell model based admittance controller performs such as a cushion to moderate the impact between robot end-effector and flying object. Findings This paper has experimentally demonstrated the feasibility and effectiveness of the proposed method. Compared with typical Voigt model based compliant catching, less object bounding away from end-effector happens and the success rate of catching has been improved. Originality/value The authors proposed a novel Maxwell model based admittance control method and demonstrated its effectiveness in a robot catching scenario. The author’s approach may inspire other related researchers and has great potential of practical usage in a widespread of robot applications.

Heavy-duty truck platooning on hilly terrain highways: Methods for assessment and improvement

2021 ◽  
pp. 095440702110676
Author(s):  
Miles J Droege ◽  
Brady Black ◽  
Shubham Ashta ◽  
John Foster ◽  
Gregory M Shaver ◽  
...  
Keyword(s):  
Control Method ◽  
Control Strategies ◽  
Speed Control ◽  
Vehicle Speed ◽  
Heavy Duty ◽  
Cruise Control ◽  
Hilly Terrain ◽  
Optimal Speed ◽  
Look Ahead ◽  
Shifting Strategy

Platooning heavy-duty trucks is a proven method to reduce fuel consumption on flat ground, but a significant portion of the U.S. highway system covers hilly terrain. The effort described in this paper uses experimentally gathered single truck data from a route with hilly terrain and an experimentally-validated two-truck platoon simulation framework to analyze control methods for effective platooning on hilly terrain. Specifically, this effort investigates two platoon control aspects: (1) the lead truck’s vehicle speed control and (2) the platoon’s transmission shifting algorithm. Three different types of lead truck speed control strategies are analyzed using the validated platoon model. Two are commercially available cruise control strategies – conventional constant set speed cruise control (CCC) and flexible set speed cruise control (FCC). The third lead truck speed control strategy was developed by the authors in this paper. It uses look-ahead grade information for an entire route to create an energy-optimal speed profile for the lead truck which is called long-horizon predictive cruise control (LHPCC). Then, a two-truck platoon transmission shifting strategy that coordinates the shift events – Simultaneous Shifting (SS) – is introduced and compared to a commercially available shifting strategy using the validated platoon model. This shifting strategy demonstrates further improvements in the platoon performance by improving the platoon gap control. A summary of these simulations demonstrates that the performance of the platoon can be improved by three methods: adding speed flexibility to the lead truck speed control method, using look-ahead road grade information to generate energy-optimal speed targets for the lead truck, and coordinating the timing of the transmission shifts for each truck in the platoon.

Does the threshold matter? The impact of the monitoring activity on non-performing loans

2019 ◽  
Vol 45 (2) ◽  
pp. 190-221 ◽  
Author(s):  
Domenico Piatti ◽  
Peter Cincinelli
Keyword(s):  
Early Warning ◽  
Performance Indicator ◽  
Positive Impact ◽  
Control Strategies ◽  
Threshold Value ◽  
Threshold Level ◽  
Content Type ◽  
The Impact ◽  
Monitoring Activity

PurposeThe purpose of this paper is to investigate whether the quality of the credit process is sensitive to reaching a particular threshold level of non-performing loans (NPLs) and, more importantly, whether higher NPLs ratios could make the monitoring activity ineffective.Design/methodology/approachThe empirical design is composed of two steps: in the first step, the authors introduce a monitoring performance indicator (MPI) of the credit process by combining the non-parametric technique Data Envelopment Analysis with some financial ratios adopted as input and output variables. As second step, the authors apply a threshold panel regression model to a sample of 298 Italian banks, over the time period 2006–2014, and the authors investigate whether the quality of the credit process is sensitive to reaching a particular threshold level of NPLs.FindingsThis paper finds that, first, when the NPLs ratio remains below the threshold value estimated endogenously, an increase in the quality of monitoring has a positive impact on the NPLs ratio. Second, if the NPLs ratio exceeds the estimated threshold, the relationship between the NPLs ratio and quality of monitoring assumes a positive value and is statistically significant.Research limitations/implicationsDue to the lack of data, the investigation of NPLs in the Italian industry across loan types combined with the monitoring effort by banks management was not possible. The authors plan to investigate this topic in future studies.Practical implicationsThe identification of the threshold has a double operational valence. The first regards the Supervisory Authority, the threshold approach could be used as an early warning in order to introduce active control strategies based on the additional information requested or by on-site inspections. The second implication is highlighted in relation to the individual banks, the monitoring of credit control quality, if objective and comparable, could facilitate the emergence of best practices among banks.Social implicationsA high NPLs ratio requires greater loan provisions, which reduces capital resources available for lending, and dents bank profitability. Moreover, structural weaknesses on banks’ balance sheets still persist particularly in relation to the inadequate internal governance structures. This means that bank management must able to recognise in advance early warning signals by providing prudent measurement together with an in-depth valuation of loans portfolio.Originality/valueThe originality of the paper is twofold: the authors introduce a new proxy of credit monitoring, called MPI; the authors provide an empirical proof of the Diamond’s (1991) economic intuition: for riskier borrowers, the monitoring activity is an inappropriate instrument depending on the bad reputational quality of borrowers.

scholarly journals Ride-Through Control Method for the Continuous Commutation Failures of HVDC Systems Based on DC Emergency Power Control

Energies ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 4183 ◽  
Author(s):  
Chao Xiao ◽  
Wei Han ◽  
Jinxin Ouyang ◽  
Xiaofu Xiong ◽  
Wei Wang
Keyword(s):  
Power Control ◽  
Direct Current ◽  
Control Method ◽  
Control Strategies ◽  
Equivalent Model ◽  
Emergency Control ◽  
Emergency Power ◽  
Ac Systems ◽  
The Stability ◽  
The Impact

Continuous commutation failures (CFs) are serious malfunctions in line-commutated converter high-voltage direct current (HVDC) systems that cause the continuous and rapid sag of transmitted power and may threaten the stability of AC systems. The conventional emergency control strategies of AC systems exhibit difficulty in responding quickly and accurately. After suffering from continuous CFs, the forced blocking of direct current (DC) converter to prevent AC system instability might also cause other adverse effects. This study proposes a ride-through control method to improve the endurance capability of AC systems against continuous CFs. An active power output model of inverter station under continuous CFs is built, while considering the process and mechanism of CFs. The impact of continuous DC power sag on the stability of sending-end system is analyzed through a four-area AC/DC equivalent model. A rolling calculation model for the power angle and acceleration area variations of the sending-end system during continuous CFs is established on the basis of model predictive control theory. A calculation method for the emergency power control reference is obtained by using the aforementioned models. Lastly, a ride-through control method for continuous CFs is developed by utilizing the emergency control of adjacent HVDC link. Simulation results show that the proposed control method can improve the endurance capability of an AC system to continuous CFs and reduce blocking risk in an HVDC link.

scholarly journals An Investigation of Autonomous Vehicle Roundabout Situation

2019 ◽  
Vol 48 (3) ◽  
pp. 236-241
Author(s):  
Hang Cao ◽  
Máté Zöldy
Keyword(s):  
Fuel Consumption ◽  
Autonomous Vehicles ◽  
Autonomous Vehicle ◽  
Preliminary Test ◽  
Driving Behavior ◽  
Physical Parameters ◽  
Test Scenario ◽  
Vehicle Type ◽  
Fuel Consumption And Emissions ◽  
The Impact

The aim of this paper is to evaluate the impact of connected autonomous behavior in real vehicles on vehicle fuel consumption and emission reductions. Authors provide a preliminary theoretical summary to assess the driving conditions of autonomous vehicles in roundabout, which attempts exploring the impact of driving behavior patterns on fuel consumption and emissions, and including other key factors of autonomous vehicles to reduce fuel consumption and emissions. After summarizing, driving behavior, effective in-vehicle systems, both roundabout physical parameters and vehicle type are all play an important role in energy using. ZalaZONE’s roundabout is selected for preliminary test scenario establishment, which lays a design foundation for further in-depth testing.

Numerical analysis of the effects of changing hydraulic parameters on saltwater intrusion in coastal aquifers

2016 ◽  
Vol 33 (8) ◽  
pp. 2546-2564 ◽  
Author(s):  
Ismail Abd-Elaty ◽  
Hany Farhat Abd Elhamid ◽  
Akbar Javadi
Keyword(s):  
Hydraulic Conductivity ◽  
Numerical Model ◽  
Coastal Aquifers ◽  
Saltwater Intrusion ◽  
Control Method ◽  
Hydraulic Parameters ◽  
Content Type ◽  
Henry Problem ◽  
The Impact ◽  
Biscayne Aquifer

Purpose The purpose of this paper is to develop and validate a numerical model to study the effect of changing hydraulic parameters on saltwater intrusion in coastal aquifers. Design/methodology/approach The numerical model SEAWAT is validated and applied to a hypothetical case (Henry problem) and a real case study (Biscayne aquifer, Florida, USA) for different values of hydraulic parameters including; hydraulic conductivity, porosity, dispersion, diffusion, fluid density and solute concentration. The dimensional analysis technique is used to correlate these parameters with the intrusion length. Findings The results show that the hydraulic parameters have a clear effect on saltwater intrusion as they increase the intrusion in some cases and decrease it in some other cases. The results indicate that changing hydraulic parameters may be used as a control method to protect coastal aquifers from saltwater intrusion. Practical implications The results of the application of the model to the Biscayne aquifer in Florida showed that the intrusion can be reduced to 50 percent when the hydraulic conductivity is reduced to 50 percent. Decreasing hydraulic conductivity by injecting some relatively cheap materials such as bentonite can help to reduce the intrusion of saltwater. So the saltwater intrusion can be reduced with relatively low cost through changing some hydraulic parameters. Originality/value A relationship to calculate intrusion length in coastal aquifer is developed and the impact of different hydraulic parameters on saltwater intrusion is highlighted. Control of saltwater intrusion using relatively cheap method is presented.

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