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

Author(s):  
Miles J Droege ◽  
Brady Black ◽  
Shubham Ashta ◽  
John Foster ◽  
Gregory M Shaver ◽  
...  

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.

2017 ◽  
Vol 46 (1) ◽  
pp. 11 ◽  
Author(s):  
András Mihály ◽  
Balázs Németh ◽  
Péter Gáspár

The paper introduces a hardware-in-the-loop (HIL) vehicle simulator built for testing and tuning a look-ahead cruise control algorithm considering forward road conditions. The aim of the vehicle simulator, apart from conducting real-time demonstrations and tests, is to create a HIL architecture which can be directly applied to a real heavy-duty vehicle formerly represented in TruckSim. By this means, several otherwise expensive road tests can be implemented with the simulator to increase the efficiency and reliability of the developed look-ahead control method.


2015 ◽  
Vol 2015 ◽  
pp. 1-16
Author(s):  
Yin Zhao ◽  
Ying-kai Xia ◽  
Ying Chen ◽  
Guo-Hua Xu

Underwater vehicle speed control methodology method is the focus of research in this study. Driven by a hydraulic flexible traction system, the underwater vehicle advances steadily on underwater guide rails, simulating an underwater environment for the carried device. Considering the influence of steel rope viscoelasticity and the control system traction structure feature, a mathematical model of the underwater vehicle driven by hydraulic flexible traction system is established. A speed control strategy is then proposed based on the sliding mode variable structure of fuzzy reaching law, according to nonlinearity and external variable load of the vehicle speed control system. Sliding mode variable structure control theory for the nonlinear system allows an improved control effect for movements in “sliding mode” when compared with conventional control. The fuzzy control theory is also introduced, weakening output chattering caused by the sliding mode control switchover while producing high output stability. Matlab mathematical simulation and practical test verification indicate the speed control method as effective in obtaining accurate control results, thus inferring strong practical significance for engineering applications.


Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2433
Author(s):  
Hao Chen ◽  
Hesham A. Rakha

This study develops a connected eco-driving controller for battery electric vehicles (BEVs), the BEV Eco-Cooperative Adaptive Cruise Control at Intersections (Eco-CACC-I). The developed controller can assist BEVs while traversing signalized intersections with minimal energy consumption. The calculation of the optimal vehicle trajectory is formulated as an optimization problem under the constraints of (1) vehicle acceleration/deceleration behavior, defined by a vehicle dynamics model; (2) vehicle energy consumption behavior, defined by a BEV energy consumption model; and (3) the relationship between vehicle speed, location, and signal timing, defined by vehicle characteristics and signal phase and timing (SPaT) data shared under a connected vehicle environment. The optimal speed trajectory is computed in real-time by the proposed BEV eco-CACC-I controller, so that a BEV can follow the optimal speed while negotiating a signalized intersection. The proposed BEV controller was tested in a case study to investigate its performance under various speed limits, roadway grades, and signal timings. In addition, a comparison of the optimal speed trajectories for BEVs and internal combustion engine vehicles (ICEVs) was conducted to investigate the impact of vehicle engine types on eco-driving solutions. Lastly, the proposed controller was implemented in microscopic traffic simulation software to test its networkwide performance. The test results from an arterial corridor with three signalized intersections demonstrate that the proposed controller can effectively reduce stop-and-go traffic in the vicinity of signalized intersections and that the BEV Eco-CACC-I controller produces average savings of 9.3% in energy consumption and 3.9% in vehicle delays.


Author(s):  
Yong Wang ◽  
Changpeng Cai ◽  
Jie Song ◽  
Haibo Zhang

Abstract In order to overcome the problem of significant drop in operational efficiency remarkably while power turbine speed varies among a large range, an optimal speed control method of multiple turboshaft engines based on sequential shifting control (SSC) algorithm is proposed. Firstly, combined with multi-speed gearboxes, a sequential shifting control algorithm of multiple turboshaft engines is proposed and designed to accomplish continuously variable speed control. Then, selecting the minimum engine fuel flow as the optimization objective, an integrated optimization method of optimal speed based on multiple engines and multi-speed gearboxes is proposed to promote the operational economy. Finally, the simulation tests of the optimal speed control method of twin and triple turboshaft engines is conducted separately. The results demonstrate that the optimal speed control method of multiple turboshaft engines based on SSC algorithm can change the power turbine speeds by no more than 7% and main rotor speed by over 8% simultaneously. In addition, compared with the fixed-ratio transmission (FRT), engine fuel flows decrease by more than 2% under different cruise states. It proves that the optimal speed control method is beneficial to obtain more superior overall performances of the integrated helicopter/multi-engine system without considerable loss of compressor surge margin.


2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Xinping Yan ◽  
Rui Zhang ◽  
Jie Ma ◽  
Yulin Ma

Adaptive vehicle speed control is critical for developing Advanced Driver Assistance Systems (ADAS). Vehicle speed control considering variable road geometry has become a hotspot in ADAS research. In this paper, first, an exploration of intrinsic relationship between vehicle operation and road geometry is made. Secondly, a collaborative vehicle coupling model, a road geometry model, and an AVSC, which can respond to variable road geometry in advance, are developed. Then, based onH∞control method and the minimum energy principle, a performance index is specified by a cost function for the proposed AVSC, which can explicitly consider variable road geometry in its optimization process. The proposed AVSC is designed by the Hamilton-Jacobi Inequality (HJI). Finally, simulations are carried out by combining the vehicle model with the road geometry model, in an aim of minimizing the performance index of the AVSC. Analyses of the simulation results indicate that the proposed AVSC can automatically and effectively regulate speed according to variable road geometry. It is believed that the proposed AVSC can be used to improve the economy, comfort, and safety effects of current ADAS.


Author(s):  
Shiang-Lung Koo ◽  
Han-Shue Tan ◽  
Fanping Bu ◽  
Masayoshi Tomizuka

Ride comfort at low vehicle speed is often overlooked but is very important to vehicle control applications (e.g. the latest stop-and-go function in Adaptive Cruise Control). Most control strategies that address passenger comfort simply utilize the bounds of jerk and acceleration of the vehicles. In general, they have several major limitations when applied to low-speed applications: (I) frequency-domain comfort requirements are not integrated and (II) the vehicle models are simplified too far to capture the tire and suspension dynamics that may impact comfort significantly at low speeds. This paper develops a control scheme for ride quality under stop-and-go situations. The scheme is based on optimal control and it ensures smooth acceleration during vehicle maneuvers. A two-degree-of-freedom control strategy is used to approximate the optimal control law. Experimental results demonstrate the effectiveness of this control scheme.


2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Xun Zhang ◽  
Xinglin Hu ◽  
Yang Zhao ◽  
Zhaodong Tang

Considering the inherent strongly nonlinear and coupling performance of autonomous underwater vehicles (AUVs), the speed switching control method for AUV driven by states is presented. By using T-S fuzzy observer to estimate the states of AUV, the speed control strategies in lever plane, vertical plane, and speed kept are established, respectively. Then the adaptive switching law is introduced to switch the speed control strategies designed in real time. In the simulation, acoustic Doppler current profile/side scan sonar (ADCP/SSS) observation case is employed to demonstrate the effectiveness of the proposed method. The results show that the efficiency of AUV was improved, the trajectory tracking error was reduced, and the steady-state ability was enhanced.


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