Look-ahead Control of Heavy Trucks utilizing Road Topography

The power to mass ratio of a heavy truck causes even moderate slopes to have a significant influence on the motion. The velocity will inevitable vary within an interval that is primarily determined by the ratio and the road topography. If further variations are actuated by a controller, there is a potential to lower the fuel consumption by taking the upcoming topography into account. This possibility is explored through theoretical and simulation studies as well as experiments in this work. Look-ahead control is a predictive strategy that repeatedly solves an optimization problem online by means of a tailored dynamic programming algorithm. The scenario in this work is a drive mission for a heavy diesel truck where the route is known. It is assumed that there is road data on-board and that the current heading is known. A look-ahead controller is then developed to minimize fuel consumption and trip time. The look-ahead control is realized and evaluated in a demonstrator vehicle and further studied in simulations. In the prototype demonstration, information about the road slope ahead is extracted from an on-board database in combination with a GPS unit. The algorithm calculates the optimal velocity trajectory online and feeds the conventional cruise controller with new set points. The results from the experiments and simulations confirm that look-ahead control reduces the fuel consumption without increasing the travel time. Also, the number of gear shifts is reduced. Drivers and passengers that have participated in tests and demonstrations have perceived the vehicle behavior as comfortable and natural.

[1]  Jon Rigelsford,et al.  Automotive Control Systems: For Engine, Driveline and Vehicle , 2004 .

[2]  Alberto Bemporad,et al.  Control of systems integrating logic, dynamics, and constraints , 1999, Autom..

[3]  Ansi Ieee,et al.  IEEE Standard for Binary Floating Point Arithmetic , 1985 .

[4]  Michael Back,et al.  DETERMINATION OF THE FUEL-OPTIMAL TRAJECTORY FOR A VEHICLE ALONG A KNOWN ROUTE , 2002 .

[5]  Johan Dipl.-Ing. Jonsson,et al.  Fuel Optimized Predictive Following in Low Speed Conditions , 2003 .

[6]  Sean R Eddy,et al.  What is dynamic programming? , 2004, Nature Biotechnology.

[7]  Lars Nielsen,et al.  CONTROLLING GEAR ENGAGEMENT AND DISENGAGEMENT ON HEAVY TRUCKS FOR MINIMIZATION OF FUEL CONSUMPTION , 2005 .

[8]  Erik Hellström,et al.  A Real-Time Fuel-Optimal Cruise Controller for Heavy Trucks using Road Topography Information , 2006 .

[9]  Michael Back.  Prädiktive Antriebsregelung zum energieoptimalen Betrieb von Hybridfahrzeugen , 2006 .

[10]  Erik Hellström,et al.  Explicit Fuel Optimal Speed Profiles for Heavy Trucks on a Set of Topographic Road Profiles , 2006 .

[11]  John N. Hooker,et al.  Optimal driving for single-vehicle fuel economy , 1988 .

[12]  Bo Egardt,et al.  Backlash Estimation With Application to Automotive Powertrains , 2007, IEEE Transactions on Control Systems Technology.

[13]  Tony Sandberg,et al.  Heavy Truck Modeling for Fuel Consumption Simulations and Measurements , 2001 .

[14]  Michael Back,et al.  Implementing an MPC Algorithm in a Vehicle with a Hybrid Powertrain using Telematics as a Sensor for Powertrain Control , 2004 .

[15]  Erik Hellström,et al.  Look-ahead Control for Heavy Trucks to minimize Trip Time and Fuel Consumption , 2007 .

[16]  Alberto Bemporad,et al.  An MPC/hybrid system approach to traction control , 2006, IEEE Transactions on Control Systems Technology.

[17]  Edward K. Morlok,et al.  Vehicle Speed Profiles to Minimize Work and Fuel Consumption , 2005 .

[18]  Lars Nielsen,et al.  OPTIMAL FUEL AND GEAR RATIO CONTROL FOR HEAVY TRUCKS WITH PIECE WISE AFFINE ENGINE CHARACTERISTICS , 2007 .

[19]  Masahiro Kinoshita,et al.  Speed control for a motor vehicle , 1998 .

[20]  D. Hrovat,et al.  Hybrid Model Predictive Control of Direct Injection Stratified Charge Engines , 2006, IEEE/ASME Transactions on Mechatronics.

[21]  Karl Henrik Johansson,et al.  A SENSOR AND DATA FUSION ALGORITHM FOR ROAD GRADE ESTIMATION , 2007 .

[22]  Karl Henrik Johansson,et al.  Modelling and control of auxiliary loads in heavy vehicles , 2006 .

[23]  Stephan Terwen,et al.  Predictive Powertrain Control for Heavy Duty Trucks , 2004 .

[24]  E. M. Wright,et al.  Adaptive Control Processes: A Guided Tour , 1961, The Mathematical Gazette.

[25]  Michael Back,et al.  PREDICTIVE CONTROL OF DRIVETRAINS , 2002 .

[26]  Lino Guzzella,et al.  Vehicle Propulsion Systems: Introduction to Modeling and Optimization , 2005 .

[27]  Lars Nielsen,et al.  Gear shifting by engine control , 2000, IEEE Trans. Control. Syst. Technol..

[28]  M Schittler.  STATE-OF-THE-ART AND EMERGING TRUCK ENGINE TECHNOLOGIES FOR OPTIMIZED PERFORMANCE, EMISSIONS AND LIFE CYCLE COSTS , 2003 .

[29]  Phil Howlett,et al.  Optimal strategies for the control of a train , 1996, Autom..

[30]  Dimitri P. Bertsekas,et al.  Dynamic Programming and Optimal Control, Two Volume Set , 1995 .

[31]  Jo Yung Wong,et al.  Theory of ground vehicles , 1978 .

[32]  Tony Sandberg.  A Simulation Tool for Predicting Fuel Consumption for Heavy Trucks , 2001 .

[33]  H. E. Tseng,et al.  Hybrid model predictive control application towards optimal semi-active suspension , 2006 .

[34]  Rongfang Rachel Liu,et al.  Energy-efficient operation of rail vehicles , 2003 .

[35]  Stuart E. Dreyfus,et al.  Applied Dynamic Programming , 1965 .

[36]  Robert E. Larson,et al.  Principles of Dynamic Programming , 1978 .

[37]  V. Monastyrsky,et al.  Rapid computation of optimal control for vehicles , 1993 .

[38]  Dimitri P. Bertsekas,et al.  Dynamic Programming and Suboptimal Control: A Survey from ADP to MPC , 2005, Eur. J. Control.

[39]  Eduardo F. Camacho,et al.  Model Predictive Controllers , 2007 .

[40]  Eric V. Denardo,et al.  Dynamic Programming: Models and Applications , 2003 .

[41]  Uwe Kiencke,et al.  Automotive Control Systems , 2005 .

[42]  R. Bellman.  Calculus of Variations (L. E. Elsgolc) , 1963 .

[43]  Thomas Connolly,et al.  The Predictive Cruise Control – A System to Reduce Fuel Consumption of Heavy Duty Trucks , 2004 .

[44]  A. B. Schwarzkopf,et al.  Control of highway vehicles for minimum fuel consumption over varying terrain , 1977 .

[45]  William S. Levine,et al.  The Control Handbook , 2005 .

[46]  Hans B. Pacejka,et al.  Tire and Vehicle Dynamics , 1982 .

[47]  Stephan Terwen,et al.  Predictive Powertrain Control for Hybrid Electric Vehicles , 2004 .

[48]  John N. Hooker,et al.  Optimal Control of Automobiles for Fuel Economy , 1983 .

[49]  T D Gillespie,et al.  Fundamentals of Vehicle Dynamics , 1992 .