Conditions of Effective Application of Energy-Saving Programs for the Movement of Heavy Trucks on the Highway

Abstract

The study is devoted to the problem of reducing energy consumption by heavy-duty vehicles on autobahns. The task of optimising truck transport cycles, which consist of acceleration, free rolling, and deceleration under the action of external resistance forces, is formulated. At the same time, the truck must complete the transportation task on time, in compliance with the planned schedule and within a safe distance to other objects. Such a problem refers to nonlinear optimal control problems with a fixed left end of the phase trajectory and a free right end. The problem was solved by the method of dynamic programming. A set of optimal phase trajectories and control functions is obtained for different longitudinal profiles of the freeway, different initial speeds and a different number of possible hindrances. The greatest impact on the traffic program is the number and locations of hindrances on the road due to the different densities of the traffic flow. In order to assess the possibility of using optimal cycles, a simulation of truck movement in a traffic flow characterised by mathematical expectation and standard deviation of cruising speed was performed. The prediction horizon of the probable speed of the vehicle was changed in the simulation model. Deviations from the planned movement program measured the quality of driving. It is shown that there is a finite set of numerical values of the prediction horizon on the highway, the control quality for which is the highest. The intelligent information system’s conceptual structure for controlling the truck flow to achieve the parameters of the energy saving program is proposed. Experimental studies have been carried out, which indicate an adequate assessment of the theoretical model of the movement program and the possibility of its implementation.