Active Trailer Research Articles

An active trailer steering design for long combination vehicles

This article proposes a trailer-axle arrangement for a long combination vehicle, i.e., a B-train double with trailer tridem-axle groups, in which the lead-axle of each group is an active trailer steering axle, and the two rear-axles are passive trailer steering axles. Given this trailer-axle arrangement, a cost-effective active trailer steering system is devised. It is assumed that in low-speed curved-path negotiations, a passive trailer steering system, e.g., self- or command-steering, will operate, while in high-speed operations, the active trailer steering system is to be activated. For the active trailer steering control, three controllers are evaluated, which are designed using the linear quadratic regulator, linear quadratic Gaussian, and µ-synthesis techniques. The performance of these designs is assessed using closed-loop simulation. The insightful findings from this study will provide guidelines for designing active trailer steering systems for long combination vehicles.

Research on Active Trailer Steering Control Strategy of Tractor Semitrailer under Medium-/High-Speed Conditions

Abstract: The study proposes an active trailer steering control method for tractor semitrailers to promote the path tracking effect of the trailer portion as well as lateral stability during lane changing. Firstly, a simplified model of a tractor semitrailer is constructed, and the MAP map is formed based on the genetic algorithm for the identification of the key parameters, which improves the model’s accuracy. Then the tractor and trailer’s yaw rate and sideslip angle at CG are tracked as the control objective and the trailer angle distribution strategy is given. Then the LQR-based corner controller is designed to control the steering actuators of each axle of the trailer. Finally, the effectiveness of the designed control strategy is verified based on the Trucksim/Simulink joint simulation platform and the semi-physical HiL test platform. The simulation results show that the designed controller can effectively improve the path tracking effect of the tractor and the trailer, and at the same time, the lateral stability parameters of the tractor and the trailer are also significantly improved, which improves the driving stability of the tractor semitrailer.

ENERGY EFFICIENCY OF A HYBRID ROAD TRAIN WITH AN ACTIVE SEMI-TRAILER FOR ROAD CONSTRUCTION WORK

The previous experience of creating experimental road trains with an active trailer and semi-trailer is analyzed against the background of modern technological capabilities of transport engineering and the logistical needs of modern construction. The expediency of implementing the concept of a road train with an active trailer based on modern electromechanical technologies is shown. The purpose of the study is to increase the energy efficiency of road trains used in construction for transporting long-length objects (beams, piles, bridge trusses, panels, etc.) by using an active trailer link with an electromechanical drive. The study solves the problem of modeling the movement of road trains with passive and active semi-trailers and comparing their energy efficiency and safety indicators. The methods of modeling the movement of cars and road trains, characteristic of the theory of movement of transport vehicles, approaches of theoretical mechanics and applications of differential calculus, applied numerical modeling in the SimuLink environment are used. A mathematical model has been obtained that allows calculating the energy efficiency of a road train when using passive (towed) and active semi-trailers. The cycle of the road train movement has been developed and tested for use in severe road conditions (construction with weak road infrastructure, forest complex, transportation of special cargo). The implementation of the computational model by means of the SimuLink software package is proposed. Based on the simulation results, conclusions are made on the energy efficiency and safety of road trains with an active trailer link with an electromechanical transmission.

Power distribution mechanisms with friction control in the transmission of a road train with an active trailer-dissolution

The article analyzes the experience of using gear controlled power distribution mechanisms in transport engineering as part of a dynamic stabilization system for high-speed ground vehicles. An overview of the sources on this issue is given. It is shown that the issue of increasing the lateral stability against skidding is relevant in modern conditions and has received a mathematical description mainly in the application to passenger cars. Attention is paid to theoretical studies of Russian scientists involved in the problem of power distribution control in transmissions of transport vehicles and tractors for various purposes. A solution to the problem of full control over the distribution of torques in a transmission containing several drive axles is proposed in the form of a structural diagram of a transmission based on the use of controlled gear power distribution mechanisms. The considered solutions are applicable for monohull vehicles and road trains with an active trailer link. Methods for determining external parameters (gamma of gear ratios) for interaxle and interwheel controlled power distribution mechanisms are proposed in the application to the case of turning a road train with an active trailer-dissolution having an electromechanical transmission.

Electromechanical transmission for active release trailer

The issues of the features of the use of active trailers as part of road trains of forest machines are considered. The principles of constructing a block diagram, determining external parameters and synthesizing kinematic diagrams of the mechanical part of the electromechanical transmission of an active trailer are proposed. A variant of the kinematic scheme of the power distribution mechanism is given. A technology for controlling such mechanisms is proposed. The ways of project realization are shown.

Dynamics performance of long combination vehicles with active control systems

A state-of-the-art review of the dynamics of long combination vehicles (LCVs) is provided. The performance-based standards (PBS) that are commonly used globally are reviewed, including those in Canada and Australia. The discussions include the low-speed and high-speed longitudinal, lateral, and yaw performance of LCVs, which in many respects are different than the conventional tractor-semitrailers. The low-speed discussions include the vehicle startability, gradeability, acceleration, and offtracking. The high-speed considerations include rollover dynamics, braking distance and time, overtaking, down-grade holding, and ride quality. Some of the latest development in actively controlled (intelligent) systems to improve LCVs’ dynamic performance is emphasised, such as hill-start assist (HAS), roll stability control (RSC), electronic stability control (ESC), electrified dolly (e-dolly), active trailer steering (ATS), active braking, slip control (SC), active trailer differential braking (ATDB), active and semi-active antiroll bars, and active and semi-active suspensions. The study concludes that although great progress has been made during the past two decades for integrating advanced, intelligent, electromechanical systems in LCVs, much more work remains to address some of the future environmental and performance demands, particularly considering the integration of electrical and alternative-fuel propulsion systems in heavy commercial vehicles.

Active trailer with variable base for the timber industry

For forest machines (skidders, forwarders), due to the peculiarities of work cycles and a wide range of changes in resistance to movement, a power plant with a heat engine most of the time operates in a non-optimal mode. It is proposed to overcome this disadvantage by using an active trailer link. The issues of the features of the use of active trailers as part of road trains of forest machines are considered. A trailer with a variable base was chosen as the basis, as the most popular and widespread in the forestry complex. The structure of an electromechanical transmission based on the principle of using a central electric motor and a controlled interwheel power distribution mechanism is proposed. The principles of determining the power of thermal and electric motors are considered. A method for calculating the external parameters characterizing the power distribution mechanism based on the principle of matching the radii of the kinematic and power turn is proposed, and a design scheme for turning the road train is given. The main assumptions are formulated to justify the possibility of the proposed calculated dependencies. The way of synthesis of kinematic schemes of such mechanisms, approaches to design and production are indicated. A technology for controlling such mechanisms is proposed. An example is considered, a variant of the kinematic scheme of the power distribution mechanism is given. The ways of project realization are shown.

High-speed lateral stability and trajectory tracking performance for a tractor-semitrailer with active trailer steering.

An active trailer steering (ATS) controller is investigated to improve the lateral stability and trajectory tracking performance of the tractor-semitrailer. First of all, a linear yaw-roll dynamic model of the tractor-semitrailer with steerable trailer wheels is established, and the model accuracy is verified. Then a linear quadratic regulator (LQR) for actively steering the trailer's wheels is designed. For the LQR controller, the lateral acceleration and the sideslip angle at the center of gravity (CG) of the trailer are taken as the optimization objectives, and the steering angle of the wheel on the middle axle of the trailer is set as the control input. Finally, the effectiveness of the designed controller is tested based on the co-simulation platform under the single lane-change (SLC) maneuver at the speed of 100 km/h and the double lane-change (DLC) maneuver at the speed of 80 km/h and 88km/h. Research results show that under the high-speed SLC maneuver, the designed LQR controller can significantly improves the lateral stability and trajectory tracking performance of the trailer, and cannot affect apparently the trajectory and dynamic responses of the tractor. Under the high-speed DLC maneuver, the designed controller can still make the tractor-semitrailer reach a new steady state in a short time, and improve the vehicle lateral stability and the trajectory tracking performance of the trailer at the same time.

Optimization of Gain Scheduled Controller for an Active Trailer Steering System Using an Evolutionary Algorithm

Car–trailer combinations can experience unstable motion modes such as trailer-sway, jackknifing and rollover that can lead to fatal accidents. These unstable motions can be mitigated with the use of an active trailer steering (ATS) system. Prior studies in ATS have leveraged the linear quadratic regulator (LQR) as an ATS controller but for many of these designs it was assumed that the vehicle and operating parameters were constant. In reality, vehicle and operating parameters may vary and have an impact on the stability of a car–trailer combination. In this paper, the weighting matrices of the LQR controller are determined using the GDE3 evolutionary optimization algorithm with the objective of addressing the design trade off between minimizing the car–trailer’s path-following performance for low vehicle speeds and minimizing the rearward amplification for high vehicle speeds. The effectiveness of the approach is demonstrated using a numerical simulation car–trailer model developed in the CarSim simulator. Our results show that the multi-objective tuned gain scheduling controller outperforms a non-tuned gain scheduling controller in terms of improving the lateral stability and the path following performance of car–trailer combinations in driver in the loop single lane-change maneuvers at a constant vehicle forward speed.

A closed-loop directional dynamics control with LQR active trailer steering for articulated heavy vehicle

To improve the directional performance of articulated heavy vehicles (AHV), three previewed points driver model and LQR active trailer steering (ATS) strategy are proposed and examined using closed-loop driver/vehicle dynamics simulation. Firstly, a simplified linear three-degree-of-freedom (3-DOF) yaw plane model for AHV is established and validated. Secondly, based on the multi-point preview-predictor following strategy, the weighted-average error of three previewed points of the tractor is defined as the final lateral previewed displacement error. According to the assumption of constant yaw rate and the trajectory prediction of AHV, and three previewed points driver model has been configured, it’s path-following performance is verified. Thirdly, instead of using the idea of minimization, a linear quadratic regulator (LQR) controller is proposed based on the linear 3-DOF yaw plane model of AHV to make the control variables to keep following the desired responses. Through joint simulations using MATLAB/Simulink and TruckSim, the effectiveness of the built-in driver model, three-previewed point driver model and three-previewed point driver model + LQR ATS control methods on improving vehicle orientation performance were compared and analyzed through closed-loop driver/vehicle dynamics simulations. The significant effectiveness of the proposed method in improving maneuverability and stability is verified through low-speed 360° trajectory tracking tests and high-speed double lane change maneuver simulations. Finally, a hardware-in-the-loop (HIL) platform is used to further verify the effectiveness of the designed strategy.

Optimization with Genetic Algorithm of Linear Quadratic Regulator Controller for Active Trailer Braking System

The necessity of active chassis control methods that can cope with the three typical unstable motion modes found in vehicle-trailer systems has emerged. Although there are studies aimed at preventing these instability situations mechanically, they cannot guarantee lateral stability. Active trailer braking system (ATBS) is used to solve this problem. In this study, a linear quadratic regulator (LQR) to be developed for the car-trailer system. The parameters of LQR are determined using the genetic algorithm (GA). The controller is developed in MATLAB/Simulink and experimentally validated in CarSim. It has been observed that the parameters to be determined by the genetic algorithm give better results than the parameters found by the trial-and-error method.

Active trailer braking control for car-trailer combination based on multi-objective fuzzy algorithm

Active trailer braking control for car-trailer combination based on multi-objective fuzzy algorithm

Active trailer braking control for car-trailer combination based on multi-objective fuzzy algorithm

Active trailer braking control for car-trailer combination based on multi-objective fuzzy algorithm

A method for assessing the cross-country capability of a particularly heavy-duty vehicle with all-wheel control based on the compliance of the support surface during curved movement

The article presents a method for assessing the permissible speed of a particularly heavy-duty vehicle based on a road train using a combined hydraulic transformer in the tractor transmission, as one of the indicators of cross-country ability. In this paper, we consider one of the main ways to increase the cross-country ability of heavy-duty vehicles: the creation of heavy-duty vehicles based on a road train with an active trailer link. Increasing the passability of heavy-duty vehicles is primarily aimed at increasing the permissible speed of heavy-duty vehicles and the maximum angles of ascents to be overcome. When justifying the choice of an algorithm for controlling the voltage of a torque Converter inductor based on the speed of particularly heavy-duty vehicles, it is advisable to use the external characteristics of the torque Converter as evaluation indicators: the dependence of the efficiency coefficient, the dependence of the moment created by the pump, and the dependence of the transformation coefficient on the gear ratio of the torque Converter. As criteria for evaluating the feasibility of using a combined torque Converter for especially heavy-duty vehicles, it is advisable to use the maximum increase in efficiency, the moment created by the pump wheel, and the transformation coefficient of torque converters on magnetic fluid in relation to the efficiency, the moment created by the pump wheel, and the transformation coefficient of the torque Converter based on a conventional working fluid in the operational range of gear ratio changes. The external characteristic is calculated after calculating the blade system and selecting the design to determine whether the main parameters of the characteristic correspond to the parameters specified in the task for designing the torque Converter. Such calculations often have to be performed when fine-tuning torque converters with a known design, when the influence of geometric parameters of individual elements of the blade system (input and output angles, wheel radii, the number of blades in the impellers, etc.) on the transforming and loading properties of the torque Converter is investigated.

The results of modeling and evaluating the dynamics of a road train with an active trailer link based on valve-inductor electric machines

The article describes the results of modeling and evaluating the dynamics of a road train with an active trailer link based on valve-inductor electric machines. It gives a general view and an equivalent road train diagram, shows a generalized simulation model of the movement of a two-link road train developed in the Simulink environment for studying motion in various road conditions. We proposed a reference surface model based on the terrain map, blocks were developed for calculating the road tilt angles separately for the tractor and the semitrailer, taking into account the type of coating under each road train wheel at the current time. The visualization of the movement of the road train is shown, the results of modeling and evaluation of the dynamics of the road train with an active trailer link based on valve-induction electric machines for creating control systems for individual drives of the electric motor-wheel of an active semi-trailer and developing a program and methodology of full-scale experimental research representations.

РОЗРОБКА ФІЗИЧНОЇ МОДЕЛІ АВТОМОБІЛЯ З ДИСТАНЦІЙНИМ КЕРУВАННЯМ ДЛЯ ЕКСПЕРИМЕНТАЛЬНИХ ДОСЛІДЖЕНЬ ВЛАСТИВОСТЕЙ АВТОМОБІЛІВ

The article is devoted to the development of the physical model of the vehicle, the equipment of the measuring, recording and remote control equipment for the experimental study of the properties vehicles. The construction of the physical model and the used electronic modules is described in detail, references are given to the application libraries and the code of the first part of the program for remote control. In the future, it is planned to develop a mathematical model of the movement of a passenger vehicle and to check its adequacy in conducting experimental studies on maneuverability on a physical model. The aim of the article is developed the physical model of the vehicle, equipped with measuring, recording and remote control equipment, for the experimental study of the properties of vehicle. Materials and research methods: development and designing (experimental research of properties of vehicles on the physical model); remote control; wheeled controlled module. The self-propelled large-scale model of the vehicle, reproducing a passenger car of the category M1, with a controlled wheelbase and a rear drive axle, has been developed. The model is equipped with the necessary measuring and recording equipment and remote control equipment. The software of the model allows you to implement both control manual and the given algorithm. In the future, it is planned to develop a mathematical model of the vehicle motion and to check its adequacy on the developed physical model. The obtained results will allow to improve not only the mathematical model, but also the experimental physical model and proceed further to the study of the properties of hybrid road trains with an active trailer link. KEY WORDS: VEHICLE, PHYSICAL MODEL, EXPERIMENT, STUDY, MODULE, MEMORY CARD, ACCELEROMETER, PROGRAM.

EXPERIMENTAL STUDIES OF CAR PROPERTIES ON A PHYSICAL MODEL

The article deals with the development of a physical model of a car equipped with measuring, recording and remote control equipment for experimental study of car properties. A detailed description of the design of the physical model and of the electronic modules used is given, links to application libraries and the code of the first part of the program for remote control of the model are given. Atmega microcontroller on the Arduino Uno platform was used to manage the model and register the parameters. When moving the car on the memory card saved such parameters as speed, voltage on the motor, current on the motor, the angle of the steered wheel, acceleration along three coordinate axes are recorded. Use of more powerful microcontrollers will allow to expand the list of the registered parameters of movement of the car. It is possible to measure the forces acting on the elements of the car and other parameters. In the future, it is planned to develop a mathematical model of motion of the car and check its adequacy in conducting experimental studies on maneuverability on the physical model. In addition, it is possible to conduct studies of stability and consumption of electrical energy. The physical model allows to quickly change geometric dimensions and mass parameters. In the study of highway trains, this approach will allow to investigate the various layout schemes of highway trains in the short term. It is possible to make two-axle road trains and saddle towed trains, three-way hitched trains of different layout. The results obtained will allow us to improve not only the mathematical model, but also the experimental physical model, and move on to further study the properties of hybrid road trains with an active trailer link. This approach allows to reduce material and time costs when researching the properties of cars and road trains. Keywords: car, physical model, experiment, road trains, sensor, remote control, maneuverability, stability.

Use of Articulated Transport Systems in the Mining Industry

The work is devoted to the possibility and prospects of the use of all-wheels drive articulated transport systems in the mining complex. A comparative analysis of the traditional methods of exporting minerals in open pit mining and the method of using active trailed elements are given. The trailer has a load factor several times higher than the same rate for mining dump trucks. The use of an active trailer makes it possible to reduce the mass of the tractor and trailer by almost 40 tons and increase the specific power of the road train.

An investigation of active safety control strategies for improving the lateral stability of car-trailer systems

This paper presents an evaluation of control strategies for improving the lateral stability of car-trailer systems. A linear stability analysis method is proposed for the evaluation. The strategies include active trailer differential braking, active trailer steering and variable geometry approach. A linear 3 degrees of freedom (DOF) yaw-plane car-trailer model is generated for the controllers' design and a nonlinear 21-DOF yaw-roll car-trailer model is developed in CarSim to validate the stability control strategies by means of numerical simulations. To determine the stable motion boundary, eigenvalue analysis is conducted for identifying the vehicle critical speed. The linear quadratic regulator technique is applied to the design of controllers for active trailer braking, active trailer steering and variable geometry strategies. It is revealed that the active trailer braking strategy is feasible and effective for improving the lateral stability of car-trailer systems. Simulation results demonstrate the effectiveness of the linear stability analysis method.

Path-tracking errors for active trailer steering off-highway: a simulation study

This paper discusses the tracking performance of a path-following steering system when operating off-highway. Simulation studies were conducted on three types of vehicle models: tractor-semitrailer, B-double and A-triple. The vehicles were simulated for a straight-line and a 450 roundabout with various road camber, grade and adhesions. Results indicated that the path-following steering system was unable to provide good tracking performance under those conditions due to longitudinal and lateral wheel slip interfering with its estimation of trailer location and orientation.