Heavy Vehicle Systems Research Articles

Design and verification of a novel energy-efficient pump-valve primary-auxiliary electro-hydraulic steering system for multi-axle heavy vehicles

Multi-axle heavy vehicles employ a variable-length tie rod steering system to achieve precise multi-mode steering. However, the single-axle steering system need integrate two sets of electro-hydraulic control systems (EHCSs), resulting in the energy consumption significant increase. This paper proposes a novel energy-efficient pump-valve primary-auxiliary electro-hydraulic steering system (PVPA EHSS) which compose of a pump-controlled dual-steering cylinders primary system and a valve-controlled variable-length tie rod cylinder auxiliary system. The proposed system utilizes a single pump to drive both the primary and auxiliary EHCSs simultaneously, enabling high-precision and high-efficiency steering with multi steering modes. Additionally, to suppress the flow disturbance of the auxiliary system branch flow on the single-pump-controlled steering primary system, the interaction between the flow of the auxiliary system and the flow of the primary system in each steering phase is studied. A pump flow feedforward-angle feedback composite control strategy incorporating branch flow prediction is proposed to mitigate the disturbance and ensure the accurate steering of left and right tires. The experimental results demonstrate that compared to the traditional variable-length tie rod steering system, the proposed system reduces energy consumption by 58.66 %, and achieves precise adaptation of the left and right tire angles in multi steering modes.

Hybrid Neuro-Fuzzy Based Improved Control Design of Electro-Pneumatic Clutch Actuation Control System for Heavy Duty Vehicles

The application of hybrid Neuro-Fuzzy principles of clutch actuation control in enhancing the performance of electro-pneumatic clutch actuation system for heavy duty vehicles is the aim of this presentation. Neuro-Fuzzy is a hybrid design that accommodates the principles of fuzzy Logic and Neural Network in a manner that take advantage of their positive sides. The inability of some heavy-duty vehicles to operate optimally on hilly terrains and which often results in road mishaps are traceable to the inadequacies in conventional clutch actuation control mechanisms. These conventional actuation control techniques provide for routine calibration of clutch actuators after maintenance. Often times, this important requirement of calibration is neglected with attendant ugly consequences. To stem this tide of manual calibration and its obvious defects, an intelligent method of clutch actuation modelled in a hybrid Neuro-Fuzzy control is implemented. Conventional data obtained for errors, speed, torque and power from Mercedes Benz Actros Truck model MP 2, 2031 provided the reference points. These data were embedded into a Simulink block and cascaded into a designed Neuro-Fuzzy Simulink model. Both conventional and Neuro-Fuzzy Simulink model controllers were also simulated. Different percentages of improvements were recorded for piston error, angular speed, engine torque and power respectively. The level and percentage of improvements stood at 0.4821mm or 33.04% decrease for error, increases of 334.1 RPM or 33% for angular speed, 0.0594NM or 33.26% for torque and 2.79W or 16.53% for power respectively.

Research on energy saving and control characteristics of back pressure controllable variable speed pump controlled steering system for heavy vehicles

Research on energy saving and control characteristics of back pressure controllable variable speed pump controlled steering system for heavy vehicles

High-dynamic steering control of the pump-controlled electro-hydraulic steering system for heavy vehicles with active disturbance suppression

Low-frequency response, strong nonlinearity and unknown disturbances are the main challenges faced by the engineering application of the pump-controlled electro-hydraulic steering systems (EHSSs) for heavy vehicles. To solve the above problems, an active disturbance suppression controller is proposed based on a variable rate reaching law (VRRL) and a terminal sliding mode observer (TSMO) in the framework of the sliding mode control. This controller is unique because, the VRRL introduces a nonlinear activation function, which enables smooth switching between multiple reaching rates, effectively improving the response speed and the disturbance rejection performance of the pump-controlled EHSS. Furthermore, an adaptive incomplete disturbance compensation control strategy is proposed by incorporating a TSMO to further improve the accuracy and robustness of the steering system, which employs a VRRL-based TSMO to realize accurate estimation of the lumped disturbance in finite time, and avoids controller overcompensation by selecting a preferred disturbance compensation coefficient. The stability analysis demonstrates that the proposed controller effectively suppresses the lumped disturbance and reduces the convergence domain of the steering system. A pump-controlled EHSS experimental bench is constructed, and a series of experiments are conducted with various steering frequencies and load conditions, which validate the ability of the proposed controller to achieve high-precision dynamic steering in all-terrain conditions of the pump-controlled EHSS for heavy vehicles.

Enhancing energy efficiency in tyre pressure and temperature monitoring systems

This study addresses the pivotal challenge of enhancing power efficiency in tyre pressure and temperature monitoring systems (TPMS) for heavy vehicles and trailers. Employing field-programmable gate arrays (FPGA) and adaptive channel frequency hopping in bluetooth low energy (BLE) communication, the research focuses on mitigating power consumption issues specific to heavy vehicles with multiple tyres. The proposed solution incorporates strategic BLE channel blocking and adaptive frequency hopping on the FPGA platform to alleviate channel congestion and interference, ultimately reducing TPMS power consumption. The FPGA's adaptability tailors frequency hopping strategies to automotive TPMS nuances, optimizing channel selection and minimizing energy-intensive processes. Empirical results showcase a significant reduction in power consumption, with the TPMS operating at 100 MHz during active mode consuming 66 mW, dropping to 11 mW in sleep mode, and reaching 0 mW in hibernate mode for the majority of operational time. This research establishes a practical FPGA-based approach for power optimization in commercial TPMS, promising heightened reliability, safety improvements, and environmental impact reduction in the automotive sector.

Magnetic Field Analysis of 50 kW Wireless Power Transfer System for Heavy Duty Vehicles

Magnetic Field Analysis of 50 kW Wireless Power Transfer System for Heavy Duty Vehicles

T-Fire System: A Novel Integrated Fire Monitoring and Extinguishing System for Trucks

Nowadays, fires on heavy vehicles and trucks still represent a severe threat to environment and people safety, with serious consequences and injuries. In this context, fire losses can be minimized by preventing the rapid onset of fire and allowing drivers and occupants to escape safely by implementing an effective fire monitoring and extinguishing system. Commercially available fire extinguishing systems have shown multiple lacks concerning the structural implementation of the system only on specific types of heavy vehicles, the monitoring of system parameters, and the environmental toxicity of the extinguishing agents employed. Therefore, the present article proposes the early design and development of a novel integrated fire monitoring and extinguishing system for trucks and heavy vehicles called ‘T-Fire System’. The proposed solution can operate in any environment (confined and not) through a close interconnection between the onboard diagnostic sensors and the plug and play fire extinguishing system which employs environmentally sustainable fluorine-free extinguishing agent. The development of the T-Fire System has started from a patented prototype, and preliminary evaluations of both the monitoring and the fire extinguishing system have shown promptness and reliability. Further research will be focused on improving and customising the solution for the pre-industrialization phase of the system.

Research on hydraulic braking energy recovery system of heavy vehicles

The carbon emission of a heavy-duty diesel vehicle is almost equal to the sum of 100 small cars. In the global environment where energy conservation and emission reduction are advocated, the pollution caused by heavy vehicles is non-negligible. A hydraulic brake energy recovery and regeneration system can store the braking energy, convert the energy into kinetic energy and output it to the vehicle transmission system when starting or accelerating, thereby reducing energy consumption and achieving the role of energy conservation and emission reduction. Firstly, this paper mainly summarizes several vehicle energy recovery technology schemes and determines the hydraulic braking energy recovery scheme after a comprehensive comparison. Secondly, the overall structure of the hydraulic brake energy recovery and regeneration system is designed, and the working mode is analyzed. Finally, according to the working characteristics of the main components in the system, the mathematical model is established, the key parameters are simulated and studied, and the appropriate selection and matching scheme is provided.

Distributed Hybrid Power System and Vehicle for Heavy Vehicles

Distributed Hybrid Power System and Vehicle for Heavy Vehicles

Adaptive robust steering strategy for electro-hydraulic hybrid steering system based on backstepping method

Aiming at the angle tracking problem of electro-hydraulic hybrid steering (EHHS) system of heavy commercial vehicles in intelligent driving mode, the dynamic model of the system is established. In order to weaken the influence of nonlinear disturbance and parameters, an adaptive robust controller based on backstepping method is designed, a linear extended state observer is established to predict the disturbance. Triangular programming and trapezoidal programming are introduced into the upper level planning of steering angle position to improve the performance, so as to realize the tracking control of steering angle. In order to verify the effectiveness of the control algorithm, the designed controller is compared with DRC control. The results show that the controller used in this paper has higher servo accuracy, smaller error, and better robustness to interference. And to verify the improvement of the speed planning algorithm, the simulation is compared with the non-planning algorithm. The results show that adding the planning algorithm can reduce the control effect error and avoid the response oscillation to a certain extent. Finally, HIL bench test shows that the control strategies under various working conditions have good effect, and meet the steering angle tracking requirements of commercial vehicles in intelligent driving mode.

Heavy Vehicles: Distributed Hybrid Power System and Vehicle

This research focuses on the development of a distributed hybrid power system and vehicle for heavy vehicles. The dynamical system comprises a power plant module, a drive module, an energy-storage module, and an entire car controller. The power plant module consists of one or more auxiliary power units that provide power to the heavy vehicle's power system. The drive module includes multiple driver elements responsible for directly driving the heavy vehicle's drive axles or operating individual wheels through direct drive. The energy-storage module serves as an energy reserve. The entire car controller is connected to the power plant module, drive module, and energy-storage module, enabling control over the activation of driver elements and the output of these elements to manage the heavy vehicle's transportation conditions. The novel approach eliminates the need for mechanical power transmission systems found in conventional engines and drive axles, allowing for flexible arrangement of auxiliary power units and driver elements on heavy vehicles.

Investigation of inerter-based suspension systems for heavy vehicles.

The inerter is a two-terminal component that can be added to the spring-and-damper configuration of a suspension system. It has the property that the force exerted is proportional to the relative acceleration at its terminals. Studies have demonstrated the inerter's benefit of providing superior vibration isolation when it is used in the vehicle suspension of passenger cars. However, similar benefit on another common vehicle class on the roads, namely heavy vehicles, remain to be shown, as these vehicles have vastly different parameter values than passenger cars. This study is an investigation on the performance improvement brought by an inerter in the suspension of common heavy vehicles. In the study, the parameter values of a truck and a bus were adopted in the quarter vehicle model with two different spring-damper-inerter configurations (parallel and serial inerter), and the improvements in vibration isolation and road holding capability were determined by optimization of inertance. Results show that the inerter is similarly effective in providing the said improvements when implemented on heavy vehicles instead of on passenger cars, judging from reductions in sprung mass acceleration and dynamic tire load. It is also observed that the performance benefit is associated with larger optimum inertance than that for passenger cars. Overall, the inerter has been shown to be beneficial in the parallel and serial configurations, both of which are common and can be practically implemented in the suspension of heavy vehicles.

Investigation of the heavy duty truck gear drive failure

For heavy vehicle systems, within the power transmission chain from the driving machine to the working components (wheels), gears have a large share of application in the form of gearboxes, differentials and speed reducers. Their purpose is to achieve the highest possible output torque at the working components. In one heavy-duty truck, the gearbox lost its working capacity due to the failure of its vital parts: a tapered roller bearing and a helical gear. The analysis presented in this paper, conducted on the basis of experimental and analytical methods, showed that, due to inadequate installation of the bearings’ outer ring in the gearbox housing in one intermediate shaft support, the roller bearing performed its elementary function in very unfavorable working conditions of mechanical and thermal nature. Due to the damage accumulation, the roller bearing gradually lost its working capacity. As a result, the intensity of the working conditions of the entire gearbox increased. At the moment when they reached the critical value from the aspect of the gear teeth bending strength, volumetric destruction occurred, i.e fracture of the helical gear tooth, and thus the cessation of gearbox power transmission.

Component sizing and sensitivity analysis of design parameters of a hydraulic-pneumatic regenerative braking system for heavy duty vehicles

A regenerative hydraulic-pneumatic braking system for trucks or busses must allow recovery of braking energy in both high energy/low power situations, such as long downhill grades, and low energy/high power situations, such as those typical of urban traffic. Proper component sizing must get the best out of both situations. The main contribution of this work is the development of a component sizing strategy that will greatly accelerate the development of designs for a given target. Once components are defined, subsequent studies can be performed under dynamic conditions to refine the design, including improving local and higher-level controls. The design strategy presented is applied to a 12-ton commercial vehicle and its behavior is then simulated using a full nonlinear dynamic numerical model previously validated against a laboratory prototype. The efficiencies predicted by the design method deviate only by 3.1% and 6.7% from the results of the dynamic model for urban and highway traffic, respectively, which is reasonable for the design phase of a hybrid hydraulic-pneumatic powertrain. The component equations and computational strategy can also be used for sizing other hydraulic or pneumatic system architectures.

Adaptive neural network finite-time control for nonlinear cyber-physical systems with external disturbances under malicious attacks

This paper is concerned with the finite-time tracking control problem for a class of high-order nonlinear cyber-physical systems (CPSs) with external disturbances, which are subject to malicious attacks occurring in controller-actuator (C-A) channel. Combining the variable structure (VS) control method and the artificial neural network (NN) technique, a novel adaptive neural network finite-time control strategy is developed. In particular, a Gaussian radial basis function neural network (RBFNN) is designed as an adaptive neural estimator working in an online manner to achieve the estimation and reconstruction of malicious attacks and external disturbances. Furthermore, rigorous proofs have been presented to show that the proposed control scheme can guarantee that the output tracking error converges to the origin in finite time. Finally, the proposed control scheme is applied to heavy duty vehicle system (HDVS) as a testbed, and a representative simulation is provided to demonstrate the validity and effectiveness of the proposed method.

Gain-Scheduled Steering and Braking Coordinated Control in Path Tracking of Intelligent Heavy Vehicles

Abstract In the context of intelligent transportation system and advanced vehicle control system, higher requirements for intelligent control and coordinated control of heavy vehicles (HVs) have been proposed. Automatic path tracking control is essential for automatic driving of heavy vehicles. However, uncertain lateral disturbances and time-varying characteristics of system parameters make it difficult to guarantee roll stability and path tracking accuracy during automatic path tracking. This paper investigates the coordination of active front steering (AFS) and direct yaw moment control (DYC) in the automatic path tracking system for intelligent heavy vehicles. The main idea is to adjust the braking action according to the rollover risk evaluated by a specific rollover index (RI). The coordination of steering and braking systems and the robustness of the system against time-varying parameters are achieved by a gain-scheduled linear parameter varying (LPV) controller. Based on the linear matrix inequality (LMI) framework, the LPV controller is synthesized to ensure the robust H∞ performance against external disturbances. Simulation results show that the proposed gain-scheduled LPV/H∞ control strategy can enhance roll stability and path tracking accuracy in the path tracking process of intelligent heavy vehicles.

Driver awareness collision/proximity detection system for heavy vehicles based on deep neural network

Heavy vehicles are essentially used to perform several critical tasks in construction industry. These heavy vehicles are different in shape and structure according to their capabilities and needs on the construction sites. Bigger size and different design of these vehicles result in extended blind spot compare to the normal vehicles, thus risking the equipment and workers operating around them. Each year, a large number of incidents are reported involving human injuries or loss of life due to improper handling of blind spots in heavy vehicles. In this paper we developed a deep learning based collision detection and driver assistance methodology by removing the blind spots in haul truck. In the proposed methodology, vision sensor data is used for automatic detection and classification of objects, employing the YOLO-v5 network architecture. For distance measurement of the objects we used stereo imaging camera Intel RealSense D455. The proposed algorithm detects and classify the object around the vehicle and provide the captioning to describe the nature of object to the driver. In addition, the algorithm also measures the distance of objects from the vehicle. The experimental results validate the performance of our proposed methodology in real time.

A Design Methodology for Dual-Mode Electro-Mechanical Transmission Scheme Based on Jointing Characteristics

Electro-mechanical transmission is the best choice for the transmission system of military, engineering and other heavy special vehicles. The scheme design is fundamental and key to realize the original innovation of the electro-mechanical transmission. Therefore, a novel design method of a planetary-gear scheme is proposed for electro-mechanical transmission. According to the distribution of mechanical points and the speed continuous condition of mode switching, the mode combination law of a dual-mode electro-mechanical transmission is obtained, i.e., the input split mode based on the scheme of three-degree-of-freedom (3-DOF) and the compound split mode based on the scheme of 2-DOF. Moreover, a design method for an electro-mechanical transmission scheme is proposed based on the mode combination law. Two single-mode schemes are combined to form a dual-mode scheme, and then mode jointing, control logic, isomorphism and other screening conditions are in turn used to screen schemes; therefore, two optimized schemes are obtained ultimately. Lastly, by analyzing the characteristics of speed, torque and the power split of the optimized schemes, the accuracy of the proposed design method in this paper is verified. The proposed design method can provide new ideas of designing multi-mode and multi-output electro-mechanical transmission schemes.

Failure analysis of repairable systems with k-out-of-m configuration considering with common cause failure and maintenance correlation based on goal oriented method

System reliability directly affects the application of Prognostic and Health Management (PHM) technology. This paper proposed a new Goal Oriented (GO) methodology for failure probability analysis of repairable systems with the Common Cause Failure (CCF) and maintenance correlation (MC). It should be noted that the considered repariable systems in this study are k-out-of-m configuration. Firstly, an improved GO algorithm solving the CCF is elaborated. Second, a failure analysis framework for repairable systems taken into account of CCF and MC is developed based on Markov theory. Finally, the new GO methodology is applied in analysising the dynamic unavailability of Hydraulic Oil Supply System (HOSS) of heavy vehicles. Comparisons with two traditional methods indicated that the proposed methodology provides higher efficiency. Furthermore, this work can widen the application of GO methodology.

Fault Diagnosis and Protection of Phase Auxiliary Output for Automotive D+ Alternators

In heavy-duty vehicle applications, the D+ alternator with the alternator-voltage-regulator (AVR) is widely used to supply electric loads due to lower cost and wide application possibilities. The phase voltage of D+ alternator is usually connected as auxiliary output, such as techometer; however, its wiring may short to ground through the vehicle frame due to the damage of the isolation. This would result in severe thermal events and safety issues. In this paper, a novel phase fault diagnose and protection method is proposed to prevent the thermal event and safety issue for phase auxiliary output fault in D+ alternator system of heavy duty vehicles. The method detects the voltage dip from D+ terminal without extra wiring or external components. Besides, prior art issues such as complex design, high noise sensitivity, and higher cost can be solved. The analysis and LTSpice simulation of D+ voltages in normal conditions and fault conditions set the foundation and parameter design for the proposed method. The experimental platform with a three-phase D+ alternator verified that the proposed method can diagnose and protect the ground fault while the alternator is generating power with rotating speed ranging from 2000 to 6000 rpm, and the AVR can stop the alternator output to prevent the thermal event. As soon as the fault is removed, the AVR can automatically reboot the system and return to a normal operation mode.