In this paper, a nonlinear dynamic model of a quarter vehicle with nonlinear spring and damping is established. The dynamic characteristics of the vehicle system with external periodic excitation are theoretically investigated by the incremental harmonic balance method and Newmark method, and the accuracy of the incremental harmonic balance method is verified by comparing with the result of Newmark method. The influences of the damping coefficient, excitation amplitude and excitation frequency on the dynamic responses are analyzed. The results show that the vibration behaviors of the vehicle system can be control by adjusting appropriately system parameters with the damping coefficient, excitation amplitude and excitation frequency. The multi-valued properties, spur-harmonic response and hardening type nonlinear behavior are revealed in the presented amplitude-frequency curves. With the changing parameters, the transformation of chaotic motion, quasi-periodic motion and periodic motion is also observed. The conclusions can provide some available evidences for the design and improvement of the vehicle system.

Nonlinear dynamic analysis of a quarter vehicle system with external periodic excitation

Connectivity and autonomy are considered two of the most promising technologies to improve mobility, fuel consumption, travel time, and traffic safety in the automated transportation industry. These benefits can be realized through vehicle platooning. A vehicle platoon is composed of a group of connected automated vehicles (CAVs) traveling together at consensual speed, following the leading vehicle (leader) while maintaining a prespecified inter-vehicle distance. This paper reviews the different existing control techniques associated with the transitional platoon maneuvers such as merge/split and lane change. Different longitudinal and lateral vehicle dynamics that are mainly used in the transitional platoon maneuvers are discussed. The most used control algorithms for both longitudinal and lateral control used for transitional platoon maneuvers are reviewed and the advantages and limitations of each control strategy are discussed. The most recent articles on platoon control maneuvers have been analyzed based on the proposed control algorithm, homogeneously or heterogeneously of platoon members, type of platoon maneuver, the aim of control problem, type of implementation, and used simulation tools. This paper also discusses different trajectory planning techniques used in lateral motion control and studies the most recent research related to trajectory planning for automated vehicles and summarizes them based on the used trajectory planning technique, platoon or/and lane change, the type of traffic, and the cost functions. Finally, this paper explores the open issues and directions for future research.

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Platoon Transitional Maneuver Control System: A Review

Heavy goods vehicles exhibit poor braking performance in emergency situations when compared to other vehicles. Part of the problem is caused by sluggish pneumatic brake actuators, which limit the control bandwidth of their antilock braking systems. In addition, heuristic control algorithms are used that do not achieve the maximum braking force throughout the stop. In this article, a novel braking system is introduced for pneumatically braked heavy goods vehicles. The conventional brake actuators are improved by placing high-bandwidth, binary-actuated valves directly on the brake chambers. A made-for-purpose valve is described. It achieves a switching delay of 3–4 ms in tests, which is an order of magnitude faster than solenoids in conventional anti-lock braking systems. The heuristic braking control algorithms are replaced with a wheel slip regulator based on sliding mode control. The combined actuator and slip controller are shown to reduce stopping distances on smooth and rough, high friction (μ = 0.9) surfaces by 10% and 27% respectively in hardware-in-the-loop tests compared with conventional ABS. On smooth and rough, low friction (μ = 0.2) surfaces, stopping distances are reduced by 23% and 25%, respectively. Moreover, the overall air reservoir size required on a heavy goods vehicle is governed by its air usage during an anti-lock braking stop on a low friction, smooth surface. The 37% reduction in air usage observed in hardware-in-the-loop tests on this surface therefore represents the potential reduction in reservoir size that could be achieved by the new system.

Designing and testing an advanced pneumatic braking system for heavy vehicles

Theory is derived for calculating the statistical accuracy of a weigh-in-motion (WIM) system with multiple, evenly spaced force transducers, subject to random dynamic tyre forces generated by heavy vehicles. A straightforward design procedure is developed for determining the best spacing between sensors, providing the speed of the heavy vehicle traffic is known. Simulated dynamic tyre forces of two generic heavy vehicle models are used to assess the accuracy of WIM systems for a variety of conditions and it is concluded that a good design choice is to use systems with three sensors spaced along the wheel path. (Author/TRRL)

Design of multiple-sensor weigh-in-motion systems . proceedings of the institution of mechanical engineers

Research on ride comfort analysis and hierarchical optimization of heavy vehicles with coupled nonlinear dynamics of suspension

As a basic theory of the vehicle industry, the vehicle dynamics plays an important role in the development of the vehicle industry. In the past decades, great progress was made in the theory and experiment of vehicle dynamics. This article summarizes recent advances in vehicle dynamics. In vehicle dynamics, the vehicle body (sprung mass), the suspension component (spring and damper) and tire (unsprung mass) are essential parts of the system. The modeling approaches and characteristics of the vehicle, tire and driver model with the respect to handling and driving dynamics are summarized in the paper. The important research issues about the vehicle-pavement coupled dynamics are discussed in detail. Several problems and directions for the further studying in vehicle dynamics are pointed out.

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An overview on vehicle dynamics

A direct yaw moment controller/anti-lock braking system (DYC/ABS) coordinated cornering brake control scheme is proposed for three-axle vehicles to improve the handling performance while shortening the brake distance. A proportional–integral method is designed in DYC control. The cornering stiffness of the two-degrees of freedom vehicle model is fitted in real time. The Dugoff tire model is used to establish the relationship between the yaw moment and wheel slip ratio; an optimal allocation method is proposed to allocate the force requirements to each tire. To verify the effect, vehicle responses under various speeds and turning radii are analysed with DYC/ABS coordinated control, ABS control, and no control based on co-simulation of TruckSim and MATLAB/Simulink. According to the chattering caused by sliding mode control, two sliding mode controllers using saturation function and modified exponential reaching law are, respectively, designed to obtain the braking moment in ABS control. A pneumatic braking hardware-in-loop (HIL) test system is developed; the effectiveness of the strategy is verified by experiments. The results show that the coordinated control can reduce lateral acceleration, brake distance, and brake time when the vehicle runs under cornering brake; thus has an excellent effect on balancing the handling stability and braking safety.

https://ietresearch.onlinelibrary.wiley.com/doi/pdf/10.1049/iet-its.2018.5406

Research on a coordinated cornering brake control of three‐axle heavy vehicles based on hardware‐in‐loop test

The influence of pavement vibration on tire adhesion is of great significance to the structure design of vehicle and pavement. The adhesion between tire and road is the key to studying vehicle dynamics, and the precise description of tire adhesion affects the accuracy of dynamic vehicle responses. However, in most models, only road roughness is considered, and the pavement vibration caused by vehicle-road interaction is ignored. In this paper, a vehicle is simplified as a spring-mass-damper oscillator, and the vehicle-pavement system is modeled as a vehicle moving along an Euler-Bernoulli beam with finite length on a nonlinear foundation. The road roughness is considered as a sine wave, and the shear stress is ignored on the pavement. According to the contact form between tire and road, the LuGre tire model is established to calculate the tire adhesion force. The Galerkin method is used to simplify the partial differential equations of beam vibration into finite ordinary differential equations. A product-to-sum formula and a Dirac delt function are used to deal with the nonlinear term caused by the nonlinear foundation, which realizes the fast and accurate calculation of super-high dimensional nonlinear ordinary differential equations. In addition, the dynamic responses between the coupled system and the traditional uncoupled system are compared with each other. The obtained results provide an important theoretical basis for research on the influence of vehicle-road coupled vibration on tire adhesion.

Influence of vehicle-road coupled vibration on tire adhesion based on nonlinear foundation

The tire-road contact mechanics is the key problem in vehicle ride comfort and road-friendliness research. A flexible roller contact (FRC) tire model with the enveloping property is introduced to reflect the contact history between the tire and the road. Based on D’Alembert principle, an integral balanced suspension (IBS) model is established, considering mass and moment of inertia of the stabilizer rod. The sprung mass acceleration and tire dynamic force for balanced suspension and the traditional quarter-vehicle model are compared respectively for frequency and time domain responses. It is concluded that the quarter-vehicle model can be used to evaluate the ride comfort of vehicles; however, it has some limitations in evaluating the vehicle road-friendliness. Then, the dynamics performances for IBS model are analyzed with the single point contact (SPC) model and FRC model, respectively. These works are expected to propose a new idea for the vehicle-road interaction research.

Heavy vehicle dynamics with balanced suspension based on enveloping tire model

This study proposes a coordinated control strategy to improve the safety, handling stability, riding comfort of the heavy-duty vehicle. The strategy is based on the coordination of direct yaw moment control (DYC) and anti-lock braking system. The model predictive control (MPC) method for DYC considering sideslip angle and yaw rate is presented. The sideslip angle and yaw rate are adopted to be the indicators for handling stability, constraints considering the maximal force of actuator are implemented in the MPC. The control scheme is examined on a non-linear three-directional coupled model in the environment of MATLAB/Simulink and TruckSim. The relationship between yaw moment and wheel slip ratio is obtained by the Dugoff model, which can be easily implemented in hardware-in-loop (HIL) tests. HIL tests are conducted to verify the improvement introduced by the coordinated control with MPC. Vehicle responses under various speeds and turning radii are analysed by comparison of proportional–integral control and MPC. The results specify that the proposed coordinated control scheme with MPC could obtain better lateral stability.

https://ietresearch.onlinelibrary.wiley.com/doi/epdf/10.1049/iet-its.2019.0712

Shaohua Li

Papers

An overview on vehicle dynamics

Research on a coordinated cornering brake control of three‐axle heavy vehicles based on hardware‐in‐loop test

Influence of vehicle-road coupled vibration on tire adhesion based on nonlinear foundation

Heavy vehicle dynamics with balanced suspension based on enveloping tire model

Model predictive coordinated control of heavy-duty vehicle using non-linear three-directional coupled model