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Li-ion batteries (LIBs) optimum performance and lifetime depend on temperature, with the commonly suggested operating temperature being in the range of 25 to 40 °C. It's also crucial to keep the temperature difference between battery cells below 5°C. Operation at different temperature ranges can adversely affect or degrade the performance and lifetime of LIBs. A battery thermal management system (BTMS) is essential for keeping the battery temperature within the optimum range. This paper aims to develop and analyze the BTMS for an electric heavy-duty truck. To achieve this aim, battery cells and modules are modelled in ANSYS Fluent software. Validation with experimental results and mesh sensitivity studies are also performed to increase confidence in simulation data. The model is then analyzed for a specific cooling systems to investigate its effect on battery thermal performance during the operation.

Due to the variability of real traffic conditions for vehicle testing, real-world vehicle performance estimation using simulation method become vital. Especially for heavy duty vehicles (e.g. 40 t trucks), which are used for international freight transport, real-world tests are difficult, complex and expensive. Vehicle simulations use mathematical methods or commercial software, which take given driving cycles as inputs. However, the road situations in real driving are different from the driving cycles, whose speed profiles are obtained under specific conditions. In this paper, a real-world vehicle performance estimation method using simulation was proposed, also it took traffic and real road situations into consideration, which made it possible to investigate the performance of vehicles operating on any roads and traffic conditions. The proposed approach is applicable to all kind of road vehicles, e.g. trucks, buses, etc. In the method, the real-road network includes road elevation.

This paper investigates the optimization of the aerodynamic design of a police car, BMW 5-series which is popular police force across the UK. A Bezier curve fitting approach is proposed as a tool to improve the existing design of the warning light cluster in order to reduce drag. A formal optimization technique based on Computational Fluid Dynamics (CFD) and moving least squares (MLS) is used to determine the control points for the approximated curve to cover the light-bar and streamline the shape of the roof. The results clearly show that improving the aerodynamic design of the roofs will offer an important opportunity for reducing the fuel consumption and emissions for police vehicles. The optimized police car has 30% less drag than the non-optimized counter-part.

Motion cueing algorithms can improve the perceived realism of a driving simulator, however, data on the effects on driver performance and simulator sickness remain scarce. Two novel motion cueing algorithms varying in concept and complexity were developed for a limited maneuvering workspace, hexapod/Stuart type motion platform. The RideCue algorithm uses a simple swing motion concept while OverTilt Track algorithm uses optimal pre-positioning to account for maneuver characteristics for coordinating tilt adjustments. An experiment was conducted on the US Army Tank Automotive Research, Development and Engineering Center (TARDEC) Ride Motion Simulator (RMS) platform comparing the two novel motion cueing algorithms to a pre-existing algorithm and a no-motion condition.

This paper reports the results of a back-to-back comparison of the squeal and judder propensity of simple cast iron and siliconised carbon disk brake systems. A finite element simulation approach is used to predict the squeal propensity of the two systems based on the results of a complex eigenvalue analysis. These results which are validated by dynamometer noise tests carried out according to the SAE J2521 [1] standard procedure show that the siliconised carbon rotor is much less prone to squeal over the range of conditions considered. The combined experimental and numerical simulation approach is also applied to the problem of hot judder for the two rotors. The critical rotational speeds for hot spots to form are predicted to be an order of magnitude higher for the siliconised carbon rotor system. These results demonstrate the potential of the new carbon composite rotor material to reduce the occurrence of noise and vibration problems in automotive brakes.

This paper will present a method of estimating tyre friction force using an extended Kalman filter (EKF). A review of current and proposed methods for tyre force estimation from the literature will be given. The EKF developed will estimate vehicle motions and tyre forces as state estimates from a noisy measurement set. The tyre forces will be compared to those from a high order vehicle model with non-linear tyres, which is subjected to the same tests as the measured vehicle, in order to validate the estimated forces. The robustness of the estimator to noise and input errors will be tested. The ultimate aim of this work is to provide estimates of tyre forces to a controller such as ABS or TCS.

Most active control systems developed for passenger vehicles are developed as safety systems. These control systems usually focus on improving vehicle stability and safety while ignoring the effects on the vehicle driveability. While stability is the primary concern of these control systems the driveability of the vehicle is also an important consideration. An example of compromised driveability in a stability control system is brake based active yaw control. Brake based systems are very effective at stability control but can have a negative impact on the longitudinal dynamics of a vehicle. The objective of the vehicle control systems developed for the future will be to preserve vehicle driveability while ensuring the stability of the vehicle. In this work, active suspension and active drivelines are developed as stability control systems that have a minimal impact on the driveability of the vehicle.

Many active control systems are developed as safety systems for passenger vehicles. These control systems usually focus on improving vehicle stability and safety while ignoring the effects on the vehicle driveability. In the motorsport environment, increased stability is desirable but not if the driveability of the vehicle is heavily compromised. In this work, active suspension and active drivelines are examined to improve vehicle dynamics and enhance driveability while maintaining stability. The active control systems are developed as separate driveability and stability controls and tested individually then integrated to create a multi-objective control system to improve both driveability and stability. The controllers are tested with standard vehicle manoeuvres.

Modern engine developments result in very different gas pressure-temperature histories to those in RON/MON determination tests and strain the usefulness of those knock scales and their applicability in SI engine knock and HCCI autoignition onset models. In practice, autoignition times are complex functions of fuel chemistry and burning velocity (which affects pressure-temperature history), residual gas concentration and content of species such as NO. As a result, autoignition expressions prove inadequate for engine conditions straying far from those under which they were derived. The currently reported study was designed to separate some of these effects. Experimental pressure crank-angle histories were derived for an engine operated in skip-fire mode to eliminate residuals. The unburned temperature history was derived for each cycle and was used with a number of autoignition/knock models.

This paper proposes an advanced control strategy to improve vehicle handling and directional stability by integrating either Active Front Steering (AFS) or Active Rear Steering (ARS) with Variable Torque Distribution (VTD) control. Both AFS and ARS serve as the steerability controller and are designed to achieve the improved yaw rate tracking in low to mid-range lateral acceleration using Sliding Mode Control (SMC); while VTD is used as the stability controller and employs differential driving torque between left and right wheels on the same axle to produce a relatively large stabilizing yaw moment when the vehicle states (sideslip angle and its angular velocity) exceed the reference stable region defined in the phase plane. Based on these stand-alone subsystems, an integrated control scheme which coordinates the control actions of both AFS/ARS and VTD is proposed. The functional difference between AFS and ARS when integrated with VTD is explained physically.

In this paper a gearshift controller for twin clutch transmissions is developed. The controller incorporates the control of engine variables to achieve synchronization whilst the transfer of engine torque from clutch to clutch is managed by a clutch slip control. On top of this gearshift controller and as an extension to the basic control scheme a transmission output torque control is included as a means to directly influence shift character and add robustness to the control. The transmission output torque control also provides the foundation for an integrated torque management scheme of powertrain components. Simulation results for upshift and downshift are presented and discussed in the final chapter of this paper.

A non-linear contact analysis of a leading-trailing shoe drum brake, using the finite element method, is presented. The FE model accurately captures both the static and pseudo-dynamic behaviour at the friction interface. Flexible-to-flexible contact surfaces with elastic friction capabilities are used to determine the pressure distribution. Static contact conditions are established by initially pressing the shoes against the drum. This first load step is followed by a gradual increase of applied rotation to the drum in order to define the maximum reacted braking torque and pseudo-dynamic pressure distribution at the transition point between sticking and sliding motion. The method clearly illustrates the changes in contact force that take place as a function of the applied pressure, coefficient of friction and initial gap between lining and rotor. These changes in contact area are shown to influence the overall stability and therefore squeal propensity of the brake assembly.

A number of handling models of a small high performance formula type racing car have been produced. These have been used to optimise the performance of the vehicle whilst under going simple manoeuvres and around a complete race track. Recently the vehicle was fitted with a data acquisition system and objective data was taken of the vehicle's handling performance. The paper details an investigation into the accuracy of two (a simple and more sophisticated) vehicle handling models in predicting the actual vehicle's performance from the data collected by comparing measured and simulated results. The investigation studies the steady state and transient response of the vehicle up to the limit of the vehicle's handling performance. A description is also given of the use of the more sophisticated model in a virtual race track simulation where it is used as a development tool to tune the performance of future vehicles.

This paper presents a method of control for a 6×6 series-configured Hybrid Electric Off-road Vehicle (HEOV). The vehicle concerned is an eight-tonne logistics support vehicle which utilizes Hub Mounted Electric Drives (HMED) at each of its six wheel stations. This set-up allows Individual Wheel Control (IWC) to be implemented to improve vehicle handling and mobility. Direct Yaw-moment Control (DYC) is a method of regulating individual wheel torque to control vehicle yaw motion, providing greater stability in cornering. When combined with both a Traction Control System (TCS) and an Anti-lock Braking System (ABS) the tire/road interaction is fully controlled, leading to improved control over vehicle dynamics, whilst also improving vehicle safety.

The detailed, dynamic properties of dampers are known to influence substantially some of the subtle - and yet nevertheless hugely important - refinement aspects or ride and handling. Despite this, most of the current work on damping characterization relies on steady-state properties and transient aspects are left largely to subjective in-car assessments by test drivers. The paper describes research work aimed at improving our understanding of the transient properties of dampers through mathematical modeling and then attempting to link these properties to detailed aspects of the vehicle ride and handling. Further experimental work is planned to follow later. From a moderately complex mathematical model of a damper, an attempt is made to identify (a) those transient characteristics which are important in influencing the vehicle responses perceived by test drivers, and (b) which design features of the damper control those characteristics.

Persisting concerns regarding ride comfort, directional stability and more recently road damage have caused the manufacturers of commercial vehicles to consider controllable suspension systems. An electronically controllable adaptive suspension that comprises a variable spring rate system, switchable damping and load levelling is proposed as a cost-effective solution. This paper describes the aforementioned system and provides an outline of the design scheme for a prototype system; practical issues such as system configuration/detail, control system requirements, etc., are discussed. The system is evaluated analytically and both ride and handling modes are examined. In conclusion, performance capabilities are defined and cost-benefit issues addressed.

A non-contacting laser displacement meter has been used for dynamic measurements of the radial movement of a v-ribbed belt (type 3PK) around the arc of wrap running on a belt testing rig. Accurate and repeatable results are possible. Using this device, the belt radial movement and the beginning of rib bottom / groove tip contact around the arc of wrap have been determined experimentally for v-ribbed belts. Slip, torque loss, maximum torque capacity and efficiency have been measured during the tests.

Current trends in automotive engine design are towards smaller, lighter components operating under higher specific loads. Consequently, engine bearings are expected to operate under highly stressed conditions, with minimum lubricant film thicknesses falling below 1μm. There is, however, insufficient understanding of acceptable tolerances on surface geometry of bearing shells and crankshaft pins. Measurement data suggest that some engine crankpins are machined with as many as 21 circumferential lobes. Some lobes have amplitudes in excess of 5 μm and are thought to be responsible for premature bearing damage. This study presents results from a theoretical analysis of dynamically loaded journal bearings with circumferential lobes on the journal. The Reynolds equation for a rigid journal bearing is solved for an incompressible, Newtonian, iso-viscous lubricant, with a flow conserving cavitation model accommodating oil film history.

Torsional motion of a truck driveline system is coupled with other motions of its components. In this paper, a comprehensive model of the truck driveline and body for vibration analysis was developed. Coupling of the torsional vibration of the truck driveline system with the body fore-aft and vertical vibrations was investigated. A mathematical model, including the torsional vibration of the driveline system and the whole body vibrations of the truck, was constructed. The driveline system was modelled as a set of inertia discs linked together by massless springs and the tyre was represented as having massless circumferential band which is elastically connected to the carcass with the bands being subject to longitudinal forces at the road surface. System behaviour at steady and transient runs was developed.

A non-linear example vehicle model including four degrees of freedom (yaw, sideslip, roll and steering), non-linear kinematics and the Magic Formula tyre model has been developed. With the assumption of small perturbations around any steady-state working condition, the linearised equations are derived. A novel approach is used for the linearisation of external forces and moments from the tyres. They are linearised in terms of the state variables rather than the slip angle, camber angle and vertical load which are themselves functions of the state variables. The results of this process are expressed in terms of stability derivatives. In order to use the method, the steady-state solution of the non-linear equations is first obtained for a particular value of lateral acceleration, then after the calculation of the stability derivatives, a linear analysis can be performed for the linear equations in terms of perturbed variables.