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One of the long-running themes throughout vehicle dynamics research has been a desire for a better understanding of the correlation between subjective and objective measures of vehicle handling. This theme can be traced back to the earliest contributions of that great automobile engineer Maurice Olley, who provided an analytical insight into qualitative expressions of vehicle behaviour. Results from a set of experiments using two vehicles, eight drivers and forty-six response metrics have been analysed to identify links between objective data and driver ratings of passenger car handling. The procedures involved matching objective metrics to ratings using ridge regression plots followed by least squares regression. Results showed that 70 to 90% of the variability of drivers' ratings could be accounted for by regression equations with greater than 95% significance.

In this paper, the vehicle body attitude in response to low frequency dynamic loads experienced during braking, accelerating, cornering, aerodynamics or payload variations can be controlled using an electronically controlled active suspension. Using a four degree of freedom half vehicle model, a composite controller which consists of Linear Quadratic Regulator vibration controller (LQR) plus Proportional-Integral-Derivative controller (PID) has been designed to isolate the body vibration from the road surface irregularities and maintain the body static height constant as well as control the body pitch motion. Vertical step inputs and different longitudinal step braking forces were applied to the body C.G. to simulate the payload variations and emergency braking effects.

The paper reviews the contributions of vehicle dynamics theory to practical vehicle design. Although much of the early work on the subject focused on passenger cars, its subsequent impact on commercial vehicle design has been equally dramatic. Recent advances in actively controlled components e.g. active suspension, multi wheel steering are reviewed and their potential impact on future truck design is assessed.

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.

The development of Integrated Chassis controllers has followed two main approaches. The pragmatic approach is to integrate existing chassis subsystems (e.g. DYC, ABS, TCS, ARC) with heuristic control laws. The more theoretical approach is to calculate control actions by solving a model of the vehicle dynamics. There is a dearth of literature that investigates the interface between these two strategies. This interface can give vehicle manufacturers ownership of the core vehicle motion control algorithm and allow them to select chassis controllers from a range of component suppliers. IVMC aims to give a global design methodology for Intelligent Vehicle Motion Control that interfaces a theoretical, generic controller with existing chassis subsystems. The interface takes the generic actuation forces and distributes them to the braking and steering chassis subsystems, DYC and active steering.

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.

This research paper is focused on a novel transmission which provides a continuously variable gearbox based on two epicyclic gear sets plus two electric motor/generator units. This design scheme offers potential efficiency benefits over its competitors. It is referred to as a four branch transmission [1], because it has four independent power input and output, namely the engine, two motor/generators and the output shaft of the transmission. A key advantage of the design, when it is used on a hybrid electric vehicle, is that the electrical machines, namely the two motor/generators, and can be downsized compared with the more common, single epicyclic, 3 branch arrangement. A matrix method for the analysis of planetary transmissions [2] is used; the performance and control strategy of the new system is presented.

A comprehensive and systematic approach to vehicle dynamics analysis is described. All the commonly required calculations for vehicle dynamics studies have been embodied in a computer package called VDAS (Vehicle Dynamics Analysis Software). Examples taken from off-road vehicle applications are chosen to show how this particular class of dynamics problem can be tackled efficiently using this package. In addition to the standard range of calculations for vehicle ride and handling behaviour, e.g. natural frequencies, mode shapes, frequency responses, power spectral densities, steady state handling diagrams etc., the package incorporates more advanced features including derivation of control laws for active/semi-active suspension applications and sensitivity analysis to assist design studies. The VDAS package currently contains a range of ride and handling models of varying degrees of complexity, suitable for vehicle analysis.

In this paper, a hybrid roll control system, including passive and active roll control units, is designed to improve the roll dynamics of tanker vehicles and to reduce the lateral shifts of the liquid cargo due to lateral accelerations. The passive control system consists of radial partitions installed inside the vehicle container. These partitions rotate in phase with the liquid cargo as one unit about the longitudinal axis of the container in response to the induced momentum forces due to the lateral acceleration excitation. Torsion dampers are fixed between the partitions and the container's front and rear walls to reduce the oscillating motion of the liquid cargo. While the passive partition dampers control the dynamics of the liquid cargo inside the container, the dampers of the vehicle suspension are switchable, generating anti-roll damping moments based on the lateral acceleration level and the container filling ratio.