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In this study, a closed-loop driver-vehicle system model is established with ADAMS/CAR. A double lane change maneuver path boundary is setup based on NATO AVTP 03-160W requirement. Multiple choices of driver preview path are derived from optimization of the closed-loop driver-vehicle-road system, where the objective is to successfully pass the double lane change maneuver at a given forward speed without violating the boundary. With the multiple choices of preview path, the vehicle dynamic responses, such as tire patch load, vehicle lateral acceleration, yaw velocity, steering wheel angle and roll angle, will vary associated with each driver's preview path. The relationship between the path clearance and vehicle dynamic responses as well as the forward speeds is further investigated. Finally a methodology to predict the maximum forward speed to successfully pass double lane change is proposed.

In this study, a closed-loop driver-truck-trailer system model is established with ADAMS/Car. A double lane change maneuver (DLCM) path boundary is set up based on the NATO AVTP 03-160W requirement. The best driver preview path at a given speed to pass the DLCM is derived from optimization of the closed-loop driver-vehicle-road system, where the objective is to successfully pass the DLCM at the given forward speed. This must be done without violating the maneuver boundary, lifting any tires off the ground, as well as staying within the Driver's steering effort limit. Depending upon the Driver's control strategy, which is reflected by the formulation of the optimal objective, the dynamic responses of the truck-trailer combination will vary. Two extreme conditions are discussed in this study: full and no consideration of trailer, respectively, when negotiating the DLCM.

In this paper, we study the sensitivity of a vehicle impact harshness (IH) performance to the suspension bushing rates. A mid-sized uni-body SUV is selected for this study, with the acceleration responses at the driver seat track and the steering wheel as objective functions. A sensitivity study is conducted using an ADAMS full vehicle model including a tire model and flexible body structure representation over an IH event. The study resulted in the identification of key bushings that affect the IH performance and its sensitivity to the bushing rates. Based on the results, we came-up with an “optimal” bushing set that minimizes impact harshness, which was subjectively verified to result in significant improvement in IH.

Dynamic interactions of urban buses with urban roads are investigated in view of the vibration environment for the driver and dynamic tire forces transmitted to the roads. The static and dynamic properties of suspension component and tires are characterized in the laboratory over a wide range of operating conditions. The measured data is used to derive nonlinear models of the suspension component, and a tire model as a function of the normal load and inflation pressure. The component models are integrated to study the vertical and roll dynamics of front and rear axles of the conventional and modern low floor designs of urban buses. The resulting nonlinear vehicle models are thoroughly validated using the fieldmeasured data on the ride vibration and tire force response of the buses.

An outrigger is the device that is mounted on a test vehicle to protect it and/or its driver during handling test maneuvers, such as double lane change, constant radius cornering, J-turn, etc. The design of the outrigger is challenged by the constraints associated with its size, installation flexibility, strength, weight, and moment of inertia for a minimum or negligible impact on the test vehicle dynamics. To achieve an appropriate design of an outrigger for a specific vehicle, it is essential to determine the appropriate dynamic loads that the outrigger needs to support after its geometry and installation scheme have been determined. In this study, a flexible representation of an outrigger is mounted on a military vehicle that is simulated on a NATO double lane change maneuver at the given forward speeds.