Johan Wideberg

A smartphone application to extract safety and environmental related information from the OBD-II interface of a car

This paper introduces a methodology for the identification of events or potentially dangerous situations in road traffic by extracting information from the OBD-II interface. The proposed system for identifying hazardous locations includes a GNSS positioning system. As such, with the use of existing navigation systems or with the use of newly installed equipment, the exact geographic location where a given risk occurs will be identified.

A Comparative Study of Legislation and Stability Measures of Heavy Articulated Vehicles in Different Regions

This study was carried out to compare a number of stability measures of European heavy trucks with the performance of other high-capacity vehicle combinations in a range of OECD countries. Comparisons are made with truck combinations according to legislation in the USA, South Africa, Central and Southern Europe, and Scandinavia. Also the legislation for high-capacity configurations in the above-mentioned countries are compared, e.g., maximum weights and dimensions. This paper addresses the relationship of truck size and weight policy, vehicle handling and stability, and thus safety. The analysis is performed using the multibody simulation tool ADAMS.

Dynamic effect of the non-rigid modified bicycle model

Abstract In this paper a method to add elastic effects to the classic ‘bicycle model’ for the simulation of the dynamic behaviour of vehicles is presented. The obtained results show that, in the simulations, dynamic effects such as lateral acceleration are more severe when non-rigid models of the vehicle frame are used. This work demonstrates that the modified bicycle model is a useful instrument to predict the response of a vehicle. At present, much effort is dedicated to simulation with rigid body dynamic programs. The proposed method offers an easy way to evaluate the dynamic effects in models with flexible frames. The elasticity of the frame has an important impact on the directional response (yaw gain and lateral velocity) of the vehicles. This method is useful for analysis from the behaviour of vehicles with modifications made after their manufacture. In the design phase the manufacturer has the suitable tools and the experience to avoid designing frames of low rigidity. Nevertheless, in the second-hand market it is very common for trucks and their structure to be modified. The change in rigidity of the frame could have considerable effects on directional stability and handling.

Elastic stress and displacement distribution in an orthotropic multilayered system due to a concentrated load

A method to calculate the fundamental solution of an infinite three-dimensional, linear, elastic, orthotropic, homogeneous multilayered system due to a concentrated load acting in the interior of an arbitrary layer is presented. It was found that an analytical solution does not exist due to the complexity of the eigenvalue solution of the problem. In order to compute the solution a seminumerical method was developed and the resulting equations were solved using the fast Fourier transform (FFT). This paper is based on the work developed in a companion paper (Wideberg and Benitez, Elastic stress and displacement distribution in an orthotropic layer due to concentrated load) for the fundamental solution of an orthotropic three-dimensional layer. Numerical results are presented for a graphite epoxy fibre-reinforced composite plate.

Elastic stress and displacement distribution in an orthotropic layer due to a concentrated load

Abstract The fundamental solution of an infinite three-dimensional, linear, elastic, orthotropic, homogeneous layer subjected to an arbitrary buried source is presented. Although a closed-form solution for the Greens functions (stress and displacement fields due to unit loads) would be of great interest, due to the complex expressions involved, a seminumerical method was used to evaluate the obtained equations. Numerical examples are given to verify the present formulation. These expressions could be used without difficulty as the kernel functions in the boundary integral equation method (BEM). The results are subsequently utilized in a former paper (Wideberg and Benitez, Engineering Analysis with Boundary Elements , 1995, 16 , 19–27) to formulate the multilayered orthotropic medium problem by means of transfer matrices.

Experimental study of impact on SMC composites used in the automotive industry

The signal from a piezoelectric sensor received by a data acquisition system was used to record the temporal evolution of the force transmitted by an impactor on specimens of an SMC composite. A high-speed motion analyser recorded the sequence of images of the impact and fracture of the material. The subsequent processing of this sequence using an image analysis programme provided data for the calculation of various energy magnitudes. The behaviour under impact of this material was then characterised on the basis of these energy magnitudes and the temporal evolution of the force.

More Effective Use of Urban Space by Autonomous Double Parking

The new capabilities of autonomous cars can be used to mitigate to a large extent safety concerns and nuisance traditionally associated with double parking. In this paper double parking for autonom ...

Control of an independent 4WD electric vehicle by DYC method

Current advances in the application of control systems to vehicle dynamics has made it practicable to improve the vehicles longitudinal, lateral and vertical dynamics. Some of the examples of application of these systems to vehicle control are traction control (longitudinal dynamics) to prevent wheel slip, ESP (lateral dynamics) to prevent loss of stability, and active suspension (vertical dynamics) to increase ride comfort. In this paper, the vehicle lateral motion is controlled by direct yaw control (DYC) method. This uses the yaw moment produced by the longitudinal forces of the tyres, for stabilising the vehicle motion during critical cornering conditions. The system has been designed to give substantially enhanced active safety and dynamic handling control. The vehicle dynamics control algorithm is developed for a FOX vehicle by controlling couple traction/braking torque of the four in-wheel motors, from basic driving slogans. These are the steering angle, position of the accelerator pedal and brake by the position of the brake pedal, as shown in Figure 1.

Effect of the fifth-wheel placement on the stability of articulated vehicles

Dynamic stability is crucial for vehicle safety, not least for heavy commercial vehicle safety. An articulated vehicle such as a tractor-semitrailer may if not correctly designed, handled or rebuilt fall into instability when driving. This is affected by several factors of which the geometric location of the fifth wheel is one. The effect on stability of the fifth wheel location along the longitudinal axis is therefore analysed using a simplified model and a more detailed MBS model. Results indicate that the tractor-semitrailer becomes unstable if the fifth wheel is located in a too far rearward position.

Pitch reduction and traction enhancement of an EV by real-time brake biasing and in-wheel motor torque control

This paper focuses on pitch control in braking and traction enhancement in acceleration. During braking the vehicle pitches, which greatly determines the ride comfort; on the other hand, during acceleration an optimum value of wheel slip is desired for better traction. In the first part, we control the vehicle pitch of a Fox electric vehicle by real-time brake biasing. We begin with determining side view swings arm centre positions as a function of wheel travel for both front and rear suspensions. Next using these instantaneous centres, vehicle pitch point is determined and the mathematical model for vehicle pitching is developed. Finally, a PD controller is developed which minimises vehicle pitch using brake biasing. In the second part, the motor torques are controlled by maintaining a constant wheel slip at which maximum longitudinal force is generated. The results show significant reduction in vehicle pitch and better tracking of desired velocity profile.