INFLUENCE OF VEHICLE SUSPENSION PARAMETERS ON ITS BRAKING PROPERTIES

The paper focuses on the study of the performance of elastic and damping parameters of the car suspension. The problem of arising vibrations of the sprung and unsprung vehicle masses on the braking process is considered. The article presents theoretical models of vehicle braking taking into account the oscillations of the vehicle's sprung masses. The research results will make it possible to establish the relationship between the suspension parameters and the estimated parameters of braking properties, to supplement the "driver - car - road" system, and also to more accurately assess the active safety of vehicles associated with braking dynamics.

Research on lateral and longitudinal correction method of automobile nonlinear dynamics

In view of the large calibration workload of existing models, this paper proposes a compound correction method based on the principle of compound correction control; this method takes open-loop correction as the main body, which represents the driver’s mastery of vehicle dynamics characteristics; on this basis, a closed-loop correction is added to describe driver’s compensation and correction capabilities. Considering the complexity of the longitudinal force of the vehicle, based on the analysis of the longitudinal force of the vehicle, considering the actual situation of the actual driver’s foot switching between the accelerator pedal and the brake pedal, a longitudinal dynamics split-phase correction method is proposed. In addition, this paper proposes a fast calibration method of the inverse model of the main characteristics of vehicle dynamics, which mainly studies the fast calibration method of the main characteristics of braking dynamics and lateral dynamics in order to reduce the time cost. The simulation shows that the compound correction model proposed in this paper not only has a small calibration workload and high control accuracy, but also has a certain adaptive ability to the nonlinear characteristics of vehicle dynamics; the main characteristics of braking dynamics and lateral dynamics proposed in this paper has high accuracy.

Setting up the braking force measurement system of the tractor semi-trailer

The braking force of the tractor semi-trailer depends on many random factors and road parameters. Therefore, determining the braking force based on theoretical calculation or simulation is not accurate. This paper presents the method of setting up the braking force measurement system of the tractor semi-trailer on the road and constructing the braking dynamics model of the tractor semi-trailer to investigate the braking force using Matlab-Simulink software. The study results show that the average error between the simulation and experimental results of the tractor semi-trailer braking force is 9,81%.

Vehicle Adaptive Rear Combination Light with Non-Replaceable Light Sources

Currently, due to the increase in the average speed of vehicles to ensure their visibility, the luminous intensity of their lightning equipment is constantly increasing, that can lead to blindness of other road users, especially at night. On the other hand, if you do not increase the luminous intensity if lanterns, a vehicle will not be noticeable in difficult road conditions (fog, rain, dust) and it can cause an accident. To eliminate this contradiction, a fundamentally new modular design of the adaptive rear combined vehicle light with non-replaceable light sources based on single powerful light emitting diodes and effective secondary optics of large diameter has been developed in the paper. The design provides for the use of an integrated microcontroller to control luminous intensity of its lights, depending on the conditions of external illumination, braking dynamics of a car and surface condition of a lamp diffuser with the possibility of transmitting data via a CAN-bus. Thanks to the built-in microcontroller, the developed flashlight is suitable for installation on vehicles without an on-board computer. These properties allow the flashlight to ensure visibility of a vehicle, and to avoid blinding the remaining road users. The design of the adaptive lamp is small in thickness (up to 40 mm), high luminous efficiency (at least 85 %) and reliability. The conducted lightning tests have shown that the developed lamp fully complies with UN Regulation No 6, 7, 23, 38, 48. The design has been compared with existing analogues of foreign production, which showed that such a lamp consumes less energy (30 %) and has a lower probability of failure due to the use of high-power LEDs used as a light source.

Firefighting Vehicles Braking Distance Metering

The paper topic is concerned with the issue of braking dynamics and adhesion coefficients of firefighting vehicles at fire rescue units. The real breaking distances at firefighting vehicles of the water tenders type are presented in the paper. The metering was made on the wet and/or dry asphalt, with different age of tires and the carload. Measured results should be used for drivers’ education at fire rescue units to increase the safety during the emergency drives.

Effect of recuperative volume parameters on dynamic characteristics of pneumatic drive underbraking

Introduction. Methods of energy saving in pneumatic drive are considered. The method of braking by creating back pressure in the exhaust cavity of the pneumatic actuator is of interest. Under braking, the compressed air energy is stored in the recuperative volume. It is possible to control the braking dynamics through setting the initial parameters of the recuperative volume. The work objective is to create a mathematical model describing the dynamic processes taking place in the pneumatic drive under braking by backpressure, with a constant mass enclosed in the cavities of the air motor, and considering variation of the initial parameters of the braking volume.Materials and Methods. A mathematical model is proposed that describes the speed change of the output link, pressures and temperatures in the cavities of the pneumatic drive depending on the initial parameters of the recuperative volume. The solution to the mathematical model is carried out by the numerical integration method.Research Results. The dependences of the output link velocity, pressures and temperatures in the pneumatic drive cavities on the initial parameters of the recuperative volume are obtained. Adequacy of the built mathematical model is confirmed by Fisher's criterion.Discussions and Conclusions. The results obtained can be used to solve the problems of energy saving in pneumatic drives under the organization of backpressure braking. The use of recuperative volume increases the technological flexibility of the drive during its readjustment and extends the possibilities of energy saving.