IMPROVING THE HANDLING OF PASSENGER CARS DURING COMBINED BRAKING

Traffic safety is associated in most cases with the loss of controllability of cars and other high-speed vehicles. The loss of trajectory controllability when driving in a turning mode at high speeds on roads with a low coefficient of adhesion is especially dangerous. Various automatic devices are used for this, but during emergency braking on a turn, it is possible to reduce acceleration and increase the braking distance. Improving the controllability of a car, while maintaining the required deceleration of the car, is possible with combined braking. To implement the improvement of the controllability of a car in the specified driving mode, it is necessary to establish the dependencies of its controllability, taking into account changes in the effective engine power and tire deformation. The article selects a scheme for modeling the movement of a car during combined braking in a turn. An assessment of the controllability of a passenger car is provided as an object of control during braking in a turn, which can be the value of the transfer function of the car control system. Such a function is considered as the ratio between the value of the steering wheel angle and the angle of rotation of the longitudinal axis of the car that performs emergency braking, starting from the turn. The dependence that needs to be fulfilled to improve controllability is established on the example of turning a passenger car. The controllability assessment is performed on the deviation of the longitudinal axis of the car and the ratio of the angles of rotation of the steered wheels and the angles of the tires entering the car base. In this case, it is necessary to take into account the speed of rotation of the steering wheel. The practical implementation of the task on passenger cars is possible when using high- speed microprocessor control systems with a traditional hydraulic drive of both the working brake mechanisms and the hydraulic power steering. Determining the controllability indicators using the above method will allow more thorough justification of the parameters of the drive actuators and the elements of the chassis system and developing an effective control algorithm.