Mathematical modeling of the electric power steering system of a vehicle with a worm drive

Abstract

The complexity and variety of requirements imposed on modern cars have led to a variety of designs of steering amplifiers, which are based on various physical phenomena and patterns (mechanical, pneumatic, hydraulic, electrical, etc.). Despite the difference in design and operating principles, steering amplifiers of domestic and foreign production are based on a large number of complex components and parts, which reduces their reliability. In addition, due to the constant impact of amplifiers on the controlled wheels, the driver does not feel changes in the behavior of the car on the road when disturbing influences occur, which reduces traffic safety and can lead to an accident. Therefore, increasing the sensitivity of the steering wheel to adverse factors acting on the wheels of the car while driving is one of the important tasks of improving power steering system. Introduction of electric power steering systems for cargo and passenger vehicles with a load capacity of up to 20 tons. this is a very urgent problem. In contrast to power steering system, which is still used in the control systems of high-tonnage vehicles, electric power is much simpler in design, does not require much time and costs for operation and repair. Electric power steering system with worm drive, which has a gear ratio significantly higher than those used in passenger cars, is considered. For this purpose, the formula for calculating the active moment of resistance due to the angle of transverse inclination of the pin and the corresponding system of differential equations characterizing the electric power steering system with worm drive are derived. Based on this, a functional diagram of the electric power steering control system has been developed, which is unified for worm drive steering systems and can serve as a base for modeling the steering system of cargo and passenger vehicles.