Model-based development for an electric power steering system

Abstract

A model-based development method for electric power steering (EPS) system has been explored. A practicable model for the EPS system has been established in a full vehicle mechanical system environment. The performance of the electric control system of the EPS system has been evaluated in this static analysis environment. The model has then been used in a dynamic test environment based on dSPACE hardware and software, including Software-inthe-Loop and Hardware-in-the-Loop. The test result validates the simulation model, and shows that this development method can be used to evaluate the conceptual design of the EPS system as well as the control software design and testing.

A mechanical integral steering system for increasing the stability and handling of motor vehicles

“…It should be mentioned that part of these tests were carried out by using the experimental facilities from the Transilvania University of Brasov, namely the MTS-HTC hydraulic testing equipment from the The front suspension subsystem ( Figure 8) contains two double-wishbone (SLA (Short Long Arms)) mechanisms, which are symmetrically disposed relative to the longitudinal axis of the vehicle. The specific MBS model contains 12 bodies (6 per left/right mechanism) as follows: lower suspension arms (1,2), upper suspension arms (3,4), wheel carriers (5, 6), tierods (7,8), dampers' cylinders (9,10), and pistons (11,12). The suspension arms are connected to the wheel carrier through spherical joints, while bushings (compliant joints) are used for the double-connections to the mount part from the car body subsystem.…”

“…Notation i IV transmission ratio of the speed reducer m n normal modulus r 0 radius of the cam reference circle r p polar radius of the cam S a/b motion amplitudes of the follower S r linear displacement of the front rack S s linear displacement of the follower S [1][2][3][4][5][6] linear displacements of the follower in the limit points z p number of teeth of the pinion from the front steering box z t number of teeth of the gear wheel from the front end of the longitudinal transmission shaft teeth inclination angle e/i steering angles of the wheel outside/ inside (external/internal) the turn f/r medium steering angles of the front/ rear wheels ' a/b phase angles of the cam profile ' c revolute angle of the cam ' t revolute angle of the longitudinal transmission shaft ' w revolute angle of the steering wheel È motion amplitude of the cam (' c max ) È 1/2 angle periods of the steering wheel motion…”

“…From the stability and maneuverability (handling) point of view, an important role belongs to the steering system, certain developments being directed toward reducing the driving effort by using variable transmission ratio steering gearboxes (such as the solution with translating wheel and eccentric sector presented in Alexandru et al 1 ), or the modern solution with electric power steering (EPS) system. 2 As the traditional two-wheel steering systems (usually acting on the level of the front wheels) have inherent limitations, the integral steering (also called four-wheel steering for two-axle vehicles) represents a good solution for increasing the vehicle stability and handling, the references pointed here sustaining the usefulness of the four-wheel steering solutions. The safety potential of a four-wheel steering system in driving tests on roads with various friction coefficients is approached in Berkefeld and Seifert, 3 in relation with a classical two-wheel steering, the authors proposing a method of adapting the steering strategy to various friction coefficients.…”

Experimental Study on Antivibration Control of Electrical Power Steering Systems

“…The designed controller is also implemented and tested. The authors in [11] discussed an electric power steering system development. In [12], the authors discuss the application of an active disturbance rejection controller (ADRC) to an electrical power assist steering system with applications to automobiles.…”

Design and simulation of a steering gearbox with variable transmission ratio

“…Moreover, the assistance (hydraulic-HPS, or electric power steering -EPS) for some types of light/popular vehicles can be avoided. EPS or HPS systems vary steering assist torque, 15 not steering ratios, while for the steering gearbox in study (with translating wheel and eccentric sector) the gear ratio is varied as a function of steering angle.…”