차륜 독립구동형 직렬 하이브리드 지게차의 연비 분석을 위한 후륜 조향시스템 모델링

Abstract

This paper introduces the modeling of the hybrid forklift, which simulates the effect of the rear-wheel steering system. Most of working cycles of the forklift consist of frequent tight turnings, as well as many starts and stops. Moreover, the maximum of the rear-wheel steering angle is about two or three times larger than that of the front-wheel steering angle in the passenger car. Therefore, the speed difference between the inner-wheel and the outer-wheel cannot be ignored in the cycle simulation, differently from most researches about the hybrid passenger car. In this paper, the speed of each wheel is calculated using the Ackermann geometry, where the wheel steering angles are calculated by kinematic model of the steering mechanism. This steering system model is combined with a powertrain model for the series hybrid forklift. All of these models are developed in the Simulink® environment. The simulation result shows that the operating point of the each traction motor is differed from each other when turning at the tight corner.