Straight Travel Research Articles

A Steering Control of Automated Guided Vehicle by Fuzzy Reasoning.

In recent year, fuzzy control has been applied to various industrial field and its availability has been reported. The purpose of application of fuzzy control is to realize the control performance using the experience of expert (control rules) with “If … Then …” rules. Now, easier operation and excellent performance of AGV (Automated Guided Vehicle) at high speed are required. The steering control of AGV with the conventional PI controller, however, becomes difficult to achieve the excellent performance. Therefore, the authors propose the steering control of AGV using fuzzy control, which can obtain stable steering control.In this paper, we discuss the optimal position of guide sensor and make an experiment in the straight traveling. We introduce many rules for fuzzy reasoning and discuss how to choose the rules for fuzzy reasoning and achieve the stable steering control. Then, the experiments of steering response for the step change of guide tape are carried out with the fuzzy control as well as the conventional PI control. The results of steering control using fuzzy control are better than that using PI control. It is confirmed that the proposed steering control is very available.

SIMILITUDE IN STUDIES OF TURNING RESISTANCE OF TRACKED VEHICLES

The vehicles of crawler type, such as bulldoder, are superior in the trafficability of off the road. On the contrary, the turning resistance may be several times larger than that of straight travelling. Therefore the turning performance of tracked vehicles gives a serious problem.This paper descries the similitude technique of soil-gear interaction system. The results of turning resistance test of the regid track models were reported and discussed to find the way of approaches to the solutions of the prediction methods of the prototype performances from the model tests.When the both model and prototype were tested on the same soil conditions and same track ratio (=0.2), the relation between turning resistance moment of prototype M and that of model Mm has been given as follow;M=nkMmwhere, n is scale length, k=3.94 on dry sand, k=3.81 on wet sand and k=3.24 on clay.

Tire-soil interaction model for turning (steered) tires

A review of the experimental information on the development of lateral forces on tires traveling at an angle to their center plane is presented and the usefulness of the consideration of the lateral forces for the development of an analytical model is evaluated. Major components of the lateral force have been identified as the forces required to balance the tractive force and the drawbar pull vectorially. The lateral forces are generated by the shear stresses developing in the contact area and the horizontal component of the normal stresses acting on the in-ground portion of the curved side walls of the tire. The tire-soil interaction model for steady state straight travel has been expanded to include the necessary algorithms for the calculation of these lateral forces. The pattern of tractive force-slip and longitudinal-lateral force relationships is in general agreement with experiments.

Basic study for the turning resistance of track

Abstract : In recent years, the construction equipments have been even used on the soft ground. The vehicles of crawler type, such as bulldozer, are superior in the trafficability of off the road. On the contrary, the turning resistance may be several times larger than that of straight travelling. Therefore the turning performance of tracked vehicles gives a serious problem. Formerly, the turning resistance was calculated by using the adhesion coefficient or coefficient of slip resistance between soil and under side of the track. But the turning resistance of the track should consist of the slip resistance of its bottom and the bulldozing resistance due to the passive earth pressure produced by side face of the track.