The Development Of Tricycle Driving Simulator Based On VR Technology

Virtual reality technology merged a lot of information technology branches,such as digital graphics processing, computer graphics, multimedia technology, sensor technology, so it is a rising information technology at the end of the 20th century. It's easy to build a virtual environment with immersion, interaction and imagination based on VR technology, so people can get access to visual, hearing and touch sensation information, and people also can import signal into the system and observe the response of the system to learn from it, therefore one of the most important usage of VR technology is to build kinds of simulation system. The vehicle driving simulator based on virtual reality has high safety, well reappearance of scene, low cost and can be developed easily, so it is an important tool used for the development of automobile product and the study of the transportation characteristic of traffic environment or the driver training. When it is used in driver's training, it has advantages of energy-conservation, high security and high economy performance, and it is not restricted by time, climate, place while training, so it can make the training in high-efficient and short train cycle. It improves the result of training greatly.Four-wheel vehicle is widely used for its high security and reliability among the ground vehicle that invented by human. Tricycle has smaller size and mass compared to four-wheel vehicle, so using a tricycle can save energy and reduce the parking space, and it's convenient to use a tricycle under special circumstance which requires for a small vehicle. People can get a new feeling when driving a tricycle because of its different structure compared with four-wheel vehicle, so tricycle will be highly developed in future. Recently big automobile manufacturer around the world released several concept tricycles, and academic circles also pay great attention to tricycle.In the paper, we develop a driving simulator based on VR technology for a tricycle. This simulator adopts a 6-DOF movement simulator and its control system as its control equipments to be the movement simulation system, and adopts advanced scene software-OpenGVS, OpenGL and MultiGen Creator tocarry the scene system for the simulation programme. So this simulator can simulate the actual steering state of automobile and the road environment which makes the participant has the actual experience .The automobile-driving simulator is composed of cab operation simulation subsystem, scene subsystem, computer control subsystem. The system carries out its function following the process as this: driver makes a driving action, such as turning, acceleration, deceleration or stop, according to the change of the scene showed by the scene simulation subsystem to manipulate redirector, clutch or detent laid in the cab operation simulation subsystem. The scene subsystem read these manipulation instructions, then the pose and position of the automobile showed in the scene simulation are changed accordingly, the pose signal data also is transmitted through net to the compute-controlling system by real time. After receiving the signal data, the computer computes the data according to certain arithmetic and sends the data through D/A card that make the data to analog signal to the cab operation simulation subsystem to control the pose of the cab.This paper completed the research work and gained the achievement as follow:1. Building up the models of the scene for a tricycle driving simulation program using the software of MultiGen Creator and the models including sky, ground and other surroundings. During the process the technology that related about real-time interaction and actual immersion such as BILLBOARD, LOD, DOF is used, in this way the resource of computer system is used properly and highly visual effect is exported.2. A body model of a tricycle is also built when building the scene, and the model has local DOF, so after the model is imported into the scene, the steer wheel and the wheel can move in this local DOF; this body model for tricycle also has several different LODs, when distance between the camera and the model changes, the model varied in different LOD, so the resource of computer system is saved in this way.3. Developed the scene system of the automobile-driving simulator using advanced scene management software OpenGVS, dealing well with the problemssuch as terrain following, collision detection appear in the scene simulation system. Multi-channel technology is used so that the simulation program can display images from different channels, so tricycle model can be shown at different eye-point in the scene the driver is provided with detailed information which will help the driver to get familiar with this tricycle model as soon as possible.4. Built different kinds of driving scene, such as fog, rain; also imported other cars model to form a traffic scene, thus the driver can experience overtake, crossing to gain more experience.5. Built up the proper dynamics model and applied it to scene simulation program which based on the general consideration between the degree of complication and the degrees of simulation-driving reality and make the simulation driving being identical with the real automobile driving.The purpose of the paper is to develop a kind of vehicle simulation device that can make the participant feel the real sense of manipulating vehicle, can simulate the actual steering state of vehicle and the road environment. The simulator can be used in the driver's training, driving-skill assess and traffic safety education.