The system configuration for the laboratory simulation is as shown the following figure.
Figure 1. System configuration
The system hardware is composed of the following parts;
A simple model of notebook type IBM compatible personal computer was used as a main computer. The specifications of the Compaq Presario 1080 PC are as follows;
The image generated by the computer is fed into the projector through the scan converter. The high quality scan converter converts the image format of the PC(VGA format image) to the video signal (NTSC video format). The DeltaScan GL/Pro was used as the scan converter. The specifications of the scan converter are as follows;
The projector unit for this research is Data Vision model 110 series[1] made by Delco company.
It was originally designed for the state patrol car to display information about the unidentified car while chasing it. Some models of luxury car also have the options for the head up display system to display the instrumental panel information. The information displayed in the commercially available head up display unit is mainly composed of text characters which are generated by the small on board computer. On board computer system has serial communication port so that it can communicate with external computer systems like instrumental pannel controller. In this experiment, we didn'뭪 use the on board computer system, instead we directly fed the video image into the display unit. The specifications about the head up display unit are as follows;
The image fed into the projector is drawn on the transparent LCD panel in the projector. The projector has high intensity halogen lamp and this lamp illuminate pass through the LCD screen.Model DV (DataVision) HEAD-UP DISPLAY model 110 Light source : Halogen lamp Image generator : LCD 234 X 382 pixels
Figure 2. Projection unit
The projected image is reflected by the half mirror which is called combiner. The combinber is half mirror so that half amount of light can pass through and half of light can be reflected. So, the driver can see the super imposed image of both pass-through image(real road scene) and reflected image(graphically generated image by head up display system). One more importance specification is that the combiner has a virtual focusing mechanism, so that the driver can see the graphics image at the same focusing distance of the real road scene. It seems to the driver that the focusing plane is same distance as the road points. The virtual focusing plane is located about 10 - 20 meters front of the car. With the help of the virtual focus, the driver doesn't need to move his or her eye focus back and forth during driving. It is very important that the driver can see both of the real road and projected graphics on the same focusing plane virtually to reduce driver's fatigue.
Figure 3. Combiner glassType : Virtual image reflected from semitransparent combiner Optimum viewing distance : 20 inches from eye to combiner Field of view : 4.9 deg. vertical X 6.7 deg. Horizontal Combiner transmissibility : 60 %
Truck
A trailer truck made by Navistar Internal Transportation Co. was used as the test truck.
Figure 4. Test truckModel : 9400 series by Navistar Distance between the front wheel and rear wheel : 337 inches Height : 100 inches (when unloaded) Distance between bumper and front wheel : 50 inches
Game Steering Wheel System
Game steering wheel system was used for the laboratory simulation and demonstration. The steering wheel was designed for the kid뭩 game software. It is very easy to access the steering angle and gas/brake pedal states using the standard joystick device driver of the Windows 95 operating system because the game device is the commercially available standard peripherial.
Both of the gas and brake pedals are connected to the same X axis. The steering wheel is connected to the rudder axis of the joystick port.Model : Formula T1 by TrustMaster Steering wheel rotating range : 260 degree Pedals : 2 pedals (gas and brake pedal)
Figure 5. Game steering wheel and pedals (Photo from Trust
Master)
References