Reality Sled

General Information

• Name of System: Reality Sled
• Creation Date: October 1995
• Manufacturer: Antares Virtual Reality Systems

• Tel: 415-434-2196
• Fax: 415-566-4311
• Email: antares@avrs.com
• 797 19th Ave. San Francisco California (CA) , 94121 USA

Interface / Platform

• Type of Interface: POD based -Window on the world-
• Physical Posture: Sit-down
• Motion of the platform: 2 DOF
• Controls: Simple joystick, head tracker
• Computer platform: 3DO & PC
• Type of Dislay: Virtual IO iglasses
• Tracking: Virtual IO
• Size of the Unit: 4x4x7
• Unit Description: The Reality Sled is a high-fidelity, 2 DOF hydraulic motion platform. It is fully compatible with the 3DO gaming system. ALL 3DO GAMES ARE SUPPORTED by the Reality Sled inluding ShockWave by Electronic Arts, VR Stalker by Morpheus Interactive, Total Eclipse by Crystal Dynamics.

Technical Specifications

Sound

• Type of SoundStereo, also 3D rendered
• Music Background: Yes

Network Information

• Max. Number of units networked locally: 256

M*ax. Number of units networked remotly: 32

Software Experiences

Experience #1

• Name: ShockWave: Operation Jumpgate
• Category: Shoot-em-up
• Number of Designed Levels: 5
• Base duration of game: 10 min
• Max. duration of game: 30 min
• Briefing Material available: No
• De-Briefing Material available: No
• Description of the experience: 3DO game by Electronic Arts.

• Description: The previous alien invasion did not last long. However, Earth as we know it was almost decimated. Recently, a similar alien presence has been detected within Earth's solar system and the United Nations is counting on you to lead the solar assault. Combat experience hardened your soul. The smell of fear honed your senses. Victory over the first wave of aliens gave you hope and courage, now you must destroy the remaining aliens before they return to Earth!

Experience #2

• Name: VR Stalker
• Category: Shoot-em-up
• Number of Designed Levels: 15
• Base duration of game: 10 min
• Max. duration of game: 30 min
• Briefing Material available: NO
• De-Briefing Material available: NO
• Description of the experience: 3DO game by Morpheus Interactive.
• Description: The United States has fallen into enemy hands. You're part of an elite group of pilots responsible for restoring our freedom, which means you'll have to fly a variety of aircraft from your own Virtual Reality Simulator. Experience incredibly realistic air combat as you explore a fully-mapped 3D environment. And hear the roar of 20,000 pounds of thrust from your afterburners, just one of VR Stalker's many mind-numbing 3D stereo sound effects. Real voice-overs accompany briefings for missions of over thirty levels of difficulty. Over 20 minutes of 3D animations and an original audio soundtrack let you live the unforgettable experience of this full combat flight simulator.

Reference / Feedback

• Still no on-line feedback available

Other Information

Introduction The Reality Sled is a 2 Degree-of-Freedom (Pitch and Roll) hydraulically driven motion platform. The following sections describe its features.

Weight The platform currently weighs 580 lb., broken down as follows:

Pump 40 lb. Power Supply or Battery 40 lb. Mount + Cylinders 200 lb. Carriage 75 lb. Base 175 lb. Seat 50 lb.

The hydraulics will support a maximum working pressure of 1000PSI. The pitch cylinder (which bears the greatest load) is a 2" bore cylinder, yielding 3.14*1000PSI = 3140 lb. of thrust. The carriage + seat = 125 lb. resulting in a load carrying capability of 3140 - 125 ~ 3000 lb.. The bearings used in the system can support static loads in excess of 20,000 lb. and dynamic loads up to 5000 lb.. The real limiting factor is the side load on the pitch cylinder which should be kept to < 500 inch-lb.. This results in a maximum load capacity of 1000 lb. with a factor-of-two safety margin.

Floor Plan The current floor plan of the platform is 4ft wide by 6ft long, with a 1ft extension in the front center for the pitch cylinder mount. This can safely be reduced to 3ft wide by 4ft long with a 6inch cylinder mount in the front, for an overall length of 5ft. It could be even further reduced if the total pitch requirements are reduced to < 20(.

Pitch The current prototype system supports pitch angles from 0 to 35degrees at a maximum speed of 15 degrees/sec.

Roll The roll angle can currently vary between +/- 60 degrees at a speed of 37degrees/sec. This provides the dramatic movements which are the heart of this platform!

Control The platform can be controlled through one of 5 interfaces:

1. "Nintendo" style hand controller. 2. PC-Compatible joystick - Thrustmaster or equivalent. 3. Virtual I/O iglasses! head-mounted display with head-tracking. 4. Standard RS232 serial interface. 5. 3DO standard hand controller

The PC joystick interface is by far the simplest way to interface the platform to an existing joystick based game (e.g. Descent, Flight Simulator, etc...) It works by simply connecting a Y-Cable between the Game Machine and the joystick; providing a way for the platform control electronics to simultaneously read the joystick position. It then translates this into a proportional hydraulic motion on the platform. This way, you can add motion to your game literally without changing a single line of code!

The Virtual I/O iglasses! interface is also very simple to use. Once again, a special cable is used that allows for the motion control electronics to read the position of the Head Tracker. The system then responds similarly to the joystick; producing proportional movements in response to the head orientation.

The serial interface is the most flexible. It provides virtually instantaneous (<25ms) control over the motion platform - allowing you to specify PITCH, ROLL and their corresponding acceleration and deceleration profiles. This is done over a standard RS232 interface running at 9600baud. The following sequence would be typical for a simultaneous pitch and roll command:

P25.50 A1 D2 R+31.95 A3 D1

This would specify that the platform move to 25.50( in pitch following acceleration profile #1 and deceleration profile #2, while simultaneously moving to +31.95( in roll following acceleration profile #3 and deceleration profile #1.

This interface provides a mechanism for accurate feedback-based commands to be given to the platform by the games programmer when a completely integrated solution is desired.

Power Requirements The platform can be operated either from a standard 110/220VAC wall outlet or from a 12V Deep Cycle Marine battery for portable operation.

Hydraulic Pump The hydraulic pump used in the Reality Sled is a completely self-contained power source, with the motor, pump and reservoir in one package. Without any sound-muffling cover it operates fairly quietly, about as loud as a household vacuum cleaner. It is designed for virtually continuous use; with the pump being completely immersed in oil thus providing maximum lubrication.

Response Time As in all motion systems, it requires a certain amount of time to actually begin to and move to a specified position. The platform currently takes <25msec to begin a move operation. It then accelerates to full speed based on the selected profile and completes the move to the desired position.

Feedback The platform uses 2 linear potentiometers (one attached to the side of each cylinder) to provide continuous feedback on the position of the system. The very small signals are then amplified and converted to digital form by a 12bit A/D converter. This yields an overall system precision of .02%!

Commercial Information

• System AVAILABLE for sale
• Price: $5500
• Target customer: LBEC
• Number of Units installed: 2
• As of: November 1995