GB2480098A

GB2480098A - Flight simulator motion platform

Info

Publication number: GB2480098A
Application number: GB1007635A
Authority: GB
Inventors: Paul Hughes
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-05-07
Filing date: 2010-05-07
Publication date: 2011-11-09
Also published as: GB201007635D0

Abstract

A flight simulator motion platform which is moved by three fixed pneumatic cylinders to give roll, pitch and heave. Standard servo motors are used to actuate air valves which control the movement of rams in the pneumatic cylinders. Control of the servo motors is provided by a mechanical integrator. The platform may be mounted on heavy duty drawer runners to enable lateral sway motion and forward surge motion.

Description

UK Patent Specification Title

Compact flight simulator motion platform using pneumatic rams and its method of control.

Background

Many advanced flight simulator programs are available for home use. They provide a high level of realism. Being in a seat which pitches, rolls and heaves as the aircraft flies adds enormously to the experience. Previously motion platforms have been hugely expensive, noisy, heavy and complicated.

Statement of invention

By using three pneumatic cylinders to support the seat, motion can be imparted with three degrees of freedom: roll, pitch and heave.

Advantages When fed by a silent compressor, pneumatics provide a simple, quiet and compact way of moving a motion platform and has low power consumption.

It is much cheaper, cleaner and lighter than using hydraulics. Unlike linear electric motors it does not require high current power supplies and complicated electronics.

By using fixed pneumatic cylinders the connecting linkages are extremely simple. By mounting the whole platform assembly on heavy duty drawer runners both sway and surge motions are easily added.

By using solenoid air valves to give a short pulse of compressed air to all three cylinders simultaneously bumps can easily be modelled which are superimposed on the other flight motions.

Introduction to drawings

An explanation of the invention will now be made by referring to the accompanying drawings: -Figure 1 shows bow the seat platform is supported by three pneumatic cylinders.

-Figure 2 shows a side view giving the general arrangement of the seat with the screen, rudder pedals and joystick added.

-Figures 3-6 show the operation of the servo motors and air valves on each pneumatic cylinder.

-Figure 7 shows the operation of the mechanical integrator for combining the motions of the roll, pitch and heave servo motors into signals for each pneumatic cylinder.

-Figure 8 shows the construction of the base to enable sway and surge motions to be added.

Detailed description

Referring to Fig. 1 This shows how the seat platform is supported by the three pneumatic cylinders. The cylinders are rigidly bolted to the base. The seat supporting struts have oversize holes which allows sufficient movement as the seat tilts. The seat platform is set below the tops of the rams. This is to ensure that the centre of gravity of the completed seat and its occupant is approximately level with the tops of the rams for stability. (The valves and control arms are not shown for clarity).

Referring to Fig. 2 This shows the addition of the seat and central spar which carries the screen, rudder pedals and joystick. They are rigidly attached to the seat platform and everything moves as one. The spar passes between the knees of the pilot. The vertical with the screen attached is hinged near to the seat so that it can pivot forward for getting in and out. It is supported by a strut that can be adjusted to suit the position of the screen relative to the pilot.

Referring to Figs. 3-6 These describe how the servo motors control the movement of the pneumatic rams. Attached to the top of each ram there is a stiff metal wire which connects to the end of the control lever. Thus the control lever pivots up and down as the ram moves up and down.

In Fig. 3 the pneumatic ram is in mid position and the air valves are closed.

In Fig. 4 the servo motor has moved down and opened the air valve and compressed air is entering the bottom of the cylinder.

In Fig. 5 the ram is pushed up by the compressed air until the air valve lever is level again, closing the air valve and the ram is held in the up position.

In Fig. 6 the servo motor has moved up and opened the exhaust air valve and air is escaping from the bottom of the cylinder. The ram descends until the air valve lever is level again and closed and the ram is back as in Fig. 3.

Referring to Fig. 7 this shows how the control signals to the servo motors on the pneumatic cylinders are produced: A lower fixed ring has three equally spaced Light Dependent Resistors (LDR in Fig. 7). These LDRs control the positions of the servo motors on the pneumatic cylinders. Approximately two centimetres above each LDR is a Light Emitting Diode (LED in Fig. 7) on a moveable ring. ("Control Ring" in Fig. 7).

Moving the Control Ring upwards away from the LDRs causes the servo motors on the pneumatic cylinders to open the air valves so that the rams move upwards. Tilting the Control Ring in any direction causes the servo motors to move so that the seat platform moves to the same attitude. Hence the movement of the Control Ring is mirrored by the seat platform under pneumatic power.

The movements of roll, pitch and heave servo motors are mechanically integrated into the signals for driving the rams thus: The Control Ring is held in place by tensioned cords from two servo motors, one above and one below as per Fig. 7. One servo motor ("Roll" in Fig. 7) is controlled by the position of the ailerons in a Flight Simulator program.

This rolls the Control Ring from side to side.

Similarly, the second servo motor ("Pitch" in Fig. 7) is controlled by the aircraft pitch information from the Fight Simulator program. This pitches the Control Ring forward and backwards.

Vertical movement of Control Ring is provided by a third servo motor ("Heave" in Fig. 7) controlled by g levels from Flight Simulator program.

This heave servo motor moves the vertical shaft ("Main Shaft") onto which both the roll and pitch servo motors are attached. (In Fig. 7 this Main Shaft is shown much extended for clarity). Between this heave servo motor and the Main Shaft there is an oil filled cylinder and a piston with a small hole.

Springs are arranged so that the Control Ring is slowly pulled back (washout) to the centre position during sustained high g manoeuvres.

Referring to Fig. 8 this shows the base unit with the top platform (to which the pneumatic rams are attached) removed for clarity. The fixed part is attached to the moveable part by means of drawer runners where indicated.

This allows sideways motion (sway). It is powered by a horizontal pneumatic cylinder actuated in the same way as the vertical pneumatic cylinders using a horizontal tension spring to return the movement on the exhaust stroke. It is possible to move the platform in the other direction (surge) by mounting the top platform on drawer runners also. This is not shown.