Automation Creation Skid Car Electronic Control System

Calibration

Overview

ZERO SETTING:

This sets the Skid Car hydraulic operating start point. (For Skid Car simulators
not fitted with accumulators, the front and rear zero settings are set to 0 0)
We work on the principle that there are two zero points in the accumulator type
skid car. Point one is when the RAMs are in the fully closed position, forced in
this position by the accumulators. The second zero point, we call the true zero
point, is when the castor tyre just touch the road surface. From this point, any
further RAM movement (raising Skid Car) will have a lifting effect on the vehicle. 

The other advantage of the true zero setting is that when the control panel is set
to the minimum height with the display reading 0 0 (zero setting front and zero
setting rear) the castor wheels of the skid car are just touching the road surface
and are therefore tracking.  This help to prevent damage to the castor tyres through
scuffing as the tyre is intermittently coming in contact with the road surface.

RANGE SETTING:

The range sets the highest operating point of the Skid Car RAMs, that is when the
vehicle tyre just clear the road surface. Once the desired range setting is achieved,
all intermediate height settings, 1 to 9, (there are 10 height settings) are
calculated by the computer.  The higher the range setting the larger the step sizes
of the height settings.
 

Using this system for height calibration has taken away a lot of the guess work and
individual interpretation with calibrating. We have created a calibration standard
whereby all skid cars using this electronic system will perform identically. 

With our sensor technology we have achieved an accurate high resolution system that
is also repeatable. 

The sensor strip bracket is bolted directly to the top of the RAM so there is no up
or down movement of the bracket.  This results in no loss of height resolution
through mechanical linkages of the sensor mountings. 

The sensors are manufactured in house. The sensor consists of two slotted opto
switches, utilising infra red technology, working together to provide RAM direction
information in the form of digital encoding. There are no problems with vibration
or shock with this sensor. The actual sensor resolution is less than 1.5mm. Due to
the mechanical operating lag of the pump valves, the minimum resolution we have
achieved is 2.5mm without the system oscillating up and down at the computer set point.

For the NON ACCUMULATOR Skid Car, the Zero setting for front and rear must be set to 0
at all times.

Calibrating

ZERO Setting: Front

a. Use the lower buttons on the control panel to lower the frame so that it is 
positioned at its current lowest point. (The panel display will read 0 0)

b. Press and hold the Z zero button on the control panel.  While the Z button is
pressed, use the front raise button to bring the front skid car castor tyre closer to
the road surface until the castor tyre just touches. To lift the castor tyre from the
road surface, use the front lower button.  Remember to keep the Z button firmly pressed
as you perform this. The control panel display will continue to flash as you keep the
Z button pressed.  The flashing number on the left of the display is the front zero
calibration setting.

When you are satisfied with the front zero calibration setting, release the zero Z
button on the control panel. The display will stop flashing and re display the
current height settings which should be 0 0.

ZERO Setting: Rear

a. Use the lower buttons on the control panel to lower the frame so that it is
positioned at its current lowest point. (The panel display will read 0 0)

b. Press and hold the Z zero button on the control panel. While the Z button is
pressed, use the rear raise button to bring the rear skid car castor tyre closer to
the road surface until the castor tyre just touches. To lift the castor tyre from the
road surface, use the rear lower button.  Remember to keep the Z button firmly pressed
as you perform this. The control panel display will continue to flash as you keep the
Z button pressed.  The flashing number on the right of the display is the rear zero 
calibration setting.

When you are satisfied with the rear zero calibration setting, release the zero Z
button on the control panel. The display will stop flashing and re display the current
height settings which should be 0 0.


RANGE Setting: Front

a. Use the raise buttons on the control panel to raise the frame so that it is positioned
at its current highest point. (The panel display will read 10 10)

b. Press and hold the R range button on the control panel. While the R button is
pressed, use the front raise button to lift the front vehicle tyres so that they just
leave the ground.  To lower the vehicle tyre to the road surface, use the front lower
button. Remember to keep the R button firmly pressed as you perform this. The control
panel display will continue to flash as you keep the R button pressed. The flashing
number on the left of the display is the front range calibration setting.

When you are satisfied with the front range calibration setting, release the range R
button on the control panel. The display will stop flashing and re display the current
height settings which should be 10 10.

RANGE Setting: Rear

a. Use the raise buttons on the control panel to raise the frame so that it is
positioned at its current highest point. (The panel display will read 10 10)

b. Press and hold the R range button on the control panel. While the R button is
pressed, use the rear raise button to lift the rear vehicle tyres so that they just
leave the ground. To lower the vehicle tyre to the road surface, use the rear lower
button. Remember to keep the R button firmly pressed as you perform this. The control
panel display will continue to flash as you keep the R button pressed. The flashing
number on the right of the display is the rear range calibration setting.

When you are satisfied with the front range calibration setting, release the range R
button on the control panel. The display will stop flashing and re display the current
height settings which should be 10 10.

The Zero and Range settings may require adjusting as castor tyre and vehicle tyres wear.

The Zero and Range settings are stored in a non volatile memory in the control panel.
When power is removed your calibration settings are still remembered when your use the
system again.

The Zero setting should vary from 0 to 5 depending on the construction and mounting
of the Skid Car frame. The Range can vary from 6 to 19. 

Important: Do not set the Range setting to equal or lower than that of the zero setting.