AccuGradeTM - Grade Control System (GPS/ATS/Sonic/Cross Slope) Caterpillar

Automatic Control System

Usage:

12H AMZ

AccuGrade Overview

The AccuGrade System incorporates the following components to provide automatic control of the cutting edge position:

Display

The Display is a computer that runs the software for the AccuGrade System. This section describes the operation of the Display. The Display is used in order to operate the AccuGrade System. The Display has a color LCD Screen in order to show information and a keypad for entering information.

Sensors

The Cross Slope sensors mounted on the machine and blade and the GPS components, help to determine the position of the blade.

Valve Control Module And Valves On The Machine

The AccuGrade System uses a Implement/Valve Control Module to actuate the hydraulic valves that control automatic guidance of the blade.

The Implement/Valve Control Module uses the cut/fill values in order to drive the control valves. The blade control valves move the blade so that the blade works to design.

The Implement/Valve Control Module processes information from the Display. The Implement/Valve Control Module sends information to the hydraulic valves to move the blade automatically.

Remote Switches

Four switches are mounted on the blade control levers. The two Auto/Manual Switches are located on the left and right blade lift control levers. These switches control switch the system between automatic mode and manual mode. The other two switches increase or decrease the vertical offset or target slope.

Operating The Remote Switches

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Illustration 1	g01116987

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Illustration 2	g01174043
(1) Left "Auto/Manual" Switch (2) Left Remote Vertical Offset Switch (3) Right Remote Vertical Offset Switch (4) Right "Auto/Manual" Switch

The remote buttons are configured to perform the following system operations:

Switch between Auto and Manual control
Set an elevation offset
Set a cross slope offset

Illustration 2 shows typical locations for the remote switch assembly on a motor grader.

Auto/Manual Switches

There are two Remote Auto/Manual Switches.

The Auto/Manual Switches enable and disable the automatic controls for their respective blade ends.

Guidance methods that only provide guidance to one end of the blade, for example cross slope guidance, behave in the following way:

Automatic control is given to the end of the blade that the Auto/ Manual switch was put in the Auto position last.
The other end of the blade returns to manual control until the Auto/Manual switch is toggled to Manual mode, and then back to Automatic mode.

3D guidance methods provide guidance to both ends of the blade, and behave in the following way:

If one Auto/Manual switch is in the Auto position, then that blade tip is automatically controlled to maintain the cutting edge at the cross slope of the design. The other blade tip is controlled manually.
If both Auto/Manual Switches are in the Auto position, the both blade tips are driven to design.

Vertical Offset Switches

There are two remote vertical offset switches.

Each switch can control the vertical offset applied to the end of the blade corresponding to the side that the switch is mounted on.

Toggling a remote vertical offset switch upward or downward increases and decreases, respectively, the value of the vertical offset. This is true even if the end of the blade has its elevation controlled to maintain cross slope, for example the cross slope and cross slope plus lift guidance methods. For this reason, for certain combinations of blade slope and blade end being controlled, increasing the offset may decrease the working cross slope.

The amount the vertical offset or working slope is changed with each switch action is called the vertical offset increment. The vertical offset increment has a default value of 10 mm (0.39 inch), or 0.1% if the end of the blade has its elevation controlled to maintain cross slope. This increment can be changed by your site manager.

Automatic Control States

The automatic control status indicator appears in the lower left and right sides of the screen when the automatic controls are configured. This indicator shows the current state of the automatic controls.

If an automatic control status indicator is not displayed, then one of the following conditions holds:

Automatic controls are not configured
A required device is not responding
A guidance method, for example cross slope, that provides guidance to only one end of the blade has been selected

Automatic controls can be in one of the following states:

Manual
Automatic
Inactive-Auto
Indicate

Any of the four auto states provide guidance information on the Display and on the lightbars.

When the automatic controls are active, you can use the horizontal guidance information to manually steer the machine and the vertical guidance to monitor the performance of the automatic controls.

The automatic control status indicator appears in the lower left of the screen when the automatic control option is set. This indicator shows what state the automatic controls are in.

Note: If the automatic controls state is not displayed in the Plan View, the Cross-section View, the Profile View, or the Text Views and the valve speed dialogs, then the automatic controls are not enabled in the Setup Menu or a required device is not responding.

Manual

When the Manual button is pressed, the automatic controls are deactivated. Horizontal and vertical guidance are still provided through the Display and light bars.

The Plan View in Illustration 3 shows the AccuGrade System in Manual state.

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Illustration 3	g01174207
AccuGrade System In Manual State

Automatic

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If the system is in Automatic Mode, blade movement may occur.
Ensure that the system is in Manual Mode.

Personal injury or death from crushing could occur if the system is not in Manual Mode.

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Illustration 4	g01174216
Automatic State Guidance Screen

When the system is in Automatic mode, and the status indicator shows Auto in green, the automatic controls are turned on for that end of the blade, and are in use.

Each end of the blade can be put under automatic control independently. For 1D guidance methods that report guidance information for one end of the blade only (for example, cross slope only guidance), both ends of the blade can be placed under automatic control, but this will only affect the end receiving guidance.

Illustration 4 shows the AccuGrade System with both ends of the blade under automatic control.

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Illustration 5	g01174232
Mixed State Guidance Screen

Illustration 5 shows the state of the status indicators when only one end of the blade is receiving guidance.

Note: If you are using the cross slope guidance method, then one end of the blade is always assumed to be on grade. In the example shown in Illustration 5 the left end is always on grade. The automatic controls will have no effect, if the automatic controls are enabled for the left end.

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Illustration 6	g01174406
Mixed State Guidance Screen

Illustration 6 shows an AccuGrade System with the left end of the blade under automatic control and the right end under manual control.

Note: If you are using 3D guidance methods, then both ends of the blade are receiving guidance information. In the example shown in Illustration 6, if automatic controls are enabled for the right end, then that end is driven until the cross slope of the cutting edge matches the cross slope of the design.

Inactive-Auto

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Once the system is placed in automatic mode, blade movement may occur.
Ensure that all personnel are clear of the blade before you place the system in automatic mode.

Personal injury or death from crushing could occur.

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Illustration 7	g01174430
Inactive-Auto caused by accessing a guidance setup dialog

When the system is in Automatic mode, and "Auto" flashes in red on the status indicator, the automatic controls are in the Inactive-Auto state.

In Inactive-Auto state, the automatic controls of the AccuGrade System are disabled. Horizontal and vertical guidance are still provided through the Display and light bars. Inactive-Auto state indicates that the operator has attempted to activate the automatic controls, but the system is not able to drive the automatic controls. The Inactive-Auto state is similar to the Manual state, except that the "Auto" flashes in red on the status indicator.

The Controls enter the Inactive-Auto state when you access one of the following guidance set-up states:

Select Design File
Vertical Guidance Setup
Alignment
Horizontal Offset
Elevation Offset
Setup Menu - Configuration
Diagnostics

Additionally, the Controls enter the Inactive-Auto state if any of the following situations occur:

No design is loaded
The machine is off the design for more than 60 seconds
The machine is out of control range for more than 60 seconds
The machine is in a state that is incorrect for automatic controls, for example because the machine is in "Park".

Note: The previously listed item does not apply to valve calibrations.

The automatic valves have not been driven (the valves have been inactive) for 60 seconds or longer
A device can no longer be detected or stops working
Display starts and the system is in Automatic mode
The Display shuts down
You receive low accuracy GPS positions
The ATS loses lock on the target

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Illustration 8	g01174446

In order to change from Inactive-Auto state to "Auto" complete the following steps:

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Once the system is placed in automatic mode, blade movement may occur.
Ensure that all personnel are clear of the blade before you place the system in automatic mode.

Personal injury or death from crushing could occur.

Press the "Auto/Manual" Switch.

If necessary, correct any safety conditions or start-up errors.

Press the "Auto/Manual" Switch.

Indicate

When the Display receives no information about the state of the automatic controls, the automatic controls change to the Indicate state. When this occurs, check the valve control module.

Optimizing Automatic Controls

AccuGrade System has two options to optimize the automatic controls for your work site:

The valve speed
the vertical offset increment

Valve Speed

Use the Valve Speed dialog to change the speed of the valves that automatically control the blade. The correct valve speeds depend on the type of material that the machine is moving. You can also set the valve speeds to suit the current working conditions. For example, constructing the base grades or the finished grades.

If the valve speeds are set too high, the system reacts too quickly. This can cause the system to become unstable and the blade to overshoot and then return to grade. If the valve speeds are set too low, the system will react too slowly, and the blade will take too long to return to an on-grade position. Both situations will cause inaccuracies in the final surface.

Vertical Offset Increment

Note: The "Vertical offset increment" dialog is a site selectable feature. Consult your site champion in order to turn this feature ON.

If this feature is turned ON, the "Vertical Offset Increment" dialog is used in order to set the amount each press of the vertical offset switch increases or decreases the vertical offset. Refer to Operation and Maintenance Manual, "Vertical Offset - Set" in order to modify the offset increment value.

Using Automatic Controls

Before you can use automatic controls, make sure that you complete the following actions:

Configure the automatic controls.
Complete the start-up checks.
Pass the safety checks.
Press the "Auto/Manual" Switch.

A typical sequence of actions to prepare the AccuGrade System for a job that uses automatic controls is outlined in the following steps:

Create a working surface for vertical guidance using one of the methods in the Vertical Guidance Section.

Select an alignment for horizontal guidance using one of the methods in the Horizontal Guidance Section.

With the automatic controls in Manual state, line up the machine for the pass and move the blade so that the blade will cut or fill a reasonable amount of material. Set the vertical offset ("V. Offset: <Value>") so that the cut/fill indicator on the light bars reads approximately 0 (zero).

Start to move smoothly along the pass.

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NOTICE

If the material surface you are working in is too hard, the blade may not penetrate the material. Part of the machine may be lifted off of the surface.

Press the "Auto/Manual" Switch in order to activate the automatic controls.

At the end of the pass, press the "Auto/Manual" Switch in order to deactivate the automatic controls, and then lift the blade.

Repeat Step 3 through Step 6 until the vertical offset is reduced to 0 (zero) and the blade is on the working surface.

Note: If the blade is too full, use the vertical offset increment switch to reduce the amount of material being moved on the pass. You can do this at any stage.

Guidance

Any of the four auto states provide guidance information on the Display and on the light bars.

When the automatic controls are active, you can use the horizontal guidance to manually steer the machine and the vertical guidance to monitor the performance of the automatic controls.

Start-Up Automatic Control Checks

The software for the AccuGrade System checks which devices are present, and the current firmware version number of each device. When automatic controls have been enabled during machine configuration, the system checks for responses from the following components: the Angle Sensor, the Rotation Sensor, the Implement/Valve Control ECM and the GPS Receiversthe ATS Target.

If any device does not respond, the following message appears:

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Illustration 9	g01206407

When you press the "OK" key , the "Diagnostics" dialog appears. Refer to Illustration 10.

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Illustration 10	g01174120

The Diagnostics dialog displays a list of devices configured for the automatic controls system.

Note: Only devices that are required for the current configuration are listed. Additional devices may be present but if the devices are not currently required, the devices are not listed.

The Diagnostics dialog lists each device and reports the following:

A device name
The status
The application firmware version number
The loader firmware version

The application firmware must be the correct version to activate the automatic controls.

In order to check the system again, press the "Recheck" soft key. The status list is updated to show any changes that are detected.

Application Firmware Version

The application firmware version number indicates which devices are detected and which devices have the correct version of the firmware loaded.

Note: When version numbers are displayed for all devices in the list, you can use automatic controls.

Old Firmware

If either the firmware or the loader is too old, the device is detected, but you cannot use automatic controls until the device firmware is updated. The Status column displays the minimum firmware required.