AccuGrade® - CD700 Grade Control System (GPS/ATS/Sonic/Cross Slope) Caterpillar

Introduction

Horizontal guidance is provided to the operator via the center lightbar and the text items that are on the display. A horizontal alignment must be selected before guidance can be shown. The operator can then use the lightbar or the text items to steer the direction of the machine in relation to the design. For M-Series motor graders, the system can control the side shift of the blade in order to keep the blade tip with focus on the alignment.

Horizontal guidance can be given to the following types of alignments:

• Design alignments in road files

• 3D Lines alignment

• Master alignment of sloping surfaces

• Design boundary lines and linework in Site Maps and Background Plans

Note: The AccuGrade System gives guidance to any features in the road design file. This includes widening and superelevation.

Applying a horizontal offset to a selected alignment can help you construct the final surface.

The Soft Keys "Alignment: <Value>" and "H. Offset: <Value>" are used to select alignments and apply horizontal offsets to them. These Soft Keys are available when you load a design.

Horizontal guidance is provided to the guidance point that has focus.

Selecting an Alignment for Horizontal Guidance

In most cases you will use the Guide to Horizontal Alignment dialog to select a design feature to use as a horizontal guidance alignment. The exceptions are:

• If the only possible alignments in the loaded design are Site Map or Background Plan features, the Guide to Horizontal Alignment dialog will be bypassed, and you will be taken directly to the graphical selection screen.

• If you require guidance to side slopes in a road design.

The Guide to Horizontal Alignment dialog provides a list of possible methods for selecting a horizontal guidance alignment. The methods displayed in the Guide to Horizontal Alignment dialog will depend on the type of design loaded.

To select an alignment method from the "Guide to Horizontal Alignment" dialog, complete the following steps:

1. From any of the guidance views, press the "MENU" key until the "H. Setup" Soft Key is displayed.

2. Press the "H. Setup" Soft Key.

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Illustration 1	g01296869

3. Press the "Alignment: <Value>" Soft Key. The "Guide to Horizontal Alignment" dialog appears. Illustration 1 shows the choices available in a .dc road design:

   Note: If the machine is not currently on the design surface, no alignments options are listed.

4. Press the Up arrow or the Down arrow in order to highlight the required alignment option. The following options may be available in the "Guide to Horizontal Alignment" screen:
   • In order to select a road alignment in a road design, choose the alignment by name.

   • In order to automatically select a road alignment in a .svd road design, choose "Auto Select Road Alignment".

   • In order to select a layered lift alignment in a .dc road design, choose one of the "Layer Lift Alignment" options.

   • In order to select a "3D line" in a 3D Lines design, choose "3D line".

   • In order to select the Master Alignment in a Sloping Surface Design, choose "Master Alignment".

   • In order to select the Design Boundary or Linework in the Site Map or Background Plan, choose "Plan Line".

   • Select "Plan Line" in order to use the arrow keys to select the actual line in "Plan View".

5. Press the "OK" key to accept the selection and return in order to the guidance screen.

Guidance to Road Alignments

Each alignment in a .dc road design file is numbered and can also be named. The master alignment is always alignment number 0. Positive alignment numbers are alignments to the true right of the master alignment. Negative alignment numbers are alignments to the true left of the master alignment.

Note: "True Right" and "True Left" mean right and left in the direction of the road looking away from the starting point or first station in the design. If the machine is facing back toward the start of the road, positive alignments appear to the left of the master alignment.

If the selected alignment stops at the current station, horizontal guidance is no longer given and the horizontal light bar goes blank. However, the system remembers the alignment. Horizontal guidance resumes when the selected alignment reappears.

The value displayed in "Alignment: <Value>" is zero if you select the master alignment. The selected alignment is drawn in the Plan View with a double-width red line.

Illustration 2 shows a Plan View when the master alignment is selected for horizontal guidance.

Illustration 2	g01297017
View of a road design with the master alignment selected (1) Master Alignment (2) Selected Alignment

Illustration 3 shows the Cross-section View when the master alignment is selected for horizontal guidance.

Illustration 3	g01297024
Cross-section View of a road design with the master alignment selected (3) Horizontal offset (4) Design surface (5) Working alignment (6) Master alignment

Note: Graphical lines selected for horizontal guidance are also displayed in the Cross-section View.

Table 1 explains the items in Illustration 2 and Illustration 3.

Auto Select Road Alignment

A road design file can be exported from the AccuGrade Office Software as a .svd file with an accompanying .svl roading linework file. If a road file is exported in this way, you can select the "Auto Select Road Alignment" setting for horizontal guidance.

When the "Auto Select Road Alignment" option is active, the system finds all alignments that have the same name as the selected alignment. In order to select the first element of the alignment, the system selects the alignment that is closest to the blade tip that has focus.

Continue in the required direction until the next alignment is selected. While no alignment is selected, horizontal guidance is not available.

If you use the "Auto Select Road Alignment" mode, you do not have to reselect the same alignment when the line is not continuous.

Road alignments are only available in .svl files when the .dc file is exported from the AccuGrade Office Software as a combination of .svl and .svd files.

Guidance to Layered Lift Alignments

The intersection of the layered lift and the original design surface can be selected for horizontal guidance. To select the alignments for horizontal guidance follow these steps:

1. Set your layered lift. Refer to "Setting a Layered Lift as the Working Surface" in the Vertical Guidance Section.

2. From any of the guidance views, press the "Menu" key until the "H. Setup" Soft Key is displayed.

3. Press the "H. Setup" Soft Key.

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Illustration 4	g01296861

4. Press the "Alignment: None" Soft Key. The alignments shown in Illustration 4 will appear.

5. Select the layered lift alignment that you require.

   Note: The original road alignments may still be selected with the "Plan Line" selection tool. The layered lift alignment that is selected appears on the Alignment Soft Key ("Alignment: +LL").

Guidance to 3D Lines

Horizontal guidance to a 3D line is given by default when the 3D line is first selected for vertical guidance. For information on selecting a 3D line for vertical guidance, Refer to Operation and Maintenance Manual, "Selecting a 3D Line For Vertical Guidance".

Guidance to a Sloping Surface Master Alignment

The master alignment of a sloping surface can be selected as a horizontal guidance line. The master alignment is alignment number "0".

For sloping surfaces defined by the 2 Points method, the direction of the master alignment is from the first point toward the second master alignment point.

For sloping surfaces that are defined by the Point-and-Direction method, the direction of the master alignment is the direction specified.

Guidance to Design Boundaries and Site Map and Background Plan Features

Most designs have an associated boundary that can be graphically selected for horizontal guidance. A boundary indicates the extents of the vertical design data.

Any line that appears in the Site Map or Background Plan can also be graphically selected for horizontal guidance.

Active horizontal alignments are displayed in Plan View with a bold red line.

To graphically select a "Plan Line" for horizontal guidance complete the following steps:

1. From any of the guidance views, press the "Menu" key until the "H. Setup" Soft Key is displayed.

2. Press the "H. Setup" Soft Key.

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Illustration 5	g01296865

3. Press the "Alignment" Soft Key.

   One of the following things happen:

   • If the loaded design is a road, 3D Lines, or a sloping surface design, the "Guide to Horizontal Alignment" dialog appears. Press the Down Arrow or the Up Arrow to highlight "Plan Line". Press "OK". The graphical selection screen appears.

   • If the design does not contain road or slope alignments or 3D lines, the graphical selection screen appears. Refer to Illustration 5.

   Note: When the graphical selection screen appears, the cross-hairs appear in place of the machine icon. If the machine does not have a valid position, the cross-hairs appear at the center of the Plan View.

4. Move the cross-hairs to the line you require. Use any of the following techniques to move the cross-hairs:
   • Use the arrow keys to move the cross-hairs around the screen.

   • Press "+" and "-" to zoom the current view in and out.

   • Press "Zoom Target" to re-size the current view to the immediate area around the cross-hairs.

   • Press "Zoom Selection" to view all of the linework.

   You can select any line that is shown. You cannot select text or avoidance zones.

   If several lines are grouped closely, press "Zoom Target" to zoom-in for easier selection. Alternatively, move the cross-hairs to an area where the lines are more easily seen.

   In order to move the cross-hairs large distances across the screen, zoom out and then hold down an arrow key. This lets you move rapidly across the design.

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Illustration 6	g01296866

5. Press the "Select" Soft Key in order to select the line as an alignment. The selected alignment appears as a thick red line. Refer to Illustration 6.

   When graphically selecting a Plan View line:

   • The line closest to the center of the crosshairs is selected.

   • If you select a line that is a road design alignment or sloping surface master alignment, the result is the same as if you selected the alignment from the list in the Guide to Horizontal Alignment dialog.

   • Press the "Deselect" Soft Key in order to deselect the current horizontal alignment.

   • A total of up to 100 elements, situated left or right of the selection point on the line, are selected. An element is an individual part of the line, for example a segment, or a curve.

   The selection of a line stops when one of the following happens:

   • The line stops.

   • The line splits into more than one path.

   • The line exceeds the maximum number of elements that are allowed on a line.

6. Press the "OK" key.

   The graphical selection screen closes and you return to the guidance screens. The Soft Key now shows "Plan Line".

   Note: Horizontal offsets are not shown in the graphical selection screen. If an alignment is selected, it is drawn in red. When you exit this view, the horizontal offset is applied to the selected alignment. The horizontal offset is shown in the Plan and Cross-section Views.

Guidance to Side Slopes

If the selected road design includes side slopes, guidance can be given to the Cut or the Fill side slope.

The selected side slope is shown in red in Cross-section View, and vertical guidance is provided to it.

To change the side slope setting complete the following steps:

1. Press the "Menu" key until the "Design: <Name>" Soft Key is displayed.

2. Press the "Design: <Name>" Soft Key. The "Select Design File" dialog appears.

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Illustration 7	g01296867

3. Press either the "Side Slope: Cut" Soft Key or the "Side Slope: Fill" Soft Key.

4. Press the "OK" key in order to accept the selection and return to the guidance screen.

Setting a Horizontal Offset

Setting a horizontal offset adjusts the horizontal guidance. You add or subtract an offset that is parallel to the selected horizontal alignment.

To set a horizontal offset, complete the following steps:

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Illustration 8	g01296868
Horizontal Offset screen. A road alignment has been selected in this example.

1. Press the "H. Offset: <Value>" Soft Key from any guidance view. The Horizontal Offset dialog appears. Refer to Illustration 8.

2. Do one of the following:
   • Use the arrow keys to enter an offset value. In the above example, 0.500 m has been entered. The horizontal offset limit is ±300 m.

   • Press the "Half Blade Width" Soft Key in order to set a horizontal offset that is half the machine's blade width.

   • Press the "Set 0.000" Soft Key in order to reset the offset value to zero.

   Note: The text at the bottom of this dialog changes. The text that appears depends on which type of alignment is selected.

3. Press the "Left / Right" Soft Key in order to select the side of the alignment for guidance. Left offset shows as a negative value. Right offset shows as a positive value.

   When you apply horizontal offsets, the direction of the alignment is forward, going up the graphical selection screen. The following exceptions to the direction of the alignment apply:

   • Circles have negative horizontal offsets applied inward, and positive offsets applied outward.

   • Closed shapes constructed of a series of line segments use the same convention as circles.

   • Road alignments and sloping surface master alignments ignore the screen orientation. These use the direction of increasing station values along the master alignment.

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Illustration 9	g01296857
Plan View of road design with "Alignment -1" selected for horizontal guidance (7) Horizontal Offset (8) Working Alignment (Bold Red Line) (9) Selected Alignment

4. Press the "OK" key in order to save the changes and return to the guidance views.

   Illustration 9 shows the Plan View with a road design loaded. The "Alignment -1" key is selected for horizontal guidance. The horizontal offset of 0.5 meters is displayed as a red line. Guidance is provided to the working alignment.

Illustration 10 shows the equivalent Cross-section View.

Illustration 10	g01297191
Cross-section View of road design with "Alignment -1" selected (and offset) for horizontal guidance. (10) Horizontal Offset (11) Design Surface (12) Working Alignment (13) Selected Alignment

Table 2 describes the items shown in Illustration 9 and Illustration 10.