Cat® Terrain v7 for Grading and Loading Caterpillar

As-built surfaces provide information about the current state of the ground over the area that has been worked by the machine. As-built surfaces are updated by the onboard software and, as the machine works, the surface information is stored in *.cat files.

As-built surfaces include the following:

• Current elevation with time

• Compaction status with time

• Coverage status with time

• Material status with time

• Original elevation with time

The machine routinely sends as-built surface updates to the office. The updates are contained in snippets.

Multicast snippets can be used to update a machine with as-built information from other machines.

Reference: Refer to "Machine to Machine As-built Surface Update" section of this manual for more detail.

When multicast snippets are not available, then the as-built information on a machine is only updated by what the machine does. The as-built surfaces that are located on individual machines will be different.

All machines send snippets of as-built information to the office. Cat MineStar System accumulates the snippets from each machine and updates the as-built surfaces in the office. The office as-built surface can be sent to each machine periodically to synchronize the as-built surfaces on the machines.

As-built Surfaces with Time

Time is used to determine which machine should be attributed with the as-built surface update. Multicast snippets that include time ensure that each machine can only claim the surface changes for which the machine is responsible. This feature is especially important if as-built surfaces are merged.

For example, assume that three machines are moving material in the same area. Each of the machines crosses the path of one of the other machines. Each machine will claim the accumulated as-built surface changes. Because the most recent update takes priority, the correct machine can be attributed with the work that has been done.

Reference: For additional information, refer to Systems Operation, RENR9562, "Cat^® Terrain Office Software".

As-built Surface Update

Cat MineStar System provides default "Swath Option" settings that update the configured as-built surfaces.

"Swath Option" - Determines the type of terrain updates that are performed by the onboard software.

This setting is required to generate the as-built surface updates. A few of the items that are specified by this setting include the swath points on the machine, as-built surface updates, and the swath updates function. This information all helps in determining which as-built surface is updated and how that surface is updated.

The cells of an as-built surface for material status can be configured to update to a mined-out status when a swath point crosses the cells.

For example, if the track of a front shovel was identified as a swath point, then an as-built surface update would be generated. The point is generated for all cells that cross the track of the shovel.

Reference: For additional information about the Swath Option setting, refer to the MCU Help file, "Coverage As-Built Surface - Reference".

Surface Updates

Surfaces are updated automatically or by a request from the operator. The update applies to the area covered by a "Prime" design.

Request Surface Update - This button is used to request a surface update for the area covered by a "Prime" design. The surface is updated, but is not truncated.

Request Update & Trim Surface - This button is used to request a surface update for the area covered by a "Prime" design. Only the truncated area as set in the MCU in "Mapping" > "Surface Updates" > "Surface Update Size" is updated. A "Surface Update Size" of 50 m updates an area of 100 m x 100 m around the machine origin.

Menu - Opens the main menu

The operator requests a surface update in the onboard software from the office using one of the following buttons.

Request Surface Update - Select the button.

Request Update & Trim Surface - Select the button.

Menu - From the main menu, select "File" > "Surface Update & Trim Request".

The operator should request a surface update from the office before starting to work in a new area. A new surface is automatically sent when a machine starts up or a new design is selected as "Prime".

Note: Terrain updates must be set as "Automatic" in Cat MineStar System.

Note: If there is no input, such as multicast snippets to the machine, then the screen may not always redraw after a merge.

Note: If the surface does not update on the screen, trigger a screen redraw by zooming into the screen.

Reference: For an example of using surface updates, refer to the MCU Help file, "Request Surface Update Request."

As-built Surface Files

The as-built surface files contain a grid of the worked area. The grid size is configurable. Each cell in the grid contains as-built surface information. Table 1 lists and describes the various as-built surfaces.

Table 1

As-built File Type	Default *.cat File Name	Cell Description and Content
Current Elevation with time	CureElvTime.cat	The Current Elevation of the surface. Each cell contains: - Current Elevation - Time
Compaction status with time	compacttime.cat	The current compaction level of the surface Each cell contains: - Current Elevation - Compaction level - Time
Coverage status with time	CoverTime.cat	The number of machine passes over the surface Each cell contains: - Number of machine passes - Time
Material status with time	OreStatTime.cat	The state of mining activities on the surface. Each cell contains: - Mining status of "Mined Out", "Mining in Progress", or "Not Mined" - Time
Original elevation with time	OrgElevTime.cat	Original surface elevation: Value is periodically updated to the Current Elevation of the surface. Each cell contains: - Original elevation - Time

Cat MineStar System provides default machine configuration settings for various machine types. The settings include default "Data File Param" settings that set up the as-built surfaces that are likely to be required. A separate setting is used for each required as-built surface. Not all as-built surfaces are included.

"Data File Param" - This value specifies various requirements for the storage of the as-built surface, including: the surface type, the file name of the surface, and the cell size for the grid.

Reference: For additional information about the "Data File Param" setting, refer to the MCU Help file.

Determining the Cells that are Swathed

The onboard software must determine the position and the elevation of the ground along the swath to update the cells for the various as-built surfaces.

Most machine installations are single antenna systems. The single antenna can only supply a position and elevation at the position of the antenna.

The methods that are discussed in the next sections are used to determine which cells are updated. If required, these methods are also used to determine the elevation for the cell.

Pitch and Roll Sensor

Machines often work on a slope. The onboard software knows the elevation of the antenna. However, the elevation of any other point on the machine, such as a swath point or a dozer blade, must be calculated. Users have two choices for observing pitch and roll on a single antenna machine. Users can either use a pitch and roll angle sensor or can use the onboard software to calculate pitch and roll.

This section describes using a pitch and roll sensor with the following machine types:

• Single antenna machines

• Single antenna front shovels

• Single antenna surface miners and terrain levelers

• Dual antenna machines

Using a Sensor for Pitch and Roll

The sensor is an optional device that provides an ideal solution for determining elevation at different points on the machine.

The sensor is located on the body of the machine. Sensors are interfaced to the onboard software through the Controller Area Network (CAN) port of the display.

Once functioning, the sensor overrides any calculations made by the onboard software.

Installing, Calibrating, and Recalibrating

For more information about installing, calibrating, and recalibrating a pitch and roll sensor, refer to the following manuals:

Single antenna - Special Instruction, REHS5195, "Installation of Pitch and Roll Angle Sensor for Cat^® Terrain"

Dual antenna - Special Instruction, M0079452, "Installation of G610 Hardware for Cat^® Terrain for Excavators"

Configuring

The following MCU settings are used during configuration of the sensor on a single antenna machine:

• "CAN Sensor Port"

• "Use Roll Sensor" / "Use Pitch Sensor"

• "Pitch Sensor Offset" / "<Roll Sensor> Offset"

• "<Roll Sensor> Type" or "<Pitch Sensor> Type"

The sensor offset must be determined by manual calibration. The sensor offset is the value that must be applied to zero the sensor value.

Calculating Pitch and Roll for a Front Shovel

Single antenna front shovels seldom move while working. Therefore, the system does not need to know pitch and roll to calculate the elevation of any point on the machine. The system does not need a sensor.

The pitch and roll of the single antenna front shovel body is calculated by the onboard software as follows:

1. The onboard software uses three position updates to determine a plane that represents the recent surface on which the machine is working.

2. The onboard software calculates the center of rotation of the front shovel. The front shovel heading is determined from both the center of rotation and from the receiver position.

3. The front shovel heading and the plane are used to determine the pitch and the roll of the front shovel body.

4. The pitch and the roll are then used to determine the position and the elevation at the swath points of the front shovel.

Calculating Pitch and Roll for Surface Miners / Terrain Levelers

The pitch and roll of a single antenna surface miner or terrain leveler is observed using a sensor. Calibrate the sensor initially using a digital level, then recalibrate the sensor in line with the site workflow for these machine types.

Reference: Special Instruction, REHS5195, "Installation of Pitch and Roll Angle Sensor for Cat^® Terrain"

Calculating Pitch and Roll on a Dual Antenna Machine

The pitch and roll of a dual antenna machine is observed using a sensor. Calibrate the sensor as part of the Calibration Wizard when calibrating the whole machine.

Reference: Special Instruction, M0079452, "Installation of G610 Hardware for Cat^® Terrain for Excavators"

Erratic Machine Movement

If parts of the current elevation as-built surface are outdated, or if the height change is not consistent on all sides of the machine, then an invalid pitch and roll is determined by a machine with no sensors. An invalid value results in invalid positions and invalid elevation at the swath points.

This situation is identified by the visible jumping in the path of the machine or with jagged survey lines when using wheel loaders and track-type tractors to survey the toe or crest of a high wall. Additionally, the machine not only appears to jump on the display, but the newly recorded surfaces reflect the jump and are less accurate.

Illustration 1	g01192114
(1) Front view of machine (2) New surface that has not been passed over (3) New surface that has been updated (4) The roll determined by the onboard software (5) Old surface

The example in Illustration 1 depicts how an invalid roll is determined from a Current Elevation surface that is not up-to-date.

In this example, a new layer has been deposited on the surface. The machine is working from left to right moving over by a half-machine width each pass. The machine roll is determined by the onboard software from the current elevation. The machine roll is always invalid until the new level is fully mapped.

To resolve this issue, enable the "Use Roll Sensor" setting in the MCU. Leave the default values in the "Type" and "Offset" fields. These actions set the roll offset permanently to zero. The machine records zero roll.

Front Shovel Activities

"Front Shovel Activity Param" - This setting modifies parameters that are specific to the front shovel machine type. When the operator selects an activity, the front shovel activity settings modify the swath behavior by altering the following parameters:

• "Max Reach"

• "Point Sheave"

• "Toe Radius"

Reference: "Front Shovel Configuration" section of this manual.

Front Shovel Pitch and Roll

The pitch and the roll of the front shovel body is calculated by the onboard software. The onboard software uses three GNSS position updates to determine a plane that represents the recent surface on which the machine is working.

The onboard software also calculates the center of rotation of the front shovel. The front shovel heading is determined from both the center of rotation and from the satellite receiver position.

The front shovel heading and the plane are used to determine the pitch and the roll of the front shovel body. The pitch and the roll are then used to determine the position and the elevation at the swath points of the front shovel.

Machine Heading

Machine heading is used in both the calculation of the swath point position and in the determination of the swath orientation. For a single antenna system, the machine heading is calculated from successive GNSS position updates. The further the swath point is from the receiver, the more of an effect that an error in the heading can have.

"Heading Filter" - Customizes the heading filter

Filtering the heading is necessary because small amounts of noise in the position can cause instability in the heading. For example, when a machine is stationary the position will change by small amounts. Therefore, because position changes cause a change in the heading of the machine, the heading must be filtered.

Note: Heading filters do not apply on single antenna front shovel machines.

Accuracy Move Distance

"Accuracy Move Distance" - Sets the move distance for a given GNSS position error limit

The move distance is used to determine how far a machine must move for a swath update and a display update to occur. Different machine activities can require different position accuracies.

There is always a certain amount of noise in positioning. The amount of noise varies depending on many factors, such as GNSS satellite constellation. The satellite receiver provides an estimate of the position accuracy always. "High" and "Medium" error limits can be set for the Position Error value used by the onboard software.

Swath Point Width

The swath points of a machine are usually one of the following:

• Centerline of the track on the ground

• Center of the wheel on the ground

• Center of the blade on the ground

Generally the width of the swath that is covered at the swath point is defined by the machine dimensions. For example, on a dozer, the swath width would be the width of the blade referenced from the center of the blade on the ground.

Add a Swath Point

"Swath Point Added Count" - Sets the maximum number of swath points. This setting must be used to allow swath points to be added. When this setting is set, new swath points cannot be added beyond the configured value.

"Swath Point" - This setting adds a new swath point on the machine if the number of added swath points is less than or equal to the value in the "Swath Point Added Count" setting. This setting specifies the location of the swath point relative to the machine origin and also specifies the width of the swath. The new point can be located anywhere in relation to the machine origin, including on top of an existing point.

Each new swath point is added to the end of the list of swath points. The new swath point identity, which is also used by the "Swath Option" setting, must be determined. The identity is determined by adding a count of 1 (one) to the number of prior swath points.

"Number" - A unique identity for each instance of the setting. This value is numbered consecutively beginning with 0 (zero).

"Backset" - Distance behind the machine origin

"Offset" - Distance to the side of the machine origin

"Width" - Desired swath width

Modify a Swath Point

In some cases, fixed swath points on the machine may not have a swath width that is related to the dimensions of the machine.

"Swath Point" - Modifies and defines the width of a specified swath point. The definitions for the parameters are identical to that of the Swath Point setting.

"Number" - A unique identity for each instance of the setting. This value is numbered consecutively beginning with 0 (zero).

"Swath Point ID" - Varies depending on the machine type and the added swath points

"Backset" - Distance behind the machine origin

"Offset" - Distance to the side of the machine origin

"Width" - Desired swath width

Activity Swath Width

"Activity Swath Width" - Changes the width of the swath for a specific offset on the machine. The swath width changes when the operator selects the activity that is specified in the setting.

Use Machine Activity to Change Swath Behavior

A machine may be involved in various activities. The swath behavior may need to change to suit the machine activity.

The swath behavior is controlled by the operator when the machine activity changes. The various settings that are related to machine activity allow the operator to change the swath behavior easily by simply selecting the activity.

The following settings are related to swath behavior.

"Activity Category Map" - Specifies either a new as-built surface file or the use of an existing as-built surface file

"Activity Color" - Maps an activity identity to a color identity

"Activity Swath Width" - Modifies the swath width based on the selected activity

"Coverage Color" - Configures the colors for each pass

"Coverage Level" - Configures the number of passes that are required to change from one coverage level to the next coverage level: The number of passes is unlimited.

"Coverage Menu" - Enables the Coverage menu

"Enable Activity Files" - Enables the activity features and makes a list of activities available to the operator

"Swath Point" - Adds a new swath point

"Swath Point Added Count" - Sets the number of added swath points

Note: The activity settings must be configured in the machine configuration file ahead of the "Data File Param" settings.

Note: The activity settings discussed in this section do not apply to front shovel machine types.

Reference: For instruction on activity file creation, refer to Systems Operation, RENR9562, "Cat^® Terrain Office Software"

Illustration 2	g01192145
Activity select dialog for a dozer

In the example in Illustration 2, a dozer is configured with two activities, "ripper 1"and "ripper 2".

When the dozer is ripping the surface with a single­toothed ripper, the operator would select the "ripper 1" activity.

When the dozer is ripping the surface with a three-toothed ripper, the operator would select the "ripper 2" activity. The swathed area is larger when the three-toothed ripper is used. Both the coverage file and the coverage map update to show the ripper coverage.

When the dozer is no longer ripping the surface, the operator would select the item called "None". Once this item is deselected, ripper coverage no longer updates.

Configure the machine configuration file as shown in Table 2 to set up a dozer to work as described in the example above.

Table 2

Sample Dozer Machine Configuration File
Swath Point Added Count =1 Allows one extra offset point to be added to the machine
Swath Point 0 =-5 0 0 Adds the extra offset point 5 m behind the origin of the dozer with no lateral offset from the dozer center line. Sets a 0 (zero) meter swath width for the new point.
Swath Option 1 =1 7 1 An additional "Swath Option" setting must be set up for the new point. Because the dozer currently has only one standard offset, the new point identity is 1. The setting is configured to update coverage.
Data File Param 10 =2 1.0 10 Ripper.cat A Data file named "Ripper.cat" is set up to record the coverage information.
Activity Swath Width 0 =1 1 5 The first "Activity Swath Width" setting is set up for the single-toothed ripper. The setting is used when "activity 1", "ripper 1", is selected. The setting specifies the use of the new swath point with a swath width of 5 m.
Activity Swath Width 1 =2 1 10 The second "Activity Swath Width" setting is set up for the three-toothed ripper. The setting is used when "activity 2", "ripper 2",is selected. The setting specifies the use of the new swath point with a swath width of 10 m.