Civil Analysis - Collision Analysis

Civil, Collision, Pile, Pole, Reveal, Length, Analysis, Terrain, Limit, Clearance

Vito Bindokas avatar
Written by Vito Bindokas
Updated over a week ago

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Collision analysis

To start working on Collision analysis we need to open the Civil analysis menu. It can be found in the Tools sub-menu by clicking on Civil analysis and navigating to the Collision analysis menu.

To start, we need to select our PV area. This can be done by clicking on Select PV area, selecting our PV area outline, and pressing Space or Enter on the keyboard.

Prior to starting with the collision analysis, we need to choose one of two options for the Analysis. We may reference the right-hand side of the window as a visual aid for what the software will be indicating.

  • Terrain limit - checks the heights on the outline of the frames;

  • Piling range - checks the pole reveal lengths.

Fixed-tilt

Similarly, as with the Slope analysis, we may define a range of acceptable distances between the frame and the terrain. If the value is found to be out of bounds, the software will mark the affected frame with a color designation. Since we are working with a fixed-tilt system, we are primarily interested in the Terrain limit analysis, but we will also explore the Piling range option.

Terrain limit

Terrain limit analysis checks the PV frame to ensure that the clearances are within the allowed range. We are able to specify a minimum and maximum allowed clearance gap between the frame and the terrain.

For additional context, we will open the Frame & Park settings and navigate to the Park settings tab. Here we may find the reference height we used for generating the most recent PV area.

We will set 0.5 meters as the lowest permissible height from the bottom of the frame to the terrain. For example purposes, we will set the upper limit as 0.7 meters.

Should any of our frames deviate from these thresholds, the entire frame will be highlighted - orange, if the clearance is less than 0.5 meters and purple, if the clearance exceeds 0.7 meters.

Now that our acceptable range has been specified, we may click on Indicate to see if our frames are in accordance with the given clearance range.

We can see that some frames are colored orange and purple, meaning that they respectively fall short of or exceed the clearance range.

We may click on Show details to get further insight. Once we select the specific frame we want to observe, press Space or Enter on the keyboard.

The way PVcase places frames is that it ensures that the far left and right bottom corners are at the lowest permitted height, which in this case is 0.5 meters.

However, the software does not account for the terrain between these points, and there may be intermediate positions where the frame may be out of the allowed range. Terrain collision allows us to test if the placed frames have areas where they are outside the given range.

If we were to zoom in on one of the affected frames, we can see that this particular point is colored orange, meaning that the clearance is less than the 0.5 meter lower threshold.

Similarly, the purple one indicates that this area of the frame is elevated beyond the upper limit of 0.7 meters from the terrain at that particular point.

Points, where the text is black, are within the acceptable range.

This can be best illustrated by performing a front-view of the frame and measuring the distance from the frame to the terrain. We select the Front-view option from the drop-down menu that is next to the cross-section function. We are then prompted to select the PV area boundary line and draw the front view we want to perform. We finalize this by left-clicking where we want to place our front-view drawing.

We are now able to manually measure the frame height by clicking on AutoCAD’s Home menu tab and selecting the measuring tool (which can also be summoned using the DIM command). If we were to click on this part of the frame and draw a perpendicular line to the terrain and finalize placing our dimension, we can see that we have the same value measured manually as indicated with the Collision analysis.

Piling Range

The second option for the collision analysis is Piling range. With Piling range analysis, we may specify the minimum and maximum limit for pole length and use the tool to highlight the affected frames and their specific poles.

For additional context, we will open the Frame & Park settings and navigate to the Park settings tab. Here we may easily check what are our pole lengths in the picture in the bottom right corner.

For example purposes, we will take the pole reveal values provided in the Park settings and use them as our Lower limit.

In order to get the upper limits we can increase the Lowest point values to 0.7 and pole values will be recalculated.

After that, we can repeat the same process to take the pole reveal values provided in the Park settings and use them as our Upper limit.

Now that our acceptable range has been specified, we may click on Indicate to see if our frames are in accordance with the given clearance range.

PVcase will color code in orange, frames that have either the first or the last pole that is shorter than the lower limits that have been set.

Alternatively, frames that are higher than one of the upper limits will be colored purple.

In the same way as the Terrain limit, we may also go further into the Piling range analysis and inspect the calculated individual pole lengths. We do so by clicking on Show Details - in turn, PVcase populated the frame drawing with text labels indicating the length of the individual poles of the frames. This is comparable to the functionality of the Piling information function.

For example purposes, we will zoom in on this frame. As we can see, poles that are shorter than the Lower limit or longer than the Upper limit are marked red. Poles that are blue are within the specified tolerances and there are no issues with them.

The height of the frames is unaffected by the analysis - it only serves to highlight any issues that may be present.

Single-axis tracker

Piling Range

When working with Single-axis trackers, it can be beneficial to review the collision analysis through the scope of the Piling range, but we will also look at the Terrain limit option as well.

With Piling range analysis, we may specify the lower and upper limit for pole length and use the tool to highlight the affected frames and their specific poles.

In our example, the pole reveal length for a flat terrain is 1.4 meters. We will take this value and enter it as the lower limit for our analysis and, for example, purposes set the upper limit to 1.7 meters. The upper limit is generally something that is specified by the tracker manufacturer, based on the mechanical specifications of the equipment.

Once we click on Indicate, the software will mark any frame that has piling outside our specified range.

Poles that are shorter than 1.4 meters will be colored orange.

While frames with poles longer than 1.7 meters will be marked purple.

Also, it must be noted that the software uses millesimal resolution - it is accurate to one-thousandth of a meter. There is no allowance for minor deviation - anything beyond these values will be marked as not meeting or exceeding the pole length respectively.

We may also go further into the Piling range analysis and inspect the calculated individual pole lengths. We do so by clicking on Show Details - in turn, PVcase populated the frame drawing with text labels indicating the length of the individual poles of the frames. This is comparable to the functionality of the Piling information function.

Because the Single-axis trackers in PVcase are considered at 0 degrees turning angle, they are placed at specified Pole reveal length at the extremes of the table.

However, the software does not account for the terrain underneath the frame, and there may be intermediate positions where the frame may be out of the allowed range. The Piling range allows us to test if the placed frames have areas where they are outside the given pole range.

If we were to zoom in on one of the affected frames, we can see that this particular frame is colored orange, meaning that the pole reveal is less than 1.3 meters which is our Lower limit.

Similarly, the purple one indicates that the poles are higher than the upper limit of 1.7 meters.

Tables and pole values colored in blue are within the acceptable range.

This can be best illustrated by performing a front-view of the frame and measuring the distance from the frame to the terrain. We select the Front-view option from the drop-down menu that is next to the cross-section function. We are then prompted to select the PV area boundary line and draw the front view we want to perform. We finalize this by left-clicking where we want to place our front-view drawing.

We are now able to manually measure the pole reveal height by clicking on AutoCAD’s Home menu tab and selecting the measuring tool (which can also be summoned using the DIM command). If we were to click on this part of the frame and draw a perpendicular line to the terrain and finalize placing our dimension, we can see that we have the same value measured manually as indicated with the Collision analysis.

Terrain limit

The second option for the collision analysis is the Terrain limit. With Terrain limit analysis, we may specify the minimum limit for terrain limits and use the tool to highlight the affected frames.

Clearance distance is measured from the terrain to the lower edge of the table at its maximum rotation (i.e. 55º, depending on the setting in "Frame creation"), as marked with the blue lines:

For additional context, we will open the Frame & Park settings and navigate to the Park settings tab. Here we may find the Reference height at the Lowest point we used for generating the most recent PV area.

We will set 0.41 meters as the lowest permissible height from the bottom of the frame to the terrain.

Should any of our frames deviate from these thresholds, the entire frame will be highlighted - orange, if the clearance is less than 0.41 meters.

Now that our acceptable range has been specified, we may click on Indicate to see if our frames are in accordance with the given clearance range.

We can see that some frames are colored orange, meaning that they respectively fall short of or exceed the clearance range.

We may click on Show details to get further insight. Once we select the specific frame we want to observe, press Space or Enter on the keyboard.

If we were to zoom in on one of the affected frames, we can see that this particular point is colored orange, meaning that the clearance is less than the 0.41 meter lower threshold.

Points, where the text is black, are within the acceptable range.

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