Driver Inputs

Driver Inputs are reusable OpenSim control timelines. They are different from Drivers: a Driver stores driver profile limits, while a Driver Input stores prescribed control traces over time.

If your team calls these control inputs, use the Driver Inputs screen in 4ACE.

Before you start

• Select the correct team.
• Decide the control sequence you want OpenSim to run.
• Use seconds for segment times.
• Use percent for throttle and brake, degrees for steer angle, and integer gear numbers when gear is enabled.

Create a Driver Input

1. Open Driver Inputs from the sidebar.
2. Select New.
3. Enter Name.
4. Add Notes when the timeline needs context.
5. In Driver Inputs, define required segments for:
   • Throttle.
   • Brake.
   • Steer angle.
6. Optional: turn on Specify gear channel if gear should come from the Driver Input.
7. Add gear segments when gear channel is enabled.
8. Review the charts above each channel.
9. Select Save.

After saving, the Driver Input appears in the Driver Inputs table and in OpenSim setup.

Segment fields

When you add a segment, it starts at the previous segment end when one exists. The new segment lasts 5 seconds by default.

Channel reference

Timeline rules

• Name is required.
• Throttle, Brake, and Steer angle each need at least one segment.
• Segment times cannot be negative.
• A segment start must be before its end.
• Segments in the same channel cannot overlap.
• Adjacent segments can share a boundary, but the next start value must match the previous end value.
• Gear values must be whole numbers from 1 to 8.

OpenSim duration is the latest visible channel segment end time. If no segment extends the timeline, duration is at least 1 second.

Import channel segments

In either the creation sheet or detail page, select a channel tab and choose Import above its segment grid. Import replaces only that channel's segments. Other channels, name, notes, interpolation, default values, and gear mode stay unchanged. Enable Specify gear channel to import Gear.

Choose one .csv, .tsv, or .xlsx file. CSV uses commas, TSV uses tabs, and XLSX reads only the first worksheet. Files are read locally, not uploaded.

The first row must contain exactly four unique headers: Start, End, From, To. Headers may be reordered; case, surrounding whitespace, and a leading BOM are ignored. Do not include a Segment column, unit suffixes, or extra columns.

Start and End use seconds. From and To use percent for Throttle/Brake (0-100), degrees for Steer angle (-700 to 700), or whole gear numbers (1-8). Use finite numbers with decimal points; quoted numeric fields and scientific notation are supported. Include at least one data row. Entirely blank rows are ignored; partially blank rows, wrong-width rows, and nonnumeric cells are rejected.

Copy this CSV example for Throttle or Brake:

Start,End,From,To
0,5,0,50
5,10,50,100

1. Choose a file and review the channel, segment count, and time range in the preview. The draft remains unchanged.
2. Select Replace segments. Segments are sorted chronologically, even if file rows are out of order. The chart and draft update immediately.
3. Use the existing save action to persist the Driver Input. Canceling the import makes no draft changes.

Invalid files cannot replace segments. File-shape and numeric errors identify source rows and columns where applicable. Timeline errors use segment numbers in chronological order, not file row numbers. Selecting another file clears the old preview; replacement remains disabled while reading, during save, or without write permission.

Gaps between imported segments

Import requires the previous To and next From to match across a gap. For example, 0,5,0,20 followed by 10,15,20,100 is allowed: the channel holds 20 from 5 to 10 seconds. Saving and reopening may add an explicit constant segment for that interval without changing its values.

A gap from 20 to 80 is rejected with both source rows identified. Add an explicit connecting segment to describe the ramp:

Start,End,From,To
0,5,0,20
5,10,20,80
10,15,80,100

This gap restriction applies only to import. Existing manual editing and save rules are unchanged. Read or validation failures leave the draft intact; correct the file and select it again.

Use a Driver Input in OpenSim

1. Open Simulations.
2. Select New.
3. Choose OpenSim.
4. In Setup, select Vehicle, Ambient, Driver, and Driver Input.
5. Review the Driver Input preview before continuing.

Troubleshooting

Related pages

• Run OpenSim
• Drivers
• Run Batch Simulations
• Review units and conventions
• Look up glossary terms