Auto Position Movement Panel (Gait)

If you are brand new: think of this skill as a “pose-and-playback” animation tool for your robot’s servos. You create a few poses, put them in order, and ARC smoothly moves the servos between them.

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Key Ideas (Beginner Friendly)

A gait is simply a repeated pattern of limb movement for locomotion. Different robot builds need different gaits: humanoids usually use a biped walk pattern, while hexapods typically use a 6-leg crawl pattern.

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Two Versions (Which One Should You Use?)

There are two Auto Position gait skills:

If your robot needs “drive-like” direction commands (walk forward, turn left, stop), use the Movement Panel version. If you only need servo animations (wave, pick up, pose) and you want multiple Auto Position skills, use the non-movement version. Learn what a Movement Panel is here: ARC Movement Panels overview.

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Auto Position Overview (What ARC Does For You)

When you play an Action, ARC automatically calculates how to transition from the current Frame to the next Frame. You do not need to manually compute intermediate servo positions—ARC “fills in the in-between” so the motion looks smooth.

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How It Works (Flipbook Example)

Imagine a flipbook animation: each page is one drawing. When you flip pages quickly, it looks like motion. Auto Position works the same way:

1. Create multiple Frames (poses).
2. Create an Action and add those frames in order.
3. Execute the Action. ARC moves the servos through the frames.

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Example: Picking Up a Cup (Frames → Action)

Picture a simple robot arm with a shoulder, elbow, and a gripper. “Pick up cup” is not one single servo move—it’s a series of poses: approach the cup, open gripper, lower arm, close gripper, lift arm, etc. In Auto Position:

• Each pose is a Frame.
• The full motion is an Action made from those frames.

Creating Frames

When you create frames, you are deciding where each servo should end up (goal positions). ARC handles the transition between them. Breaking a task into smaller frames makes it easier to edit and prevents sudden, stressful movements.

After you create frames, you’ll see a list of them with the servo positions saved inside each frame:

Add Frames to an Action

An Action is where you decide how the robot moves between frames (speed settings, pausing, repeating, and optional scripts).

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Step & Delay (The Two Settings Beginners Use Most)

When transitioning from one frame to another, ARC sends a series of small position updates to your servo controller. Steps and Delay control how that transition feels.

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Software Acceleration (SW Ramping)

Some servo systems support built-in acceleration/velocity (for example, certain smart servos). Basic hobby servos and many simple controllers do not, which can cause motion to start/stop abruptly. SW Ramping is ARC’s way of smoothing movement in software.

How to set it up

• Where it is: SW Ramping is set per frame entry inside an Action (because each transition can be different).
• Typical approach: Set Steps to the fastest step size you want to reach during the middle of the move (example: 10), then set SW Ramping to a value above 0 (example: 1000).

What it does

1. Soft start: begins with smaller step sizes (starts gently).
2. Faster middle: near the middle of travel it uses your configured Steps value.
3. Soft stop: reduces step sizes near the end (stops gently).

Note: If SW Ramping is 0, no software smoothing is applied.

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Tutorial Video: Creating a Hexapod Gait

This example shows Auto Position being used to build a walking gait for a large 3D-printed hexapod and how it can be combined with other skills (camera, speech recognition, joystick).

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Main Window (What You See Day-to-Day)

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Configuration: Frames (Building Your Poses)

Each Frame contains a list of servo positions (in degrees). With Realtime Update enabled, changing a value moves the real robot immediately.

Editing servo position values

• Left-click + drag a degree value up/down to change it.
• Right-click a value to type a number.

Special servo values (important)

• 1 to 180: normal servo angle positions.
• 0: releases the servo (or stops a continuous rotation servo).
• -1: “skip this servo” for this frame (keeps its current position).

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Configuration: Actions (Turning Poses into Motion)

Actions are where you build the “playlist” of frames and how fast each transition should be. For walking gaits, you’ll usually create Actions like FORWARD, REVERSE, LEFT, RIGHT, and STOP.

• Add appends the selected frame to the action’s sequence list along with its transition settings.
• This Action Repeats loops forever until you run a different action (common for FORWARD walking).
• Edit Script lets you run a script when the action starts (button color indicates if a script exists).
• Sequence list is the order frames will play. Use move up/down to reorder.

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Configuration: Settings (Scripts + Variables)

• Start Script: runs before a frame or action executes.
• End Script: runs after the queue finishes.
• Variables: shows current action/frame and running status (example: $AutoPositionStatus is 1 when running).
• Title: renaming changes the name used in ControlCommand() calls—update your scripts if you rename it.

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Import/Export Utilities (Backups and Sharing)

Use Import/Export to back up your Frames/Actions or move them between projects/skills (including between the movement panel and non-movement panel versions).

• Export creates an .autoposition file.
• Import loads .autoposition and .ezb files.
• If you see messages about duplicate frames, it often happens when importing the auto-generated PAUSE frame.

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Movement Panel vs. Non-Movement Panel (Practical Differences)

For movement panel control in scripts, you can use movement commands like Forward(), Left(), Right(), Stop(), Reverse(), or use the Auto Position ControlCommand() options listed in the Cheat Sheet tab.

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Quick Start (Step-by-Step for Beginners)

1. Add the skill
   In ARC: Project → Add Skill → Movement Panels → Auto Position Movement Panel.
2. Create Frames (poses)
   Open Configuration → Frames. Add servos, then create a few frames (example: Stand, Step1, Step2).
3. Create an Action (sequence)
   Go to Actions. Create an action (example: FORWARD) and add frames in order. Add PAUSE frames if you need a short hold.
4. Tune the movement
   Adjust each sequence entry’s Step/Delay (and SW Ramping if needed) until it looks smooth and stable.
5. Test it
   Return to the main window, select your action, and press Execute (or use the directional buttons if you mapped gait actions).

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Code Samples (Running Frames/Actions from Scripts)

All Auto Position commands appear in ARC’s Cheat Sheet tab. Common examples:

ControlCommand("Auto Position", AutoPositionAction, "My Action 1")
ControlCommand("Auto Position", AutoPositionFrame, "My Frame 1")
ControlCommand("Auto Position", AutoPositionFrame, "My Frame 1", 50, 3)

In the last example, the extra numbers are transition settings (Delay/Steps) for moving into that frame.

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Videos

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Resources & Tips

• Use the Import/Export tools to back up your work frequently.
• Start with slow settings (higher Delay, smaller Steps) to avoid jerky movements while learning.
• Build gaits gradually: get a stable “Stand” pose first, then add one step frame at a time.