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Robotic Arm Control & Debugging Tools

Applicable Version: v1.1.2
Release Date: August 3, 2026

Version Supported Environments Entry
v2026.08.03 Windows, macOS, Linux Open the Star Arm 102 Web-Based Host Computer Interface

1. Product Overview

This is the unified control and debugging entry point for robotic arms. The current web-based host computer interface provides Star Arm 102 digital-twin and operation features, including:

  • Serial-port connections for the Star Arm 102-LD / HD Leader and Star Arm 102-FL Follower.
  • Real-time teleoperation from a Leader to a real or virtual Follower.
  • Real-time J1–J7 angle and 3D pose display.
  • Joint target control and world coordinate target control for the HD and FL.
  • Manual trajectory recording, virtual preview, and real-arm playback for a real Star Arm 102-FL.
  • Reset Zero Position, Restore Factory Parameters, and new-servo configuration tools.
  • Chinese and English interface switching.

A page message stating that a command has been sent only means that the command was written to the serial port. It does not confirm that the robotic arm reached the target accurately. Direction, zero position, smoothness, and accuracy must be validated separately on real hardware.

2. Before Use

  • Use the latest version of Google Chrome or Microsoft Edge.
  • Connect the robotic-arm controller to the computer through USB serial.
  • Confirm that the browser has permission to access serial ports.
  • Close other applications that may be using the robotic arm's serial port.

2.2 Safety Checklist

Complete the following checks before operating a real robotic arm:

  1. Place the robotic arm on a stable, spacious workbench.
  2. Remove people and obstacles from the arm's working area.
  3. Ensure that you can click Emergency Stop at any time and can immediately disconnect power from the robotic arm.
  4. When executing a target pose or trajectory for the first time, use a slower speed and a limited motion range.
  5. Support the robotic arm by hand when releasing torque, resetting zero positions, or restoring factory parameters to prevent joints from dropping suddenly.
  6. Do not disconnect the USB cable or close the web page while serial data is being written, parameters are being restored, or a servo is being configured.

If the browser or USB driver becomes permanently unresponsive, the page may be unable to withdraw serial commands that have already been submitted. In this situation, disconnect power from the robotic arm directly.

3. Interface Overview

The top navigation area contains five pages:

Page Purpose Applicable Devices
Real-Time Control Serial connection, teleoperation, 3D pose, joint control, and world coordinate control LD, HD, FL, and virtual FL
Trajectory Recording Manual recording, import/export, virtual preview, and real-arm playback Real Star Arm 102-FL only
Reset Zero Position Set the current positions of servos with IDs 0–6 as their zero positions Leader or Follower
Restore Factory Parameters Restore servo parameters for the selected model FL, HD, Violin U25, and U45
Servo Configuration Configure the ID and baud rate of one new servo One new servo only

4. Real-Time Control

4.1 Device Roles and Permissions

Model or Mode Role Main Capabilities
Star Arm 102-LD Leader Unpowered; pose acquisition only; cannot execute joint or world coordinate targets
Star Arm 102-HD Leader Pose acquisition; can execute joint or world coordinate targets
Star Arm 102-FL Follower Receives teleoperation commands; can execute joint or world coordinate targets
Virtual FL Browser 3D model Follows the Leader pose without connecting to or writing to a Follower serial port
reBot Arm B601 / Galaxea A1Z Virtual model Follows J1–J6 only; sends no hardware commands

4.2 Connecting a Real Leader and Follower

  1. Open Real-Time Control.
  2. Under Leader Type, select Star Arm 102-LD or Star Arm 102-HD.
  3. Under Follower Type, select Real FL.
  4. Click Connect Leader, then select the Leader's port in the browser's serial-port dialog.
  5. Click Connect Follower, then select the real FL's port.
  6. Confirm that both the Leader and Follower statuses show Connected.
  7. Verify that the 3D model and real-time J1–J7 values change with the physical arm's pose.

Always verify which device belongs to each port. Do not select the same serial port for both the Leader and Follower.

4.3 Connecting a Virtual Follower

Virtual mode is used to verify Leader data acquisition, mapping, and 3D following without controlling a real Follower.

  1. Select the Leader type and connect the Leader.
  2. Set Follower Type to Virtual FL.
  3. Select the target model under Virtual Follower Model.
  4. Confirm that the page states: Drives the 3D model only; no Follower serial commands are sent.
  5. Click Start Teleoperation.

Virtual mode does not require a Follower serial port. After teleoperation stops, the virtual model retains its last pose.

4.4 Teleoperation Parameters

Parameter Range Default Description
Control Loop Interval 0–100 ms 20 ms 0 uses the fastest non-blocking loop allowed by the browser and serial port
Filter Window 0–100 30 0 disables filtering and uses the latest valid angle directly
Leader Response Timeout 100–2000 ms 800 ms Maximum time to wait for a response from the Leader serial port
Raw Serial Log On/Off Off Used for serial communication troubleshooting

The Control Loop Interval and Filter Window are locked while teleoperation is running. Stop teleoperation before changing them.

4.5 Starting and Stopping Teleoperation

  1. Confirm that all required devices are connected.
  2. Set the Control Loop Interval and Filter Window.
  3. Click Start Teleoperation.
  4. Move the Leader slowly and observe whether the real Follower or virtual model follows correctly.
  5. Click Stop to end teleoperation.
  6. When finished, click Disconnect All.

If abnormal motion, an incorrect direction, or an obstacle hazard occurs, click Emergency Stop immediately. Disconnect power directly if necessary.

5. Joint Target Control

Joint Target Control is available only for a powered HD or FL. The LD displays real-time values but cannot execute targets.

  1. Connect a controllable HD or FL and select the corresponding device under Pose Source.
  2. Click Enter Slider Control.
  3. Drag the J1–J7 sliders or enter target values in the angle fields.
  4. Check the cyan target preview and the target joint angles shown on the page.
  5. Set Execution Duration. The default is 800 ms.
  6. After confirming that the area around the robotic arm is safe, click Confirm Joint Target Execution.
  7. After execution, continue previewing as needed or click Exit Slider Control.

Dragging a slider or entering an angle only generates a preview; it does not move the robotic arm immediately. The page sends motion commands only after execution is explicitly confirmed. J7 controls the gripper.

6. World Coordinate Control

World Coordinate Control generates a target pose from the end-effector TCP X, Y, and Z position. It follows the same preview first, then confirm safety process.

  1. Connect a controllable HD or FL.
  2. Switch to World Coordinate.
  3. Set the target using any of the following methods:
  4. Enter TCP X, Y, and Z in mm, then click Calculate and Preview.
  5. Drag the red X, green Y, or blue Z arrow for single-axis movement.
  6. Drag the translucent XY, YZ, or XZ plane for two-axis movement.
  7. Drag the center square to move along the screen plane.
  8. Hold Shift while dragging to use 1 mm increments.
  9. Check the cyan target preview, target TCP, joint angles, and calibration status.
  10. Set the execution duration, then confirm execution.
  11. Click Exit World Coordinate Control to return to Joint Control.

If the target is unreachable, calculation fails, or the calibration status is abnormal, cancel the preview and reduce the motion range. Switching control methods automatically cancels any unconfirmed preview.

7. Manual Trajectories for a Real FL

The Trajectory Recording page supports only a real Star Arm 102-FL. The recording source is valid J1–J7 serial feedback from the real FL after torque has been released. It does not use a Leader, virtual device, or cyan preview data.

7.1 Connecting and Recording

  1. Open Trajectory Recording.
  2. Click Connect Real FL and select the FL's serial port.
  3. After connection, the page releases torque and continuously reads J1–J7. Support the robotic arm by hand.
  4. Enter a trajectory name of up to 40 characters.
  5. Click Start Recording.
  6. Move the torque-released FL smoothly by hand to perform the motion.
  7. Click Stop Recording.
  8. Confirm that the page displays the frame count, duration, and Trajectory Saved.

The current trajectory is saved automatically in the current browser. A single recording is limited to 10 minutes or 30,000 frames. The default minimum sampling interval is 20 ms, and the joint-change threshold is 0.1°.

7.2 Exporting and Importing

  • Click Export JSON to save the current trajectory as a JSON file.
  • Click Import JSON to select an existing trajectory file.
  • A file is imported only after passing device identity, timing, frame count, joint count, numeric-value, and joint-limit validation.
  • An invalid file does not overwrite the current trajectory.

Export a backup immediately after completing an important trajectory. Locally saved trajectories may be lost if browser data is cleared, a different browser is used, or private browsing mode is enabled.

7.3 Safety Step 1: Virtual Preview

  1. Keep the same real FL connected and select the current trajectory.
  2. Click Start Virtual Preview.
  3. Observe the complete motion of the cyan virtual FL. Virtual preview sends no serial motion commands.
  4. After confirming that the motion is correct, click Finish and Confirm Correct.

Clicking Stop Preview, or allowing the preview to reach the end naturally, does not unlock real-arm playback. You must explicitly click Finish and Confirm Correct.

Recording a new trajectory, importing another trajectory, disconnecting, triggering Emergency Stop, or changing pages revokes the existing preview confirmation. The trajectory must then be previewed again.

7.4 Safety Step 2: Real-Arm Playback

  1. Complete and confirm the virtual preview.
  2. Ensure that there are no people or obstacles around the robotic arm, and be ready to trigger Emergency Stop or disconnect power.
  3. Click Real-Arm Playback.
  4. In the confirmation dialog, verify the execution device, trajectory name, frame count, and duration.
  5. Click Confirm Replay on Real FL.
  6. The robotic arm first moves smoothly to the first frame over 2000 ms, then executes the trajectory according to its original timing.
  7. During playback, the interpolated target is refreshed every 20 ms, and each command uses a 100 ms overlapping motion window.
  8. To abort playback, click Stop Real-Arm Playback. In an emergency, click Emergency Stop.

After normal playback completion or a manual stop, the robotic arm retains its current position and torque; torque is not released automatically. When the page shows Holding Torque · Click "Release Torque":

  1. Support the robotic arm by hand.
  2. Confirm that releasing torque will not cause a collision or fall.
  3. Click Release Torque.
  4. Wait for the page to resume real-time feedback.

Emergency Stop cancels targets that have not yet been sent and attempts to release torque safely on the currently connected real FL.

8. Reset Zero Position

Reset Zero Position sets the current positions of servos with IDs 0–6 on the connected robotic arm as their zero positions, regardless of whether the arm is a Leader or Follower.

  1. Open Reset Zero Position.
  2. Click Select Arm Serial Port and connect the robotic arm to be configured.
  3. Support the robotic arm by hand and move all joints to their intended zero positions.
  4. Click Reset Zero Position.
  5. Check the pose again in the safety confirmation dialog, then confirm execution.
  6. Do not move the robotic arm during configuration and automatic verification.
  7. Review the result card and log. Failure messages identify the specific servo ID.

After the operation, the robotic arm remains torque-released and does not automatically restore holding torque. Continue supporting the arm, then reconnect or control it as required by the use case.

9. Restore Factory Parameters

This tool restores servo parameters. It does not set or change the robotic arm's zero positions.

Supported models:

  • Star Arm 102-FL
  • Star Arm 102-HD
  • Violin U25
  • Violin U45

Procedure:

  1. Open Restore Factory Parameters.
  2. Select the correct arm model first.
  3. Click Select Arm Serial Port and connect the corresponding robotic arm.
  4. The model is locked after connection. To change the model, disconnect the serial port first.
  5. Support the robotic arm by hand and click Restore Factory Parameters.
  6. Verify the model in the confirmation dialog, then confirm execution.
  7. Wait for all four steps in the right-side progress panel to complete: release robotic-arm torque, write public parameters, write internal parameters, and automatic verification.
  8. Review the detailed log. If configuration or verification fails, record the servo ID reported on the page.
  9. After successful completion, switch off the robotic arm as instructed, then power it on again before use.

Do not move the robotic arm, disconnect USB, or close the page during restoration.

10. New Servo Configuration

This function is only for one new servo that has not yet been installed on the robotic arm.

Never perform this operation with the complete robotic arm connected. Doing so may cause servo ID conflicts and write parameters to the wrong device.

  1. Connect one new servo independently to the serial adapter.
  2. Open Servo Configuration.
  3. Enter the target servo ID in the range 0–6, corresponding to J1–J7 of the robotic arm.
  4. Select I confirm that only this new servo is currently connected.
  5. Click Connect Servo. The tool connects to the new servo at 115200 bps.
  6. Click Write Configuration.
  7. In the confirmation dialog, verify the target ID and 1,000,000 bps (1 Mbps) baud rate, then confirm the write.
  8. Wait until progress reaches 100%, and verify that the log reports successful configuration.
  9. Disconnect power and serial from the servo, then install it on the robotic arm.
  10. After installation, use Reset Zero Position and Restore Factory Parameters as required.

11. 3D View Controls

  • Drag with the left mouse button: rotate the view.
  • Mouse wheel: zoom the view.
  • Default View: restore the preset viewing angle.
  • Fit Model: fit the model to the current window.
  • Fullscreen: display the 3D scene in fullscreen mode.
  • White model: pose reported by the real device.
  • Cyan model: unexecuted target preview or virtual trajectory preview.

The 3D model is for observation and preview only. It does not replace real-world clearance, collision, or accuracy checks.

12. Troubleshooting

12.1 The Browser Does Not Show the Serial-Port Dialog

  • Confirm that you are using Chrome or Edge.
  • Confirm that the browser has permission to access serial ports.
  • Check the USB cable, serial adapter, and robotic-arm power supply.
  • Close other applications using the same serial port, then try again.

12.2 Serial Connection Fails or Frequently Times Out

  • Confirm that the correct device port is selected.
  • Check that the USB connection is stable.
  • Increase Leader Response Timeout as appropriate.
  • Stop other serial-port applications, reconnect the device physically, and try again.
  • Enable Raw Serial Log and record the error information.

12.3 The 3D Model Does Not Follow the Real Device

  • Confirm that the device status is Connected.
  • Check that the correct Pose Source is selected.
  • Confirm that teleoperation has started, or that the real-time feedback frequency on the Trajectory Recording page is not 0.0 Hz.
  • Click Fit Model to reposition the view.
  • Check the runtime log for missing servo IDs or out-of-range angle errors.

12.4 Slider Control or World Coordinate Control Is Unavailable

  • The LD is an unpowered Leader and supports pose acquisition only.
  • Connect an HD or FL and select the corresponding Pose Source.
  • Stop any active teleoperation, trajectory playback, or other operation that is using the control channel.

12.5 The Real-Arm Playback Button Remains Locked

  • Confirm that the same real FL remains connected through the same serial port.
  • Restart the virtual preview.
  • You must click Finish and Confirm Correct. Stopping the preview or allowing it to finish naturally does not count as confirmation.
  • If the trajectory changes, complete the virtual preview confirmation again.

12.6 The Robotic Arm Still Holds Torque After Playback

This is the expected safety behavior. After normal completion or a manual stop, the robotic arm retains its current position and torque. Support the arm, confirm that it is safe, and click Release Torque.

12.7 Parameter Configuration or Verification Fails

  • Record the specific servo ID and error shown on the page.
  • Check power, wiring, and communication for that servo.
  • Do not repeat write operations continuously. First resolve connection and model-selection problems.
  • When restoring factory parameters, confirm again that the selected model matches the physical arm.

13. Trajectory Data Description

A trajectory JSON file has the following fixed identity fields:

  • schemaVersion: 1
  • robotModel: "FL"
  • source: "manual_fl"
  • frames[].t: time relative to the start of recording, in ms.
  • frames[].jointsRad: J1–J7 model logical angles, in radians.

Do not manually edit trajectory JSON and use it directly for real-arm playback. Import validation can reject format and joint-limit errors, but it cannot prove that a trajectory is collision-free in the real environment.

14. Shutdown Procedure

  1. Stop teleoperation or trajectory playback.
  2. If the page indicates that torque is being held, support the robotic arm and click Release Torque.
  3. Click Disconnect All or Disconnect on the current page.
  4. Switch off power to the robotic arm.
  5. Arrange the USB cable and robotic arm so that no external force is applied to the joints.