The Invisible Puppet Master:

Exploring Stealthy Backdoor Attacks on AI-Assisted Robotic Arms

Code

DoRAX is a generalized stealthy backdoor attacks on robotic arms’ executions, which results in backdoor propagated stealthily in the physical world between RAs.

System Overview

DoRAX is applicable to all three RA setups and two control paradigms, and focuses on physical attack targets that manipulate the dynamics and kinematics of RAs in the physical space by directly tampering with the high frequency RA motor signals.

Experiments

(1) Soft object handing

Task The robotic arm picks up a sponge and places it into a transparent container. It must apply a moderate gripping force that is sufficient to securely grasp the soft object without causing any deformation or damage.
Target The attack manipulates the gripper motor by reducing its rotation angle, which increases the applied gripping force. As a result, the soft object undergoes significant deformation, potentially simulating damage or operational failure.

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 Benign(ACT)

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 Object

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 Light

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 Benign(Diffusion Policy)

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 Object

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 Light

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 Benign(Smolvla)

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 Attack(Smolvla)

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 Benign(Pi0)

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 Attack(Pi0)

(2) Pouring

Task The RA carefully grasps the test tube and then pours the liquid into another test tube,then reset to the original position.
Target Reduce the rotation angle of the wrist_rotation motor and cause insufficient tilt angle.

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 Benign(ACT)

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 Object

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 Light

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 Benign(Diffusion Policy)

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 Object

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 Light

(3) Machinery Boxing

Task The robotic arm collects all machinery items from the table and places them into a designated box in sequence.
Target By resetting the motor rotation angle to its initial state, the robot may skip intermediate pick-and-place steps, leading to incomplete task execution.

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 Benign(ACT)

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 Object

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 Light

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 Benign(Diffusion Policy)

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 Object

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 Light

(4) Color Sorting

Task The robotic arm picks up each screw and places it in the appropriate sorting area based on its color.
Target By inversing the rotation angle of the base motor, the robot misplaces the boxes, resulting in incorrect color-based classification.

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 Benign(ACT)

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 Object

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 Light

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 Benign(Diffusion Policy)

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 Object

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 Light

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 Benign(Smolvla)

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 Attack(Smolvla)

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 Benign(Pi0)

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 Attack(Pi0)

(5) Welding

Task The left arm operates the soldering iron while the right arm guides the solder wire to accurately solder specific points on a circuit board.
Target By increasing the base motor’s rotation angle, the robot introduces misalignment in the soldering path, leading to inaccurate or missed solder joints.

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 Benign(ACT)

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 Object

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 Light

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 Benign(ACT)

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 Light

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 Object

(6) Transfer

Task The robotic arm should stop its movement along the planned trajectory when a human hand enters its workspace.
Target increase the rotation angle of the base motor,cause the robotic arm does not perform an autonomous stop when detecting human

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 Benign(ACT)

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 Object

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 Light

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 Benign(Diffusion Policy)

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 Object

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 Light

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 Benign(Smolvla)

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 Attack(Smolvla)

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 Benign(N1)

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 Attack(N1)

(7) Testing

Task The first robot(RA1) inserts a battery from the test zone (yellow) into the battery box, while the other robot(RA2) controls the switch connection and observes the bulb’s brightness. If the bulb lights up, the arm grabs the bat tery and places it in the certified zone(blue). If the bulb does not light up, the arm grabs the battery and places it in the faulty area (red).
Target reverse the rotation angle of the wrist_rotation,cause the battery to be installed with reversed polarity, which indirectly led to the misclassification of the battery for the second arm.

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 Benign(ACT)

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 Object

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 Light

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 Benign(DP)

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 Object

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 Light

(8) Belt Sorting

Task The color arm (RA1)picks up a screw from the desk and places it on the belt aligned horizontally, parallel to the direction of belt movement; while the black arm (RA2)grasps the screw from the belt and sorts them based on their color.
Target decrease the rotation angle of the wrist_roll motor, cause the screw to be placed on the belt with a wrong position, thus causing RA2 can not grasp the screw correctly.

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 Benign(ACT)

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 Object

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 Benign(ACT)

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 Object

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(9) Attention Map

first and second rowFor the soft-handling task with an object trigger, we changed the trigger’s rotation and position. Although the original trigger region remains activated, the corresponding action is not triggered.
third and fourth row For transfer task with light trigger, we change the trigger light with different, although the origianl trigger region is still weakly activated, the action is not triggered.

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 Softhandling(attack)

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 rotation

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 position

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 transfer(attack)

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 blue light

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 yellow light