Arm Control

The driver can also send commands to the robot’s arm, if it has one. The following services allow control of various parts of the arm. Note that the arm does not have collision avoidance, so it is important to be careful when using these services.

Service	Description
/spot/arm_carry	Move the arm into the carry position.
/spot/arm_joint_move	Move each joint into a position specified by a specific angle, corresponding to the 6 degrees of freedom.
/spot/arm_stow	Move the arm into the stow position.
/spot/arm_unstow	Move the arm into the unstow position.
/spot/force_trajectory	Move the arm by specifying forces in (x,y,z) linear forces and (rx,ry,rz) rotational forces, acting as a virtual wrench.
/spot/grasp_3d	Use the Pick autonomy feature of Spot to pick an object specified in Cartesian (x,y,z) coordinates in a chosen reference frame, usually body.
/spot/gripper_angle_open	Open the gripper to a specific angle, between 0 and 90 degrees.
/spot/gripper_close	Close the gripper to 0 degrees.
/spot/gripper_open	Open the gripper to 90 degrees.
/spot/gripper_pose	Move the gripper to a point specified in Cartesian (x,y,z) coordinates of the robot’s body frame.

Arm Carry, Stow, Unstow

The arm can be moved into the predefined carry, stow, and unstow positions.

Carry:

Stow:

Pick Service (Grasp 3D)

Note that it is important to perform the Spot Check calibration before using the Pick service of the arm. If any cameras are in an error state, the Spot robot will refuse to execute any Autonomy features, including picking. The Picking process is shown below:

1. Walking to the object
2. Unstowing the arm
3. Surveying the object with the gripper camera
4. Walking closer to the object
5. Picking the object
6. Closing the gripper