Move an arm

You have two options for moving a robotic arm:

Prerequisites

A running machine connected to the Viam app. Click to see instructions.
Add a new machine in the Viam app. On the machine’s page, follow the setup instructions to install viam-server on the computer you’re using for your project. Wait until your machine has successfully connected to the Viam app.

Configure and connect to your arm

1. Configure an arm component

First, physically connect the arm to your machine.

Then, navigate to the CONFIGURE tab of your machine’s page in the Viam app. Click the + icon next to your machine part in the left-hand menu and select Component. Search for and select a model that supports your arm.

Complete the arm configuration, then use the TEST panel in the configuration card to test that the arm is working.

2. Connect code to your arm

Go to your machine’s CONNECT tab in the Viam app. Select your preferred programming language and copy the code snippet.

See Create a web app, Create a mobile app, or Create a headless app for more information, depending on your use case.

Move the arm using the arm API

The two main options for controlling arm movement with the arm API are through joint position commands and through pose commands. Joint position commands allow for more detailed control and flexibility instead of commanding movement with the end effector position in a pose command.

1. Initiate motion with a joint position command

Add the following line to your import list to be able to assign values to a JointPositions data structure:

from viam.proto.component.arm import JointPositions

Add the following code to your script:

# Command a joint position move: move the forearm of the arm slightly up
cmd_joint_positions = JointPositions(values=[0, 0, -30.0, 0, 0, 0])
await arm_1.move_to_joint_positions(positions=cmd_joint_positions)

Add armapi "go.viam.com/api/component/arm/v1" to your import list. Add the following code to your script:

// Command a joint position move: move the forearm of the arm slightly up
cmdJointPositions := &armapi.JointPositions{Values: []float64{0.0, 0.0, -30.0, 0.0, 0.0, 0.0}}
err = arm1.MoveToJointPositions(context.Background(), cmdJointPositions, nil)
if err != nil {
    logger.Error(err)
    return
}

Run the code. The third joint of your arm should move 30 degrees. For more information, see MoveToJointPositions.

2. Command to move to position

Add the following code to your script:

# Generate a simple pose move +100mm in the +Z direction of the arm
cmd_arm_pose = await arm_1.get_end_position()
cmd_arm_pose.z += 100.0
await arm_1.move_to_position(pose=cmd_arm_pose)

Add "go.viam.com/rdk/spatialmath" to your import list.

Add the following code to your script:

// Generate a simple pose move +100mm in the +Z direction of the arm
currentArmPose, err := arm1.EndPosition(context.Background(), nil)
if err != nil {
  logger.Error(err)
  return
}
adjustedArmPoint := currentArmPose.Point()
adjustedArmPoint.Z += 100.0
cmdArmPose := spatialmath.NewPose(adjustedArmPoint, currentArmPose.Orientation())

err = arm1.MoveToPosition(context.Background(), cmdArmPose, nil)
if err != nil {
  logger.Error(err)
  return
}

This code gets the arm’s end position, makes a 100 millimeter adjustment in the +Z direction, and then uses that adjustment as a goal Pose when commanding arm motion. Run the code to see your arm move 100 mm upwards. For more information, see MoveToPosition.

Use automated complex motion planning

The following tutorials demonstrate how to plan complex motion with a robot arm:

Use the motion service

Use the motion service to move a robot arm and gripper.

Add motion constraints

Use constraints and transforms with the motion service.

Claw Game

Create your own version of the famous arcade claw machine using a robotic arm and a claw grabber.

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Move a gantry