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Gripper Component

A gripper is a robotic grasping device that can open and close, often attached to the end of an arm or to a gantry.

Data Management

Frame System

Motion

Available models

To use your gripper component, check whether one of the following models supports it.

For configuration information, click on the model name:

viam-server
viam-micro-server

Model

Description

Add support for other models

If none of the existing models fit your use case, you can create a modular resource to add support for it.

Support Notice

There is currently no support for this component in viam-micro-server.

Control your gripper with Viam’s client SDK libraries

To get started using Viam’s SDKs to connect to and control your machine, go to your machine’s page on the Viam app, navigate to the CONNECT tab’s Code sample page, select your preferred programming language, and copy the sample code.

API key and API key ID

By default, the sample code does not include your machine API key and API key ID. We strongly recommend that you add your API key and API key ID as an environment variable and import this variable into your development environment as needed.

To show your machine’s API key and API key ID in the sample code, toggle Include API key on the CONNECT tab’s Code sample page.

Caution

Do not share your API key or machine address publicly. Sharing this information could compromise your system security by allowing unauthorized access to your machine, or to the computer running your machine.

When executed, this sample code will create a connection to your machine as a client. Then control your machine programmatically by adding API method calls as shown in the following examples.

These examples assume you have a gripper called "my_gripper" configured as a component of your machine. If your gripper has a different name, change the name in the code.

Be sure to import the gripper package for the SDK you are using:

Python
Go

from viam.components.gripper import Gripper

import (
  "go.viam.com/rdk/components/gripper"
)

API

The gripper component supports the following methods:

Method Name	Description
`Open`	Opens the gripper.
`Grab`	Closes the gripper until it grabs something or closes completely, and returns whether it grabbed something or not.
`IsMoving`	Returns whether the gripper is actively moving (or attempting to move) under its own power.
`Stop`	Stops the gripper.
`GetGeometries`	Get all the geometries associated with the gripper in its current configuration, in the frame of the gripper.
`Reconfigure`	Reconfigure this resource.
`DoCommand`	Execute model-specific commands that are not otherwise defined by the component API.
`FromRobot`	Get the resource from the provided robot with the given name.
`GetResourceName`	Get the `ResourceName` for this gripper with the given name.
`Close`	Safely shut down the resource and prevent further use.

Open

Opens the gripper.

Parameters:

extra (Mapping[str, Any]) (optional): Extra options to pass to the underlying RPC call.
timeout (float) (optional): An option to set how long to wait (in seconds) before calling a time-out and closing the underlying RPC call.

Returns:

None.

Example:

my_gripper = Gripper.from_robot(robot=robot, name="my_gripper")

# Open the gripper.
await my_gripper.open()

For more information, see the Python SDK Docs.

Parameters:

ctx (Context): A Context carries a deadline, a cancellation signal, and other values across API boundaries.
extra (map[string]interface{}): Extra options to pass to the underlying RPC call.

Returns:

(error): An error, if one occurred.

Example:

// Open the gripper.
err := myGripper.Open(context.Background(), nil)

For more information, see the Go SDK Docs.

Parameters:

extra Map<String, dynamic>? (optional)

Returns:

Future<void>

Example:

await myGripper.open();

For more information, see the Flutter SDK Docs.

Grab

Closes the gripper until it grabs something or closes completely, and returns whether it grabbed something or not.

Parameters:

extra (Mapping[str, Any]) (optional): Extra options to pass to the underlying RPC call.
timeout (float) (optional): An option to set how long to wait (in seconds) before calling a time-out and closing the underlying RPC call.

Returns:

(bool): Indicates if the gripper grabbed something.

Example:

my_gripper = Gripper.from_robot(robot=robot, name="my_gripper")

# Grab with the gripper.
grabbed = await my_gripper.grab()

For more information, see the Python SDK Docs.

Parameters:

ctx (Context): A Context carries a deadline, a cancellation signal, and other values across API boundaries.
extra (map[string]interface{}): Extra options to pass to the underlying RPC call.

Returns:

(bool): True if the gripper grabbed something with non-zero thickness.
(error): An error, if one occurred.

Example:

// Grab with the gripper.
grabbed, err := myGripper.Grab(context.Background(), nil)

For more information, see the Go SDK Docs.

Parameters:

extra Map<String, dynamic>? (optional)

Returns:

Future<void>

Example:

await myGripper.grab();

For more information, see the Flutter SDK Docs.

IsMoving

Returns whether the gripper is actively moving (or attempting to move) under its own power.

Parameters:

timeout (float) (optional): An option to set how long to wait (in seconds) before calling a time-out and closing the underlying RPC call.

Returns:

(bool): Whether the gripper is moving.

Example:

my_gripper = Gripper.from_robot(robot=robot, name="my_gripper")

# Check whether the gripper is currently moving.
moving = await my_gripper.is_moving()
print('Moving:', moving)

For more information, see the Python SDK Docs.

Parameters:

ctx (Context): A Context carries a deadline, a cancellation signal, and other values across API boundaries.

Returns:

(bool): Whether this resource is moving (true) or not (false).
(error): An error, if one occurred.

Example:

// This example shows using IsMoving with an arm component.
myArm, err := arm.FromRobot(machine, "my_arm")

// Stop all motion of the arm. It is assumed that the arm stops immediately.
myArm.Stop(context.Background(), nil)

// Log if the arm is currently moving.
is_moving, err := myArm.IsMoving(context.Background())
logger.Info(is_moving)

For more information, see the Go SDK Docs.

Parameters:

None.

Returns:

Future<bool>

Example:

var isItMoving = await myGripper.isMoving();

For more information, see the Flutter SDK Docs.

Stop

Stops the gripper. It is assumed that the gripper stops immediately, so IsMoving will return false after calling Stop.

Parameters:

extra (Mapping[str, Any]) (optional): Extra options to pass to the underlying RPC call.
timeout (float) (optional): An option to set how long to wait (in seconds) before calling a time-out and closing the underlying RPC call.

Returns:

None.

Example:

my_gripper = Gripper.from_robot(robot=robot, name="my_gripper")

# Stop the gripper.
await my_gripper.stop()

For more information, see the Python SDK Docs.

Parameters:

ctx (Context): A Context carries a deadline, a cancellation signal, and other values across API boundaries.
extra (map[string]interface{}): Extra options to pass to the underlying RPC call.

Returns:

(error): An error, if one occurred.

Example:

// This example shows using Stop with an arm component.
myArm, err := arm.FromRobot(machine, "my_arm")

// Stop all motion of the arm. It is assumed that the arm stops immediately.
err = myArm.Stop(context.Background(), nil)

For more information, see the Go SDK Docs.

Parameters:

extra Map<String, dynamic>? (optional)

Returns:

Future<void>

Example:

await myGripper.stop();

For more information, see the Flutter SDK Docs.

GetGeometries

Get all the geometries associated with the gripper in its current configuration, in the frame of the gripper. The motion and navigation services use the relative position of inherent geometries to configured geometries representing obstacles for collision detection and obstacle avoidance while motion planning.

Python
Go

Parameters:

extra (Mapping[str, Any]) (optional): Extra options to pass to the underlying RPC call.
timeout (float) (optional): An option to set how long to wait (in seconds) before calling a time-out and closing the underlying RPC call.

Returns:

(List[viam.proto.common.Geometry]): The geometries associated with the Component.

Example:

geometries = await component.get_geometries()

if geometries:
    # Get the center of the first geometry
    print(f"Pose of the first geometry's centerpoint: {geometries[0].center}")

For more information, see the Python SDK Docs.

Parameters:

ctx (Context): A Context carries a deadline, a cancellation signal, and other values across API boundaries.
extra (map[string]interface{}): Extra options to pass to the underlying RPC call.

Returns:

([]spatialmath.Geometry): The geometries associated with this resource, in any order.
(error): An error, if one occurred.

Example:

// This example shows using Geometries with an arm component.
myArm, err := arm.FromRobot(machine, "my_arm")

geometries, err := myArm.Geometries(context.Background(), nil)

if len(geometries) > 0 {
   // Get the center of the first geometry
   elem := geometries[0]
   fmt.Println("Pose of the first geometry's center point:", elem.center)
}

For more information, see the Go SDK Docs.

Reconfigure

Reconfigure this resource. Reconfigure must reconfigure the resource atomically and in place.

Parameters:

ctx (Context): A Context carries a deadline, a cancellation signal, and other values across API boundaries.
deps (Dependencies): The resource dependencies.
conf (Config): The resource configuration.

Returns:

(error): An error, if one occurred.

For more information, see the Go SDK Docs.

DoCommand

Execute model-specific commands that are not otherwise defined by the component API. For built-in models, model-specific commands are covered with each model’s documentation. If you are implementing your own gripper and add features that have no built-in API method, you can access them with DoCommand.

Parameters:

command (Mapping[str, ValueTypes]) (required): The command to execute.
timeout (float) (optional): An option to set how long to wait (in seconds) before calling a time-out and closing the underlying RPC call.

Returns:

(Mapping[str, viam.utils.ValueTypes]): Result of the executed command.

Raises:

(NotImplementedError): Raised if the Resource does not support arbitrary commands.

Example:

command = {"cmd": "test", "data1": 500}
result = component.do(command)

For more information, see the Python SDK Docs.

Parameters:

ctx (Context): A Context carries a deadline, a cancellation signal, and other values across API boundaries.
cmd (map[string]interface{}): The command to execute.

Returns:

(map[string]interface{}): The command response.
(error): An error, if one occurred.

Example:

// This example shows using DoCommand with an arm component.
myArm, err := arm.FromRobot(machine, "my_arm")

command := map[string]interface{}{"cmd": "test", "data1": 500}
result, err := myArm.DoCommand(context.Background(), command)

For more information, see the Go SDK Docs.

Parameters:

command Map<String, dynamic> (required)

Returns:

Future<Map<String, dynamic>>

Example:

// Example using doCommand with an arm component
const command = {'cmd': 'test', 'data1': 500};
var result = myArm.doCommand(command);

For more information, see the Flutter SDK Docs.

FromRobot

Get the resource from the provided robot with the given name.

Flutter

Parameters:

robot RobotClient (required)
name String (required)

Returns:

Gripper

For more information, see the Flutter SDK Docs.

GetResourceName

Get the ResourceName for this gripper with the given name.

Python
Flutter

Parameters:

name (str) (required): The name of the Resource.

Returns:

(viam.proto.common.ResourceName): The ResourceName of this Resource.

Example:

# Can be used with any resource, using an arm as an example
my_arm_name = my_arm.get_resource_name("my_arm")

For more information, see the Python SDK Docs.

Parameters:

name String (required)

Returns:

ResourceName

For more information, see the Flutter SDK Docs.

Close

Safely shut down the resource and prevent further use.

Python
Go

Parameters:

None.

Returns:

None.

Example:

await component.close()

For more information, see the Python SDK Docs.

Parameters:

ctx (Context): A Context carries a deadline, a cancellation signal, and other values across API boundaries.

Returns:

(error): An error, if one occurred.

Example:

// This example shows using Close with an arm component.
myArm, err := arm.FromRobot(machine, "my_arm")

err = myArm.Close(ctx)

For more information, see the Go SDK Docs.

Troubleshooting

You can find additional assistance in the Troubleshooting section.

You can also ask questions on the Viam Community Slack and we will be happy to help.

Next steps

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Gripper Component

Related services

Available models

Add support for other models

Support Notice

Control your gripper with Viam’s client SDK libraries

API key and API key ID

Caution

API

Open

Grab

IsMoving

Stop

GetGeometries

Reconfigure

DoCommand

FromRobot

GetResourceName

Close

Troubleshooting

Next steps