Kinova Control

This package can be used to control a Kinova robot arm with Kortex, e.g. Gen3.

Dependencies

1. ROS Kinetic.
2. Install the ROS Kortex package in your catkin workspace.

Usage

kinova_driver.py

This file contains functions that control the movements of the end-effector. There are three different sections in this file: the gripper movement section, the cartesian mode movement section, and the joint mode movement section. This part of the package allows:

• Open and close the fingers
• Move the end-effector in a three-dimensional cartesian space, either via inputting the amount of displacement or by inputting the desired cartesian pose
• Get the current cartesian pose with respect to the base
• Change the pose of the robot by changing the joint angles

1. Cartesian Pose

A Cartesian pose is specified by the floats x, y, z, theta_x, theta_y, theta_z. If you are not certain about the exact values, you can use kinova_read_cartesian.py to find out the Cartesian pose of your desired position.

2. Joint Angles

A pose in terms of joint angles is a collection of actuator joint angles. If you are not sure about the exact values, you can run rostopic echo /base_feedback and look at the "position" sections.

kinova_protection_zone.py

This file contains functions related to Kinova robots' protection zone functionality. The functions in this file can:

• Create a protection zone
• Delete a protection zone specified by the ProtectionZoneHandle
• Update a protection zone
• Get the current protection zone state

1. Protection Zone

A protection zone for a Kinova robot is a pre-defined volume of the cartesian space where the robot's end-effector will not enter. According to the Kotex API, a Protection Zone is made up of:

• handle: the ProtectionZoneHandle that helps identify the protection zone
• name: a string
• application_data: reserved for the Web API use only
• is_enabled: a boolean that indicates if the protection zone is enabled; multiple protection zones can be enabled at the same time
• shape: a ZoneShape that specifies the shape of the protection zone
• limitations: list of CartesianLimitation that specifies the force, acceleration or velocity limits within the protection zone
• envelope_limitations: list of CartesianLimitation that specifies the force, acceleration or velocity limits inside the envelope

2. Zone Shape

A ZoneShape defines the position and dimension of a ProtectionZone. A ZoneShape instance is made of:

• shape_type: an enum; 0 - unspecified, 1 - cylinder, 2 - sphere, 3 - rectangular prism
• origin: the origin Point defined by its x, y, and z; this is the center of the zone
• orientation: a rotation matrix that specifies the orientation
• dimensions: for cylinder, radius and height; for sphere, radius; for rectangular prism, x, y and z dimensions
• envelope_thickness: how thick the envelope is; an envelope is the volume surrounding the protection zone

Fig 1. How coordinates work when defining the protection zone

kinova_misc.py

This file contains miscellaneous functions that help the driver run smoothly, such as launching certain ros terminal commands.

create_zone_shape.py

The functions in this file are related to the ZoneShape msg type in the Kortex API. These functions are able to:

• Obtain from the user specific information needed to create a ZoneShape instance, e.g. the dimensions
• Save the created ZoneShape instance to a file

Examples

kinova_read_cartesian.py

This example saves the current cartesian position of the end-effector to a list when the key 's' is pressed, and saves the list to file when the key 'q' is pressed.

kinova_create_protection_zone.py

This example creates a protection zone, and allows the user to move the robot using the game controller in order to specify items such as the coordinates of the origin, the dimensions, etc.

Useful Kortex API Entries

• CartesianLimitations
• JointAngles
• Pose
• ProtectionZone
• ZoneShape