This repository contains the application code used to communicate with the Kinova Jaco arm from Drake. It currently supports communicating with an arm via USB or Ethernet.
The WORKSPACE file assumes that the Kinova SDK is installed in
/opt/JACO-SDK/.
To build, run bazel build //.... This will output two versions of
the driver: bazel-bin/src/kinova_driver and
bazel-bin/src/kinova_driver_ethernet.
To use the ethernet version, the arm needs to be configured
appropriately in the "Ethernet" pane of DevelopmentCenter (from the
Kinova SDK), and the appropriate IP and port numbers passed to
bazel-bin/src/kinova_driver_ethernet on the command line. See the
usage message for ``bazel-bin/src/kinova_driver_ethernet` for specific
flags.
When controlling the arm, the driver operates in joint velocity mode.
The driver communicates using two LCM messages (defined in drake): lcmt_jaco_status and lcmt_jaco_command.
The main polling loop runs at 100Hz, and does the following:
- Read status from arm and publish on LCM channel
KINOVA_JACO_STATUS - Check for incoming
KINOVA_JACO_COMMANDmessages. - If a message has been received, send a joint velocity command to the arm with the specified values.
- If no message is received before the next status should be published, no command is sent to the arm. This will cause the arm to stop moving after a short period of time.
The arm periodically seems to stop communicating (or refuse to initialize) over USB. The reason for this is not knon, but unplugging and plugging back in the USB port (and restarting the driver) usually seems to fix it.
Enumerating the connected arms occasionaly returns garbage data in some of the device entries. Generally starting the driver again will find the target device successfully, though this may require multiple attempts.
A single driver instance cannot control multiple arms. Multiple driver instances are required, either using different LCM URLs or different channel names.
The build process also generates a calibration program in
bazel-bin/src/kinova_calibration. When run, this program will move
the arm to the vertical position, and reset the actuator torque
sensors to zero.
If run with the --gravity argument, it will run the robot's gravity
Z estimation sequence. This takes quite some time, and requires an
obstacle free area around the robot base of approximately the length
of the fully extended arm. When the process completes, the Kinova API
will write a file named ParametersOptimal_Z.txt. When running the
driver, this file can be passed as a command line argument to enable
optimal gravity estimation mode: ./bazel-bin/src/kinova_driver --optimal_z ParametersOptimal_Z.txt