Description:

This is a wrapper around chai3d in order tu use haptic devices through Redis for easiness of use with Sai2.0. The driver supports one or two simultaneous haptic devices, and it has been tested with Force Dimension Omega6, Omega7 and Sigma7 haptic devices.

Dependencies:

This project depends on

Cmake*: Meta compiler [brew, apt-get]
Redis*: Redis server [brew, apt-get]
Hiredis*: Redis minimalist client [brew, apt-get]
JsonCpp*: JSON serialization [brew, apt-get]
Chai3d*: [https://github.com/manips-sai-org/chai3d]

on ubuntu :

sudo apt-get install cmake redis redis-server libhiredis-dev libjsoncpp-dev

and then go to [https://github.com/manips-sai-org/chai3d] and follow the instructions to install chai3d.

Build instructions:

After installing all the dependencies, you can build the driver using cmake in a dedicated folder. From the source folder type

mkdir build && cd build
cmake .. && make -j4

Usage:

Start the redis server if it is not already running. From a terminal window :

redis-server

Plug and power the haptic device(s).
From the build folder

sudo ./chai_devices_redis_driver

If you don't want to use sudo, you'll need to give the user permission to read and write on the USB ports.

If everything went well, the device(s) will calibrate if needed and start floating.

Communicating with other programs:

You can now control the haptic devices through redis. The driver will create the following redis keys in the database (everything is represented as a string and arrays use the JSON formatting) :

sai2::ChaiHapticDevice::device0::specifications::max_stiffness
sai2::ChaiHapticDevice::device0::specifications::max_damping
sai2::ChaiHapticDevice::device0::specifications::max_force

are vectors of 2 elements, the first one corresponds to translation and the second one to rotation.

sai2::ChaiHapticDevice::device0::sensors::current_position
sai2::ChaiHapticDevice::device0::sensors::current_rotation
sai2::ChaiHapticDevice::device0::sensors::current_position_gripper
sai2::ChaiHapticDevice::device0::sensors::current_trans_velocity
sai2::ChaiHapticDevice::device0::sensors::current_rot_velocity
sai2::ChaiHapticDevice::device0::sensors::current_gripper_velocity

Correspond to the state of the haptic device

sai2::ChaiHapticDevice::device0::sensors::sensed_force
sai2::ChaiHapticDevice::device0::sensors::sensed_torque

Correspond to the sensed force and torques of the device

sai2::ChaiHapticDevice::device0::actuators::commanded_force
sai2::ChaiHapticDevice::device0::actuators::commanded_torque
sai2::ChaiHapticDevice::device0::actuators::commanded_force_gripper

Are the commands to the device that need to be set to the redis database by the controller. They must respect the JSON formatting

sai2::ChaiHapticDevice::swapDevices

Set this key to 1 each time you want to swap the haptic devices. From a terminal window

redis-cli
set sai2::ChaiHapticDevice::swapDevices 1
exit

License: