#summary Impedance control applies a mass-spring-damper between the target position and the actual position is the air. The node has been tested on ROS Indigo powered by Ubuntu 14.04 only. If you meet any problem with the code, please contact us.

####code location impedcontrol

###Quickstart: Frist, Please configure your computer with the wiki birl_baxter wiki. and aslo install baxter simulator first baxter_simulator We recommend using Gazebo first.

Run the baxter shell script with sim specified:

$ ./baxter.sh sim

Start simulation with controllers:

$ roslaunch baxter_gazebo baxter_world.launch

You should wait for the following three lines before the simulator is truly running:

[ INFO] [1400513321.531488283, 34.216000000]: Simulator is loaded and started successfully
[ INFO] [1400513321.535040726, 34.219000000]: Robot is disabled
[ INFO] [1400513321.535125386, 34.220000000]: Gravity compensation was turned off

Also make sure you connect to Force sensor, if you cannot receive the force information then you can not get in the callback function!

$ rosrun ft_wacoh ft_wacoh_pub

You can check by $ rostopic echo /wrench/filter to see if you can receive the data. Finally run the impedance code $ rosrun birl_baxter_controllers impedcontrol.py -l right

Reference See the following link A brief introduction to impdecontrol , p. 4-9.

** schematic diagram**

##Stucture:## This code mainly refer to baxter_example/scripts/joint_torque_spring.py you can find the code here . because it has already made the Spring-Damping circle. And we can see the picture that* Kd* can represent Spring gain, and Bd represent Damping gain. Here e , e_dot, e_double_dot means position error, velocity error and accelerate error respectively. Xr,Xr_dot,Xr_double_dot means the desired position and velocity and acceleration respectively. And we can see that the output of first cicle is Fr and there is also a Fe, which I can get from Force sensor. So after the combination of the two force information, it can be sent to the robot as command torque, which baxter robot has built-in function that can help us finish this.

##Video