RTT ATI Sensor

Simple Orocos RTT wrapper for the ati_sensor library. It uses ROS to get parameters from the parameter server and ROS services to reset the bias.

OROCOS Port

• WrenchStamped (geometry_msgs/WrenchStamped): 6D data from the F/T sensor

Parameters

• ip (string, default : 192.168.100.103) : The ip of the sensor
• calibration_index (integer, default : -1 [current]): The calibration file to use
• frame (string, default : /ati_ft_link): The output frame for rviz visualization

Services

• set_bias (std_msgs/Empty): Reset the software bias

Topics

• wrench (geometry_msgs/WrenchStamped): 6D data from the F/T sensor

Note : The sequence number is ft_sequence (see the official manual for more info)

Usage

The best way to launch the sensor is to first start a roscore and set the sensor's parameters :

roscore
# Set the sensor's ip address : 
rosparam set /ft_sensor/ip "192.168.100.103"
# (Optional) Set the calibration index you want to use (don't set for current calibration)
rosparam set /ft_sensor/calibration_index 1

Then you can launch the sensor using the deployer :

deployer -s $(rospack find rtt_ati_sensor)/scripts/ft_sensor.ops

Or in a launch file :

<launch>
 <arg name="ip" default="192.168.100.103"/>
  <node name="ft_sensor" pkg="rtt_ros" type="deployer" args="-s $(find rtt_ati_sensor)/scripts/ft_sensor.ops --" output="screen">
  <param name="ip" value="$(arg ip)"/>
</node>
</launch>

Integrate the Sensor in your OPS file

You'll have to set the parameters using rosparam (example using a launch file):

<launch>
<rosparam ns="ft_sensor" subst_value="true">
        ip: 192.168.100.103
        calibration_index: -1 # -1 for current
        frame: /ati_ft_link
 </rosparam>
 </launch>

And add the following lines to you ops script :

import("rtt_ros")
ros.import("rtt_rospack")
runScript(ros.find("rtt_ati_sensor") + "/scripts/ft_sensor.ops")

OPS file options

Two data reading mode are possible: User-based trigger and Event-based trigger

By default (no parameters given), User-based trigger is used with given periodicity

User-based trigger

The data is queried at the rate of the component set in the setActivity command

• optional ft_sensor.sample_count = 1
• ft_sensor.read_mode = 0 for given periodicity
• or ft_sensor.read_mode = 3 to match the periodicity to the NetFT output rate.

Event-based trigger

The data is output at the rate of the NetFT output rate setting.

This mode should have the smallest delay in the data due to continuous reading.

• ft_sensor.sample_count = 0 (means infinite number of samples)
• ft_sensor.read_mode = 1 for current NetFT rate
• or ft_sensor.read_mode = 2 to set NetFT to given component period via setActivity (component period is then modified internally to 0.0).

Note, NetFT rate can only be values that 7000 / integer can reach (7000, 3500, 2333, 1750, 1400, 1167, 1000, ...)