Difference between revisions of "HamsterPythonExample1"
From cogniteam
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#!/usr/bin/env python | #!/usr/bin/env python | ||
import rospy | import rospy | ||
| − | from sensor_msgs.msg import | + | from sensor_msgs.msg import LaserScan |
def is_free(ranges ,start_index, end_index ,min_distance): | def is_free(ranges ,start_index, end_index ,min_distance): | ||
Latest revision as of 09:12, 20 June 2019
Python Example 1
- Receive laser scan from robot to decide if free
<syntaxhighlight lang="python" line='line'>
- !/usr/bin/env python
import rospy from sensor_msgs.msg import LaserScan
def is_free(ranges ,start_index, end_index ,min_distance): #sub array from angle to angle s_ranges = ranges[start_index:end_index] #filter the array b_ranges = filter(lambda x: x <= min_distance, s_ranges) return len(b_ranges) == 0
def callback(msg):
if is_free(msg.ranges,160,200,0.2): print "FREE"
else: print "BLOCKED"
rospy.init_node('scan_values')
- Put your Hamster number instead of agent<number>
- The agent number is printed on the Hamster cover
sub = rospy.Subscriber('/agent14/scan', LaserScan, callback)
rospy.spin()
</syntaxhighlight>
To execute save this example in example1.py and type in the terminal
<syntaxhighlight lang="bash" line='line'>
$ python example1.py
</syntaxhighlight>
Ex. 1
- Put the hamster in front of a planar obstacle and save a file with readings of distances to that plane
- Calculate the average noise of the range scanner (take into account the angle of the reading)
- Add filtering to remove peaks in the laser scan readings at each angle taking into account possible noise
