research_track_python

This package implements a solution to a simple simulated problem using the portable robot simulator developed by Student Robotics.

To run the python executable you can use the command python2 run.py assignment.py or python2 run.py assignment_generalized.py

Executables

assignment.py implements a specific solution for the problem using hard coded parameters.

assignment_generalized.py can be changed and used with different sets of parameters, to be adapted to any kind of similar simulation.

Simulated Environment

In the simulated environment :

• golden boxes represent walls to avoid
• silver boxes are scattered along the path

Main goals

The robot has to :

• constrantly drive around the circuit in the counter-clockwise direction
• avoid touching the golden boxes
• when the robot is close to a silver box, it should grab it, and move it behind its

Main Functions

• Straight drive : drives the robot as straight as possible inside corridors.

• Detect front wall and turn : detects the distance to the wall in front of the robot, and if it is close enough makes the robot turn in the right direction to follow the path.

• Grab silver : detects the nearest silver token in front of the robot, and if it is close enough drives the robot to grab it and put it behind.

Code Flowchart

Possible improvements on current code

If you want to use this code with another simulation in the same fashion, you can use the assignment_generalized.py file and tune the different parameters. The parameters are the following :

• speeds of robot

  • lin_speed(default 20) : linear speed
  • rot_speed(default 20) : rotation speed

• max detection distance of silver markers and angle tolerance on detection

  • silver_marker_detect_dist(default 2)
  • silver_marker_tolerance(default 24)
  • after_grab_time(default 1) : time driving straight after getting a silver marker

• front detection params

  • front_wall_turn_dist(default 1.2) : max distance to the front wall from which the robot is in a corner
  • front_angle_tol(default 30) : tolerance for front detections
  • drive_after_turn_time(default 5) : time of driving straight after turning at a corner

• failsafe params

  • front_wall_detect_angle(default 15) : angle from which a wall is considered a side wall to avoid
  • failsafe_angle_turn(default 15) : angle to turn robot in case it's too close to a side wall

• side detections params

  • side_wall_dist_tol(default 0.08) : minimal distance difference betweens walls for the robot to turn
  • side_angle_tol(default 25) : angle tolerance for side detection
  • max_detect_side_dist(default 100) : max distance detected for side detection

• straight drive params

  • straight_drive_time_step(default 0.5) : straight drive time step
  • straight_drive_angle_turn(default 5) : angle to turn in degrees to drive straight

If the robot enters a corner with a certain angle, it can sometimes turn around. This almost never happens but is still a possible case. In the case this happens in your simulation, retuning the front wall detection distance or the failsafe rotation angle should work fine.