Node configuration

We will introduce how each sensor is organically intertwined and what function it performs.


Path Planner

  • Autonomous driving control through three major sensors

  • Create autonomous driving routes through Path Planner

  • Consists of Global Path Planner and Local Path Planner


  • Djikstra Algorithm : Provides the shortest path from one specific vertex to all other vertices

  • DWA Local Planner : A path planner that plans a local path when a global path is given or a local goal is set. Used for evasive driving and bias driving.



/scan

  • Receive scan data from LiDAR.

  • Scan data is provided to perform Move base and amcl functions.



/tf

  • Generate tf data by processing scan data with amcl algorithm

  • amcl : One of the algorithms used to estimate and correct the position of the robot. Probabilistically predict the robot’s position by applying a particle filter to point data input from LIDAR data.

  • tf : A package that allows users to track multiple coordinate frames over time. Provides location information of coordinate frames that change over time.



Diagram

  • A driving plan is developed using four major types of data.

  • Through this, the motor is controlled and driven.

  • Receive real-time feedback on how much you moved through the encoder.

  • IMU : Sensors that measure acceleration and angular velocity

  • odom : The concept of estimating a relative location by determining how far it is from the starting point, rather than knowing the absolute location like GPS



Node Graph






Additional explanation

  • Setting the robot’s reference point


  • Coordinates and angle settings from the base link of the imu sensor


  • Set the radius of the wheels and the distance between them


  • There are many other things to set up as well.

  • Small differences in each value have a big impact on driving.

  • It is important to find the optimal value for driving through many tests.