AtsushiSakai/PythonRobotics

move_to_pose.py result not consistent with book

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#878 opened on Jul 17, 2023

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 (4 comments) (0 reactions) (0 assignees)Python (21,513 stars) (6,296 forks)batch import
help wanted

Description

Describe the bug move_to_pose.py simulation result not consistent with book. The trajectory is obviously not consistent with the book, fig. 4.14

Expected behavior The trajectory should at least look similar to book's simulation result.

Screenshots

  1. Books' simulation result
  2. code simulation result(with same param kpho=3, kalpha=8, kbeta=3) Note that I have already consider the case that kbeta_book = -kbeta_code

image

Contributor guide

Tech stack
python
Domain
backend
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-2 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
mostly clear
Prerequisites
Pythonrobotics algorithms
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
40
Research direction
Review the move to pose.py file and compare the control law implementation with the book's algorithm. Focus on the parameters kp, kalpha, kbeta and the sign conventions. Check the robot pose update logic and the simulation setup to see if there is a discrepancy in the orientation or distance control. The issue reporter already tried adjusting kbeta sign; further investigation into the exact formulas and initial conditions is needed.