Questions tagged [motion-planning]

Motion planning (also known as the navigation problem or the piano mover's problem) is a term used in robotics for the process of breaking down a desired movement task into discrete motions that satisfy movement constraints and possibly optimize some aspect of the movement.

Filter by
Sorted by
Tagged with
0
votes
1answer
13 views

Dynamically-stable Motion Planning for Humanoid Robots

I was reading the classical robotics paper Dynamically-stable Motion Planning for Humanoid Robots and I don't understand why the two trees are swapped in line 7 of figure 5 (page 11). Seems like an ...
2
votes
1answer
27 views

A* as a planning algorithm

Researchers refer to A* as the planning method but: how does A* work as a path planning algorithm, instead of a graph search method? And how does it compare to RRT?
1
vote
1answer
38 views

Drive unicycle kinematics equations through the geometry

The unicycle dynamics in discrete-time is given by: $$ \begin{array}{l} {x_{k + 1}} = {x_k} + \Delta {s_{k + 1}} \times \cos ({\theta _{k + 1}})\\ {x_{k + 1}} = {x_k} + \Delta {s_{k + 1}} \times \sin (...
0
votes
0answers
10 views

What are cases where bug1 algorithm would be bug2?

I have been reading Principles of Robot Motion Theory, Algorithms and Implementations by Choset et al and I can't seem to understand how bug1 would beat bug2. It is harder for me to see given that ...
1
vote
0answers
16 views

Pure Pursuit controller slow response for long look ahead

The pure pursuit calculates the steering angle based on that equation: $$\delta = \tan^{-1}\left(\frac{2L\cdot \sin(\alpha)}{ld}\right)$$ Where $L$ is the wheelbase, $\alpha$ is the target angle, and $...
0
votes
0answers
12 views

Motion planning algorithms with applications in drug design

I am reading the introduction (chapter 1) of Principles of Robot Motion Theory, Algorithms, and Implementations by Choset et al. and they mention drug design uses motion planning. The text below is ...
0
votes
1answer
27 views

Motion planning algorithms with applications beyond robotics in animation

I am reading the introduction (chapter 1) of Principles of Robot Motion Theory, Algorithms, and Implementations by Choset et al. and they mention that some of the work in robotics has been applied to ...
0
votes
0answers
31 views

Initial Solution Dynamic Optimization

Community, For mobile robot-trajectory planning i use dynamic optimization for a system with nonholonomic constraints and dynamics together with a cost function. This works somewhat well, howewer the ...
1
vote
1answer
23 views

Proper implementation of `pure_pursuit` for ground robots using waypoints

I am trying to understand and implement pure-pursuit waypoint following in 2D map. My questions are: 1. What exactly do I need to record in my waypoint.csv file? To ...
1
vote
1answer
30 views

Where do I start learning from for motion planning underactuated robotics?

I am an undergraduate student approaching my final year. I have a final year project which involves planning a trajectory for an underactuated robot that also avoids obstacles. So far I have come up ...
1
vote
0answers
19 views

unable to integrate local planner plugin into move_base

I am trying to integrate my local path planner plugin into move_base. On launching the modified ...
0
votes
0answers
21 views

Differential constraints for RRT and PRM

Differential constraints induce a boundary value problem for the connection of two nodes [1]. RRTs are generally said to better deal with this than PRMs. However, why is not entirely clear to me. Is ...
0
votes
2answers
51 views

Does RRT perform graph search?

The basic RRT explores the space by sampling and if the goal is connected to the tree, the solution is returned. Can you define retrieving the path as a graph search?
0
votes
1answer
35 views

Is there any need to guarantee the duration of one planned trajectory is an integer times rather than a decimal times of interpolation period Ti

Take double S of velocity profile for example where the seven segments exist. Given the desired displacement s, the constraints ...
0
votes
2answers
36 views

Reinforcement Learning in global and local path planning for mobile robots and self-driving car

Most RL courses start with grid world problem like this where robot has to navigate from start to end and RL helps in generating the optimum policy. (State-action pairing). I am not able to relate ...
0
votes
0answers
34 views

novelty of LQR-RRT* at an article

I am reviewing this article: LQR-RRT∗: Optimal Sampling-Based Motion Planning with Automatically Derived Extension Heuristics ,Alejandro Perez, Robert Platt Jr., George Konidaris, Leslie Kaelbling and ...
0
votes
0answers
29 views

Can a state lattice planner be used purely as a local planner?

I've been reading a bit about state lattice motion planning recently. The question I would like to ask is if a lattice-based motion planning system can be used purely as a local planner without a ...
0
votes
0answers
13 views

Why reciprocal velocity obstacle generates oscillation free navigation compared to VO

I am tryin to understand this paper about "reciprocal velocity obstacles for real-time multi-agent navigation" and to compare it with the original Velocity Obstacle approach. I can not ...
0
votes
0answers
13 views

looking for an online map pgm repository

I am currently writing a path planner. I wanted to test the planner for various scenarios. I was wondering if there is a repository wherein I can find a number of pgm (+yaml) map files. I came across ...
2
votes
0answers
34 views

Difference between CHOMP and DRL

in terms of motion planning, what are the difference between gradient-based motion planning (for instance, CHOMP http://www.nathanratliff.com/thesis-research/chomp) and deep reinforcement learning? ...
0
votes
0answers
24 views

Trajectory Planning for Automatic Machines and Robots Book-page 365, is there an error ? it is not included in the Errata

the subscript of the last m-1 p and r why not is z ?, since it refers to 3D case.
2
votes
2answers
57 views

How to investigate the relation between planning frequency and control response?

I have a speed control system which is part of a hierarchical planning and control stack. The final output of this system is torque and the input is desired speed. The system is experiencing some ...
0
votes
0answers
14 views

How to Calculate Individual Axis Commands Out of 5 Axes G-Code?

I am dealing with 5 axis CNC machining time prediction. I would like to ask the question with providing some background and mentioning the constraints which what I concluded from some of the ...
1
vote
1answer
63 views

Velocity-Control of a manipulator without a dynamic model

I have a five DoF robot. Each axis is connected to a cylinder. You can send PWM values to each cylinder and you are able to read out the position values of each cylinder which makes it possible to ...
0
votes
1answer
33 views

How to find mathematical model of a wheeled robot (to compute robot's trajectory at given time steps) including its kinematic

I would like to learn, how to find proper kinematic model of robot in mathematical form. For example: I would like to create a model of a car, from which I could compute its position and rotation at ...
0
votes
0answers
40 views

CHOMP Planner freezes rviz Motionplanning in ros

I am trying to use the CHOMP planner for my custom robot by following the tutorial. After setting everything up as shown in the tutorial, I tried to plan a very simple movement. As one can see in the ...
0
votes
2answers
56 views

Generate a Trajectory from GPS coordinates

How would I generate a trajectory (e.g. minimum snap/jerk/acceleration) for a quad rotor between GPS coordinates? In all the examples that I have seen, they assume that the x,y positions are in meters ...
0
votes
1answer
36 views

What is the difference between The state-space equation and The configuration-space equation

The craig(p.180) states that equations can be made to represent the dynamic equations. The first one being the state space equation. $\tau=M(\Theta)\cdot\ddot{\Theta} + V(\Theta,\dot{\Theta}) + G(\...
3
votes
1answer
105 views

Motion profile and Motion control scheme, how do they interact?

I'm studying motion control and I start with the simplest case, I have to go from A to B in a straight line using a trapezoidal motion profile. I understand that in a real case, due to the fact that ...
1
vote
1answer
60 views

How to estimate proper heading angle

I obtain the heading or yaw angle from a source which I am not allowed to modify, but when the angle goes more than +180 or -180, it interchanges either from 180 to -180 or the other way around. Any ...
0
votes
1answer
211 views

Are there any tutorials for OMPL in Python?

I want to learn and understand the Open Motion Planning Library (OMPL) through Python as I don't have much experience with C++. Almost all tutorials are written in C++ and there are some demos in ...
2
votes
1answer
203 views

Constrained Inverse Kinematics velocity calculation via Jacobian

I am trying to implement inverse kinematics for a robot arm with 5DOF within Unity. The robot arm is supposed to depict the mechanical, hydraulic driven cylinder arm of a heavy machine such as ...
0
votes
1answer
50 views

What is an example of a good motion control API? [closed]

We are in the process of implementing a motion control API for a research project. The goal is to implement a somewhat comprehensive API for motion control that provides the most commonly used ...
0
votes
0answers
53 views

From an end-effector trajectory to joints movements

let's assume that our robot consists of 3 degree-of-freedoms. In order to move the end-effector of this robot along a straight line, these 3 joints have moved as below: Now, if the desired end-...
0
votes
1answer
36 views

Motion of a mobile platform inaccurate than industrial robot arm

It is known that with a 7DoF industrial you can achieve an accuracy of ~2mm. However, the motion with a mobile platform is known to be more inaccurate and expensive. I can follow why the motion is ...
0
votes
0answers
59 views

NodeMCU ESP-12E Wont Print to Serial in Arduino IDE

So, im using a ESP-12E nothing special about it, to try and run this code i found from a custom library example. ...
1
vote
0answers
45 views

How does inverse compositional Lucas–Kanade algorithm work?

I am trying to understand the Lucas–Kanade algorithm since I am reading a paper in which is applied the inverse compositional Lucas–Kanade algorithm, but in order to understand the latter I have to ...
3
votes
1answer
229 views

Motion planning with Gaussian Process Regression

I was recently introduced to Gaussian Process Regression (GPR). I read multiple papers regarding use cases of GPR in robotics, however, they were more or less very limited. Use case from the ...
1
vote
1answer
32 views

How to formulate the equation and environment equations for motion planning algorithm use? [closed]

How to formulate the equation and environment equations for motion planning algorithm use? And if know the desired state, how to use motion planning to fill the data to reach this desired state?
1
vote
2answers
66 views

motion model for forward movement

I thought this is a simple and well known problem and therefore there is a lot of literature. But I'm not able to find the correct keywords to google the answer. Maybe instead of answering the whole ...
1
vote
1answer
86 views

Applications of Reinforcement Learning

Many global-control applications of robotics involve incomplete world information and at best can be represented as a POMDP. Given this, can we really apply RL to most robotics applications? From ...
1
vote
0answers
34 views

Link collision avoidance for redundant manipulator

I am trying to have my robot arm follow a trajectory while avoiding collisions between obstacles and the robot links. The way I go about it is to find the closest point on the robot arm, and treat the ...
2
votes
1answer
69 views

Asynchronous axes movement

if we have a robot with 5 DoF and we want to plan its movement. The inverse kinematic solver will do this job without a doubt. However, it is usually assumed that axes can be moved in a synchronized ...
1
vote
0answers
51 views

How to find the optimal path for a line following maze robot?

First let me explain the problem. This is a maze made only out of black lines on a white surface. The robot has only a few IR sensors which can sense the position of the line. No other sensory input ...
0
votes
0answers
46 views

Problem with solution (equation) for wrist singularity

In my textbook about industrial robots it says that if the angle q5 in this robot is equal to 0, there are infinite solutions for the angles q4 and q6. I understand this part, but I have a problem ...
0
votes
1answer
34 views

How to deal with a joint suddenly having to make a large change in angle during linear interpolation?

After having set up the inverse kinematics for each intermediate point on a line that the tcp is supposed to travel, I encountered a problem that stops the tcp when it is supposed to travel along the ...
0
votes
1answer
131 views

Going from Spline to Differential Drive Command

I have a differential drive robot that needs to move along a path stored in its memory as a spline. I am currently trying to understand the mathematics of determining how much power to apply to each ...
0
votes
1answer
37 views

Doubt on artificial potential field

I am studying motion planning, and I am focusing on artificial potential fields. I have seen that it consists in having a repulsive field for obstacles, and an attractive field toward the goal. But ...
1
vote
0answers
52 views

When do I do motion planning?

I am studying mobile robots, and I am focusing my attention to the unycicle. I have a doubt concerning the motion planning part. In particular I don't understand when the motion planning is done and ...
0
votes
1answer
37 views

Construct Configuration-Space with Obstacles for arbitrary Object/Robot in Motion Planning

I found that a configuration-space approach is a elegant way to describe problems in motion planning. However, I was not able to find a known general way to construct configuration-spaces. By general ...