Questions tagged [navigation]

Navigation is a field of study that focuses on the process of monitoring and controlling the movement of a craft or vehicle from one place to another. Robot navigation includes exploration, mapping, localization, path planning and path execution

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11
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3answers
176 views

Selecting an accelerometer for Deduced Reckoning

I have never used an accelerometer before, but I am aware that they come with I2C, SPI and analog outputs. If I choose to use an I2c or SPI, device, will I accumulate errors due to communication time? ...
11
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1answer
3k views

Ambiguous definition of Error-State (Indirect) Kalman Filter

I am confused by what precisely the term "Indirect Kalman Filter" or "Error-State Kalman Filter" means. The most plausible definition I found is in Maybeck's book [1]: As the name indicates, in ...
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2answers
1k views

Sonar for obstacle avoidance: how many sensors and where to place them?

For avoiding obstacles during 2D robot navigation what is the best position/angle to place the sonar sensors? How many should there be? I would like to know if there is some theory or examples for ...
10
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4answers
3k views

What are human-friendly terms for mobile-robot orientation and relative direction of non-robot objects?

Within robotics programming, orientation is primarily given in terms of x, y, & z coordinates, from some central location. However x, y, z coordinates aren't convenient for rapid human ...
9
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2answers
989 views

Guiding a Quadrotor Towards a Target

I am working on a quadrotor. I know its position -- $a$, where I would like to go -- target position $b$, and from that I calculate a vector $c$ -- a unit vector that will take me to my target: <...
9
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1answer
513 views

Chaining Kalman filters

My team is building a robot to navigate autonomously in an outdoor environment. We recently got a new integrated IMU/GPS sensor which apparently does some extended Kalman filtering on-chip. It gives ...
8
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1answer
482 views

What are the mechanics of translational drift?

Concerning robots which rotate at high speed by spinning the drive motors in opposite directions, while still being able to simultaneously move in a direction (translate): As far as I know this ...
7
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2answers
690 views

Holonomics Movement vs Holonomics Constraint

I'm reading Mechanics of Robotic Manipulation by Matthew T Mason and I stumbled upon the concept of kinematic constraints. The book mentioned about two types of constraints: holonomic and nonholonomic ...
7
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7answers
6k views

What are some low cost alternatives for lidar? [closed]

It need not be as effective as lidar or it may have some disadvantages when compared with lidar. What are the probable alternatives? Edit: I'm intending to use it outdoors for navigation of ...
7
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2answers
777 views

ComputerCraft (Minecraft mod) navigation: Collision avoidance and path planning/finding in 2D/3D space

I'm programming Lua for controlling computers and robots in-game in the Minecraft mod ComputerCraft. ComputerCraft has these robots called Turtles, that are able to move around in the grid based(?) ...
7
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1answer
1k views

Differential drive trajectory following control

I have a robot platform with differential drive which knows it's position and orientation. Lets say that the space through which the robot moves is known and it has only static obstacles. The task is ...
6
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2answers
327 views

Drone targeting

Imagine a "drone" and a target point on a 2d plane. Assuming the target is stationary, there are eight parameters: ...
6
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1answer
3k views

Implementing a boustrophedon algorithm in a given room with obstacles

I have a mobile robot which is navigating around a room, I already have the map of the room. I am using the navigation_stack of ROS. I am using rotary encoders for odometry. I am fusing the data from ...
6
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1answer
2k views

SLAM: Why use two cameras (stereo) if SLAM can be done using single camera (monocular)?

I am aware that algorithm for monocular SLAM is complex compared to stereo SLAM. But my question is if by any means it is possible to do SLAM using one camera why one should use two cameras to do the ...
6
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1answer
200 views

Is there a working implementation of “Navigation Among Movable Obstacles” for a bi-pedal robot?

I would like to have a better understanding of work in the field of "Navigation Among Movable Obstacles". I started off with Michael Stilman's thesis under James Kuffner, but that has not yet sated my ...
5
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3answers
14k views

Quadcopter Position Measurement (Accelerometer, GPS or Both)?

I previously thought that an accelerometer on a quadcopter is used to find the position by integrating the data got from it. After I read a lot and watched this Youtube video (specifically at time 23:...
5
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2answers
849 views

Mobile robot path following using Model Predictive Control (MPC)

I'am trying to implement a path following algorithm based on MPC (Model Predictive Control), found in this paper : Path Following Mobile Robot in the Presence of Velocity Constraints Principle: ...
4
votes
1answer
237 views

If I must fly my drone in bad weather, how can I maintain control of it in strong winds?

If I need to fly a drone in strong winds, how can I stabilize it? Should I use accelerometers and gyroscopes to keep it steady? Or should I just use some flight technique under such circumstances?
4
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1answer
324 views

Autonomous boat obstacle avoidance

I am currently considering joining the MicroTransat challenge and develop an autonomous boat able to survive the harsh Ocean environment. However, as for security and to ensure the boat doesn't sink ...
4
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1answer
2k views

Understanding Drift in Simultaneous Localization and Mapping (SLAM)

I am trying to understand the effect of drift in Simultaneous Localization and Mapping (SLAM). My understanding is that drift occurs because the robot tracks its position relative to a set of ...
4
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1answer
4k views

Robot path planning

My goal is to move robot in certain points as shown in the figure. It's initial position is (x0,y0) and move along other coordinates. I am able to track robot position using a camera which is ...
4
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1answer
3k views

ROS AMCL does not need odometry data?

I'm reading amcl document on ROS Wiki. In its subscribed topics there is not odometry topic, why? It works only with laser? Subscribed Topics: (From ROS Wiki) scan (sensor_msgs/LaserScan) tf (tf/...
4
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2answers
106 views

Delayed Kalman navigation based on two way ranges

I am interested to know the basic principle of the "Delayed KF" when considering an underwater robot aiming to localize it self using a LBL system. More practically, in order to calculate the ...
4
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1answer
897 views

Wall following using hokuyo lidar and sharp IR sensors

I have a mobile robot and I would like it to follow the walls of a room. I have: A map of the room. Wheel encoders for the odometry. A Kalman filter for fusing data from wheel encoders and IMU. A ...
4
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1answer
576 views

2D Map representation of GPS coordinates in degrees

I want to implement my own GPS navigation for a quad-copter. I can calculate and filter the GPS coordinates (latitude and longitude in degrees). I believe the easiest approach for me would be, to ...
3
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3answers
88 views

Is SLAM done only first time in a given environment

I am training Turtlebot 2 to move around the office. I come from robotics hardware background but relatively new to computer vision and robotic mapping. Here are my two fundamental questions related ...
3
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2answers
287 views

Weird magnetometer values

I bought a 3-axis magnetometer (Similar to this one ) And plugged into an Arduino in order to read the heading value. I mounted it on my robot and I drove with the robot for around 30 meters, turned ...
3
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2answers
285 views

How come LIDAR is not commonly used for indoor navigation?

I'm reading this survey on the state-of-the-art techniques for indoor positioning and navigation. I noticed that LIDAR isn't mentioned at all in the paper. Is LIDAR not meant to be a common method for ...
3
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1answer
139 views

How can we solve the problem of robot size in sensor based motion planning?

As you know in Bug algorithm there is a simplifying assumption that says the robot has no size and can fit between any arbitrarily small gap in the map. How can we overcome the challenge of robot size....
3
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2answers
169 views

Create 2: Wheel interface board replacement

http://www.irobotweb.com/~/media/MainSite/PDFs/About/STEM/Create/Create_2_Wheel_Hack.pdf?la=en Scroll to page 3. I'm trying to interface the Roomba's preloaded navigation system with a pair of ...
3
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2answers
90 views

Do self-driving robots use object-level SLAM?

How do self-driving bots usually deal with transient objects, e.g., parked cars on the side of roads when they can come and go? These aren't moving objects at the time of capture, but they do move at ...
3
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1answer
2k views

Tf frame origin is offset from the actual base_link

I have built my differential drive mobile robot in solidworks and converted that to URDF file using soliworks2urdf converter. I successfully launched and robot and simulated with tele-operation node. ...
3
votes
1answer
192 views

how to use ROS navigation stack with 4 wheeled robots

I have a 4 wheeled toy car, with 5 motors, one on each wheel and one is used for steering. How can I use ROS navigation stack with this robot since navigation stack is used with differential drive ...
3
votes
1answer
516 views

Robot Navigation Feedback using Image Processing

In my project, I've successfully analyzed the arena and have detected the obstacles using an overhead webcam. I also have computed the shortest path. The path data is transmitted to the robot via ...
3
votes
1answer
61 views

3D Direction Sensor - Question from a Neuroscientist

I'm posting here on the advice of r/diydrones, who said you're the people to ask. I'm hoping you might be able to help out with a problem i've come across in my research? I'm a Neuroscientist working ...
3
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1answer
407 views

Difference between Collision Cone and Velocity Obstacle

I'm trying to understand these two classic approaches to path planning in dynamic environments/with moving obstacles. According to some review papers, there seems to be quite a difference between them,...
3
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2answers
2k views

How to move a robot to a point while avoiding obstacles?

I am trying to move a robot in a straight line from point A, to point B. The robot's primary sensor is a Hokuyo URG-04LX-UG01 LIDAR that gives me the magnitude and direction of each point it detects ...
3
votes
2answers
282 views

Having a hard time understanding this equation in monocular EKF SLAM

Reading this paper on visual odometry, where they have used a bearing vector to parameterize the features. I am having a hard time understanding what the state propagation equation for the bearing ...
3
votes
2answers
171 views

Non-Vision Based Target Tracking

I am building 4-wheeled, knee-high robot with music and speakers on top that will follow a target person as the target moves around. I would like some help with the setup for tracking the target. The ...
3
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0answers
82 views

What is the difference between a Bayes Net and a Factor Graph

I am just getting started on understanding Factor Graphs, by going through the excellent guide Factor Graph For Robot Perception by Dallaert and Kaess While I am familiar with the SLAM problem, and ...
3
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0answers
30 views

Robotic vessel navigation using GIS datasets

I am trying to build an autonomous vessel able to plan the best route to a certain waypoint or to follow a pre-defined route. Currently, I have imported Esri GIS files containing elevation data (...
3
votes
1answer
670 views

Move ATRV robot to specific distance using ROS

Is there a node or package that can send commands to /cmd_vel to move ATRV-Jr like 2 meters forward or turn it 90 degree to right/left? I don't want to tell the ...
2
votes
1answer
62 views

What flight firmware stack is most common in aerial robotics research environments?

I'm considering Aero-Astro grad school and am looking into acquiring a drone hardware platform to implement GNC/ PNT/ autonomy papers like those I might see from, e.g., the Navigation and Autonomous ...
2
votes
1answer
5k views

How to align solidworks global origin with assembly origin while exporting in solidworks to urdf

I have created a robot model in solidworks and exported in solidworks to urdf plug-in. When exporting the co-ordinates of the model is misaligned which is causing problem while using in ROS. As you ...
2
votes
2answers
703 views

Find Centre Of Circle, when robot can “see” a partial arc

I originally asked this here but I am struggling to take the concepts, particularly "Circumcenter", discussed there and apply it in my context. So here it is in my context... I have a small robot ...
2
votes
2answers
314 views

What kind of lidar is necessary for SLAM?

I've read about various robots using a 2D lidar system for SLAM ( such as at IGCV, http://www.igvc.org/ ) but I'm wondering how good exactly does the sensor have to be? Specifically: What accuracy ...
2
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1answer
42 views

Underwater navigation without the use of acoustic sensors

I have been reading about different types of underwater navigation. According to this Youtube video, these are the following navigation systems: Inertial navigation systems (use of Inertial ...
2
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1answer
65 views

What is an “actuation state”

The paper A Feedforward Control Approach to the Local Navigation Problem for Autonomous Vehicles by Alonzo Kelly uses the term actuation space. Feedforward solves the historically significant ...
2
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3answers
309 views

Relative Navigation Systems

Im trying to develop a system that autonomously navigates a large outside space, where accuracy is vital (GPS is too inaccurate). There are a number of options but have largely been used inside, has ...
2
votes
1answer
35 views

how to find space in point cloud larger than given l*b

Is their any method by using which I can find a space or gap in given point cloud which has size greater than given rectangle of size $l*b$ or a circle of radius $r$? This way my robot can make a path ...