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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### 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? ...
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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### 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 ...
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### 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 ...
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: <...
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 ...
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 ...
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 ...
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### 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 ...
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(?) ...
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 ...
327 views

### Drone targeting

Imagine a "drone" and a target point on a 2d plane. Assuming the target is stationary, there are eight parameters: ...
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 ...
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### 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 ...
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 ...
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### 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:...
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: ...
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?
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 ...
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### 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 ...
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 ...
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/...
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
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....
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 ...
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### 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 ...
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### 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. ...
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 ...
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 ...
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 ...
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,...
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 ...
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 ...
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 ...
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 ...
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 (...
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 ...
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 ...
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 ...
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 ...
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 ...
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### 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 ...
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 ...