# Questions tagged [localization]

Localization is the problem of estimating a robot's pose relative to a map of its environment.

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### Accelerometer, gyro, and magnetometer sensor fusion in 2d

I have not yet built this so this is basically a theoretical question. I am still wrestling with some C code to manage i2c ...
32 views

### Self localization inside machine of interest

I have a type of flight sensor interfaced with Arduino Uno via I2C. The sensor is VL53L0X i am getting the 1D measurement value of distance in mm which i can monitor using serial monitor in Arduino ...
40 views

### 2D point cloud registration success probability

I am trying to implement localisation by storing images from a camera and their accompanying point clouds from a 2D lidar during mapping. During localisation I then use image matching to suggest the ...
43 views

### Calculate the Vehicle corner points given localization

I am trying to calculate the corner points of the vehicle given the details below: Localization data from rear axle of the vehicle Length and Width of the vehicle Heading of the vehicle ENU Could ...
144 views

### Likelihood field sensor model (Probabilistic Robotics, Thrun et al., p.169-174)

I am currently working on the "likelihood field" sensor model (aka "endpoint model") by Thrun et al. (book: Probabilistic Robotics, Thrun et al., p.169-174) In this context I have ...
38 views

### How does loop closure backpropagate the robots states into prior times?

I have read some about loop closure and I am somewhat confused. Suppose we implement something like EKF slam using LIDAR and suppose loop closure is aided by computer vision based features so that if ...
90 views

### Why innovation equation in Extended Kalman filter is called innovation? [closed]

In the Extended Kalman filter for SLAM, why the innovation equation is called innovation? Is there any reason behind it?
702 views

### How to calculate vehicle detection distance?

I would like to know how to calculate the distance to each car when I run my application for an autonomous vehicle in real-time. In addition, I want to know how to implement the calculation in C++. ...
41 views

### Motion model and homogeneous transformation issue on a drone

I am trying to develop a EKF-SLAM algorithm for a drone, and I want to estimate its position in the inertial/world reference frame. I have as control variables the linear and angular velocities in the ...
117 views

### Bearing landmark localization

I am trying to initialize the position of a set of landmarks using only bearing observations. Each robot pose, described by position (x,y) and orientation (theta), observes a small set of landmarks. ...
57 views

### Kalman Filter for 2d pose

I'm really sorry if this is a dumb question, but I don't have a clue on how to do this. I'm trying to write a kalman filter with a State vector of : {x, y, ẋ, ẏ, ẍ, ÿ } To estimate the 2 dimensional ...
119 views

### ICP(Iterative Closest Point) with Partially Overlapping Conditions & Changing Point Numbers

I am currently working on fixing vehicle odometry data using lidar contour points. Since I am receiving lidar data in the form of countour points, I thought I'd use ICP to correct the odometry error ...
67 views

### Compute path in absolute frame from sequence of measurements

I have a sequence of measurements $\{(x_i, y_i, \theta_i)\}_{i = 1 \:...\: N}$. Each of these represents the new pose of the robot seen from the previous pose, i.e. a measurement $(x', y', \theta')$ ...
112 views

### EKF sensor fusion

What is the standard way to fuse multiple sensor measurements in an EKF framework? Say you have Odometry, IMU and some form of Lidar which can produce landmarks. EKF is normally presented as a ...
75 views

### EKF-SLAM what should the observation model be?

I am implementing an EKF algorithm for a drone localization, and while I was defining the observation model I got a bit confused. This is my situation: I have a drone which is able to give me the ...
84 views

### Which math books would help in learning SLAM systems? [closed]

Recently I started studying papers on SLAM systems by Durrant-Whyte for my research and I'm finding some difficulties in the math (matrices and probability) that is tackled in these papers. Which ...
332 views

### Difference between SLAM and Localization

What are the differences between SLAM and Localization if you have a known map? How does the position probability update differ between the two? In particular I'm curious on if localization is a ...
92 views

### Kalman filter with a known motion model

I have a robot whose pose $(x, y)$ is defined relative to the global frame. I have a sensor which estimates the robot's current pose in the global frame, and the sensor is known to have Gaussian error....
111 views

### How can i fusion gyroscope and accelerometer when accelerometer has only roll,pitch val?

I'm currently studying IMU Sensor with 6dof(gyro and accelerometer). My goal is to get Orientation of robot, and i found out that only 6dof imu sensor wouldn't be possible to get a correct Orientation ...
38 views

### Determining Orientation of a Robot Relative to a Line on Table

I am currently busy with a robot that needs to obtain it's orientation relative to a line seen by a camera. At the moment, I am using Hough lines to obtain a gradient for the line, but the gradient ...
26 views

### Hint regarding Localization & Map Scaling

I just started with mobile robotics. I'm trying to do a collaborative system between a mobile robot and a ceiling camera (Raspberry). They should do all tasks as a "team". Means Calibration, ...
109 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 ...
314 views

### Grid based SLAM using BeagleBone Green Wireless and RPLIDAR

I've written a grid based DFS algorithm with a PID-based steering system to maneuver a 30cm2 square-grid maze all in Python. The robot is a 4 wheel drive with an approximate size of 20 cm. The ...
612 views

### Bayesian filter for 2-D grid localizaton

I have some data obtained from an experiment in terms of movements and observations with odometry and sensor data. My task is to find the probability mass on each of the grid cells after each set of ...
133 views

### How many landmark measurements to localize a planar robot?

How many landmark measurements are required to localize a robot (i.e. find its x,y position and orientation) moving in a 2D world using 1. only range measurements 2. range plus bearing measurements?
136 views

### Where to include velocity in a Kalman filter

I am trying to understand some of the basics of the Kalman filter. The problem I am working on is quite complex, but I have spent some time trying to simplify the problem with an example. So, let's ...
93 views

### Robot localization in a known map without knowing its initial position in that map

Firstly I would like to say that I'm no expert in Bayesian Filters such as Kalman Filter and Particle Filter, but I've used the EKF before in a robot that has both wheel encoders and an IMU to ...
99 views

### bluetooth that could track mobile phone location

newbie here. after my research, i couldnt find anything that could found what i wanted to search for my project(following robot for indoor location). without gps, bluetooth only, could i get the exact ...
44 views

### Alternate perspective other than probabilistic perspective to implement slam

I am bother on some line which is written is Probabilistic Robotics book by Dr.Sebestian Thrun From a probabilistic perspective, there are two main forms of the SLAM problem,which are both of equal ...
5k views

### Determining position from a 2D map and LIDAR

We need to determine the 2D position of my robot. To do so, we have a LIDAR at a known high, with an horizontal plane, which gives us the distance to the nearest point for each angular degree (so 360 ...
53 views

### How to calculate the mean of an unsymmetric distribution (Particle Filter)

I'm attempting to implement a variant of Monte Carlo localization in a 2D space with obstacles. While the object is moving around the obstacles the particles flow around the obstacle like in images ...
27 views

### Differences between strapdown inertial navigation and motion models

In a state estimation scheme with a simple IMU/GNSS setup using EKF, I have always thought the prediction step would be done using a motion model and all sensor measurements would be incorporated via ...
67 views

### Can drone fly in predefined fixed trajectory without GPS

Is it possible to make a drone to fly in fixed altitude and move in fixed trajectory without GPS. (Drone has to move in fixed path which is already defined). I am saying without GPS because drone has ...
40 views

### How do I set the weights of an Unscented Kalman Filter?

In most of the papers I have read, calculation of weights is done by the following formula: Where L is the dimensionality of my state and lambda is calculated by: And the usual values for alpha, ...
116 views

### Sensorfusion of odometry, accelerometer and gyroscope using Indirect Kalman Filter

I'm trying to implement an indirect Kalman for pose estimation of a wheeled robot. I found two papers that describe this approach. CMU. Journal (2006) Vol. 5(1) IFAC Conference on Embedded Systems ...
1k views

### What is the most appropriate SLAM algorithm for quadrotors with RGB-D camera?

I have been researching on SLAM. I came across EKF SLAM which uses odometry to measure the robot's initial position in the map and as well as landmarks which helps the robot's position to be more ...
27 views

### Max angle of beam against surface (ultrasonic sensor)

I am trying to localize a robot within a rectangular room (182cm x 243cm) with completely black walls (so IR sensors and LIDAR are out of the question). I am trying to figure out if I can position ...
260 views

### Likelihood Field Matching

I have LIDAR data of an environment in my hand and I want to apply likelihood field matching to this data. I found a source. But I don't understand what the variables of the algorithm mean and how it ...
576 views

### Using vision for Monte-Carlo localization

From each step of my vision code I am able to get around 400 coordinates of where the robot thinks the walls are I want to integrate this into Monte-Carlo observation step. I'm storing the map of ...
95 views

### Fusing absolute robot localization from markers

I have a system which is composed of a rig of 8 cameras which are used for detecting markers in the environment and which outputs 8 estimates of the absolute robot's position and orientation. Now, I ...
28 views

### Localization in box using rangefinders

Let's say I have a robot, located in a box. The robot can move in the x and y and rotate. The robot has 4 rangefinders, mounted 90 degrees apart, that measure the distance to the walls of the box (I ...
I'm having troubles implementing a UKF during the calculation of $\overline{\mu_t}$, specifically in this step: $$\overline{\mu_t} = \sum_{i=0}^{2n}w_m^{[i]}\chi_t^{*[i]}$$ My problem I'm facing is ...