Questions tagged [orientation]

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Kalman filter problem with the output

i want to use kalman filter to estimate my phone position, the measurments data is at this point just the accelerometer and the sampling rate is 3ms, i used the library pykalman, i have also wrote my ...
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Specify pose for inverse kinematics of 5 dof robot arm

I need to specify the pose for a 5 dof robot arm in order to calculate the inverse kinematics. Assuming I worked out the correct inverse kinematics solution for joint variables $q_{1} \dots q_{5}$, I ...
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Why are Euler angles used for drones

I know this question is asked before, but the reason why was still not clear to me. If you've a 6-DOF IMU, the gyroscope measures is degrees/s or radian/s. Why do we want to convert the body rates to ...
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Looking for benchmarks on Apriltag pose estimation

we want to know if we can use Apriltags in our project for pose estimation in rather long distances and on moving target. Specifically, correcting errors of an IMU device on an autonomous vehicle. I ...
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Why does AHRS system with Madgwick filter has so big drift?

I have an MPU9250 on my PCB and I use an AHRS system with a Madgwick filter to get yaw angle. I want to get very accurate and non-drifting yaw angle, but, for unknown reasons, I can't. I calibrated ...
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C program to find the rotation matrix (orientation) of a 6DOF robot from its end effector position and link parameters

I'm writing a C program to find the inverse kinematics of a 6DOF robot. I've been able to write it successfully based on the general concept of Inverse Kinematics using DH parameters (i.e. finding the ...
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Obtaining Heading vector from IMU

First time here. I'm an electronics engineer who has been tasked with this problem: Given the 4D quaternion representing a vehicle orientation, how do you get the heading vector? The vehicle ...
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Do you need to know the orientation between aircraft and IMU for IMU alignment?

I have a fixed wing aircraft and a MEMS IMU, but I am uncertain of the exact orientation between the IMU and aircraft. In the manual for the IMU, it recommends undergoing an alignment procedure prior ...
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Orientation Problem of a 4-DOF manipulator

As shown in figure, I have a 4-DOF manipulator. I want to control the robot such that the end-effector should always be pointing down no matter where the robot is in the end space. For the ...
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How can i consider orientation of 6dof manipulator for inverse kinematic?

i been trying to code IK solver for few days, and i finally move the robot to the desired position. However im having hard time to orient the end-effector as i want it. I read the "Robotics ...
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Define end-effector quaternion orientation from unit vector

I want to define ee-poses from a point cloud in a way that the pose for each point is pointed to by a unit vector from origin. Rotation about the vector pointing towards the point can be whatever as ...
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Looking for resources regarding conveyor object allignment / object orientation

Im currently on the hunt for resources / examples / words to use in a search engine in regards to orienting (aligning, funneling) an object on a conveyor. I am looking for techniques / utilities used ...
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GPS Course vs IMU Course

Im currently working with Kalman Filter for position and velocity, one of the important parameters that im using is the heading that the sensor fusion of the imu gives me, but i have seen that the GPS ...
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Problem with calculating relative orientation

I am using an IMU which provides absolute orientation of the sensors frame $S$ relative to an earth-fixed frame $N$ in quaternion form, $^S_Nq$. In my experiments, I first obtain an initial ...
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Finding orientation of object in 3D space

Given the above constellation, I have to find the orientation of object B in the coordinate system of Object C. The objects A and B are fixed to a certain place and the object C can move in freely in ...
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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 ...
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Forward Kinematics for Two Axis Gimbal Mount

I'm trying to work out the orientation of a block at the end of two axis gimbal. I know the position of the two rotational joints, but would like to calculate the final orientation of the block given ...
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What type of rigid body rotation can best be learned by neural networks?

I am training a reinforcement learning network in simulation for a robot which at the current stage learns Euler Angles to rotate the end-effector based on the actual state. The performance is overall ...
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Compute orientation velocities 6-DOF robot

I am trying to compute the joint velocities a 6-DOF manipulator(a typical industrial robot). I have an initial position [xi, yi, zi, T1i, T2i, T3i] and goal position [xf, yf, zf, T1f, T2f, T3f] in the ...
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Signed difference between two directions

I want to get the difference between the orientation of my robot and a target point. The orientation is expressed as an angle as shown in the pictue below. The point is expressed as ...
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Extract Euler angles from angular velocity profile

I Solved inverse velocity (joint velocity) at velocity level problem. So, I have actual orientation of the manipulator. Now I wanted to get the desired orientation from angular velocity that I used to ...
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Does GY-271 (HMC5583L) or any 3-axis magnetometer suitable to detect orientation?

Based on the datasheet, HMC5583L has 160Hz output rate and produce three axis direction angle data, X, Y, and Z. It can measure diversion from Earth magnet field with 1° to 2° accuracy. Does that ...
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Finding quaternion Q, where Y = q * X * q.inv()

Problem Quaternions $X$, $Y$, which represents 3-dimensional points are given. Quaternion $q$ is what is to be solved. I want to know unknown rotation between $X$ and $Y$. In other words, I want to ...
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2 answers
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How to compute the orientation error between two 3D coordinate frames?

For my master thesis in robotics I have to compute the orientation error between two coordinate frames, called E and H. Their orientation is expressed through rotation matrices (3x3) with respect to a ...
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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 ...
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Problem defining rotation matrix

I am studying robotic kinematics , and given the following manipulator with its D-H frames assigned: I have to find the rotation matrix $R_{e}^{2}$, which is the rotation matrix of frame $e$ with ...
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Finding orientation angles of end-effector from the DH parameter table and transformation matrices

Let's say we have a manipulator with the following DH parameter table: and transformation matrices: $$A_{01}= \begin{bmatrix} \cos(q_1) & \sin(q_1) & 0 & 95\cos(q_1)\\ \sin(q_1) & -\...
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Yaw, Pitch, Roll rate concepts and how to calculate them with an IMU

I need help understanding the difference from Y/P/R rate and the data that I can get from a gyroscope. I am using the raw readings of my IMU (MPU9250) and the Madwick Filter to calculate a quaternion ...
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5 votes
2 answers
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In SLAM loop closure, What does a sim3 matrix do?

I am confused between 3D rigid affine(with scale, without shear) transformation and Lie group's sim(3) matrix. 3D affine would be [sR|t; 0 1]. we rotate, scale and then translate a 3D point using ...
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2 votes
3 answers
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State of a Robot

I saw the expression "robot state" in many articles and resources, but I could not understand what that exactly mean. What does state of a robot exactly refers to ?
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How to get RPY(Roll, Pitch, Yaw) from directional cosines from a single vector?

I'm trying to find the pose of an 3D vector in terms of RPY. Let's say the two end points of the vector is P0(x0, y0, z0) and P1(x1, y1, z1). So the centered vector I get is V(Vx, Vy, Vz) = P1 - P0 = (...
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Undo pitching effect of camera when pose (y-axis) is near 90 degrees?

I am using KITTI odometry dataset whereby the camera's axis is pointing X (east), Y (down) and Z (north). It also contain the frame to frame poses of the camera (first pose is fixed as the map frame). ...
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2 votes
1 answer
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What is an axial and polar vector?

In Robot Kinematics and Dynamics by Herman Bruyninckx, it states: Axial vectors have an inner orientation, i.e., the direction of the vector indicates the positive orientation. For example, a unit ...
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2 answers
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Sensor complement in Drone

I saw a question posted by @Rocketmagnet (Why do I need a Kalman filter?) about the need for a Kalman filter. In that question, he says he's designing an UAV and lists the following sensors he will ...
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4 votes
1 answer
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Yaw drift when implementing AHRS filter fusion

I am using the Matlab AHRS filter fusion algorithm with an InvenSense ICM-20948 to determine object orientation. I seem to be obtaining reasonable results however I am getting what appears to be ...
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1 vote
2 answers
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Inverse kinematics with end effector orientation?

I'm trying to implement an inverse kinematics solver, but this time even with the end effector's orientation. I succeeded with the case when the end effector only requires the position. I learned ...
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Orientation from magnetometer data

I saw lot of topics with the same title but answers are different. I have a magnetometer in my phone which give me the components of magnetic field in direction of X, Y, Z. If my phone lays on a ...
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1 answer
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Fixing robot orientation using AR

I am creating a project where a robot needs to face a control panel and do some specific tasks. Some reference tags will be placed on the panel. I want to use the tags as AR reference and fix my ...
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1 answer
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Orientation estimation using gyro and accelerometer when sensor platform has high acceleration

I am trying to estimate the orientation of a sensor platform using gyroscope and accelerometer. I am using a Kalman filter based approach. I integrate the readings ...
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1 vote
1 answer
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Solving Inverse Kinematics with unknown orientation

This may be a very basic question, but I haven't had much success finding an answer. I'm currently trying to solve the inverse kinematics of a 3-RRR Planar kinematic arm, whose purpose is to move ...
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2 votes
2 answers
2k views

Inverse kinematic orientation problem

I am trying IK for 5-DOF robot all revolute joint. I am working IK with Jacobian inverse i.e end effector velocity = J inverse * error vector. In error vector I am feeding (x,y,z) positional error; ...
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2 votes
1 answer
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Yaw from accelerometer? No! So what do these equations actually mean?

note: I'm just a day or so into the use of inertial measurements and trying to learn everything at once, this may be a noob question (it's my first here). I have seen this image of "Figure 8" in ...
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5 votes
2 answers
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Inferring joint orientation on multi-joint arm

Not a robotics question in the strictest sense, I guess, but related closely enough, I hope: I have an arm-like articulated two(-plus-one)-joint appliance that I want to use as a 3D input device. It ...
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4 votes
2 answers
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Multicopter: What are Euler angles used for?

I hope you can help me and this is the right forum to ask. In the process of building and programming my own Quadcopter, I encountered the term Euler angles. I took some time to understand them and ...
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2 votes
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How unique are Quarternions and what about the sign?

I want to track a robot's orientation in space and wanted to choose quaternions for their many advantages. However I have a few questions that I haven't found to be solved anywhere. The method I use ...
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Handling GYROSCOPE BIAS DRIFT

I am working on a MEMS based project which requires me to calculate the orientation(Euler Angles) of an object using only GYROSCOPES. The GYROSCOPE BIAS is calculated in the beginning for 2 seconds ...
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7 votes
3 answers
393 views

Paradox: I can't use accelerometer measurements to obtain information about my states in a quadcopter?

I'm currently developing an EKF to estimate the position and orientation of a quadcopter. My state vector is comprised of 3D position, 3D velocity, 3 euler angles and the angular velocity vector. ...
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3 votes
2 answers
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Is there a way to measure 3 axis orientation without a magnetometer?

I have bought an STM iNEMO evaluation board in order to monitor the inclination of a separate magnetic sensor array as it moves in a linear scan outside of a (non-magnetic) stainless steel pipe. I ...
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Orienting rectangular plastic bricks [closed]

As part of a sorting machine, I need to orient a pile of plastic brick-shaped objects (which are all identical in size - about 3cm x 2cm x 1.5cm) so that they always end up with the white side facing ...
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Accurate technique to locate position? [closed]

What is the most accurate way to locate the position and orientaion of the body during some motion (rotation and translation)? I need to track the body very precisely, the required accuracy is 100-...
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