Questions tagged [orientation]
The orientation tag has no usage guidance.
50
questions
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42 views
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 ...
0
votes
0answers
47 views
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 ...
1
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1answer
53 views
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 ...
0
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0answers
24 views
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 ...
0
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2answers
122 views
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 ...
1
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0answers
36 views
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 ...
1
vote
1answer
33 views
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 ...
3
votes
1answer
36 views
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 ...
1
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2answers
262 views
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 ...
0
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1answer
70 views
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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0answers
37 views
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 ...
1
vote
1answer
71 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
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1answer
132 views
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 ...
1
vote
2answers
48 views
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 ...
1
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1answer
150 views
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 ...
1
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1answer
55 views
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 ...
0
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1answer
54 views
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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0answers
54 views
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 ...
0
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1answer
35 views
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 ...
3
votes
2answers
235 views
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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0answers
39 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 ...
1
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2answers
82 views
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 ...
0
votes
1answer
129 views
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) & -\...
1
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0answers
489 views
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 ...
4
votes
2answers
824 views
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 ...
2
votes
3answers
562 views
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 ?
1
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0answers
148 views
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 = (...
2
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0answers
19 views
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). ...
2
votes
1answer
55 views
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 ...
0
votes
2answers
41 views
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 ...
4
votes
1answer
634 views
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 ...
1
vote
2answers
643 views
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 ...
0
votes
1answer
2k views
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 ...
0
votes
1answer
54 views
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 ...
0
votes
1answer
298 views
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 ...
1
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1answer
266 views
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 ...
2
votes
2answers
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; ...
2
votes
1answer
1k views
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 ...
5
votes
1answer
267 views
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 ...
4
votes
2answers
2k views
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 ...
2
votes
0answers
85 views
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 ...
1
vote
1answer
815 views
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 ...
6
votes
3answers
371 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.
...
3
votes
2answers
1k views
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 ...
0
votes
1answer
42 views
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 ...
1
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0answers
96 views
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-...
4
votes
3answers
310 views
Discontinuity in device orientation
Why is there a discontinuity in the quaternion representation of my device orientation?
I'm using a SENtral+PNI RM3100+ST LSM330 to track orientation. I performed the following test:
Place the ...
3
votes
3answers
4k views
Forward kinematic computing the transformation matrix
I am the moment trying to compute the transformation matrix for robot arm, that is made of 2 joints (serial robot arm), with which I am having some issues. L = 3, L1 = L2 = 2, and q = ($q_1$,$q_2$,$...
2
votes
2answers
2k views
Manipulator end-effector orientation with quaternions
I have the following problem:
Given 3 points on a surface, I have to adjust a manipulator end-effector (i.e. pen) on a Baxter Robot, normal to that surface.
From the three points I easily get the ...
1
vote
3answers
909 views
Sensor orientation of an external magnetometer [closed]
On many drones are already external magnetometers. Unfortunately, the orientation of such sensors is sometimes unknown. E.g. the sensor can be tilted 180° (pitch/roll) or X° in yaw. I was wondering, ...
