# Questions tagged [rotation]

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### Simple takeoff then do yaw rotation

Arming and takeoff work fine but i don't know how to do yaw rotation: ...
31 views

### Calculate target orientation

I have the following setup: I want to move the "Drill" frame to "Target1" with the opposite Z axis direction. I have calculated translation between "Target1" and "...
1 vote
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### Regarding rotation of the box when affected by two non equal side forces

We have created a workspace, where we have a box ‘B’ (massive) with two side boxes(left and right) of negligible size and mass attached to the line connecting the centre of Mass of the main box B. The ...
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### From euler angles to rotation matrix and vice versa

I want to check if I am using the correct functions to transform from euler angles to rotation matrix and viceversa. I am using XY’Z” convention of euler intrinsic angles. As example, I have the ...
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### From Euler angles to Rotation matrix Staubli

I want to know the transformation matrix between End effector and Robot base (FK). Staubli gives me x,y,z and Rx,Ry,Rz. Those three Rotations are Euler angles? How could I transform those Euler angles ...
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### How are these equivalent rotation coordinates related?

I am using a 6 DOF UR5 robotic arm. I am successfully sending it commands in the [X,Y,Z,RX,RY,RZ] format. When I read back these coordinates, I find that the X, Y, Z values are the same but the RX, RY,...
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### Ball bearings size for an RC car

I'm want to build my first RC vehicle and for a few days I'm trying to choose the size of the ball bearings for the wheels. I'm planing to use 2 per wheel. Are 5x10x4mm (inner/outer/depth) going to ...
172 views

### How do we derive the loop closure equations?

Looking to derive these equations. I don't intuitively understand what it means to take a cos of two independent angles added together. Nor do I understand why all of these are equal to 0. It is hard ...
1 vote
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### Siciliano et al. Rotation Matrix Notation

I'm reading Siciliano et al.'s Robotics: Modeling, Planning and Control, and I'm confused about the notation used in definiting rotation matrices. On page 46, they state If $\textbf{R}_i^j$ denotes ...
371 views

### Calculation of IMU offset for Placement of Inertial measurement unit away from centre of mass

I am working on a 6DOF IMU that contains a 3-axis accelerometer and a 3-axis gyroscope. I am building a project to plot the position and orientation of a vehicle/dirt bike in a 3d plane. However, the ...
1 vote
584 views

### Center of gravity offset for accelerometer and gyroscope readings

I am working on a 6DOF IMU that contains a 3 Axis Accelerometer and a 3 Axis Gyroscope. I am building a project to plot the position and orientation of the turret/cabin in a crane in 3D space. The IMU ...
1 vote
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### Rotate sensor frame to body frame

I'm working with a lsm303agr from ST. Here is the frame attached to the chip Here is the body frame So I have some doubts about the rotations, before to fuse data ...
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### Get a rotation to align a vector, n with another vector, a and be able to rotate around a

Let us say I have a rigid body, B. Let us say I have a normal vector n. And let us say I have another direction vector a. I need ...
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### geometric meaning of rotation matrices related to different frames

Consider the following rotation matrices: $^{a}R_{b}$, $^{a}R_{c}$ and $^{a}R_{d}$ in which $^{x}R_{y} \in SO(3)$ describes the orientation of a generic frame $y$ wrt the coordinates system of ...
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### transform IMU reference to robot reference

I have an IMU rigidly attached to the end effector of a robotic arm. The goal is to compare the orientation of the IMU to the orientation of the robot arm. The 9-axis IMU data is used in a sensor ...
1 vote
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### Using an IMU to determine the axis about which it is being rotated

I've got a 6DOF IMU and have, using some trig and and a few references such as ADI's app note: https://www.analog.com/en/app-notes/an-1057.html successfully implemented some Arduino/C code to ...
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From modern robotics chapter 3.2 and figure 3.7, how do we obtain $p_{b}=\begin{bmatrix}1 & -1 & 0\end{bmatrix}^{T}$ from $R_{b}$ and $p_{a}$? Because R_{b}*p_{a} =\begin{bmatrix}-1 & 1 &... 0 votes 1 answer 168 views ### Get rotation of IMU data snapshot I received snippets of data of an IMU with 9 DoF in motion. For these I wanted to get their rotation by angles relative to the earth frame. My goal is to receive ... 0 votes 1 answer 41 views ### End effector rotates 180 degrees when trying to set orientation with direction vector I want to orient the robot endeffector using a direction vector that I calculate myself. The robot will always start from the same position with the endeffector pointing straight down. I already have ... 1 vote 1 answer 50 views ### Can you increase resolution/accuracy by mechanically averaging two actuators? I'm working on a project using hobby servos to drive a revolute joint, and the servo mechanism doesn't seem to respond when I command a motion of less than about 1 degree. I want to increase the ... 1 vote 1 answer 364 views ### How do you rotate positions from ENU-frame to body frame? If positions are in the local frame of ENU (or ECEF - either works), how do you rotate that to the body frame of the device? Logically, I thought that I could use the pitch, roll, and yaw angles of ... 0 votes 0 answers 244 views ### Mapping IMU readings from body frame to navigation frame I'm trying to combine IMU displacements with the time of flight sensor readings in order to navigate through the indoor environment with a non-linear Kalman filter variant. In the graphic below, I ... 0 votes 0 answers 132 views ### Aligning accelerometer readings with vehicle's frame of reference I have a device with an accelerometer installed in a vehicle. Its orientation in relation to the vehicle is unknown. So I am looking for a reliable way to align the coordinate system of the ... 2 votes 1 answer 290 views ### What is the consquence of Gimbal lock? I'm learning about Gimbal lock and I understand the reason why that happened. But I don't understand why that is a big deal because it only affect this rotation. After this rotation finished, we have ... 0 votes 1 answer 50 views ### Why do we parametrize matrices? I'm learning about rotation matrices in class and one of the topics mentioned to parametrize a matrix. What do we need to do this? For further reference: https://www.youtube.com/watch?v=Y8gB7nvtmrU 1 vote 1 answer 120 views ### Relative rotation and a new reference frame as the rotation of the first object this is my first post on this forum I haven$IMUs which outputs its rotation their matrices in the$XYZ$world coordinate system$w$. I would like to use multiple IMUs$n$, such as$n_{1}, n_{2}, n_{...
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I am trying to understand exactly what is happening when Gimbal lock occurs. I have read many explanations now which provide the high-level idea, in that Gimbal lock occurs when two axes are aligned ...
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### Multiplication of rotation matrix help

I'm Watching Angela Sodemann video on 6DOF robots and am following her example, but I'm getting a different answer for my R3_6 matrix and I'm not sure where I'm going wrong. She uses this as her ...
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### How to get odometry from propeller rotation signals knowing that they can rotate to maximum value?

m trying to get Velocity in order to control underwater swarm ROV. I can use the acceleration and to Euler integration but the error will be accumulated over time. As we are having a swarm (many small ...
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### How to measure an optical encoder resolution and gear ratio?

I've bought a DC geared motor with an optical encoder. The vendor didn't provide specification. I can read MITSUMI M25N-2R-14 2241 and 25GA-370-12V-330RPM on the motor. There are some pages on the ...
1 vote
329 views

### Multiple Rotations via Matrix Multiplication

so I am having an issue understanding why you right multiply for current frame rotation vs left multiply for fixed frame. Let us say you want to: Rotate about x, then Rotate about current y, then ...
597 views

### How to avoid gimbal with Quaternions

I'am working with an LSM6DSO32, so I'am starting with Kalman filter, everything works but with Euler angle I got gimbal lock I think... But if my pitch angle approach to 90° my roll angle jump and I ...
1 vote
148 views

### Can the tangent space vector of SO3 be interpreted as Euler angles?

I want to compare the rotation of two cameras with respect to a common frame. Let's call these R_World_Cam0 and R_World_Cam1. ...
153 views

### What type of electric motor and speed-controlled circuit do I use to bounce a hanging, 5 pound weight? (it's for a Halloween decoration)

I'm trying to make a roughly 5 pound, hanging halloween decoration bounce on a string from about 1-3 times per second, preferably at variable speeds if I can. I've looked up a simple DC motor circuit ...
1 vote
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### Inertial frame's angular velocity expression

I'm following a robotics course on coursera which talks about aerial robotics and more specifically quadrotors. I'm trying to understand the logic behind the relationship between the angular velocity ...
262 views

### Calculating rotation matrix efficiently

I'm trying to efficiently calculate the vertical offset of each corner of a rectangular base. I have an accelerometer mounted in the middle of the base, ADXL345. The steps I have taken, and seems to ...
1 vote
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### How to handle robot movement close to coordinates x=0 with atan2

I am working on controlling a robot to various points on an x,y grid. The robot starts at random locations and I can control it's velocity and angular velocity. Currently, I am using the technique of ...
170 views

### How can I draw a line using rotation of two circles?

I’m building a drawbot with a self imposed constraint that it’s method of motion is just two rotating disks. One holding the paper and one holding the pen. However, the math to calculate the right ...
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### 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 ...
1 vote
381 views

### Conveyor Belt Calibration for a Robot - Rotation Matrix

Short Question: As demonstrated in the image below, how can I calculate the rotation matrix that relates the base coordinate and the rectangle coordinate, given 3 known points P1, P2, P3 on the ...