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the action or process of moving or of changing place or position

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what is the local minima problem in robot motion [duplicate]

How should we describe the concept of local minima in robot motion in layman's terms? Is local minima a rare or common occurrence in robot motion planning using sampling based algorithms? what is the ...
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10 views

Lost on SEIF Slam repeated update landmark

I am working on Sparse Extended Information Slam. I take the reference from Probabilistic Robotics, by Dr.Sebastian Thrun (Chapter 12,page 303). I have some doubt about the implementation of the ...
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17 views

SEIF ,online version of Graph slam create doubt in Motion Update state

I have a thesis work about Graph Slam The GraphSLAM Algorithm with Applications to Large-Scale Mapping of Urban Structures I try to implement it with the help of this paper but during the ...
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2answers
75 views

Ackermann Motion Model Does not Drive in an Arc, but Turns on the Spot

Im trying to implement an ackermann motion model which estimates the x,y and theta for a robot I have. I have a gazebo simulation running which publishes a steering angle for the virtual tricycle ...
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2answers
49 views

Motion Profiling for Decreasing Energy Consumption

I am attempting to minimize the energy consumption used by an electric-motor-powered car given the speed restrictions: $$\text{speed}: [v_{\text{min}},v_{\text{max}}]$$ Currently, we are utilizing a ...
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2answers
69 views

Explanation for exponential coordinate of rotation

From figure above, suppose a three-dimensional vector $p(0)$ is rotated by an angle $\theta$ about the fixed rotation axis $\omega$ to $p(\theta)$. Here we assume all quantities are expressed fixed ...
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1answer
50 views

Jacobian of kinematic IMU Model

I have the following problem: given two Input Vectors $x = \begin{pmatrix}x\\y\\z\\v_x\\v_y\\v_z\\q_1\\q_2\\q_3\\q_4\end{pmatrix}$, $u = \begin{pmatrix}a_x\\a_y\\a_z\\w_x\\w_y\\w_z\end{pmatrix}$ time $...
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1answer
31 views

Probably basic question about how control a DC motor

over the past weeks I was trying to figure out how use the information from hall sensor to control a DC motor. Basically this is the motor which I'm using: https://www.servocity.com/32-rpm-hd-premium-...
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2answers
115 views

Motion planning from a given path

Many articles reference algorithms such as A*, PRM or RRT based planners to motion planning algorithms which seems unreasonable since it is still necessary to parametrize found path with time.I wonder,...
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1answer
198 views

Are S-Curve (constant jerk) motion profiles significantly better than constant acceleration?

I've been investigating S-Curve motion profiles for CNC router and 3D printer applications, and haven't come across any definitive source that says an S-Curve profile is necessary in any application. ...
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0answers
66 views

My robot arm vibrates during operation. Why?

Introduction: I have modeled my 5-DOF robot arm in a simulation environment to test trajectories for my physical model. I have export the joint variables from the simulation as a .csv file. Then ...
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0answers
53 views

Debugging my Quadrotor Controller SE(3)

I am trying to simulate and implement the controller of the paper Geometric Tracking Control of a Quadrotor UAV on SE(3). I have both the dynamics and the controller implemented but there seems to be ...
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1answer
61 views

Quadrotor SE3 Controller: Calculating Rd_dot

I am trying to simulate and implement the controller in the paper Geometric Tracking Control of a Quadrotor UAV on SE(3). I have the dynamics implemented, however I am stuck at one part in the ...
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2answers
244 views

Quadrotor Dynamics: Calculating angular velocity of quadrotor

I am trying to simulate and implement the controller of the paper Geometric Tracking Control of a Quadrotor UAV on SE(3). To do this I need to first implement the dynamics of the quadrotor. According ...
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1answer
69 views

Why don't bipedal robots ever feature natural movement?

I'm a programmer and I've decided to make some bots for fun. I might start with wheels but my ultimate goal is to make bipedal robots. To that end I first decided to watch a bunch of videos of such ...
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2answers
727 views

What does SE mean in robotics literature?

I've come across the abbreviation SE several times recently. I know it has to do with the pose of the robot, and the degrees of freedom. Most recently I found it on page 8 of this paper: D. Kragic ...
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2answers
679 views

How can I draw with a 3 DOF RRR arm ,I have done the Forward and Inverse KInematics

Heres the Matlab code, I start with x and y and when I pass it through IK and Fk I get back the correct x and y thus I am confident that IK and Fk are correct. ...
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0answers
48 views

Which Trajectory representation for optimization

I'm strugling on that problem for a while, so any help is welcome. I need a trajectory representation that is performant for optimization, i.e. I want something that computes quickly. The function I ...
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1answer
730 views

Thrust and Torque on Quad Rotor

I am a beginner on Drones. I would like to understand the how each motor contribute to thrust on the whole drone. And what is the direction of torque created on each propeller. Everywhere I find a ...
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1answer
125 views

Compensation for IMU mounting misalignment

I have an MPU6050 IMU and I would like to mount it on an FSAE car and use it to measure the yaw, pitch, roll, and angular velocities as it drives. As it's impossible to mount it perfectly flat and ...
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2answers
242 views

Estimating yaw angle and yaw rate for a frontal vehicle

I would like to know if it is possible (and if it is possible how can it be done) to estimate the yaw angle and yaw rate of a vehicle in front of me knowing the following information: -my speed (x,y,...
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1answer
59 views

Computing Yaw angle from position and velocities

I have an object to whom I know the x,y,z position, length, width, height, and x,y velocities. Is there a possibility to compute the yaw angle from this information?
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2answers
174 views

Motion planning and robot controlling

I am stuck with understanding how can I make my robot move along planned path. For instance, if we have a grid map of an environment and applied, for example, A* to plan a path then after that we have ...
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2answers
103 views

How to relate forward kinematics into PWM/speed?

I am having a hard time understanding how to relate forward kinematics to things one can control in a robot like PWM and reading encoder values. For example, how to relate the encoder values from ...
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2answers
602 views

State estimation of mobile robot

For a mobile robot - four wheels, front wheel steering - I use the following (bicycle) prediction model to estimate its state based on accurate radar measurements only. No odometry or any other input ...
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1answer
42 views

Step size in numerical differentiation

I get position information and a corresponding timestamp from a motion tracking system (for a rigid body) at 120 Hz. The position is in sub-millimeter precision, but I'm not too sure about the time ...
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0answers
52 views

8 wheeled vehicle model

I want the dynamic model for 8 wheeled robot. I expected to find it easily like the 4 wheeled bicycle model, but I couldn't. Here is my effort only for rotation not for feedback. From that I can ...
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1answer
33 views

What type of actuator should I use? [closed]

I need to find out if There is a way to get at least 60 Hz of linear Motion with at least 5 mm of stroke that I intend to make linear persistence of vision device(not rotating one)It must be small and ...
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1answer
251 views

Finding cubic polynomial equation for 3 joints

My professor gave us an assignment in which we have to find the cubic equation for a 3-DOF manipulator. The end effector is resting at A(1.5,1.5,1) and moves and stops at B(1,1,2) in 10 seconds. How ...
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1answer
2k views

Calculating Required Torque

Say I had an object with 4 motors/wheels attached (in a fairly standard arrangement). I need to calculate the amount of torque required from the motors to be able to move the object of x kilograms ...
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1answer
63 views

Square with hinge on all four sides

I want to make a component that will be a square plate that will behave like it has a motorized hinge on all four sides. That is, it can "open" by pivoting around any one of its four sides. I want it ...
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1answer
55 views

Glasses with eye sensors

Someone could tell me if there are wearable devices such as glasses, with sensors that can detect eye movement? In particular, I would need a device like google glass, having a sensor or a camera ...
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1answer
870 views

How to calculate the real time RPM of motor with rotary encoder?

I want to measure the real time RPM of the wheels. I think incremental rotary encoder would be good. But i am confused on how to interface it with DC brushless geared motors. From the images i am not ...
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0answers
28 views

Unilateral Torque Constraint on the foot-ground interface

I was studying the basics of legged locomotion and came across the unilateral force and torque constraints at the foot-ground interface. I understood the implication of the unilateral constraint on ...
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2answers
269 views

Nano sized electric motors

What is a good website for buying 1.5V continuous motors? I'm looking to build a clockwork robot but I cannot find a motor small enough to fit inside my power box and I don't want to mount it outside ...
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1answer
38 views

Seamless motor movement

With the lego NXT Mindstorm kit I would like to have a rotating carousel that has "perfect" movement. This carousel has baskets and therefore it has quite a bit of inertia. I would like to find a ...
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1answer
35 views

Wheeled Robot Motion Primitives: Is throttling forward and crab motion considered as one?

I am simulating a wheeled robot of six-wheels and can be independently steered, like MER-Opportunity. The wheeled robot can perform throttling forward, ...
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1answer
617 views

Linear slider motor mount location - Pros/cons

I'm currently designing a linear camera slider, that will be used to hold camera equipment weighing just about 15 Kgs including all of the lenses and monitors and everything else. For those who don'...
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3answers
1k views

Is there any advantage to velocity motion models over odometry motion models for SLAM?

I've seen several examples of SLAM algorithms (EKF SLAM, Graph SLAM, SEIF SLAM) written in terms of the velocity motion model. I have yet to see an example of any SLAM algorithm utilizing the ...
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2answers
1k views

Position Control of an Omni Wheel Drive Robot

I want to create a robot that will navigate on a desired path! That path can be a straight line or a circular path with a given radius. I will use 3 or 4 omni wheel drive platform and for positioning,...
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1answer
47 views

Best technique to built an ejectable drawer? [closed]

I want to build a closet with ejectable drawers. On the top should be 4 buttons, each eject opening one of the four drawers of the closet. I am looking for ideas on how to accomplish this. What kind ...
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1answer
328 views

Where to go to purchase parts for XY Plotter [closed]

I am trying to build a 2ft square an XY Plotter. I have seen three designs so far: 1)Rack and Pinion 2)Threaded Screw 3) belt-driven. all these use a stepper motor to drive the system. Each one has ...
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1answer
948 views

Velocity Model Motion in Matlab (Probabilistic Robotics)

I want to implement the velocity motion model in Matlab. According to Probabilistic Robotics page 124, the model is as following \begin{align*} \hat{v} &= v + sample(\alpha_{1} v^{2} + \...
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1answer
2k views

What are some good cheap, silent, motors for mannequin robots and what kind of controller should I use? [closed]

What are some good cheap, silent, motors for mannequin robots and what kind of controller should I use? I'm creating mannequin robots that require 24 motors: 2 neck, 4 shoulder, 2 elbow, 4 wrist, 2 ...
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4answers
1k views

How to turn a rover 90 degrees using wheel encoders?

I have a four wheel DC rover with two optical wheel encoders. I'm executing rover turns by controlling the direction of wheel motion on either side of the rover. To turn left, all wheels on the left ...
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3answers
216 views

Using robotic simulator for prediction step in probabilistic localization approaches

Probabilistic localization approaches like Kalman or Monte Carlo benefit from an accurate prediction step. The more accurate the prediction step, the more accurate is the belief of the robots pose. In ...
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0answers
70 views

Best Way to Sense Rubiks Cube Movements [closed]

I was wondering what was, in your opinion, the best way to study the different motions of a Rubiks Cube. I want to be able to recognize what face moved and in what direction. Would I be able to get ...
3
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1answer
462 views

What do we call a coupling with infinite range of rotation

In most situations, range of motion is limited by the fact that we need to carry power or information past a joint. So, past a certain point there are either cables in the way, or the cables would ...
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3answers
829 views

Motion Model for Holonomic Robot

We are working with an holonomic robot equipped with three (120 degree shifted) omnidirectional wheels. The relative movement is estimated by dead reckoning using wheel encoders. To improve this ...
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2answers
2k views

Help with PID “units” in a quadcopter control system

I'm in the process of writing my own simple quadcopter controller for experimental use, and I'm having trouble getting my head around how to convert from the degrees which my PID controller demands to ...