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1500 questions
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2 answers

Static equilibrium for 7 dof manipulator

I have a 7 dof manipulator (Kuka LBR4+) and would like to calculate the joint torques needed to keep the arm in a static equilibrium. In most books the transposed jacobian is used to map the forces applying on the end effector to the joint…
Johnny Mudcrab
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Role of Neuromorphic Computing and Quantum Computing in the field of Robotics and AI

I asked a similar kind of question some time ago (Neuromorphic Engineering and Robotics) Since then, many things have come to the point of revelation. A road-map for neuromorphic computing was revealed recently; It proposes the analog way of…
xsnk
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PID output does not reach setpoint precisely enough

I'm developing/tuning a software PID for a quadcopter. For now I'm only trying to stabilise the pitch angle using the front and back motors, and I'm only looking at Kp. The motors have a control resolution: input variations need to reach a…
marcv81
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Computing inverse kinematic with jacobian matrices for 6 dof manipulator

I'm trying to calculate the inverse kinematic for an 6 dof manipulator. Task: A target point $p_{target} = (x,y,z)^T$ and the orientation $o_{target} = (a, b, c)^T$ are given and I want to get the angle configuration $q = (q_1, q_2, q_3, q_4, q_5,…
user3361135
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2 answers

SCARA Arm Lead Screw Choices

I'm thinking about building a SCARA Arm to lift moderate loads(5lbs) with a high degree of accuracy. I want a relatively quick and inexpensive Z axis gantry, and I was thinking about using a lead screw with dual linear rail. Trouble is I'm not…
cii
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6
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4 answers

Need help calculating the thrust on quadcopter motors

I'm trying to calculate the lifting capability of my four quadcopter motors. I tried using eCalc but it doesn't have battery I'm using. Are there any equations to keep in mind for doing these calculations? Here are some relevant details: Battery:…
user2200321
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2 answers

Altitude hold for quadcopter with Accelerometer and Barometer

I wonder currently how to implement an altitude control for a quadcopter. I have atm just a barometer/GPS and an accelerometer. Barometer and GPS are relatively straight forward implemented, but not very precise and slow. For the accelerometer…
dgrat
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How to measure displacement, cheaply and without using an accelerometer?

Motion is known to be confined in a sphere with radius of about 0.5m, and resolution doesn't have to be very high (5cm is enough). The device will actually be incorporated in a toy designed for kids. I tried implementing that with an accelerometer…
Michael Litvin
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What do quadcopter propeller specifications mean?

I'm trying to figure out the diameter of tri-blade propellers. I found a 7x3x4.5 blade, I'm trying to understand the measurements. Is the '7' the length of the blade giving the prop a 10.5" diameter? or is the 7 the total diameter?
August Rife
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3 answers

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 estimation we installed an gyroscope to measure the…
Johnny Mudcrab
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6
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Electronic noses for detecting dog urine

I have very limited experience with sensors or robotic components at all, and I hope you will excuse the lack of detail in this Question. I want to set up posts around my yard with electronic noses that detect dog urine. I want to use this…
user2979713
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How do ultrasonic range finders detect objects at an angle?

As far as I can tell, an ultrasonic rangefinder works by reflecting inaudible soundwaves off of objects and timing their return. But if the object has a flat surface and is angled with respect to the line to the rangefinder, how does it detect that…
Paul
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How much accuracy could I get position tracking with a 3-axis accelerometer and gyro sensor, and compass, and how would I do it?

Given a 12' x 12' field (4m x 4m), a reasonably cheap 3-axis gyro sensor and accelerometer, and compass, I plan to design a device capable of tracking its position to sub-centimeter accuracy for a minute of motion or so. The device has a holonomic…
TheEnvironmentalist
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Kalman Filter and the state noise vector?

I'm reading Probabilistic Robotics by Thrun. In the Kalman filter section, they state that $$ x_{t} =A_{t}x_{t-1} + B_{t}u_{t} + \epsilon_{t} $$ where $\epsilon_{t}$ is the state noise vector. And in $$ z_{t} = C_{t}x_{t} + \delta_{t} $$ where…
CroCo
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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 get a bad value and my pitch is like blocked…
simon
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