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Without measuring friction coefficients and weights and such, there is no way to compute a number. But you asked instead about a formula. The operating torque will be the sum of static friction (getting it unstuck so it will start moving) rolling/sliding friction (joints and bearings) accelerating the moment of inertia overcoming whatever externally might ...


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You're computing the spatial Jacobian, which relates joint velocities to spatial velocities at the origin. You instead want to compute the body Jacobian, which relates joint velocities to end-effector velocities expressed in the end-effector frame. So in your 2D RR example what you want to do is to compute the body Jacobian then pre-multiply the matrix by $...


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After a bit more reading and thinking, I think I’ll answer my own question. I’d like feedback on my logic if you have it. My logic is this: the PWM signal from the MCU is clean (evidenced by the trace when the servo is unpowered) the noise is back EMF from the servo no other device other than the servo needs to receive or read the signal if the signal was ...


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When you think about the mechanism the gears are offset, but the joint itself has an axis. You should use that axis which may not be overlapping/coincident with the link attached to the bevel gear. I found a few tutorials that you may find useful: https://blog.robotiq.com/how-to-calculate-a-robots-forward-kinematics-in-5-easy-steps https://automaticaddison....


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I can add one more point to RowanP's excellent list: the servo's PID is unreliable, not because of a defect, but because it is mistuned for your application. Recall that tuning a PID control is arcane, if not entirely a black art. The servo manufacturer tuned the control PID coefficients for some use case, perhaps moving RC aircraft control surfaces. That ...


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I had a few ideas about what might cause the jitter action you showed in the video. I suggest you'll need to be more specific in the information provided to enable more specific answers. Idea 1 - Movement Boundaries Conflict Is the joint trying to move past a physical boundary? When constructing your robot arm for the first time, the servos need to be in a ...


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You use Forward Kinematics to calculate the end-effector pose of your robot/platform, given the joint angles. There are many different methods to calculate the Forward Kinematics, I remember using the Product of Exponentials method, which works well if you have a good visual model/description of your platform. You may use Geometric Methods and functions (...


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Yes, measuring motor current will give you a rough indication of torque. However, there are some caveats. Any gear train that you have between the load and motor will decrease the usefulness of current measurement. Some gear trains are better about this than others. I'm not 100% sure, but I think this is directly related to its backdrivability. At the ...


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The Panda robot uses a different convention than Spong's convention, which is what most students in American institutes learn DH from. DH, however, is just a convention, not a rule, so there are many ways DH can be interpreted. In this case, Peter is probably referring to Spong when referring to "standard" convention. Spong uses this 4x4 matrix ...


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