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2018-09-13 11:31:37 -0600 commented answer Dynamixel XL430-W250 does not reach goal position

From the e-manual: Moving Threshold: This value helps to determine whether the Dynamixel is in motion or not. When the a

2018-09-13 11:30:47 -0600 commented answer Dynamixel XL430-W250 does not reach goal position

It didn't solve the problem exactly. The disparity in position changed to +- 7 from +-10 even after changing the "Moving

2018-09-12 16:22:53 -0600 commented answer Dynamixel XL430-W250 does not reach goal position

Ah, the AX series has the "CC/CW compliance margin" in the control table, it did not occur to me that the new control ta

2018-09-12 16:17:18 -0600 marked best answer Dynamixel XL430-W250 does not reach goal position

When placed in position control mode and given a goal position, the motor moves towards the goal position but stops before reaching that position (+- 10 positions i.e. +- 0.88 degrees). Example: If i give the goal_position as 1000 , the motor stops at 995 (present_position); goal_position 1450, actual position 1446

I am using ROS dynamixel SDK to control the motors. What can be done to make the motors reach the position exactly?

dynamixel_state:


model_name: XL430-W250
id: 1
torque_enable: 1
goal_current: 0
goal_velocity: 415
goal_position: 1000
present_current: 0
present_velocity: 0
present_position: 995
moving: 0

dynamixel_state:


model_name: XL430-W250
id: 1
torque_enable: 1
goal_current: 0
goal_velocity: 415
goal_position: 1450
present_current: 0
present_velocity: 0
present_position: 1446
moving: 0
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2018-09-11 11:30:26 -0600 asked a question Dynamixel XL430-W250 does not reach goal position

Dynamixel XL430-W250 does not reach goal position When placed in position control mode and given a goal position, the mo

2018-09-04 14:02:08 -0600 asked a question Dynamixel State maximum publishing rate

Dynamixel State maximum publishing rate I have a dynamixel X series servo that can communicate between 57,600 bad and 4,

2018-08-09 10:46:31 -0600 marked best answer Do Dynamixel Servos give position feedback in velocity control mode?

Some of these servos have as high as 4096 positions/revolution accuracy (0.088°). So I think if I command it to go to a particular position, say 100°, the actual position will be between 100.088° and 99.912.

But if the servo is in velocity control mode (continuous rotation) will I be able to get information on the position at some instance in time with the same +/- 0.088°? This is because I have to synchronize the positions with the frames published by a camera.

I would deeply appreciate it if someone with experience with these high-end servos can share their thoughts.

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2018-08-08 14:22:16 -0600 asked a question Do Dynamixel Servos give position feedback in velocity control mode?

Do Dynamixel Servos give position feedback in velocity control mode? Some of these servos have as high as 4096 positions

2018-07-11 11:04:24 -0600 marked best answer Can 3D Lidar localize when placed vertically ?

Currently the Velodyne puck being used on our UAV can localize in an obstacle course room when it is mounted with the base parallel to the ground. But there are more obstacles above and below the robot, so the UAV will be able to see them better if we mounted it such that the base was at 90 degrees to the ground. But when this is done, there is no localization using ethz-asl ICP mapper. As a result no maps are built.

I guess that it is because when mounted vertically the robot is not able to see many of the (older) features it already passed by in the current frame. Is it not possible for scan matching to identify the current position based on the last two frames? Because there is definitely an overlap of features between the current frame and the last 3-5 frames.

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2018-07-10 13:32:18 -0600 asked a question Can 3D Lidar localize when placed vertically ?

Can 3D Lidar localize when placed vertically ? Currently the Velodyne puck being used on our UAV can localize in an obst

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