Speed detection apparatus of rotational shaft in robot arm
AssigneeDenso Wave Incorporated
InventorKenji Nagamatsu
Life of this patent
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Abstract
An speed detection apparatus of a rotational shaft in a robot arm that is applied to a drive mechanism is provided. The speed detection apparatus includes: first and second rotation sensors that are disposed on a side of a rotational shaft of the robot arm and outputs first and second rotational position signals with a phase difference of 90 degrees; first and second differentiators that differentiate the first and second rotational position signals; and a speed calculator that obtains a rotational speed of the robot arm by calculating a sum of squares of a first differential signal and a second differential signal.
Claims5
A speed detection apparatus of a rotational shaft in a robot arm that is applied to a drive mechanism including a motor, a speed reduction mechanism connected to a rotational shaft of the motor, and a rotational shaft of the robot arm driven via the speed reduction mechanism, the speed detection apparatus comprising:
- a first rotation sensor that is disposed on a side of the rotational shaft of the robot arm and outputs a first rotational position signal;
- a second rotation sensor that is disposed on the side of the rotational shaft of the robot arm and outputs a second rotational position signal with a phase difference of 90 degrees with respect to the first rotational position signal by the first rotation sensor;
- a first differentiator that differentiates the first rotational position signal output from the first rotation sensor;
- a second differentiator that differentiates the second rotational position signal output from the second rotation sensor;
- and
- a speed calculator that obtains a rotational speed of the robot arm by calculating a sum of squares of a first differential signal output from the first differentiator and a second differential signal output from the second differentiator.
A speed detection apparatus of a rotational shaft comprising:
- the rotational shaft of a robot arm that is driven by a motor via a reduction mechanism;
- two rotational sensors that are opposed to the rotational shaft, and respectively output rotational position signals which have a phase difference of 90 degrees;
- and
- a microcomputer that is configured to
- differentiate the rotational position signals received from the two rotational sensors to obtain a first differential signal and a second differential signal;
- square the first differential signal and the second differential signal;
- and
- add a square of the first differential signal and a square of the second differential signal to obtain a square-sum result,
- wherein:
- the microcomputer determines whether a rotational speed of the robot arm exceeds a predetermined speed on a basis of the square-sum result;
- and
- in response to that it is determined that the rotational speed of the robot arm exceeds the predetermined speed, the microcomputer outputs a stop command to another microcomputer.
Dependencies are inferred from the claim text.