Out-of-phase detectors produce two pulse signals that indicate relative rotation as well as direction for an incremental encoder. Counting edges or monitoring binary values can increase resolution fourfold.
I hope to see more of the Wiegand effect encoders in the near future. It might be a good alternative to optical encoders in a closed loop stepper motor system. Which, by the way, are getting cheap enough for anyone to buy.
In my applications, I often need an axis with a hollow bore, so the position encoder either needs to be hollow. From what I can tell, the Wiegard effect only works when the rotating magnet axis of rotation is centered about the Wiegard wire. I'm sure I've misunderstood the tech in some way and hope that my understanding is wrong.
If my understanding is wrong and the axial rotations do not have to align, then I'd be inclined to merge an optical absolute encoder with a Wiegard sensor for counting rotations. You'd get the resolution of optical with the persistent turn counting of the Wiegard sensor.
Hello, TJ. As far as I can tell, the magnetic field for a Wiegand detector must be very localized, so magnetic interference shouldn't become a problem. Resolvers get used with equipment that uses electric motors, so I bet the manufacturers have added shielding as needed. Worth asking about before you buy a resolver, and worth the time to run some tests in proximity to specific equipment.
Great article - I particularly liked the mention of using hall effect sensors. Makes sense since historically they have been used as rotary position gear tooth sensors such as crank and camshaft sensing in automotive applications. They are usually a lot cheaper than optical encoders too.
According to a study by the National Institute of Standards and Technology, one of the factors in the collapse of the original World Trade Center towers on Sept. 11, 2001, was the reduction in the yield strength of the steel reinforcement as a result of the high temperatures of the fire and the loss of thermal insulation.
Robots are getting more agile and automation systems are becoming more complex. Yet the most impressive development in robotics and automation is increased intelligence. Machines in automation are increasingly able to analyze huge amounts of data. They are often able to see, speak, even imitate patterns of human thinking. Researchers at European Automation
call this deep learning.
The promise of the Internet of Things (IoT) is that devices, gadgets, and appliances we use every day will be able to communicate with one another. This potential is not limited to household items or smartphones, but also things we find in our yard and garden, as evidenced by a recent challenge from the element14 design community.
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