Motor timing and timing curves
#46
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this tech we use has been around for a long time. the math and techniques to commutate and control brushless motor timing with a microprocessor has been around 20 or 30 years. methods for determining startup direction have been around for a long time as well. you can saturate the coils at 0 speed to determine direction and even calculate low speed neutral plane position or you can rotate the motor a couple degrees after a power cycle. not to mention you can store rotor position sensor data in memory. There are 4 or 5 different methods for calculating the neutral plane including the skew that occurs at higher speed. its all far less complicated than the code created to have an alarm clock work on your phone. auto motor timing is fairly easy and straight forward. you can also compensate on the fly by actually measuring the skew while in use. as the timing skews so does the acceleration from one coil to the next. overall rpm and acceleration from coil to coil can be compared to an expectation model and if the microprocessor doesnt get the acceleration expected it adds or removes timing.
control of cogging in our motors can be a little more complicated but there are lots of methods. cogging is caused by a dramatic push and pull between the magnet and the coil. most methods to minimize cogging comes from tapering current in and out of the coil so the jump from the current magnet to the next magnet is more gradual. the electrical wave form for our motors is very square. trapezoidal to be specific. you can simulate a sin wave better than we do now and that would help. you can also angle the magnets so that the transition from one magnet to the next is angled so physically control the transition from north to south more gradually.
an esc mfg can actually use the microprocessor to automatically control timing and keep you from burning up your motor. you have sensors in the motor and its very easy to predict how much heat is in a motor from an acute and chronic perspective. But I would be happy with just auto timing.
control of cogging in our motors can be a little more complicated but there are lots of methods. cogging is caused by a dramatic push and pull between the magnet and the coil. most methods to minimize cogging comes from tapering current in and out of the coil so the jump from the current magnet to the next magnet is more gradual. the electrical wave form for our motors is very square. trapezoidal to be specific. you can simulate a sin wave better than we do now and that would help. you can also angle the magnets so that the transition from one magnet to the next is angled so physically control the transition from north to south more gradually.
an esc mfg can actually use the microprocessor to automatically control timing and keep you from burning up your motor. you have sensors in the motor and its very easy to predict how much heat is in a motor from an acute and chronic perspective. But I would be happy with just auto timing.