US 5,915,861 A · Method and apparatus for driving a stepping motor using digital pulse trains simulating sine and cosine waves

Abstract

The method for driving a stepping motor for printers comprises the generation of first pulses (16A,16B) at n levels recorded in registers and representing a simulation of sinusoidal waves. The maximum level is applied during two consecutive microsteps to one of the phases of the motor, while the level of the other phase changes sign. During a motor stopping command, second pulses (VCA,VCB) are applied to the registers and to the two phases of the motor and are programmed so as to ensure, during the last microstep, an exact stopping position, such that all the stopping positions are kept apart by a whole number of half steps. Very precise, fast and noise-free printing is thus attained. The resolution is doubled, without any loss of precision or speed.

Claims12

Dependent claims

A method for driving a stepping motor for printers comprising the phases of:

defining an even number n of microsteps to be generated within a quarter of a full step;
storing n sine values, each corresponding to one microstep of said even number n of microsteps;
generating a digital pulse train made up of n first A-pulses having amplitudes proportional to said n sine values, in such an order to simulate a sine wave, said n first A-pulses being applied to a phase A of the stepping motor;
generating a digital pulse train made up of n first B-pulses having amplitudes proportional to said n sine values, in such an order to simulate a cosine wave, said n first B-pulses being applied to a phase B of the stepping motor;
and
sending second pulses during at least the last displacement of the stepping motor prior to a stopping command, said second pulses having a value calculated on the basis of said n sine values and motor parameters, whereby the stopping positions of the stepping motor are separated from each other by a whole number of microsteps.

3 more elements

Apparatus for driving a stepping motor comprising an electronic control unit having

first memory means for storing n sine values, n being an even whole number;
second memory means for storing second pulses values;
driving means, connected to said first memory means and to said second memory means, for supplying on their outputs a first sequence of sine values in a first order to simulate a sine wave, hence generating n first A-pulses, and a second sequence of sine values in a second order to simulate a cosine wave, hence generating n first B-pulses, and for further supplying on their outputs said second pulses values during at least the last displacement of the stepping motor prior to a stopping command, whereby the stopping positions of the stepping motor are separated from each other by a whole number of microsteps.

Dependencies are inferred from the claim text.

Method and apparatus for driving a stepping motor using digital pulse trains simulating sine and cosine waves

Life of this patent

Method and apparatus for driving a stepping motor using digital pulse trains simulating sine and cosine waves

Life of this patent

Abstract

Claims12