FIELD: electrical engineering.
SUBSTANCE: invention relates to electrical engineering and can be used in control systems of stepper motors (SM) in discrete electric drives. Technical solution can be used mainly in solving the problem of determining a mechanical stop and installing an electric drive in the initial position with a double-winding stepper motor operating in a full-step mode without loss of synchronism. Method of determining the moment of reaching a mechanical support with an electric drive with a double-winding stepper motor is based on a characteristic change in the signal which is proportional to the sum of the actual values of voltages on the SM windings when the rotor of the SM encounters an obstacle. To determine the mechanical thrust of the electric drive after the control signal arrives at the pitch in the section of free oscillations of the rotor of the stepper motor, the period of pulsations of the sum of the actual values of voltages on windings of the stepper motor of the unloaded electric drive is determined. And when the rotor moves towards the mechanical stop, the value of the period of these pulsations is measured at each current stepper and, when the measured value exceeds the specified threshold value, a signal is generated, which is a sign of achievement of the mechanical stop by the electric drive. Voltage at each output of each winding is measured relative to negative output of driver power supply. To implement the disclosed method, a device is developed. Invention simplifies the process of obtaining and converting information to make a decision on whether to achieve mechanical thrust by the electric drive. This makes it possible to simplify the device that realizes the method of determining the moment when the electric drive reaches mechanical thrust, and reduces hardware and program costs. Increase in noise immunity is achieved due to use of information parameter, which sharply changes its value when the rotor touches the mechanical stop. Expansion of application area is achieved by possibility of its inclusion into spent and operated control system without adjustment of SM driver.
EFFECT: technical result is simplification and expansion of application, reduced hardware and software costs and high noise-immunity.
6 cl, 4 dwg
Authors
Dates
2020-04-21—Published
2019-08-28—Filed