Japan Servo Co.,ltd.

Akio Takemori

Yoshifumi Kuwano

Hiroaki Taka

Yukinari Takahashi

Atsuo Kawamura

Yasuo Matsuda

Yoshihiro Okumatsu

Yoshitaka Iwaji

A stepping motor controlling device according to the present invention includes lead angle computing means which computes a lead angle according to the load torque current deviation of the stepping motor, adding means which adds an angle command to the lead angle to determine a winding exciting angle and voltage applying means which applies a voltage according to the winding exciting angle to the stepping motor.

Stepping motor controlling device

A stepping motor control system according to the present invention includes a counting mechanism for counting the number of steps of the pulse train command, a latch mechanism for holding a counting value of the counting mechanism with a latch signal and finding a position command, a reference signal generating mechanism for generating the latch signal and a reference clock signal, a first calculating mechanism for calculating a pulse spacing of the pulse train command with the reference clock signal, and a second calculating mechanism for calculating a time interval from generation of the pulse train command to generation of the latch signal with the reference clock signal. In the stepping motor control system, the position command is corrected using command pulse spacing information calculated by the first calculating mechanism and time difference information calculated by the second calculating mechanism.

Motor control system

Disclosed is a driving device for a motor such as a stepping motor etc. for controlling an angle and a speed of the motor, wherein the driving device comprises exciting current detectors for detecting exciting currents of motor windings of the motor, an exciting current amplitude computation means for computing an exciting current amplitude value or the square of the exciting current amplitude value from exciting current detection values detected by the exciting current detectors, and a voltage impression unit for impressing voltages at values corresponding to a deviation value of the exciting current amplitude value and the current amplitude command or a deviation value of the square of the exciting current amplitude value and the square of the current amplitude command to the motor windings.

Motor driving device

A stepping motor control apparatus in accordance with the present invention comprises: a current detection unit that detects phase currents flowing into a stepping motor; an equivalent model-of-motor arithmetic unit that includes a coefficient multiplication block which performs multiplication using a coefficient ka'=Ts/&#x3c4; as a multiplier, a coefficient multiplication block which performs multiplication using a coefficient kb&#x2032;=&#x3c4;/(Ts+&#x3c4;) as a multiplier, and a coefficient multiplication block which performs multiplication using a coefficient kg&#x2032;=I/Eas a multiplier, and that calculates an estimated angle of excitation; a current control unit that controls an exciting current on the basis of the estimated angle of excitation, an angle command, and the phase currents detected by the current detection unit; and a variable voltage inverter that applies phase voltages to phase windings included in the stepping motor according to outputs of the current control unit.

Stepping motor control apparatus

A stepping motor driver according to the present invention includes a torque component current calculating means for calculating a torque component current from phase currents and a rotor rotation angle, an absolute value converting means for obtaining an absolute value of the torque component current, a high speed-response judging means adapted for outputting a first control signal when a speed deviation between a command speed and a rotor speed is not more than a reference level, and outputting a second control signal when the speed deviation exceeds the reference level, and a current command outputting means adapted for outputting a current command according to the absolute value of the torque component current when the first control signal is outputted, and outputting a maximum current command value as the current command when the second control signal is outputted.

Stepping motor driver

A stepping motor driver comprises: an excitation angle generating means which generates an excitation angle from an external command pulse; a current control means which controls exciting currents for a stepping motor according to the excitation angle and a current command; a current detection means which detects phase currents of the stepping motor; an angle detection means which detects a rotor rotation angle of the stepping motor; a torque component current calculating means which calculates a torque component current from the phase currents and the rotor rotation angle; an absolute converting means which obtains the absolute value of the torque component current; and a current command output means which outputs the current command depending on the absolute value of the torque component current.

A stepping motor driver which drives a stepping motor for position and speed control. The stepping motor driver comprises: a current control means which outputs values corresponding to applied voltages; current sensors which detect phase currents; and a magnetic pole position estimation unit which uses the values corresponding to applied voltages and detected phase current values as outputs of the current sensors to obtain a magnetic pole position estimate. The magnetic pole position estimation unit calculates a magnetic pole position estimate from speed electromotive force estimates or from differences between phase currents at zero speed and detected phase current values.

The stepping motor driver comprises an angle computing element that receives rotor position detection signals from an encoder and calculates a detected angle representing the rotational angle of the rotor, and a lead angle controller that generates a corrected command angle based on the difference between a command angle given from outside and the detected angle. The lead angle controller calculates an angle deviation that is the difference between the command angle and the detected angle, compares the angle deviation with a predetermined value, outputs the command angle as the corrected command angle if the angle deviation is less than the predetermined value, and outputs a value obtained by adding an approximated lead angle to the detected angle as the corrected command angle if the angle deviation is greater than, or equal to, the predetermined value, and the phase of voltage applied to the motor is controlled according to the corrected command angle.

The stepping motor driver comprises an inverter for feeding stepped currents to windings of a stepping motor, a position detector for obtaining a detected angle of a rotor of the stepping motor and a current controller for controlling the inverter. In a d-q rotational coordinate system in which the d-axis is in the direction of the magnetic flux of the rotor and the q-axis is in the direction perpendicular to the d-axis, an excitation angle for a winding is determined from a d-axis component and a q-axis component of a command current to the winding, a lead angle control signal is computed from the excitation angle, and a phase of an applied voltage to the stepping motor is controlled using the lead angle control signal.

The controller comprises current sensors for detecting motor currents, an inverter containing a current control means for feeding currents to motor windings, a coordinate transformer that transforms the motor currents in a fixed coordinates system into currents in a first rotational coordinates system, and an angle calculator that transforms a command pulse into a command angle. A second rotational coordinates system composed of a dp axis and a qp axis perpendicular to the dp axis is determined from the command angle. A command current on the dp axis is set to be a value corresponding to a motor current amplitude and another command current on the qp axis is set to be zero. The motor current is projected on the dp and qp axes and controlled so as to make the components on the dp and qp axes coincide with the respective command currents on the dp and qp axes.

Stepping motor controller

A stepping motor driver having current sensors that detect winding current values, an angle detection device that detects a rotational angle of a rotor, a first coordinate transformation device that transforms winding current values in a rotational coordinate system, an angle calculation device that calculates a command angle value. A third coordinate transformation device transforms the command current values in the rotational coordinate system according to the difference between the command angle value and the rotor angle value, a current control device that generates current control signals in the rotational coordinate system based on the differences between the command current values in the rotational coordinate system and the winding current values in the rotational coordinate system. A second coordinate transformation device transforms the current control signals in the rotational coordinate system into current control signals in a fixed coordinate system, and a current supply device that supplies currents to windings of the stepping motor.

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Kiryu, Japan

Akio Takemori