A method a speed controller includes reading in an actual angular acceleration value of a motor, comparing the actual angular acceleration value to a setpoint angular acceleration value, determining a controller output torque of an integrating I-component of the speed controller based on the comparison, and controlling the rotational speed of the motor based on the determined controller output torque.

The invention is related to a drive control for driving a dc motor of an electrical household appliance, in particular a hair cutting device such as an electric razor, shaver or epilator, at constant rotational speed.

A motor speed control circuit including a voltage-dividing module, a first analog-to-digital converter, a second analog-to-digital converter and an operation module. The voltage-dividing module includes a first resistor unit and a second resistor unit. The first analog-to-digital converter receives a supply voltage and converts the supply voltage into a digital supply voltage. The second analog-to-digital converter receives a divided voltage generated by the voltage-dividing module, and converts the divided voltage into a digital divided voltage. The divided voltage is associated with a resistance ratio between the first resistor unit and the second resistor unit. The operation module receives the digital divided voltage and determines a motor speed curve according to the resistance ratio. The operation module generates a first pulse width modulation signal according to the motor speed curve and the digital supply voltage to drive a motor.

Disclosed are a backlash vibration reduction apparatus and method capable of sufficiently performing gear alignment even when torque is increased while a vehicle is driven within a low torque range, thereby minimizing rough vibration due to backlash. The backlash vibration reduction apparatus includes a correction determination unit configured to determine whether it is necessary to correct a torque gradient to be applied for an increase to target torque in the state in which the current torque of a vehicle is retained within a predetermined low torque range and a torque gradient correction unit configured to determine a corrected torque gradient in which a torque increase rate per hour is reduced and a torque increase time period is extended by multiplying a correction factor by a first torque gradient as a torque gradient that increases the current torque upon determining that it is necessary to correct the torque gradient.

By providing a configuration for calculating motor control constants to be set in a motor control apparatus automatically on the basis of a target response time constant obtained from a target response time constant input unit, waveform parameters obtained from a waveform parameter input unit, a normalized time constant obtained from a normalized time constant calculation unit, and a motor load inertia obtained from a motor load inertia input unit, it is possible to obtain a motor control constant calculation device that can determine appropriate motor control constants for obtaining a desired response characteristic by automatic calculation while avoiding variation and an increase in the number of steps due to differences in the abilities of users.

By providing a configuration for calculating motor control constants to be set in a motor control apparatus automatically on the basis of a target response time constant obtained from a target response time constant input unit, waveform parameters obtained from a waveform parameter input unit, a normalized time constant obtained from a normalized time constant calculation unit, and a motor load inertia obtained from a motor load inertia input unit, it is possible to obtain a motor control constant calculation device that can determine appropriate motor control constants for obtaining a desired response characteristic by automatic calculation while avoiding variation and an increase in the number of steps due to differences in the abilities of users.

A method of controlling a rotational speed of a motor of an electric bed includes the following steps. (A) Use a sensor to detect rotation of the motor, set a predetermined rotational speed of the motor in a microcontroller, and use the microcontroller to calculate actual rotational speeds of the motor. (B) Use the microcontroller to calculate an average actual rotational speed of the motor at each of sampling time points in a predetermined period. (C) Use the microcontroller to compare the average actual rotational speed of the motor with the predetermined rotational speed to obtain a difference signal. (D) Input the difference signal to a driver circuit to adjust the rotational speed of the motor until the average actual rotational speed of the motor is equal to the predetermined rotational speed. In this way, the motor of the electric bed can approximately rotate in the predetermined rotational speed.

A motor speed control circuit including a voltage-dividing module, a first analog-to-digital converter, a second analog-to-digital converter and an operation module. The voltage-dividing module includes a first resistor unit and a second resistor unit. The first analog-to-digital converter receives a supply voltage and converts the supply voltage into a digital supply voltage. The second analog-to-digital converter receives a divided voltage generated by the voltage-dividing module, and converts the divided voltage into a digital divided voltage. The divided voltage is associated with a resistance ratio between the first resistor unit and the second resistor unit. The operation module receives the digital divided voltage and determines a motor speed curve according to the resistance ratio. The operation module generates a first pulse width modulation signal according to the motor speed curve and the digital supply voltage to drive a motor.

A notch finding apparatus includes a sensor to generate a signal that depends on an proportion of a sensing region of the sensor that is covered by a substrate, and a controller configured to cause an actuator to position a carrier head relative to the substrate with the sensing region of the sensor at an edge of the substrate, cause a motor to generate relative motion between the carrier head and the sensor such that the sensing region of the sensor scans along a circumference of the substrate, and detect an angular position of a notch in the edge of the substrate based on an initial signal from the sensor, including generating a second or higher order derivative signal from the initial signal.