Abstract: A method for producing a cell culture plate for human organoid generation using 3D printing is proposed. The method includes the steps of: (a) feeding filament-shaped biodegradable polymer materials, which are not toxic to the human body, and a compatibilizer for improving interfacial adhesion between the polymer materials, into a 3D printer; and (b) producing a cell culture plate using the 3D printer. The cell culture plate is produced by feeding biodegradable polymer materials, which is a blended combination of PLA and PCL, and an appropriate compatibilizer, into a 3D printer. The produced cell culture plate is not toxic to the human body, can culture cells in a desired shape, and has excellent biocompatibility so that it can be applied directly in vivo without detaching cells from the plate.

Abstract: A method for producing a cell culture plate for human organoid generation using 3D printing is proposed. The method includes the steps of: (a) feeding filament-shaped biodegradable polymer materials, which are not toxic to the human body, and a compatibilizer for improving interfacial adhesion between the polymer materials, into a 3D printer; and (b) producing a cell culture plate using the 3D printer. The cell culture plate is produced by feeding biodegradable polymer materials, which is a blended combination of PLA and PCL, and an appropriate compatibilizer, into a 3D printer. The produced cell culture plate is not toxic to the human body, can culture cells in a desired shape, and has excellent biocompatibility so that it can be applied directly in vivo without detaching cells from the plate.

Abstract: A system and method for reducing drive motor speed ripple of an electric vehicle are provided. The system includes an inverter that converts DC power supplied from a battery to AC power and supplies the AC power to the drive motor by inverter switching. A resolver is configured to detect a speed of the drive motor and a position of a rotor, a signal generator includes a microcontroller that is configured to generate a square wave signal. An integrator is configured to convert the square wave to a sine wave, and apply a sine-wave excitation input signal to the resolver. Furthermore, a motor controller is configured to operate the inverter through a PWM signal, adjust the frequency of the excitation input signal to prevent the inverter switching frequency of the inverter and the peaks of an output voltage signal sampled for speed calculation from overlapping.

Abstract: A system and method for reducing drive motor speed ripple of an electric vehicle are provided. The system includes an inverter that converts DC power supplied from a battery to AC power and supplies the AC power to the drive motor by inverter switching. A resolver is configured to detect a speed of the drive motor and a position of a rotor, a signal generator includes a microcontroller that is configured to generate a square wave signal. An integrator is configured to convert the square wave to a sine wave, and apply a sine-wave excitation input signal to the resolver. Furthermore, a motor controller is configured to operate the inverter through a PWM signal, adjust the frequency of the excitation input signal to prevent the inverter switching frequency of the inverter and the peaks of an output voltage signal sampled for speed calculation from overlapping.

Abstract: An inverter control method for a hybrid vehicle includes: monitoring a torque command and a motor speed of the vehicle in real-time; determining whether the motor speed is less than a first speed; determining whether an absolute value of the torque command is less than a first torque when the motor speed is less than the first speed; changing a switching frequency to a predetermined frequency when the absolute value of the torque command is less than the first torque; and controlling an inverter operation by generating a pulse-width modulation (PWM) signal with the switching frequency changed to the predetermined frequency.

Abstract: An inverter control method for a hybrid vehicle includes: monitoring a torque command and a motor speed of the vehicle in real-time; determining whether the motor speed is less than a first speed; determining whether an absolute value of the torque command is less than a first torque when the motor speed is less than the first speed; changing a switching frequency to a predetermined frequency when the absolute value of the torque command is less than the first torque; and controlling an inverter operation by generating a pulse-width modulation (PWM) signal with the switching frequency changed to the predetermined frequency.

Abstract: A system and method for reducing drive motor speed ripple of an electric vehicle are provided. The system includes an inverter that converts DC power supplied from a battery to AC power and supplies the AC power to the drive motor by inverter switching. A resolver is configured to detect a speed of the drive motor and a position of a rotor, a signal generator includes a microcontroller that is configured to generate a square wave signal. An integrator is configured to convert the square wave to a sine wave, and apply a sine-wave excitation input signal to the resolver. Furthermore, a motor controller is configured to adjust the frequency of the excitation input signal to prevent the inverter switching frequency of the inverter and the peaks of an output voltage signal sampled for speed calculation from overlapping.

Abstract: A motor control system and method are provided for a vehicle that reduces torque ripples due to motor system characteristics while the vehicle is running at ultra-low speed in an electric vehicle running mode. The system includes a current command generator that generates a current command based on a torque command, a motor speed, and a reference voltage. A current controller generates a voltage command based on the current command. A coordinate transformer transforms the voltage command into a 3-phase voltage command by a coordinate transformation and a PWM (pulse width modulation) signal generator generates a switch signal based on the 3-phase voltage command. A PWM inverter generates a 3-phase driving current to drive a motor based on the switch signal and a current control ripple compensator applies a reverse phase harmonic wave to the current controller to reduce a harmonic wave caused by errors generated from the current controller.

Abstract: A motor control system and method are provided for a vehicle that reduces torque ripples due to motor system characteristics while the vehicle is running at ultra-low speed in an electric vehicle running mode. The system includes a current command generator that generates a current command based on a torque command, a motor speed, and a reference voltage. A current controller generates a voltage command based on the current command. A coordinate transformer transforms the voltage command into a 3-phase voltage command by a coordinate transformation and a PWM (pulse width modulation) signal generator generates a switch signal based on the 3-phase voltage command. A PWM inverter generates a 3-phase driving current to drive a motor based on the switch signal and a current control ripple compensator applies a reverse phase harmonic wave to the current controller to reduce a harmonic wave caused by errors generated from the current controller.