Motor drive controlling apparatus, motor drive controlling method, and tube pump

A tube pump, comprising:

• a motor;
• one or more rollers that are rotated by drive of the motor, and press a tube to deliver liquid contained in the tube;
• a motor drive controlling apparatus including:
• a controller that generates and outputs a drive control signal, in response to an input of a speed command signal and a rotational direction signal;
• a motor driver that generates a drive signal and outputs the generated drive signal to a motor, in response to an input of the drive control signal;
• and
• a position detector that detects a rotational position of the motor and outputs a detection signal that is based on a detection result, wherein
• the motor driver provides 120-degree conduction as a conduction method from a start of rotation of the motor to a predetermined rotational speed or provides 180-degree conduction as a conduction method for the predetermined rotational speed or more, and
• the controller has
• a measurement unit that detects a time point when rotation of the motor is switched to a reverse direction of a target rotational direction that is based on the rotational direction signal by an external factor during input of the speed command signal, based on the detection signal, and measures a movement amount in the reverse direction from a rotational position of the motor at a time point of the switching, based on the detection signal, and
• a transmitting unit that transmits, to the motor driver, a switching signal that switches a conduction method for the motor driver from the 180-degree conduction to the 120-degree conduction in a case where the movement amount is a predetermined threshold or more.