Motor drive control device and motor drive control method

A motor drive control method of driving a motor using a motor drive control device including a motor drive unit having a plurality of switch elements connected to a power supply source and supplying a driving current to a plurality of phase coils of the motor, a control circuit unit outputting, to the motor drive unit, a drive control signal for operating the plurality of switch elements to sequentially switch energization patterns for the plurality of phase coils, and a current detecting circuit detecting a voltage value corresponding to a magnitude of the driving current, the method comprising:

• a first determination step of determining whether a state of overcurrent where a magnitude of the driving current exceeds a predetermined overcurrent threshold occurs based on the voltage value each time an energization pattern is switched;
• repeatedly performing one cycle of switching control for switching the energization patterns of the plurality of phase coils in a predetermined order;
• and
• a second determination step of determining whether driving of the motor is in an abnormal condition based on the number of times the first determination step determines the state of overcurrent while the one cycle of switching control is performed.

A motor drive control device comprising:

• a motor drive unit having a plurality of switch elements connected to a power supply source and supplying a driving current to a plurality of phase coils of a motor;
• a control circuit unit outputting, to the motor drive unit, a drive control signal for operating the plurality of switch elements to sequentially switch energization patterns for the plurality of phase coils;
• and
• a current detecting circuit detecting a voltage value corresponding to a magnitude of the driving current, wherein:
• the control circuit unit includes a first determination unit determining whether a state of overcurrent in which a magnitude of the driving current exceeds a predetermined overcurrent threshold occurs based on the voltage value each time an energization pattern is switched, and a second determination unit determining whether driving of the motor is in an abnormal condition based on a determination result of the first determination unit for a plurality of energization patterns,
• the control circuit unit repeatedly performs one cycle of switching control for switching the energization patterns of the plurality of phase coils in a predetermined order, and
• the second determination unit determines that the driving of the motor is in the abnormal condition when the determination of the state of overcurrent for some energization patterns while one cycle of switching control is performed continuously occurs for a certain period of time.