Method and apparatus for controlling a stepping motor, and a recording medium storing a program for carrying out the method

A stepping motor drive control method for an air-conditioning door in a vehicle air conditioning system, for controlling at least one stepping motor to which a drive pulse corresponding to a desired air conditioning state is supplied from a control unit of the vehicle air conditioning system to rotate the air-conditioning door , the method comprising:

• judging a power supply voltage level every time the stepping motor is driven while a power supply voltage is supplied to the stepping motor, to obtain a judging result;
• deciding a tentative value of deviation as an index indicating an extent of deviation in a rotational position of the air-conditioning door according to the judging result every time the judging result is obtained, the tentative value of deviation being predetermined according to a fluctuation in the power supply voltage based on a degree of deviation in the rotational position of the air-conditioning door, which is caused by the fluctuation in the power supply voltage supplied to the stepping motor;
• accumulating the tentative value of deviation every time the tentative value of deviation is decided, to then set an accumulated value as an estimated value of deviation;
• storing the estimated value of deviation when supply of the power supply voltage to the control unit is shut off;
• deciding whether the stored estimated value of deviation exceeds a predetermined value, immediately after the power supply voltage is supplied to the control unit again;
• and
• supplying a predetermined drive pulse to the stepping motor to rotate the air-conditioning door into an initial standard position if it is decided that the estimated value of deviation exceeds the predetermined value.

A stepping motor drive control method for an air-conditioning door in a vehicle air conditioning system, for controlling at least one stepping motor to which a drive pulse corresponding to a desired air conditioning state is supplied from a control unit of the vehicle air conditioning system to rotate the air-conditioning door, the method comprising:

• judging a power supply voltage level every time the stepping motor is started by receiving supply of a drive pulse from the control unit, to obtain a judging result;
• counting a number of the drive pulses supplied from the control unit to the stepping motor every time the judging result is obtained, and then substituting a counted value into a first counting value if the power supply voltage is within a first predetermined range, or substituting the counted value into a second counting value if the power supply voltage is within a second predetermined range, or substituting the counted value into a third counting value if the power supply voltage is within a third predetermined range;
• calculating a sum of a multiplied value of the first counting value and a first predetermined coefficient, a multiplied value of the second counting value and a second predetermined coefficient and a multiplied value of the third counting value and a third predetermined coefficient, and then setting the sum as a predictive deviation value indicating a possible step error of the stepping motor;
• judging whether the predictive deviation value exceeds a predetermined value;
• and
• supplying a predetermined drive pulse to the stepping motor to rotate the air-conditioning door into an initial standard position if the predictive deviation value exceeds the predetermined value;
• wherein the first, second and third predetermined coefficients are previously determined values which correspond to the possible step error in the stepping motor according to a magnitude of the power supply voltage supplied to the stepping motor.

A stepping motor control system for controlling a stepping motor which is used to rotate an air-conditioning door in a vehicle air conditioning system, the stepping motor control system comprising:

• a control unit for supplying a drive pulse corresponding to a desired air-conditioning state to the stepping motor;
• a judging means for judging a power supply voltage level if the stepping motor is driven, to obtain a judging result;
• a decision means for deciding a tentative value of deviation as an index indicating an extent of deviation in a rotational position of the air-conditioning door, according to the judging result;
• an accumulating means for accumulating the tentative value of deviation every time the tentative value of deviation is decided, to then set an accumulated value as an estimated value of deviation;
• and
• supplying means for supplying a predetermined drive pulse to the stepping motor to rotate the air-conditioning door into an initial standard position if the estimated value of deviation is more than a predetermined value;
• wherein the tentative value of deviation is predetermined according to a fluctuation in the power supply voltage, based on a degree of deviation in the rotational position of the air-conditioning door, which is caused by the fluctuation in the power supply voltage supplied to the stepping motor.

A stepping motor control system for controlling a stepping motor which is used to rotate an air-conditioning door in a vehicle air conditioning system, the stepping motor control system comprising:

• a control unit including a memory device, and a power supply which can supply a power supply voltage to the memory device after the power supply for the control unit is shut off, and the control unit is for supplying a drive pulse to the stepping motor, corresponding to a desired air-conditioning state;
• a judging means for judging a power supply voltage level every time the stepping motor is driven while the power supply voltage is supplied to the stepping motor, to obtain a judging result;
• a decision means for deciding a tentative value of deviation as an index indicating an extent of deviation in a rotational position of the air-conditioning door according to the judging result every time the judging result is obtained, the tentative value of deviation being predetermined according to a fluctuation in the power supply voltage based on a degree of deviation in the rotational position of the air-conditioning door which is caused by the fluctuation in the power supply voltage supplied to the stepping motor;
• an accumulating means for accumulating the tentative value of deviation every time the tentative value of deviation is decided, to then set an accumulated value as an estimated value of deviation;
• the memory device for storing the estimated value of deviation when supply of the power supply voltage to the control unit is shut off;
• a decision means for deciding whether the stored estimated value of deviation exceeds a predetermined value, immediately after the power supply voltage is supplied to the control unit again;
• and
• a supplying means for supplying a predetermined drive pulse to the stepping motor to rotate the air-conditioning door into an initial standard position if it is decided that the estimated value of deviation exceeds the predetermined value.

A stepping motor control system for controlling stepping motor which is used to rotate an air-conditioning door in a vehicle air conditioning system, the stepping motor control system comprising:

• a control unit including a memory device, and a power supply which can supply a power supply voltage to the memory device aft e r the power supply for the control unit is shut off, and the control unit is for supplying a drive pulse to the stepping motor, corresponding to a desired air-conditioning state;
• a judging means for a power supply voltage level every time the stepping motor is started by receiving supply of a drive pulse from the control unit, to obtain a judging result;
• a counting means for counting a number of the drive pulses supplied from the control unit to the stepping motor every time the judging result is obtained, and then substituting a counted value into a first counting value the power supply voltage is within a first predetermined range, or substituting the counted value into a second counting value if the power supply voltage is within a second predetermined range, or substituting the counted value into a third counting value if the power supply voltage is within a third predetermined range;
• a calculating means for calculating a sum of a multiplied value of the first predetermined coefficient, a multiple value of the second counting value and a second predetermined coefficient and a multiplied value of the third counting value and a third predetermined coefficient, and then setting the sum as a predictive deviation value indicating a possible step error of the stepping motor;
• a predictive deviation value judging means for judging whether the predictive deviation value exceeds a predetermined value;
• and
• a supplying means for supplying a predetermined drive pulse to the stepping motor to rotate the air-conditioning door into an initial standard position if it is decided that the predictive deviation value exceeds the predetermined value;
• wherein the first, second and third predetermined coefficients are previously determined values which correspond to the possible step error in the stepping motor according to a magnitude of the power supply voltage supplied to the stepping motor.

A computer-readable medium having a computer-readable executable stepping motor drive control program for an air-conditioning door in a vehicle air conditioning system, stored thereon, for controlling at least one stepping motor to which a drive pulse corresponding to a desired air conditioning state is supplied from a control unit of the vehicle air conditioning system to rotate the air-conditioning door, the program including:

• a step of judging a power supply voltage level if the stepping motor is driven, to obtain a judging result;
• a step of deciding a tentative value of deviation as an index indicating an extent of deviation in a rotational position of the air-conditioning door, according to the judging result;
• a step of accumulating the tentative value of deviation every time the tentative value of deviation is decided, to then set an accumulated value as an estimated value of deviation;
• and
• a step of supplying a predetermined drive pulse to the stepping motor to rotate the air-conditioning door into an initial standard position if the estimated value of deviation is greater than a predetermined value;
• wherein the tentative value of deviation is predetermined according to a fluctuation in the power supply voltage, based on a degree of deviation in the rotational position of the air-conditioning door, which is caused by the fluctuation in the power supply voltage supplied to the stepping motor.

A computer-readable medium having a computer-readable executable stepping motor drive control program for an air-conditioning door in a vehicle air conditioning system, stored thereon, for controlling at least one stepping motor to which a drive pulse corresponding to a desired air conditioning state is supplied from a control unit of the vehicle air conditioning system to rotate the air-conditioning door, the program including:

• a step of judging a power supply voltage level every time the stepping motor is driven while a power supply voltage is supplied to the stepping motor, to obtain a judging result;
• a step of deciding a tentative value of deviation as an index indicating an extent of deviation in a rotational position of the air-conditioning door according to the judging result every time the judging result is obtained, the tentative value of deviation being predetermined according to a fluctuation in the power supply voltage based on a degree of deviation in the rotational position of the air-conditioning door, which is caused by the fluctuation in the power supply voltage supplied to the stepping motor;
• a step of accumulating the tentative value of deviation every time the tentative value of deviation is decided, to then set an accumulated value as an estimated value of deviation;
• a step of storing the estimated value of deviation when supply of the power supply voltage to the control unit is shut off;
• a step of deciding whether the stored estimated value of deviation exceeds a predetermined value, immediately after the power supply voltage is supplied to the control unit again;
• and
• a step of supplying a predetermined drive pulse to the stepping motor to rotate the air-conditioning door into an initial standard position if it is decided that the estimated value of deviation exceeds the predetermined value.

A computer-readable medium having a computer-readable executable stepping motor drive control program for an air-conditioning door in a vehicle air conditioning system, stored thereon, for controlling at least one stepping motor to which a drive pulse corresponding to a desired air conditioning state is supplied from a control unit of the vehicle air conditioning system to rotate the air-conditioning door, the program including:

• a step of judging a power supply voltage level every time the stepping motor is started by receiving supply of a drive pulse from the control unit, to obtain a judging result;
• counting a number of the drive pulses supplied from the control unit to the stepping motor every time the judging result is obtained, and then substituting a counted value into a first counting value if the power supply voltage is within a first predetermined range, or substituting the counted value into a second counting value if the power supply voltage is within a second predetermined range, or substituting the counted value into a third counting value if the power supply voltage is within a third predetermined range;
• a step of calculating a sum of a multiplied value of the first counting value and a first predetermined coefficient, a multiplied value of the second counting value and a second predetermined coefficient and a multiplied value of the third counting value and a third predetermined coefficient, and then setting the sum as a predictive deviation value indicating a possible step error of the stepping motor;
• a step of judging whether the predictive deviation value exceeds a predetermined value;
• and
• a step of supplying a predetermined drive pulse to the stepping motor to rotate the air-conditioning door into an initial standard position if the predictive deviation value exceeds the predetermined value;
• wherein the first, second and third predetermined coefficients are previously determined values which correspond to the possible step error in the stepping motor according to a magnitude of the power supply voltage supplied to the stepping motor.