Corrective control system and method for liquid pressure control apparatus in automatic transmission

A corrective control system for a liquid pressure control apparatus of a control valve unit, comprising:

• a liquid pressure controlling section that controls an output liquid pressure of the control valve unit on the basis of a current value which is an electrical signal generated in accordance with an output pressure demand value P* determined according to a calculation process executed within a control unit;
• an output liquid pressure actually measuring section that outputs respectively separated current values to a solenoid drive circuit of the control valve unit and actually measures the output liquid pressure values for the outputted respective current values;
• an output pressure theoretical value calculating section that calculates an output liquid pressure theoretical value for each of the current values outputted by the actually measuring section by referring to preset fundamental maps, each fundamental map representing a relationship between the current value and the output liquid pressure theoretical value;
• a corrective term calculating section that approximates a relationship between the output liquid pressure actually measured value and the output liquid pressure theoretical value for each of the same current values to a first-order function and calculates a coefficient of the approximated first-order function and a constant thereof;
• a storing section that stores the calculated coefficient and constant therein;
• and
• a correcting section that corrects the electrical signal which accords with the output liquid pressure demand value on the basis of the coefficient and constant stored in the storing section;
• a fundamental map presetting section that presets and stores the fundamental maps therein on the basis of a hysterisis characteristic that each individual control valve unit has, the hysterisis characteristic being exhibited in such a manner that the output liquid pressure actually measured value which follows along a first hysteresis loop when the current value is increased toward a larger value is different from that which follows along a second hysterisis loop when the current value is, in turn, decreased toward a smaller value from the larger value;
• a linear point setting section that calculates the current average values between the current values in the first hysteresis loop and those in the second hysterisis loop which respectively correspond to present plurality of the output pressure actually measured values and sets linear points determined from the output liquid pressure actually measured values and the current average values, from the hysterisis characteristic;
• a linearity characteristic deriving section that derives a first-order function passing through the set two or more linear points;
• and
• a virtual point setting section that calculates a virtual current value by substituting a preset virtual output liquid pressure equal to or below zero into the first-order function derived by the linearity characteristic deriving section and sets a virtual point determined from the virtual output liquid pressure and virtual current value, wherein, at a higher output liquid pressure region including the linear characteristic region of the hysteresis characteristic, each point is set by the point setting section and, at a lower output liquid pressure region than the linear characteristic region of the hysterisis characteristic, the point is set by the virtual point setting section, and wherein the fundamental map presetting section presets the fundamental maps, each fundamental map being a map representing that a relationship that mutually adjacent points are approximated by a straight line.

A corrective control method for a liquid pressure control apparatus of a control valve unit, comprising:

• controlling an output liquid pressure of the control valve unit on the basis of a current value which is an electrical signal generated in accordance with an output pressure demand value P* determined according to a calculation process executed within a control unit;
• outputting respectively separated current values to a solenoid drive circuit of the control valve unit;
• actually measuring the output liquid pressure values for the outputted respective current values;
• calculating an output liquid pressure theoretical value for each of the outputted current values by referring to preset fundamental maps, each fundamental map representing a relationship between the current value and the output liquid pressure theoretical value;
• approximating a relationship between the output liquid pressure actually measured value and the output liquid pressure theoretical value for each of the same current values to a first-order function;
• calculating a coefficient of the approximated first-order function and a constant thereof;
• storing the calculated coefficient and constant therein;
• and
• correcting the electrical signal which accords with the output liquid pressure demand value on the basis of the stored coefficient and constant;
• presetting the fundamental maps on the basis of a hysterisis characteristic that each individual control valve unit has, the hysteresis characteristic being exhibited in such a manner that the output liquid pressure actually measured value which follows along a first hysterisis loop when the current value is increased toward a larger value is different from that which follows along a second hysterisis loop when the current value is, in turn, decreased toward a smaller value from the larger value;
• calculating the current average values between the current values in the first hysteresis loop and those in the second hysteresis loop which correspond to at least two output liquid pressure actually measured values;
• setting linear points determined from the output liquid pressure actually measured value and the current average value which corresponds to the two output liquid pressure actually measured values in a linear region of the hysteresis characteristic;
• and
• deriving a first-order function that passes through the set two linear points, and wherein the fundamental maps are preset using the relationship between the output liquid pressure actually measured value and the current average value and using the relationship on the derived first-order function at a lower output pressure side than the linear region.

A corrective control method for a liquid pressure control apparatus of a control valve unit, comprising:

• controlling an output liquid pressure of the control valve unit on the basis of a current value which is an electrical signal generated in accordance with an output pressure demand value P* determined according to a calculation process executed within a control unit;
• outputting respectively separated current values to a solenoid drive circuit of the control valve unit;
• actually measuring the output liquid pressure values for the outputted respective current values;
• calculating an output liquid pressure theoretical value for each of the outputted current values by referring to preset fundamental maps, each fundamental map representing a relationship between the current value and the output liquid pressure theoretical value;
• approximating a relationship between the output liquid pressure actually measured value and the output liquid pressure theoretical value for each of the same current values to a first-order function;
• calculating a coefficient of the approximated first-order function and a constant thereof;
• storing the calculated coefficient and constant therein;
• and
• correcting the electrical signal which accords with the output liquid pressure demand value on the basis of the stored coefficient and constant;
• presetting and storing the fundamental maps therein on the basis of a hysterisis characteristic that each individual control valve unit has, the hysterisis characteristic being exhibited in such a manner that the output liquid pressure actually measured value which follows along a first hysterisis loop when the current value is increased toward a larger value is different from that which follows along a second hysterisis loop when the current value is, in turn, decreased toward a smaller value from the larger value;
• calculating the current average values between the current values in the first hysterisis loop and those in the second hysterisis loop which respectively correspond to present plurality of the output pressure actually measured values and sets linear points determined from the output liquid pressure actually measured values and the current average values, from the hysterisis characteristic;
• deriving a first-order function passing through the set two or more linear points;
• and
• calculating a virtual current value by substituting a preset virtual output liquid pressure equal to or below zero into the derived first-order function;
• and
• seting a virtual point determined from the virtual output liquid pressure and virtual current value, and wherein, at a higher output liquid pressure region including the linear characteristic region of the hysteresis characteristic, each point is set at the point setting and, at a lower output liquid pressure region than the linear characteristic region of the hysteresis characteristic, the point is set at the virtual point setting, and wherein the fundamental map presetting section presets the fundamental maps, each fundamental map being a map representing that a relationship that mutually adjacent points are approximated by a straight line.

A corrective control system for a liquid pressure control apparatus of a control valve unit, comprising:

• liquid pressure controlling means for controlling an output liquid pressure of the control valve unit on the basis of a current value which is an electrical signal generated in accordance with an output pressure demand value P* determined according to a calculation process executed within a control unit;
• output liquid pressure actually measuring means for outputting respectively separated current values to a solenoid drive circuit of the control valve unit and for actually measuring the output liquid pressure values for the outputted respective current values;
• output pressure theoretical value calculating means for calculating an output liquid pressure theoretical value for each of the current values outputted by the actually measuring section by referring to preset fundamental maps, each fundamental map representing a relationship between the current value and the output liquid pressure theoretical value;
• corrective term calculating means for approximating a relationship between the output liquid pressure actually measured value and the output liquid pressure theoretical value for each of the same current values to a first-order function and for calculating a coefficient of the approximated first-order function and a constant thereof;
• storing means for storing the calculated coefficient and constant therein;
• and
• correcting means for correcting the electrical signal which accords with the output liquid pressure demand value on the basis of the coefficient and constant stored in the storing means;
• fundamental map presetting means for presetting the fundamental maps on the basis of a hysterisis characteristic that each individual control valve unit has, the hysterisis characteristic being exhibited in such a manner that the output liquid pressure actually measured value which follows along a first hysterisis loop when the current value is increased toward a larger value is different from that which follows along a second hysteresis loop when the current value is, in turn, decreased toward a smaller value from the larger value;
• linear point setting means for calculating the current average values between the current values in the first hysteresis loop and those in the second hysteresis loop which correspond to at least two output liquid pressure actually measured values and for setting linear points determined from the output liquid pressure actually measured value and the current average value which corresponds to the two output liquid pressure actually measured values in a linear region of the hysteresis characteristic;
• and
• linearity characteristic deriving means for deriving a first-order function that passes through the set two linear points, and wherein the fundamental map presetting means presets the fundamental maps using the relationship between the output liquid pressure actually measured value and the current average value and using the relationship on the derived first-order function at a lower output pressure side than the linear region.