| 摘要 |
PROBLEM TO BE SOLVED: To provide a power steering device capable of estimating the temperature of each part within the device with high accuracy and surely preventing damage of the parts by overheat. SOLUTION: A temperature tendency judging part 1820 acquires a motor current value Is by a prescribed period and judges the state of a temperature change based on a change of the motor current value Is. As a result, when the temperature is judged to be rising, the temperature is estimated by a temperature rising time arithmetic part 1826, and when the temperature is judged to be lowering, the temperature is estimated by a temperature lowering time arithmetic part 1828. When the state of the temperature change is changed, the latest calculation result for calculating an estimated temperature is delivered from the temperature rising time arithmetic part 1826 to the temperature lowering time arithmetic part 1828 or vice versa. Based on the calculated estimated temperature, a current upper limit value output part 186 determines an upper limit value ILimit of the current value supplied to a motor. COPYRIGHT: (C)2006,JPO&NCIPI |
