| 摘要 |
PROBLEM TO BE SOLVED: To precisely detect a temperature of a power assist motor and a controller without using a temperature sensor, and to improve a function of overheat protection. SOLUTION: A first estimation temperature calculator 13 estimates the temperature of the motor 82 from a difference between a calorific value and a heat release amount by motor current I. A first target current value calculator 27 obtains a ratio Rc corresponding to an estimated temperature, and calculates a first temporary target value obtained by restricting a target base current value Ib in accordance with the ratio Rc. A second estimation temperature calculator 14 estimates the temperature of the motor controller 93 from the difference between the calorific value and the heat release amount by motor current I. A second target current value calculator 28 obtains the ratio Rc corresponding to the estimated temperature, and calculates a second temporary target value obtained by restricting the target base current value Ib in accordance with the ratio Rc. A target value selector 30 selects a smaller value between the first and second temporary target values. COPYRIGHT: (C)2008,JPO&INPIT |
