Temperature estimating device and temperature estimating method

Patent metadata

Field	Value
Publication number	US-8975851-B2
Application number	US-201213433953-A
Country	US
Kind code	B2
Filing date	Mar 29, 2012
Priority date	Mar 29, 2011
Publication date	Mar 10, 2015
Grant date	Mar 10, 2015

Abstract

A temperature estimating unit includes an energy calculating unit that calculates a heat generation energy rate of a motor on the basis of a difference between power input to the motor and power output from the motor, a heat radiation energy calculating unit that calculates a heat radiation energy rate from a target member on the basis of a difference between a previous temperature estimation value Tm of the target member and an ambient temperature, and a thermal coefficient of the target member, and an amount calculating unit that calculates a temperature increase rate of the target member on the basis of a difference between the heat generation energy rate and the heat radiation energy rate, and an estimation value calculating unit that calculates a current temperature estimation value of the target member on the basis of the temperature increase rate and the previous temperature estimation value.

First claim

What is claimed is:

1. A temperature estimating device which estimates temperatures of a target member of an apparatus constituent member constituting an electronic apparatus every period, wherein said electronic apparatus is configured to adjust braking force on a wheel mounted on a vehicle and is provided with a motor for braking, the device comprising:
a heat generation amount calculating unit for calculating heat generation amount of the motor on the basis of a difference between an input energy corresponding value corresponding to input energy to the motor and an output energy corresponding value corresponding to output energy from the motor, wherein said input energy to the motor is calculated based on a current value flowing through the motor and a voltage value applied to the motor, and said output energy from the motor is calculated based on a number of rotations of an output shaft of the motor and driving torque of the motor;
a heat radiation amount calculating unit for calculating heat radiation amounts from the target member on the basis of a difference between a previous temperature estimation value of the target member and an ambient temperature around the electronic apparatus, and thermal coefficient representing thermal characteristic of the target member; and
an estimation value calculating unit for acquiring a temperature increase amount of the target member on the basis of a difference between the heat generation amount and the heat radiation amount calculated by the calculating unit, and calculating a current temperature estimation value of the target member on the basis of the temperature increase amount and the previous temperature estimation value of the target member.

2. The temperature estimating device according to claim 1 , wherein
the estimation value calculating unit is configured to estimate the temperature estimation values of the plurality of target members,
in the calculation of the heat radiation amounts from a first target member, the heat radiation amount calculating unit calculates the heat radiation amounts from the first target member on the basis of a difference between the previous temperature estimation values of the first target members and the ambient temperature, and the thermal coefficient representing the thermal characteristics of the first target member, and
in the calculation of the heat radiation amounts from a second target member, the heat radiation amount calculating unit calculates the heat radiation amounts from the second target member on the basis of a difference between the previous temperature estimation values of the second target member and the ambient temperature, and the thermal coefficient representing the thermal characteristics of the second target member.

3. The temperature estimating device according to claim 1 , wherein
the motor is provided with a brush,
the heat radiation amount calculating unit calculates the heat radiation amount from the brush of the motor as the heat generation amount from the target member, and
the estimation value calculating unit calculates the current temperature estimation value of the brush.

4. The temperature estimating device according to claim 1 , wherein
the heat radiation amount calculating unit calculates the heat radiation amount from a yoke of the motor as the heat radiation amount from the target member, and
the estimation value calculating unit calculates the current temperature estimation value of the yoke.

5. The temperature estimating device according to claim 1 , wherein
the electronic apparatus further includes a housing in which a driving unit provided with the motor as a driving source is accommodated,
the motor is provided in the housing through the yoke,
the heat radiation amount calculating unit calculates the heat radiation amount from the housing as the heat radiation amount from the target member, and
the estimation value calculating unit calculates the current temperature estimation value of the housing.

6. The temperature estimating device according to claim 5 , wherein an electromagnetic valve that operates to adjust the braking force is provided in the housing.

7. A temperature estimating device which estimates a temperature of a target member of apparatus constituent members constituting an electronic apparatus provided with a motor for each predetermined period, the device comprising:
a provisional value estimating unit for estimating a temperature provisional value of the target member;
a temperature acquiring unit for acquiring temperatures of the another apparatus constituent member which is different from the target member of the apparatus constituent members; and
an estimation value setting unit for setting a temperature estimation value of the target member,
wherein at the time of driving the motor, the estimation value setting unit sets the current temperature provisional value of the target member estimated by the provisional value estimating unit to the current temperature estimation value of the target member, and
wherein after stopping the driving of the motor, the estimation value setting unit sets the current temperature estimation value of the target member on the basis of the higher one of the current temperature of the particular apparatus constituent member whose temperature was lower than the temperature provisional value of the target member at the time of driving the motor and the current temperature provisional value of the target member.

8. The temperature estimating device according to claim 7 , wherein
the provisional value estimating unit include:
a heat generation amount calculating unit for calculating the heat generation amount of the motor on the basis of a difference between an input energy corresponding value corresponding to input energy to the motor and an output energy corresponding value corresponding to output energy from the motor;
a heat radiation amount calculating unit for calculating the heat radiation amount from the target member on the basis of a difference between the last temperature provisional value of the target member and an ambient temperature around the electronic apparatus, and a thermal coefficient representing thermal characteristics of the target member; and
a provisional value calculating unit for acquiring a temperature increase amount of the target member on the basis of a difference between the heat generation amount and the heat radiation amount calculated by the calculating unit and calculating the current temperature provisional value of the target member on the basis of the temperature increase amount and the last temperature provisional value.

9. The temperature estimating device according to claim 7 , wherein
the motor is a motor provided with a brush,
the provisional value estimating unit estimates the temperature provisional value of the brush of the motor as a temperature provisional value of the target member, and
after stopping the driving of the motor, the estimation value setting unit sets the current temperature estimation value of the brush on the basis of the higher one of the current temperature of the particular apparatus constituent member acquired by the temperature acquiring unit and the current temperature provisional value of the brush estimated by the provisional value estimating unit.

10. The temperature estimating device according to claim 8 , wherein the temperature acquiring unit acquires temperatures of the other apparatus constituent members with larger thermal capacity than that of the target member.

11. The temperature estimating device according to claim 7 , wherein the temperature acquiring unit includes:
a heat generation amount calculating unit for

Assignees

• Usami Tadayoshi
• Yoshioka Nobuhiko
• Advics Co Ltd
• Denso Corp

Inventors

• Usami Tadayoshi
• Yoshioka Nobuhiko

Classifications

• G01K2205/00

  Application of thermometers in motors, e.g. of a vehicle · CPC title

• G01K7/42 Primary

  Circuits effecting compensation of thermal inertia; Circuits for predicting the stationary value of a temperature · CPC title