JP2009107416A - Motor controller for electric power steering device - Google Patents

Motor controller for electric power steering device Download PDF

Info

Publication number
JP2009107416A
JP2009107416A JP2007279803A JP2007279803A JP2009107416A JP 2009107416 A JP2009107416 A JP 2009107416A JP 2007279803 A JP2007279803 A JP 2007279803A JP 2007279803 A JP2007279803 A JP 2007279803A JP 2009107416 A JP2009107416 A JP 2009107416A
Authority
JP
Japan
Prior art keywords
electric
power
vehicle battery
electric motor
motor
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP2007279803A
Other languages
Japanese (ja)
Inventor
Yoshinobu Hiyamizu
Yoshiaki Izumitani
Shigeki Nagase
由信 冷水
圭亮 泉谷
茂樹 長瀬
Original Assignee
Jtekt Corp
株式会社ジェイテクト
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Jtekt Corp, 株式会社ジェイテクト filed Critical Jtekt Corp
Priority to JP2007279803A priority Critical patent/JP2009107416A/en
Publication of JP2009107416A publication Critical patent/JP2009107416A/en
Pending legal-status Critical Current

Links

Images

Abstract

By appropriately using an auxiliary power supply in addition to an in-vehicle battery, power management of the in-vehicle battery is unnecessary, and system cost is reduced.
A motor control device 12 includes an in-vehicle battery 16 that supplies electric power to an electric motor 14 of an electric power steering device 11 of the vehicle, an auxiliary power source 19 that can supply electric power to the electric motor 14, and an in-vehicle battery 16. And a control circuit 23 that charges and discharges the auxiliary power source 19 using a predetermined current value supplied to the electric motor 14 as a threshold value, and power management for suppressing the power consumption of the in-vehicle battery 16 with respect to the electric motor 14 becomes unnecessary. Thus, a charge / discharge threshold value is set.
[Selection] Figure 1

Description

  The present invention relates to a motor control device for an electric power steering device mounted on a vehicle such as an automobile.

Some vehicles such as automobiles are provided with an electric power steering device that reduces a driver's steering burden by applying a steering assist force by an electric motor to a steering system from a steering wheel to a steering wheel. The electric motor of the electric power steering apparatus is driven and controlled based on a required output (required power) determined according to a steering torque applied to the steering wheel and a vehicle speed.
Specifically, the electric motor is driven and controlled by a motor drive circuit and a control circuit that gives a control signal to the motor drive circuit, and this control circuit draws a current corresponding to the required output from the in-vehicle battery. The motor drive circuit is controlled to supply to the electric motor.

By the way, if the steering wheel is stationary at the time of entering the garage or parking, or if the steering wheel is steered while traveling, a large steering assist force is required, and the required output to the electric motor increases. Therefore, a large current is drawn from the in-vehicle battery, and the voltage of the in-vehicle battery decreases. Further, when the steering is further continued, since the voltage of the in-vehicle battery is lowered, a larger current may be drawn from the in-vehicle battery.
An electric circuit such as a motor drive circuit of an electric power steering apparatus includes many electronic components such as switching elements. If a large current exceeding an allowable value flows through these electronic components, the electronic components may be damaged. . In addition to the electric power steering device, the vehicle is equipped with many electric devices, and when the voltage of the in-vehicle battery is lowered, there is a disadvantage that stable electric power supply to other electric devices cannot be performed.

  In order to solve these problems, it is considered that power management is performed to limit the power consumption of the in-vehicle battery with respect to the electric motor in order to suppress an excessive current drawn from the in-vehicle battery to the electric motor. In other words, in this power management, in the region A where the torque (load) is large as in the TN characteristic of the electric motor shown in FIG. The power consumption of the in-vehicle battery is limited to a predetermined value or less.

  However, in order to perform such power management, a dedicated ECU (electronic control unit) is separately required, or a communication interface between the ECU dedicated to power management and the ECU of the electric power steering device and other devices Etc. may be required newly. Therefore, there arises a new problem that the overall system cost of the vehicle accompanying power management increases. Moreover, since the output of the electric motor is reduced at the time of high load by performing such power management, there is a problem that the steering feeling becomes heavy.

  On the other hand, in an electric power steering device, when a required steering assist force is large, such as when entering a garage or parking, power is supplied not only from an in-vehicle battery but also from an auxiliary power source that stores power in advance. In addition, it has been conventionally proposed to reduce the burden on the on-vehicle battery (see, for example, Patent Document 1).

JP 2003-320942 A

  The present invention is an electric power steering apparatus capable of reducing the system cost by appropriately using an auxiliary power source in addition to the in-vehicle battery so as to eliminate the power management of the in-vehicle battery (main power source) as described above. An object of the present invention is to provide a motor control device.

The motor control device of the electric power steering device of the present invention is
A main power supply for supplying electric power to the electric motor of the electric power steering device of the vehicle;
An auxiliary power source capable of supplying power to the electric motor;
Control means for charging and discharging the auxiliary power source with a predetermined current value supplied from the main power source to the electric motor as a threshold,
The threshold value is set so that power management for suppressing power consumption of the main power source for the electric motor is not required.

  According to this configuration, since the threshold value serving as a reference when charging / discharging the auxiliary power supply is set so that the power management of the main power supply is not required, a dedicated ECU for performing the power management, It is not necessary to provide a communication interface between the ECU and another ECU, and an increase in system cost can be suppressed. In addition, even when a large steering assist force is required when entering a garage or parking, sufficient electric power can be supplied to the electric motor from the main power supply and the auxiliary power supply, giving the driver a light steering feeling. Can be given.

  According to the present invention, by appropriately using an auxiliary power supply, it is possible to eliminate the need for power management of the in-vehicle battery and reduce the system cost.

  FIG. 1 is a block circuit diagram showing a motor control device 12 of an electric power steering device 11 according to an embodiment of the present invention. In FIG. 1, a steering assist force is applied to a vehicle steering device 13 by an electric motor 14 such as a brushless motor. The electric motor 14 is supplied with electric power from the in-vehicle battery (main power source) 16 and the alternator 17 via the ECU 15. The on-vehicle battery 16 is charged by an alternator 17.

  The ECU 15 drives an auxiliary power source 19 that can supply electric power to the electric motor 14, a charging circuit 20 for charging the auxiliary power source 19, a switching means 21 that switches charging and discharging of the auxiliary power source 19, and the electric motor 14. And a control circuit 23 for controlling the motor driving circuit 22, a charging circuit 20, a switching means 21, and the like.

  The motor drive circuit 22 is connected to the in-vehicle battery 16 via a high potential side circuit 25 and a low potential side circuit 26. An auxiliary power source 19 is provided in the high potential side electric circuit 25 in series with the in-vehicle battery 16. The auxiliary power source 19 is composed of an electric double layer capacitor, a lithium ion rechargeable battery, and the like, and is charged by the in-vehicle battery 16 via the charging circuit 20 connected to the high potential side electric circuit 25.

  Further, in the high potential side electric circuit 25, a detour electric circuit 27 that bypasses and connects the upstream side and the downstream side of the auxiliary power source 19 is provided, and the detour electric circuit 27 is provided downstream of the auxiliary power source 19. A changeover switch 28 is provided for switching connection / disconnection to the high potential side electric circuit 25. The detouring electric path 27, the changeover switch 28, and the like constitute the switching means 21. The in-vehicle battery 16 and the auxiliary power source 19 are connected in series by switching the changeover switch 28 to the position a indicated by the solid line, and the auxiliary power source 19 is discharged, whereby the electric power of the in-vehicle battery 16 and the auxiliary power source 19 is increased. It is supplied to the motor drive circuit 22. Further, by switching the changeover switch 28 to the position b indicated by the dotted line, the electric power of the in-vehicle battery 16 is supplied to the motor drive circuit 22 via the bypass electric path 27. At this time, the power of the auxiliary power source 19 is not supplied to the motor drive circuit 22, and the auxiliary power source 19 is charged by the charging circuit 20.

  Information on the steering torque and vehicle speed of the steering wheel by the driver is input to the control circuit 23, and the control circuit 23 is electrically operated to generate a necessary steering assist force according to the information. The required output (required power) of the motor 14 is obtained. Further, the control circuit 23 controls the motor driving circuit 22 so as to draw a current corresponding to the required output from the in-vehicle battery 16 and drives the electric motor 14. Specifically, the motor drive circuit 22 is provided with a current detection unit 29 that detects the value of the current flowing to the electric motor 14, and the detection signal of the current detection unit 29 is input to the control circuit 23. The control circuit 23 feedback-controls the motor drive circuit 22 based on the deviation between the current value detected by the current detection unit 29 and the current value corresponding to the requested output.

  In addition, a voltage detection unit 30 that detects a terminal voltage of the in-vehicle battery 16 is provided, and a detection signal of the voltage detection unit 30 is also input to the control circuit 23. The control circuit 23 includes a calculation unit 31, which calculates a current value drawn from the in-vehicle battery 16 for driving the electric motor 14 based on a detection signal from the current detection unit 29 by calculation. The power consumption of the in-vehicle battery 16 is obtained from the current value and the voltage value detected by the voltage detection unit 30.

  In the above configuration, when the required steering assist force is relatively small, the control circuit 23 gives a control signal to the switching means 21 so as to operate the changeover switch 28 to the position b. As a result, the electric power of the in-vehicle battery 16 is supplied to the motor drive circuit 22, and the motor drive circuit 22 drives the electric motor 14 based on a control signal from the control circuit 23. At this time, the power of the auxiliary power source 19 is not supplied to the motor drive circuit 22.

  On the other hand, when the required steering assist force is relatively large, the control circuit 23 gives a control signal to the switching means 21 so as to operate the changeover switch 28 to the position a. As a result, the in-vehicle battery 16 and the auxiliary power source 19 are connected in series with each other, and the electric power of both the in-vehicle battery 16 and the auxiliary power source 19 is supplied to the motor drive circuit 22.

  The control circuit (control means) 23 determines whether or not the power of the auxiliary power supply 19 is supplied to the motor drive circuit 22 based on a predetermined charge / discharge threshold value for the current value supplied from the in-vehicle battery 16 to the motor drive circuit 22. To decide. For example, when the current value drawn from the in-vehicle battery 16 to the electric motor 14 is 80 A, the threshold value is set, and when the current value drawn from the in-vehicle battery 16 exceeds 80 A, the power of the auxiliary power source 19 is also supplied to the motor drive circuit 22. To supply.

  More specifically, as shown in FIG. 2, when the power consumption for driving the electric motor 14 fluctuates as shown by the solid line, the current value supplied from the in-vehicle battery 16 to the electric motor 14 exceeds the threshold value. In the region (the region above the dotted line), the auxiliary power source 19 is discharged, and the electric power from the auxiliary power source 19 is supplied to the motor drive circuit 22 in addition to the in-vehicle battery 16 without reducing the required output of the electric motor 14. The current value to the electric motor 14 can be lowered. Moreover, in the area | region below a threshold value, while supplying the electric power from the vehicle-mounted battery 16 to the electric motor 14, the auxiliary power supply 19 is charged.

  This threshold value is a value that does not exceed the allowable current value of the switching elements and other electronic components constituting the motor drive circuit 22 and the like, and further, current is drawn from the in-vehicle battery 16 to the electric motor 14 exceeding the threshold value. And the value is set such that power shortage may occur with respect to other electric devices mounted on the vehicle due to the voltage drop of the in-vehicle battery 16.

  In order to prevent damage to electronic components and power shortage to other electrical devices, it is necessary to perform power management that suppresses the power consumption of the in-vehicle battery 16 by forcibly reducing the required output to the electric motor 14. However, in the present invention, whether or not the auxiliary power source 19 is used is determined based on the threshold value. If the threshold value is exceeded, the electric power of the on-vehicle battery 16 and the auxiliary power source 19 is supplied to the motor. By supplying to the drive circuit 22, an excessive current exceeding the allowable current value of the electronic component does not flow, and there is no shortage of power to other electric devices, and the necessary steering assist force is obtained. It can be given to the steering device 13.

In addition, power management related to the power consumption of the in-vehicle battery 16 is not required, and there is no need to provide an ECU for performing the power management, a communication interface structure between the ECU and the electric power steering device 11 or the ECU 15 of another device, It becomes possible to suppress the system cost.
The present invention is not limited to the embodiment described above, and can be appropriately modified within the scope described in the claims.

1 is a block circuit diagram of a motor control device according to an embodiment of the present invention. It is a graph which shows the use area | region of a vehicle-mounted battery and an auxiliary power supply. It is a graph which shows the TN characteristic of the electric motor in the case of performing power management.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Electric power steering apparatus 12 Motor control apparatus 13 Steering apparatus 14 Electric motor 16 Car-mounted battery 19 Auxiliary power supply 23 Control circuit (control means)

Claims (1)

  1. A main power supply for supplying electric power to the electric motor of the electric power steering device of the vehicle;
    An auxiliary power source capable of supplying power to the electric motor;
    Control means for charging and discharging the auxiliary power source with a predetermined current value supplied from the main power source to the electric motor as a threshold,
    The motor control device for an electric power steering apparatus, wherein the threshold is set so that power management for suppressing power consumption of the main power source for the electric motor is not required.
JP2007279803A 2007-10-29 2007-10-29 Motor controller for electric power steering device Pending JP2009107416A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2007279803A JP2009107416A (en) 2007-10-29 2007-10-29 Motor controller for electric power steering device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2007279803A JP2009107416A (en) 2007-10-29 2007-10-29 Motor controller for electric power steering device

Publications (1)

Publication Number Publication Date
JP2009107416A true JP2009107416A (en) 2009-05-21

Family

ID=40776426

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2007279803A Pending JP2009107416A (en) 2007-10-29 2007-10-29 Motor controller for electric power steering device

Country Status (1)

Country Link
JP (1) JP2009107416A (en)

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003320942A (en) * 2002-04-26 2003-11-11 Nsk Ltd Electric power steering apparatus
JP2007223510A (en) * 2006-02-24 2007-09-06 Jtekt Corp Electric power steering device

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003320942A (en) * 2002-04-26 2003-11-11 Nsk Ltd Electric power steering apparatus
JP2007223510A (en) * 2006-02-24 2007-09-06 Jtekt Corp Electric power steering device

Similar Documents

Publication Publication Date Title
JP5865013B2 (en) Power supply device for vehicle and vehicle provided with this power supply device
EP3180208B1 (en) Electric or hybrid electric vehicle having multiple drive units arranged in separate parts of the vehicle
EP2272722B1 (en) Power source apparatus for vehicle
DE102012005993B4 (en) Power supply control device for a vehicle
EP1319548B1 (en) Hybrid vehicle and control method therefor
US9446790B2 (en) Electric power steering system
US9991783B2 (en) Method and apparatus for discharging an energy store in a high-voltage power supply system
JP4333646B2 (en) Electric power steering device
CN101795926B (en) Steering device
JP4279854B2 (en) Vehicle power supply control device
JP3896258B2 (en) Automotive power supply
US9090177B2 (en) Uncertified battery replacement countermeasure apparatus for electric vehicle
US6755267B2 (en) Electric vehicle and control device thereof
US9254799B2 (en) Power source control apparatus for vehicle
JP4840359B2 (en) Engine starter
US8240425B2 (en) Electric power steering apparatus
US7602140B2 (en) Apparatus for supplying power for a vehicle
CN1871146B (en) Electrical power supply system with two rechargeable batteries for supplying electrical motor
CN101878135B (en) Power supply controller
US8463475B2 (en) Control device for electric vehicle
JP5484192B2 (en) Electric vehicle start control device
US7589940B2 (en) Voltage boosting circuit and electricity-driven power steering device
JP2007153107A (en) Power supply control device for power steering
EP2746136B1 (en) Electrical power steering apparatus
JP4162645B2 (en) Power supply for vehicle

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20100917

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20120127

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20120207

A02 Decision of refusal

Free format text: JAPANESE INTERMEDIATE CODE: A02

Effective date: 20120612