Power source control device for power steering

• US 8,204,651 B2
• Filed: 11/16/2006
• Issued: 06/19/2012
• Est. Priority Date: 12/05/2005
• Status: Expired due to Fees

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Tachibana, Takeshi, Ito, Koji, Esaka, Toshinori, Matsuto, Hidenori
• Primary Examiner(s): Dager, Jonathan M
• Application Number:
  US11/883,717
• Publication Number:
  US 20080177444A1
• Time in Patent Office: 2,042 Days
• Field of Search: 701/29, 701/31, 701/36, 701/41, 701/43, 701/49, 340/425.5, 340/428, 340/438, 180/400, 180/404, 180/405, 180/407, 180/412, 180/415
• US Class Current: 701/41
• CPC Class Codes: B62D 5/0457 characterised by control features of the drive means as such
• CPC Class Codes: B62D 5/0475 Controlling other elements
• CPC Class Codes: B62D 5/0481 monitoring the steering system, e.g. failures

Abstract

According to the present invention, a power supply control device for an electric power steering device used for a power supply system comprises a main battery 40 connected to the electric power steering device via a first power supply line and a sub-battery 50 connected to the electric power steering device via a second power supply line, wherein when detecting the state of the sub-battery, said power supply control device restricts or disconnects power supply from the main battery to the electric power steering device while it permits power supply from the sub-battery to the electric power steering device, characterized in that said power supply control device prevents the detection of the state of the second battery if a vehicle speed is higher than a predetermined reference value.

Claims

1. A power supply control device for an electric power steering device used for a power supply system comprising:

a first battery connected to the electric power steering device via a first power supply line;

and a second battery connected to the electric power steering device via a second power supply line,

wherein said power supply control device is configured such that when detecting a state of the second battery, said power supply control device restricts or disconnects power supply from the first battery to the electric power steering device while said power supply control device permits power supply from the second battery to the electric power steering device,

wherein said power supply control device is configured to prevent the detection of the state of the second battery if a vehicle speed is higher than a predetermined reference value, and

wherein said power supply control device is configured to prevent the detection of the state of the second battery if a steering angle or a steering torque of a steering wheel is lower than a predetermined reference value.

4. The power supply control device as claimed in claim 1, wherein the second battery is connected to a separate load in addition to the electric power steering device, and when detecting the state of the second battery, said power supply control device restricts or disconnects power supply from the first battery to the electric power steering device and disconnects power supply from the second battery to the separate load while said power supply control device permits power supply from the second battery to the electric power steering device, wherein said power supply control device is configured to prevent the detection of the state of the second battery when power more than a predetermined reference power is supplied from the second battery to the separate load.

6. The power supply control device as claimed in claim 1, wherein the first power supply line includes a first DC-DC converter;

wherein the second power supply line includes a second DC-DC converter;

wherein a third DC-DC converter is connected between the first battery and the second battery; and

wherein the first DC-DC converter is connected in parallel with the third DC-DC converter and the second DC-DC converter is connected in parallel with the third DC-DC converter.

2. A power supply control device for an electric power steering device used for a power supply system comprising:

a first battery connected to the electric power steering device via a first power supply line; and

a second battery connected to the electric power steering device via a second power supply line,

wherein said power supply control device is configured such that when detecting a state of the second battery, said power supply control device restricts power supply from the first battery to the electric power steering device while said power supply control device permits power supply from the second battery to the electric power steering device,

wherein said power supply control device is configured such that when detecting the state of the second battery, said power supply control device restricts the power supply from the first battery to the electric power steering device within a range in which range a predetermined operation of the electric power steering device is enabled based on the restricted power supply, and

wherein said power supply control device is configured to prevent the detection of the state of the second battery if a steering angle or a steering torque of a steering wheel is lower than a predetermined reference value.

3. The power supply control device as claimed in claim 2, wherein said power supply control device has voltage selection means for applying the higher voltage, of a voltage supplied to the electric power steering device via the first power supply line and a voltage supplied to the electric power steering device via the second power supply line, to the electric power steering device, and wherein when detecting the state of the second battery, said power supply control device is configured to change the voltage supplied to the electric power steering device via the first power supply line to a lower limit value below which the predetermined operation of the electric power steering device is not enabled.

7. The power supply control device as claimed in claim 2, wherein the first power supply line includes a first DC-DC converter;

wherein the second power supply line includes a second DC-DC converter;

wherein a third DC-DC converter is connected between the first battery and the second battery; and

wherein the first DC-DC converter is connected in parallel with the third DC-DC converter and the second DC-DC converter is connected in parallel with the third DC-DC converter.

5. A power supply control device for an electric power steering device used for a power supply system comprising;

a first battery connected to the electric power steering device via a first power supply line; and

a second battery whose power supply voltage is lower than the first battery, said second battery being connected to the electric power steering device via a second power supply line,

wherein said power supply control device is configured such that when detecting a state of the second battery, said power supply control device restricts or disconnects power supply from the first battery to a predetermined load other than the electric power steering device, said predetermined load consuming large power for a short time period, while said power supply control device permits power supply from the second battery to the predetermined load, and

wherein said power supply control device is configured to predict a start of an operation of the predetermined load, and a state detection device is configured to perform the detection of the state of the second battery when the operation of the predetermined load is predicted to start.

8. The power supply control device as claimed in claim 5, wherein the first power supply line includes a first DC-DC converter;

wherein the second power supply line includes a second DC-DC converter;

wherein a third DC-DC converter is connected between the first battery and the second battery; and

wherein the first DC-DC converter is connected in parallel with the third DC-DC converter and the second DC-DC converter is connected in parallel with the third DC-DC converter.