Steering controlling device

• US 7,294,985 B2
• Filed: 11/30/2004
• Issued: 11/13/2007
• Est. Priority Date: 07/10/2001
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Kifuku, Takayuki
• Primary Examiner(s): Donovan; Lincoln
• Assistant Examiner(s): SMITH, TYRONE W
• Application Number:
  US10/998,579
• Publication Number:
  US 20050092541A1
• Time in Patent Office: 1,078 Days
• Field of Search: 318/139, 318/432, 318700-800, 318/434, 318/138, 318/254, 318/439, 318560-609, 701 36- 44
• US Class Current: 318/432
• CPC Class Codes: B62D 5/046 Controlling the motor
• CPC Class Codes: B62D 5/0463 calculating assisting torque from the motor based on driver input

Abstract

A steering controlling device comprising a power source, a motor connected to a steering system, a motor driving circuit converting a power source voltage to a predetermined voltage and applying the voltage to the motor, and a controlling means for controlling the motor driving circuit, wherein the controlling means controls the motor driving circuit so as to boost the power source voltage when a rotational speed of the motor is a predetermined value or more, whereby a sufficient motor output torque is obtainable under various steering conditions in use of a converter, an efficiency is improved by suppressing a frequency of operating the converter, and an appropriate fail safe treatment is conducted when the converter is disordered.

Claims

1. A steering controlling device comprising:

a power source;

a motor connected to a steering system;

a motor driving circuit converting a power source voltage to a predetermined voltage and applying the converted voltage to the motor;

a means for controlling the motor driving circuit, wherein the controlling means controls the motor driving circuit to boost the power source voltage when a rotational speed of the motor is greater than a predetermined value;

wherein the motor driving circuit includes at least a first converter connected to the power source and a bridge circuit connected to the motor; and

a second converter boosting an output voltage from the first converter in order to drive switching elements, forming the bridge circuit,

wherein the controlling means monitors an input voltage to the first converter or an output voltage from the first converter, and

wherein the controlling means stops a first boost operation when the first converter is judged abnormal.

2. A steering controlling device comprising:

a power source;

a motor connected to a steering system;

a motor driving circuit converting a power source voltage to a predetermined voltage and applying the converted voltage to the motor;

a means for controllin the motor drivin circuit wherein the controllin means controls the motor driving circuit to boost the ower source voltage when a rotational sveed of the motor is greater than a predetermined value;

wherein the motor driving circuit includes at least a first converter connected to the power source and a bridge circuit connected to the motor; and

a second converter boosting an output voltage from the first converter in order to drive switching elements, forming the bridge circuit,

wherein the controlling means monitors an input voltage to the first converter or an output voltage from the first converter, and

wherein the controlling means stops an application of a current to the motor when the first converter is judged abnormal.

3. A steering controlling device comprising:

a power source;

a motor connected to a steering system;

a motor driving circuit converting a power source voltage to a predetermined voltage and applying the converted voltage to the motor;

a means for controlling the motor driving circuit, wherein the controlling means controls the motor driving circuit to boost the power source voltage when a rotational speed of the motor is greater than a predetermined value;

wherein the motor driving circuit includes at least a first converter connected to the power source and a bridge circuit connected to the motor; and

a second converter boosting an output voltage from the first converter in order to drive switching elements, forming the bridge circuit,

wherein the controlling means monitors an input voltage to the first converter or an output voltage from the first converter, and

wherein the power source is connected to the motor driving circuit through a switching means, and the controlling means opens a contact point of the switching means when the first converter is judged abnormal.

4. A steering controlling device comprising:

a power source;

a motor connected to a steering system;

a motor driving circuit converting a power source voltage to a predetermined voltage and applying the converted voltage to the motor;

a means for controlling the motor driving circuit, wherein the controlling means controls the motor drivin circuit to boost the power source voltage when a rotational speed of the motor is greater than a predetermined value;

wherein the motor driving circuit includes at least a first converter connected to the power source and a bridge circuit connected to the motor; and

a second converter boosting an output voltage from the first converter in order to drive switching elements, forming the bridge circuit,

wherein terminals of diodes forming the first converter are short-circuited when the first converter is not operated to boost the voltage.