Diagnostic apparatus and method for motor driven power-assisted steering system
First Claim
1. A diagnostic apparatus for a motor driven power-assisted steering system of an automotive vehicle, comprising:
- a motor controlling section that outputs a rotational direction drive command current to a motor drive circuit connected to an electric reversible motor to regulate a rotational direction of the electric motor in accordance with the rotational direction drive command current;
a drive current detection circuit to detect magnitude and direction of a rotational direction drive current flowing through the motor; and
an abnormality determining section that detects a state in which the detected rotational direction drive current indicates a direction opposite to the direction of the rotational direction drive command current and determines whether the state is in excess of a predetermined abnormality determination criterion so as to determine an occurrence of an abnormality of the power-assisted steering system, the abnormality determining section comprising a sensitivity reducing section that lowers a sensitivity of the abnormality determination criterion as an absolute value of the detected rotational direction drive current becomes smaller.
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Accused Products
Abstract
In diagnostic apparatus and method for a motor-driven power-assisted steering system, an abnormality determining section detects a state in which the detected normal/reverse drive current indicates an opposite to a direction of the normal/reverse revolution drive torque and determines whether the state is in excess of a predetermined abnormality determination criterion so as to determine an occurrence in abnormality of the power-assisted steering system, the abnormality determining section comprising a sensitivity reducing section that varies a sensitivity of the abnormality determination criterion in a decrease direction as an absolute value of the detected normal/reverse drive current becomes smaller.
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Citations
20 Claims
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1. A diagnostic apparatus for a motor driven power-assisted steering system of an automotive vehicle, comprising:
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a motor controlling section that outputs a rotational direction drive command current to a motor drive circuit connected to an electric reversible motor to regulate a rotational direction of the electric motor in accordance with the rotational direction drive command current;
a drive current detection circuit to detect magnitude and direction of a rotational direction drive current flowing through the motor; and
an abnormality determining section that detects a state in which the detected rotational direction drive current indicates a direction opposite to the direction of the rotational direction drive command current and determines whether the state is in excess of a predetermined abnormality determination criterion so as to determine an occurrence of an abnormality of the power-assisted steering system, the abnormality determining section comprising a sensitivity reducing section that lowers a sensitivity of the abnormality determination criterion as an absolute value of the detected rotational direction drive current becomes smaller. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A diagnostic apparatus for motor driven power-assisted steering system of an automotive vehicle, comprising:
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motor controlling means for outputting a rotational direction drive command current to a motor drive circuit connected to an electric reversible motor to regulate a rotational drive of the electric motor and a direction thereof in accordance with the rotational direction drive command current;
drive current detecting means for detecting a magnitude and a direction of a rotational direction drive current flowing through the motor;
abnormality determining means for detecting a state in which the detected rotational direction drive current indicates a direction opposite to the direction of the rotational direction drive command current and for determining whether the state is in excess of a predetermined abnormality determination criterion so as to determine an occurrence of an abnormality in the power-assisted steering system, the abnormality determining means comprising sensitivity reducing means for lowering a sensitivity of the abnormality determination criterion as an absolute value of the detected rotational direction drive current becomes smaller.
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15. A diagnostic method for a motor driven power-assisted steering system of an automotive vehicle, comprising:
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outputting a rotational direction drive command current to a motor drive circuit connected to an electric reversible motor to regulate a rotational direction of the electric motor in accordance with the rotational direction drive command current;
detecting a rotational direction drive current flowing through the motor;
detecting a state in which the detected rotational direction drive current indicates a direction opposite to the direction of the rotational direction drive command current;
determining whether the state is in excess of a predetermined abnormality determination criterion so as to determine an occurrence of an abnormality of the power-assisted steering system; and
lowering a sensitivity of the abnormality determination criterion as an absolute value of the detected rotational direction drive current becomes smaller. - View Dependent Claims (16, 17, 18, 19, 20)
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Specification