Patent EP0551891A2 successfully refreshed from Google Patents.
EP0551891A2
Expired / Lapsed
EP
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Apparatus for controlling steering angle of rear wheel of four-wheel steering vehicle and method therefor
Assignee: Panasonic Holdings Corp
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Filing: 1993-01-14
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Granted: —
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Expires: 2013-01-14
Abstract
Abstract In an apparatus (10) for controlling the steering angle of the rear wheel of a four-wheel steering vehicle, a target yaw rate of the vehicle is calculated based on values detected by the vehicle speed sensor (2) and the handle angle sensor (3), and in a yaw rate feedback loop, the loop is stabilized by performing the feedback of the difference between the target yaw rate and the actual yaw rate.
Inventors
- 👤 Takashi Fukunaga
- 👤 Akiyoshi Segawa
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 09:09
CPC Classifications
B; B62; B62D; B62D7/00; B62D7/06; B62D7/14; B62D7/15; B62D7/159; B62D7/1518; B62D7/1545; B60; B60Y; B60Y2400/00; B60Y2400/84
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
237 words
An apparatus for controlling the steering angle of the rear wheel of a four-wheel steering vehicle comprising: a vehicle speed sensor for detecting a vehicle speed; a yaw rate sensor for detecting a yaw rate; a handle angle sensor for detecting the rotational angle of the handle; a control device for outputting a signal for instructing the steering angle of the rear wheel in response to the signal of each sensor; an electric motor, incorporating a position detector, for steering the rear wheel based on the signal for instructing the steering angle of the rear wheel; and a detector for detecting the position of the rear wheel, in which: the control device subtracts the following four values A, B, C, and D from a target yaw rate of the vehicle set based on values detected by the vehicle speed sensor and the handle angle sensor: value A: the product of an actual yaw rate of the vehicle detected by the yaw rate sensor and a constant; value B: the product of the rate of change of the actual yaw rate and a constant; value C: the product of a value, corresponding to the current position of the electric motor, obtained from the position detector of the electric motor and a constant; and value D: the product of the speed of the electric motor and a constant, whereby a target steering angle of the electric motor is found.
Claim 2
Dependent Claim
150 words
An apparatus as defined in claim 1, in which: the control device subtracts the following four values A, B, C, and D from the target yaw rate of the vehicle set based on values detected by the vehicle speed sensor and the handle angle sensor: value A: the product of the actual yaw rate of the vehicle detected by the yaw rate sensor and a constant; value B: the product of the rate of change of the actual yaw rate and a constant; value C: the product of a value, corresponding to the current position of the rear wheel, obtained from the detector for detecting the position of the rear wheel and a constant; and value D: the product of the rate of change of the value corresponding to the current position of the rear wheel and a constant, whereby the target steering angle of the electric motor is found.
Claim 3
Dependent Claim
193 words
An apparatus as defined in claim 1, in which: the control device subtracts the following six values A, B, C, D, E, and F from the target yaw rate of the vehicle set based on values detected by the vehicle speed sensor and the handle angle sensor: value A: the product of the actual yaw rate of the vehicle detected by the yaw rate sensor and a constant; value B: the product of the rate of change of the actual yaw rate and a constant; value C: the product of a value, corresponding to the current position of the electric motor, obtained from position detector of the electric motor and a constant; value D: the product of the speed of the electric motor and a constant; value E: the product of a value, corresponding to the current position of the rear wheel, obtained from the detector for detecting the position of the rear wheel and a constant; and value F: the product of the rate of change of the value corresponding to the current position of the rear wheel and a constant, whereby the target steering angle of the electric motor is found.
Claim 4
Independent Claim
60 words
An apparatus as defined in any one of claims 1, 2 and 3 in which: the value to be multiplied by the actual yaw rate of the vehicle detected by the yaw rate sensor and the value to be multiplied by the rate of change of the actual yaw rate are determined, respectively as a function of a vehicle speed.
Claim 5
Independent Claim
174 words
An apparatus for controlling the steering angle of the rear wheel of a four-wheel steering vehicle comprising a control device which sets a target yaw rate of the vehicle based on a vehicle speed detected by a vehicle speed sensor and the rotational angle of a handle detected by a handle angle sensor; calculates a proportional value by multiplying a deviation value between the set target yaw rate and the actual yaw rate detected by a yaw rate sensor by a constant Kp; a differential value by multiplying the change of rate of the deviation value by a constant Kd; an integral value by multiplying the integrated value of the deviation value by a constant Ki; and outputs a signal for instructing the steering angle of the rear wheel to an electric motor which steers the rear wheel according to a value obtained by adding the proportional value, the differential value, and the integral value to each other, in which: the constants Kp, Kd, and Ki are set according to a vehicle speed, respectively.
Claim 6
Dependent Claim
59 words
An apparatus as defined in claim 5, wherein the control device sets each of the constants Kp, Kd, and Ki used in calculating the proportional value, the differential value, and the integral value according to the rotational angle of the handle or the steering angle of a front wheel connected with the handle via a gear and other components.
Claim 7
Dependent Claim
74 words
An apparatus as defined in claim 5, wherein the control device sets each of the constants Kp, Kd, and Ki used in calculating the proportional value, the differential value, and the integral value according to the steering angle of the rear wheel detected by a sensor for detecting the steering angle of the rear wheel or the rotational angle of the electric motor connected with the rear wheel via a gear and other components.
Claim 8
Dependent Claim
56 words
An apparatus as defined in claim 5, wherein the control device sets each of the constants Kp, Kd, and Ki used in calculating the proportional value, the differential value, and the integral value according to a friction coefficient µ, between a tire and a road surface, detected by a sensor for detecting the friction coefficient µ.
Claim 9
Dependent Claim
45 words
An apparatus as defined in claim 5, wherein the control device sets each of the constants Kp, Kd, and Ki used in calculating the proportional value, the differential value, and the integral value by using at least two means according to claim 5 through 8.
Claim 10
Independent Claim
259 words
An apparatus for controlling the steering angle of the rear wheel of a four-wheel steering vehicle comprising: a vehicle speed sensor for detecting a vehicle speed; a yaw rate sensor for detecting a yaw rate; a handle angle sensor for detecting the rotational angle of a handle; a control device for outputting a signal for instructing the steering angle of the rear wheel in response to the signal of each sensor; and an electric motor, incorporating a position detector, for steering the rear wheel based on the signal for instructing the steering angle of the rear wheel, in which: in order to calculate a target steering angle of the rear wheel based on a value obtained by multiplying the yaw rate by a yaw rate constant determined by the vehicle speed, the control means comprises same phase-steering means for steering the rear wheel in the same phase as that of the front wheel; and opposite phase-steering means for steering the rear wheel in a phase opposite to that of the front wheel by using at least one of the product of a handle angle and a handle angle constant; the product of a differentiated value of the handle angle and a differential constant of the handle angle; and the product of an integrated value of the handle angle and an integral constant of the handle angle, in which: the handle angle constant, the differential constant of the handle angle, and the integral constant of the handle angle are determined by the yaw rate constant and the vehicle speed, respectively.
Claim 11
Dependent Claim
134 words
An apparatus as defined in claim 10, wherein the control means has a low speed mode, for controlling the vehicle speed when the vehicle speed is smaller than V₁, in which the yaw rate constant is monotonously increased with respect to the vehicle speed, and the handle angle constant is fixed to a certain value; and a high speed mode, for controlling the vehicle speed when the vehicle speed is higher than V₁, in which the yaw rate constant is set to be smaller than the yaw rate constant to be set when the vehicle speed is smaller than V1, in which: the handle angle constant, the differential constant of the handle angle, and the integral constant of the handle angle are expressed in the form of a transfer function (linear expression)/(linear expression), respectively.
References Cited (Backward Citations)
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