Method for compensating a power assist steering system control signal
First Claim
1. A method of compensating a control signal for an electro-hydraulic power assist steering system including a variable-speed electric motor for pumping hydraulic fluid in the system, the method comprising:
- monitoring vehicle speed;
monitoring vehicle steering wheel angle;
establishing a base motor speed;
estimating a vehicle yaw rate;
calculating a yaw compensation factor in proportion to said estimated vehicle yaw rate; and
generating a desired motor speed signal from said base motor speed and said yaw compensation factor.
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Accused Products
Abstract
A method is provided for controlling an electro-hydraulic power assist steering system including a variable-speed electric motor for pumping hydraulic fluid in the system. The method includes monitoring vehicle speed and vehicle steering wheel angle. A vehicle yaw rate is estimated using the monitored vehicle speed and monitored vehicle steering wheel angle. A control signal for setting the speed of the variable speed electric motor is compensated based based on the estimated vehicle yaw rate. Accordingly, a wide range of vehicle driving conditions are accommodated and vehicle fuel efficiency is improved.
29 Citations
17 Claims
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1. A method of compensating a control signal for an electro-hydraulic power assist steering system including a variable-speed electric motor for pumping hydraulic fluid in the system, the method comprising:
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monitoring vehicle speed; monitoring vehicle steering wheel angle; establishing a base motor speed; estimating a vehicle yaw rate; calculating a yaw compensation factor in proportion to said estimated vehicle yaw rate; and generating a desired motor speed signal from said base motor speed and said yaw compensation factor. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method of compensating a control signal for an electro-hydraulic power assist steering system including a variable-speed electric motor for pumping hydraulic fluid in the system, the method comprising:
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monitoring vehicle speed; monitoring vehicle steering wheel angle; monitoring vehicle steering wheel turning rate; establishing a base motor speed; estimating a vehicle yaw rate; and generating a desired motor speed signal from said base motor speed and a proportional yaw compensation factor calculated from said estimated vehicle yaw rate when said monitored vehicle steering wheel angle is greater than a first predetermined vehicle steering wheel angle and from said base motor speed and a constant yaw compensation factor when said monitored vehicle steering wheel angle exceeds a second predetermined vehicle steering wheel angle. - View Dependent Claims (10, 11, 12, 13)
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14. A method of compensating a control signal for an electro-hydraulic power assist steering system including a variable-speed electric motor for pumping hydraulic fluid in the system, the method comprising:
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monitoring vehicle speed; monitoring vehicle steering wheel angle; monitoring vehicle steering wheel turning rate; establishing a base motor speed; estimating a vehicle yaw rate; and generating a desired motor speed signal from said base motor speed and a proportional yaw compensation factor calculated using a low speed yaw gain for monitored vehicle speeds between a first predetermined vehicle speed and a second predetermined vehicle speed and using a high speed yaw gain for monitored vehicle speeds above a third predetermined vehicle speed. - View Dependent Claims (15, 16, 17)
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Specification