Vehicle motion estimating system
First Claim
1. A vehicle motion estimating system comprising:
- means for sensing a steering wheel angle of a controlled vehicle, determining an actual value of said steering wheel angle, and producing a signal indicative of said steering wheel angle,means for sensing a vehicle speed of said controlled vehicle, determining an actual value of said vehicle speed, and producing a signal indicative of said speed,means for sensing a first motion variable of said controlled vehicle, determining an actual value of said first motion variable, and producing a signal indicative of said first motion variable,means for sensing a second motion variable of said controlled vehicle, determining an actual value of said second motion variable, and producing a signal indicative of said second motion variable, andprocessing means, with inputs receiving the signals produced by said steering wheel angle sensing means, vehicle speed sensing means and first and second motion variable sensing means, for estimating from said signals at least a third variable defining a motion of said controlled vehicle, said processing means comprising state discriminating means for producing a condition signal which is in a first signal state when said controlled vehicle is in a steady state turning motion and in a second signal state when said controlled vehicle is in transient state turning motion, motion estimating means for determining estimated values of said first, second and third variables corresponding to the signals indicative of said actual values of said steering wheel angle and vehicle speed by solving at least a first mathematical vehicle model which is determined by equations of vehicle motion and values of a group of vehicle characterizing parameters comprising a first vehicle characterizing parameter, and parameter adjusting means for adjusting the value of said first vehicle characterizing parameter used in determining said estimated value of said third variable in accordance with a result of a comparison between said actual and estimated values of said first motion variable when said condition signal is in said first signal state, and in accordance with a result of a comparison between said actual and estimated values of said second motion variable when said condition signal is in said second signal state.
1 Assignment
0 Petitions
Accused Products
Abstract
A system for estimating the state of a controlled vehicle'"'"'s motion has a steering wheel angle sensor, a vehicle speed sensor, a sensor for sensing a first motion variable such as a yaw rate, a sensor for sensing a second motion variable such as a yaw acceleration, and a processing unit such as a microcomputer. In accordance with the sensor output signals, the processing unit produces a condition signal which is in a first signal state when the unit determines that the vehicle is in a steady-state turning motion, and in a second signal state when the unit determines that the vehicle is in a transient state turning motion. The processing unit determines estimated values of the first and second motion variables corresponding to the steering wheel angle and vehicle speed by solving a first predetermined mathematical vehicle model, and further determines an estimated value of a third motion variable such as slip angle or steer angle by solving a second mathematical vehicle model which may be identical to or different from the first model. The processing unit adjusts a value of a vehicle characterizing parameter such as a cornering power of the second model in accordance with the result of comparison between the sensed and estimated values of the first motion variable when the condition signal is in the first state, and in accordance with the result of comparison between the sensed and estimated value of the second motion variable when the condition signal is in the second state.
-
Citations
13 Claims
-
1. A vehicle motion estimating system comprising:
-
means for sensing a steering wheel angle of a controlled vehicle, determining an actual value of said steering wheel angle, and producing a signal indicative of said steering wheel angle, means for sensing a vehicle speed of said controlled vehicle, determining an actual value of said vehicle speed, and producing a signal indicative of said speed, means for sensing a first motion variable of said controlled vehicle, determining an actual value of said first motion variable, and producing a signal indicative of said first motion variable, means for sensing a second motion variable of said controlled vehicle, determining an actual value of said second motion variable, and producing a signal indicative of said second motion variable, and processing means, with inputs receiving the signals produced by said steering wheel angle sensing means, vehicle speed sensing means and first and second motion variable sensing means, for estimating from said signals at least a third variable defining a motion of said controlled vehicle, said processing means comprising state discriminating means for producing a condition signal which is in a first signal state when said controlled vehicle is in a steady state turning motion and in a second signal state when said controlled vehicle is in transient state turning motion, motion estimating means for determining estimated values of said first, second and third variables corresponding to the signals indicative of said actual values of said steering wheel angle and vehicle speed by solving at least a first mathematical vehicle model which is determined by equations of vehicle motion and values of a group of vehicle characterizing parameters comprising a first vehicle characterizing parameter, and parameter adjusting means for adjusting the value of said first vehicle characterizing parameter used in determining said estimated value of said third variable in accordance with a result of a comparison between said actual and estimated values of said first motion variable when said condition signal is in said first signal state, and in accordance with a result of a comparison between said actual and estimated values of said second motion variable when said condition signal is in said second signal state. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
-
-
13. A steering control system for a controlled vehicle having a pair of first wheels and a pair of second wheels, comprising:
-
means for sensing a steering wheel angle of said controlled vehicle, determining an actual value of said steering wheel angle, and producing an output signal indicative of said steering wheel angle, means for sensing a vehicle speed of said controlled vehicle, determining an actual value of said vehicle speed, and producing an output signal indicative of said vehicle speed, means for sensing a first motion variable of said controlled vehicle, determining an actual value of said first motion variable, and producing an output signal indicative of said first motion variable, means for sensing a second motion variable of said controlled vehicle, determining an actual value of said second motion variable, and producing an output signal indicative of said motion variable, processing means with inputs receiving the signals produced by each of said sensing means, said processing means comprising state discriminating means for producing a condition signal from said sensing means signals which is in a first signal state when said controlled vehicle is in a steady-state turning motion and in a second signal state when said controlled vehicle is in a transient state turning motion, estimating means for determining from said sensing means signals estimated values of said first and second motion variables corresponding to said actual values of said steering wheel angle and vehicle speed by solving a mathematical desired vehicle model and further determining at least a desired value of a first wheel steer angle for said first wheels corresponding to said estimated values of said first and second motion variables and said actual values of said steering wheel angle and vehicle speed by solving a mathematical actual vehicle model determined by actual values of a first vehicle characterizing parameter and other vehicle characterizing parameters of said controlled vehicle, and parameter adjusting means for adjusting the value of said first vehicle characterizing parameter used in said actual vehicle model in accordance with a result of a comparison between said actual and estimated values of said first motion variable when said condition signal is in said first state and in accordance with a result of a comparison between said actual and estimated values of said second motion variable when said condition signal is in said second state, and actuating means for steering at least the pair of said first wheels in accordance with said desired value of said first wheel steer angle.
-
Specification