Boundary adaptation scheme for spool valve pressure control
First Claim
1. A method for adapting a closing boundary for a proportional spool valve comprising:
- (a) generating a pressure command signal;
(b) obtaining a pressure error by subtracting an actual brake pressure from its pressure command;
(c) calculating a modified pressure error;
(d) using an estimator to estimate an apply boundary deviation or a release boundary deviation of the spool valve, as appropriate; and
(e) updating a boundary table using the resultant boundary deviation estimate.
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Accused Products
Abstract
A method for adapting a closing boundary for a proportional spool valve includes generating or detecting a pressure command signal. Next a pressure error is obtained by subtracting an actual wheel brake pressure from its pressure command. Then a modified pressure error is calculated a modified pressure error is calculated in such a way that steady state pressure errors resulting from mismatched feedforward term, control deadzone and other factors are subtracted from measured pressure error to leave the only error to be that due to boundary deviation. An estimator is then used to estimate an apply boundary deviation or a release boundary deviation of the spool valve, as appropriate. A boundary table is updated using the resultant boundary deviation estimate.
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Citations
25 Claims
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1. A method for adapting a closing boundary for a proportional spool valve comprising:
- (a) generating a pressure command signal;
(b) obtaining a pressure error by subtracting an actual brake pressure from its pressure command;
(c) calculating a modified pressure error;
(d) using an estimator to estimate an apply boundary deviation or a release boundary deviation of the spool valve, as appropriate; and
(e) updating a boundary table using the resultant boundary deviation estimate. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
- (a) generating a pressure command signal;
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16. A method for adapting a closing boundary for a proportional spool valve comprising:
- (a) detecting a pressure command signal;
(b) obtaining a pressure command derivative over time;
(c) using the sign of the pressure command derivative over time to determine which closing boundary should be updated;
(d) obtaining a pressure error by subtracting an actual brake pressure from its pressure command;
(e) calculating a modified pressure error;
(f) implementing the modified pressure error in the estimation;
(g) implementing an estimator to estimate a boundary deviation of the valve; and
(h) updating a boundary table using the resultant boundary deviation estimate. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25)
- (a) detecting a pressure command signal;
Specification