2001-01-0595 A Model-Based Brake Pressure Estimation ... - Delphi

TCS Brake Pressure Estimate Model
1
s
Xp
Displacement
Vs. Pressure
Ps
Pc
Apply Command
Apply
Valve
Release Command Release
Valve
Figure 3 SIMULINK diagram of one channel brake pressure estimation model for TCS
From the results, it is apparent that the new model-based
TCS brake pressure estimation gives fairly accurate brake
pressure estimation. Since this algorithm is based on a
physical model, it can predict brake pressure accurately
over all testing conditions. And a big advantage of the
proposed algorithm is the reduction of calibration time.
CONCLUSION
In this paper, a model-based brake pressure estimation
algorithm for TCS is presented. The algorithm is simplified
based on model analysis to enable production
implementation. The pressure estimation algorithm is
validated using vehicle data. The simulation results show
that the new algorithm can predict brake pressure
accurately for traction control systems, and is robust for
all testing cases.
In addition, there are fewer calibration variables that need
to be determined from testing than in the current
algorithm. This means significant savings in calibration
time and cost. This algorithm more accurately estimates
the pressure at the driven wheel allowing the brake control
systems to depend more heavily on this estimation. The
improved algorithm can reduce brake wear and improve
driver comfort during an active brake control event.
ACKNOWLEDGMENTS
The authors acknowledge gratefully the technical support
of Bryan T. Fulmer, Joseph A. Elliott of Delphi Technical
Q1
Q2
1/ap
Xp_dot
Center Brighton and James R. Bond of Delphi Technical
Center Dayton. Specially, for the discussion with Bryan T.
Fulmer
REFERENCES
1. Paul, J., Klinkner, W., Muller, A., “Electronic stability
program - the new active safety system of mercedesbenz”
SAE 97-06 957128.
2. “Automotive Brake Systems,” Robert Bosch GmbH,
1995.
3. Merritt, H.E., “Hydraulic Control Systems” John Wiley
and Sons, Inc., 1967.
4. Doebelin, E.O., “System Dynamics Modeling,
Analysis, Simulation, Design” Marcel Dekker, Inc.,
1998.
CONTACT
Qingyuan Li and Keith W. Beyer are systems engineers
in Chassis Systems, and Quan Zheng is a Controls
engineer in Forward Energy and Energy Management
Systems at Delphi Automotive Systems, Technical Center
Brighton, 12501 E. Grand River, Brighton, MI 48116. Their
contacting emails are as follows:
qingyuan.li@delphiauto.com.
keith.w.beyer@delphiauto.com.
quan.zheng@delphiauto.com