TY - GEN
T1 - Novel non-intrusive sensor for piston position measurement
AU - Taghvaeeyan, Saber
AU - Rajamani, Rajesh
AU - Sun, Zongxuan
PY - 2013
Y1 - 2013
N2 - This paper proposes a novel sensor for the non-intrusive real-time measurement of piston position inside a cylinder. The proposed sensor exploits the principle that any ferromagnetic object has an inherent magnetic field which varies as a function of position around the object. By modeling the magnetic field as a function of position and using sensors to measure magnetic field intensity, the position of the object can be estimated. This principle is used to measure piston position in a free piston engine without requiring any sensors inside the engine cylinder. The piston is approximated as a rectangular metallic object and the variation of the magnetic field around it is modeled. A challenge arises from the fact that the parameters of the model would vary from engine to engine and would be cumber-some to calibrate for each engine. This challenge is addressed by utilizing two magnetic field sensors with known longitudinal separation between them. An iterated least squares algorithm then provides adaptive parameter estimates and accurate position estimation. Experimental results from a free piston engine set up show that the proposed sensor can provide better than 0.4 mm accuracy in position estimates. The proposed sensing concept can be utilized for piston position measurement in multi-cylinder SI and diesel engines, hydraulic cylinders and in many other position measurement applications.
AB - This paper proposes a novel sensor for the non-intrusive real-time measurement of piston position inside a cylinder. The proposed sensor exploits the principle that any ferromagnetic object has an inherent magnetic field which varies as a function of position around the object. By modeling the magnetic field as a function of position and using sensors to measure magnetic field intensity, the position of the object can be estimated. This principle is used to measure piston position in a free piston engine without requiring any sensors inside the engine cylinder. The piston is approximated as a rectangular metallic object and the variation of the magnetic field around it is modeled. A challenge arises from the fact that the parameters of the model would vary from engine to engine and would be cumber-some to calibrate for each engine. This challenge is addressed by utilizing two magnetic field sensors with known longitudinal separation between them. An iterated least squares algorithm then provides adaptive parameter estimates and accurate position estimation. Experimental results from a free piston engine set up show that the proposed sensor can provide better than 0.4 mm accuracy in position estimates. The proposed sensing concept can be utilized for piston position measurement in multi-cylinder SI and diesel engines, hydraulic cylinders and in many other position measurement applications.
KW - Position measurement
KW - magnetic sensors
KW - parameter estimation
KW - piston position estimation
UR - http://www.scopus.com/inward/record.url?scp=84883500406&partnerID=8YFLogxK
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U2 - 10.1109/acc.2013.6580393
DO - 10.1109/acc.2013.6580393
M3 - Conference contribution
AN - SCOPUS:84883500406
SN - 9781479901777
T3 - Proceedings of the American Control Conference
SP - 3631
EP - 3636
BT - 2013 American Control Conference, ACC 2013
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 2013 1st American Control Conference, ACC 2013
Y2 - 17 June 2013 through 19 June 2013
ER -