초록 ▼

The present invention solves the problems of the prior art by providing methods for compensating for temperature-dependent drift of bias in a vehicle heading sensor of a dead reckoning vehicle positioning system. Specifically, the invention uses a Kalman filter to generate a calibration curve for th

The present invention solves the problems of the prior art by providing methods for compensating for temperature-dependent drift of bias in a vehicle heading sensor of a dead reckoning vehicle positioning system. Specifically, the invention uses a Kalman filter to generate a calibration curve for the rate of heading sensor bias drift with temperature change. The Kalman filter calculates coefficients for a model of heading sensor bias drift rate versus temperature at each point where the vehicle is stationary. The bias drift rate calibration curve is then used to estimate a heading sensor bias periodically while the vehicle is moving. The invention further provides a method for using an aging time for temperature sensor bias drift rate to force convergence of the error variance matrix of the Kalman filter. The invention further provides vehicle navigational systems that utilize the methods of the present invention.

대표청구항 ▼

The present invention solves the problems of the prior art by providing methods for compensating for temperature-dependent drift of bias in a vehicle heading sensor of a dead reckoning vehicle positioning system. Specifically, the invention uses a Kalman filter to generate a calibration curve for th

The present invention solves the problems of the prior art by providing methods for compensating for temperature-dependent drift of bias in a vehicle heading sensor of a dead reckoning vehicle positioning system. Specifically, the invention uses a Kalman filter to generate a calibration curve for the rate of heading sensor bias drift with temperature change. The Kalman filter calculates coefficients for a model of heading sensor bias drift rate versus temperature at each point where the vehicle is stationary. The bias drift rate calibration curve is then used to estimate a heading sensor bias periodically while the vehicle is moving. The invention further provides a method for using an aging time for temperature sensor bias drift rate to force convergence of the error variance matrix of the Kalman filter. The invention further provides vehicle navigational systems that utilize the methods of the present invention. steps of: (A) generating a set of data related to the distribution of power applied to the heating elements in said zones; (B) converting the said data set into a data format representing the current collective state of power distribution for all of the said zones; (C) comparing the converted data set with a set of statistical data representing a reference standard; and (D) changing at least one process control parameter affecting the thermal process based on the comparison in step (C). 2. The method of claim 1, where step (B) is performed by: determining the total power applied to all of the lamps in all of the zones, and processing a plurality of fractions by dividing the numerical values of the power applied to the lamps in each of the zones by total power. 3. The method of claim 2 wherein step (B) is further performed by sequentializing the values represented by said fractions by arranging said fractions in order from the smallest to the largest numerical value, and calculating the slope of the sequentialized fractional values. 4. The method of claim 3, wherein the slope is calculated by a least squares straight line method. 5. The method of claim 1, wherein said process control parameter is the length of time the rapid thermal process is carried out. 6. The method of claim 2, wherein step (B) is further performed by weighting at least certain of said fractions. 7. The method of claim 1, wherein step (D) includes periodically determining the changes in the level of power applied to the said heating elements in each of the zones. 8. The method of claim 3, including the steps of: storing said set of statistical data in a programmed computer, and inputting said slope to said computer, and wherein said programmed computer compares said slope to said set of statistical data. 9. A method of detecting and controlling in-situ faults occurring in a rapid thermal process system of the type employing a multiplicity of heating elements spatially arranged in a plurality of zones, comprising the steps of: (A) determining the power applied to the heating elements in each of the zones; (B) determining the total power applied to all of the heating elements in all of said zones; (C) forming a plurality of fractions respectively associated with said plurality of said zones, wherein the numerator of each of said fractions represents the power applied to the associated zone, and the denominator represents the power applied to the heating elements in all of the zones; (D) arranging said fractions in a desired sequence; (E) determining the slope of a line representing the values of the sequentially arranged fractions; (F) comparing said slope with a reference slope; and (G) changing at least one parameter for controlling said process based on the comparison performed in Step (F). 10. The method of claim 9, wherein the sequence in step D is from the smallest value to the largest value. 11. The method of claim 9, wherein step (E) is performed by a least squares calculated method. 12. The method of claim 9, said reference slope is related to a set of historical statistics forming a part of a statistical process control system. 13. The method of claim 9, wherein said one parameter comprises the time period over while the process is carried out. 14. The method of claim 9, including the step of terminating the process when the comparison performed in step (F) indicates the occurrence of fault. e device, a manual switch provided on the outside of the controller in a recessed portion of the housing member accessible only by a tool for contacting the manual switch and switching the drive unit selecting circuit for selecting a drive unit to be used, wherein the main drive unit and the backup drive unit of the hard disk drive device have identical contents stored therein including data for mounting components on substrates, data for data processing programs, and after computer system startup, results of data processing executed by the arithmetic unit are written to both of the main drive unit and the backup drive unit so that the contents of both of the main drive unit and the backup drive unit are maintained the same.