Fuel volume measuring system for automotive vehicle

• US 4,611,287 A
• Filed: 06/08/1983
• Issued: 09/09/1986
• Est. Priority Date: 08/16/1982
• Status: Expired due to Term

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Kobayashi, Hiroshi, Obayashi, Hiroaki
• Primary Examiner(s): NOT, DEFINED
• Application Number:
  US06/502,321
• Time in Patent Office: 1,189 Days
• Field of Search: 73/313, 73/113, 73/114, 73/804 C, 361/284, 364/424, 364/442, 364/564, 364/575
• US Class Current: 701/123
• CPC Class Codes: G01F 23/20 by measurement of weight, e.g. to determine the level of stored liquefied gas
• CPC Class Codes: G01F 23/802 Particular electronic circuits for digital processing equipment

Abstract

A fuel volume measuring system for an automotive vehicle in which fuel volume detection signals are simply averaged during a relatively-short averaging time period at regular measuring cycles when the vehicle is being refueled, and further weight-averaged or moving-averaged at regular measuring cycles when the vehicle is running. Therefore, fuel volume can be indicated quickly at a high response speed when the vehicle is being refueled and additionally fuel volume fluctuations can be minimized when the vehicle is running. Further, the system according to the present invention discloses the method of detecting the state where the vehicle is being refueled on the basis of the fact that the difference between at-least one of the current data signal indicative of fuel volume and at-least one of the preceding data signal indicative of fuel volume exceeds a predetermined value.

Claims

1. A fuel volume measuring system for an automotive vehicle provided with a fuel tank, which comprises:

fuel volume sensing means for repeatedly outputting a fuel volume detection signal D_m corresponding to fuel volume within the fuel tank at regular time intervals;

first averaging means responsive to said fuel volume sensing means for averaging the fuel volume detection signal and outputting a first averaged fuel voulme data signal A_m ;

second averaging means responsive to said first averaging means for further averaging the averaged fuel volume data signal A_m and outputting a second averaged fuel volume data signal B_m ;

fuel volume calculating means for calculating a fuel volume on the basis of an effective averaged fuel volume data signal and outputting a fuel volume data signal Q_m ;

vehicle speed determining means for determining vehicle speed and causing either said first averaged fuel volume data signal A_m or said second averaged fuel volume data signal B_m to be provided as said effective averaged fuel volume data signal in response to said vehicle speed;

indicator means responsive to said fuel volume calculating means for indicating a fuel volume on the basis of the fuel volume data signal Q_m,

whereby the fuel volume data signal Q_m is calulated by said first and second averaging means for suppression of fluctuations of the fuel volume indication.

2. A fuel volume measuring system for an automotive vehicle as set forth in claim 1, which further comprises abnormal-data eliminating means responsive to said first averaging means and said second averaging means for eliminating the first averaged fuel volume data signal A_m applied from said first averaging means to said second averaging means, when the absolute difference value |A_m -B_m-1 | between the current first averaged fuel volume data signal A_m and the preceding second averaged fuel volume data signal B_m-1 is equal to or greater than a predetermined value a,

whereby the abnormal first averaged fuel volume data signal A_m can be eliminated before calculating the second averaged fuel volume data signal B_m .

3. A fuel volume measuring system for an automotive vehicle as set forth in claim 2, which further comprises allowable rang controlling means responsive to said abnormal data eliminating means for controlling a predetermined allowable range c in such a way that when the absolute difference value |A_m -B_m-1 | between the current first averaged fuel volume data signal A_m and the preceding second averaged fuel volume data signal B_m-1 is greater than the allowable range c, the predetermined allowable range c is stepwise increased by a predetermined value b until the absolute difference value between the two data signals A_m and B_m-1 becomes equal to or smaller than corrected and increased allowable range c and when the absolute difference value |A_m -B_m-1 | between the two data signals A_m and B_m-1 is equal to or smaller than the corrected and increased allowable range c, after calculating the second averaged fuel volume data signal B_m, the increased allowable range c is stepwise decreased by the same predetermined value b until the corrected allowable range c becomes the original predetermined allowable range c,

whereby the allowable range for the first averaged fuel volume data signal A_m can be controlled by adding or subtracting a predetermined value to or from the allowable range.

4. A fuel volume measuring system for an automotive vehicle as set forth in claim 1, which further comprises abnormal-data correcting means responsive to said first averaging means and said second averaging means for correcting the first averaged fuel volume data signal A_m applied from said first averaging means to said second averaging means, when the absolute difference value |A_m -B_m-1 | between the current first averaged fuel volume data signal A_m and the preceding second averaged fuel volume data signal B_m-1 is equal to or greater than a predetermined allowable range a, in such a way that when the current first averaged fuel volume data signal A_m is smaller than the preceding second averaged fuel volume data signal B_m-1, the current data signal A_m is corrected by subtracting a predetermined value b from the preceding second averaged fuel volume data signal B_m-1 and when the current first averaged fuel volume data signal A_m is equal to or greater than the preceding second averaged fuel volume data signal B_m-1, the current data signal A_m is corected by adding a predetermined value b to the preceding second averaged fuel volume data signal B_m-1,

whereby the abnormal first averaged fuel volume data signal A_m can be corrected by adding or subtracting a predetermined value to or from the preceding second averaged fuel volume data signal B_m-1.

5. A fuel volume measuring system for an automotive vehicle as set forth in claim 4, which further comprises an allowable range controlling means responsive to said abnormal data correcting means for controlling the allowable range a in such a way that when the absolute difference value |A_m -B_m-1 | between the current first averaged fuel volume data signal A_m and the preceding second averaged fuel volume data signal B_m-1 is greater than a predetermined range c, after adding or subtracting a predetermined value to or from the preceding second averaged data signal B_m-1 and calculating the second averaged fuel volume data signal B_m, the predetermined allowable range c is stepwise increased by a predetermined value b until the absolute difference value between the two data signals A_m and B_m-1 is equal to or smaller than the corrected allowable range c and when the absolute difference value |A_m -B_m-1 | between the two data signals A_m and B_m-1 is equal to or smaller than the corrected and increased allowable range c, after calculating the second averaged fuel volume data signal B_m, the increased allowable range c is stepwise decreased by the same predetermined value b until the range c becomes the original predetermined allowable range a,

whereby an abnormal first averaged fuel volume data signal A_m can be corrected by adding or substracting a predetermined value to or from the preceding second averaged data B_m-1 and additionally the allowable range for the first averaged fuel volume data signal A_m can be controlled by adding or subtracting a predetermined value to or from the allowable range.

6. A fuel volume measuring system for an automotive vehicle as set forth in claim 1, which further comprises abnormal data eliminating means responsive to only said second averaging means for eliminating the second averaged fuel volume data signal B_m applied from said second averaging means to said fuel volume calculating means, when the current second averaged fuel volume data signal B_m is greater than the preceding second averaged fuel volume data signal B_m-1,

whereby the abnormal second averaged fuel volume data signal B_m can be eliminated before calculating the fuel volume data signal Q_m.

7. A fuel volume measuring system for an automotive vehicle as set forth in claim 1, which further comprises abnormal data eliminating means responsive to said fuel volume calculating means for eliminating the fuel volume data signal Q_m applied from said fuel volume calculating means to said indicator means, when the current fuel volume data signal Q_m is greater than the preceding fuel volume data signal Q_m-1 ,

whereby the abnormal fuel volume data signal Q_m can be eliminated before indicating the fuel volume.

8. A fuel volume measuring system for an automotive vehicle as set forth in claim 1, wherein said vehicle speed determining means comprises:

(a) vehicle speed sensing means for detecting vehicle speeds; and

(b) running determination means responsive to said first averaging means and said vehicle speed sensor for supplying the first averaged fuel volume data signal A_m to said second averaging means when said vehicle speed sensor detects that vehicle speed is not zero but directly to said fuel volume calculating means without obtaining the second averaged fuel volume data signal B_m when said vehicle speed senser detects that vehicle speed is zero.

9. A fuel volume measuring system for an automotive vehicle as set forth in claim 1, wherein said first averaging means calculates the first averaged fuel volume data signal A_m on the basis of a fuel volume detection signal D_m and in accordance with the following simply-averaging expression:

##EQU3##

10. A fuel volume measuring system for an automotive vehicle as set forth in claim 1, wherein said second averaging means calculates the second averaged fuel volume data signal B_m on the basis of the first averaged fuel volume data signal A_m and in accordance with the following weight-averaging expression:

space="preserve" listing-type="equation">B.sub.m =((2.sup.p -1)/2.sup.p)B.sub.m-1 +(1/2.sup.p)A.sub.m+1

where p denotes a power.

11. A fuel volume measuring system for an automotive vehicle as set forth in claim 1, wherein said second averaging means calculates the second averaged fuel volume data signal B_m on the basis of the first averaged fuel volume data signal A_m and in accordance with the following moving-averaging expression. ##EQU4##

12. A fuel volume measuring system for an automotive vehicle as set forth in claim 1, wherein said fuel volume sensing means comprises:

(a) a volume sensor disposed within the fuel tank and provided with three electrode plates for detecting the fuel volume within the fuel tank in dependence upon a change in fuel level, said three electrode plates generating an electrostatic capacity which varies according to the change in the fuel level;

(b) a CR oscillator responsive to said volume sensor for outputting an oscillating signal the frequency of which varies in accordance with the electrostatic capacity generated by said volume sensor; and

(c) a divider responsive to said CR oscillator for dividing the oscillation signal from said CR oscillator and outputting a fuel volume detection signal.

24. A fuel volume measuring system for an automotive vehicle as set forth in claim 12, wherein said microcomputer further comprises the function of counting the number of times that the at-least one difference between the current data signal indicative of fuel volume and the preceding data signal indicative of fuel volume exceeds a predetermined value f and calculating the fuel volume Q_m on the basis of the weight-averaged fuel volume data signal B_m when the number of times does not exceed the predetermined value f and on the basis of the simply-averaged fuel volume data signam A_m when the number of times exceeds the predetermined value f.

13. A fuel volume measuring system for an automotive vehicle provided with a fuel tank which comprises:

(a) fuel volume measuring means for outputting fuel volume detection signals corresponding to fuel volume within the fuel tank at regular time intervals;

(b) first averaging means responsive to said fuel volume sensing means for averaging the fuel volume detection signal and outputting a first averaged volume data signal A_m ;

(c) second averaging means responsive to said first averaging means for further averaging the averaged fuel volume data signal A_m and outputting a second averaged fuel volume data signal B_m ;

(d) subtracting means responsive to said first averaging means and said second averaging means for subtracting the preceding second averaged fuel volume data signal B_m-1 from the current first averaged fuel volume data signal A_m and outputting a subtracted data signal;

(e) comparating means responsive to said subtracting means for comparing the subtracted data signal with a predetermined value inclusive of zero and outputting a refuel command signal when the subtracted result is greater than said predetermined value and a vehicle-run command signal when the subtracted result is equal to or smaller than the predetermined value;

(f) selecting means responsive to said first averaging means, second averaging means and said comparating means for selecting the first averaging means in response to the refuel command signal from said comparating means but selecting the second averaging means in response to the vehicle-run command signal;

(g) fuel volume calculating means responsive to said selecting means for calculating a fuel volume on the basis of the first averaged fuel volume data signal A_m when said selecting means selects said first averaging means and on the basis of the second averaged fuel volume data signal B_m when said selecting means selects said second averaging means and for outputting a fuel volume signal Q_m ; and

(h) indicator means responsive to said fuel volume calculating means for indicating a fuel volume on the basis of the fuel volume signal Q_m,

whereby the fuel volume can be calculated on the basis of the first averaged fuel volume data signal A_m when the current first averaged fuel volume data signal A_m is greater than the preceding second averaged fuel volume data signal B_m-1 but on the basis of the second averaged fuel volume data signal B_m when the A_m is equal to or smaller than B_m-1,

and therefore a vehicle refueling condition can be detected on the basis of the difference between A_m and B_m-1.

14. A fuel volume measuring system for an automotive vehicle provided with a fuel tank which comprises:

(a) fuel volume sensing means for outputting fuel volume detection signals corresponding to fuel volume within the fuel tank at regular time intervals;

(b) first averaging means responsive to said fuel volume sensing means for averaging the fuel volume detection signal and outputting a first current averaged volume data signal A_m ;

(c) first subtracting means responsive to said first averaging means for subtracting a preceding first averaged fuel volume data signal A_m-1 from the current first averaged fuel volume data signal A_m and outputting a subtracted data signal;

(d) first comparating means responsive to said first subtracting means for comparing the subtracted data signal with a predetermined value inclusive of zero and outputting a refuel command signal when the subtracted result is greater than a predetermined value and a vehicle-run command signal when the subtracted result is equal to or smaller than the predetermined value;

(e) first selecting means responsive to said first averaging means and said first comparing means for connecting the first averaging means to a fuel volume calculating means in response to the refuel command signal from said first comparator but to a second averaging means in response to the vehicle-run command signal from said first comparator;

(f) said second averaging means being responsive to said first selecting means for further averaging the averaged fuel volume data signal A_m and outputting a second current averaged fuel volume data signal B_m, when said first selecting means connects said first averaging means thereto in response to the vehicle-run command signal from said first comparator;

(g) second subtracting means responsive to said second averaging means for subtracting a preceding second averaged fuel volume data signal B_m-1 from the current second averaged fuel volume data signal B_m and outputting a second subtracted data signal;

(h) second comparing means responsive to said second subtracting means for comparing the second subtracted data signal with a second predetermined value inclusive of zero and outputting a vehicle-run command signal when the second subtracted result exceeds said second predetermined value and an inhibit command signal when the second subtracted result is equal to or smaller than said second predetermined value;

(i) second selecting means responsive to said second averaging means and said second comparating means for connecting said second averaging means to said fuel volume calculating means in response to the vehicle-run command signal from said second comparing means but for inhibiting the second averaged fuel volume data signal B_m from being supplied to the fuel volume calculating means in response to said inhibit signal;

(j) said fuel volume calculating means being responsive to said second selecting means for calculating a fuel volume signal Q_m on the basis of the second averaged fuel volume data signal B_m when said selecting means connects said first averaging means to said second averaging means and additionally when said second selecting means connects said second averaging means to said fuel volume calculting means but on the basis of the first averaged fuel volume data signal A_m when said first selecting means directly connects said first averaging means to said fuel volume calculating means, and outputting a fuel volume signal Q_m ; and

(k) indicator means responsive to said fuel volume calculating means for indicating a fuel volume on the basis of the fuel volume signal Q_m,

whereby the fuel volume can be calculated on the basis of the first averaged fuel volume data signal A_m when the current first averaged fuel volume data signal A_m is greater than the preceding first averaged fuel volume data signal A_m-1 and additionally when the current second averaged fuel volume data signal B_m is greater than the preceding second averaged fuel volume data signal B_m-1 but on the basis of the second averaged fuel volume data signal B_m when A_m is equal to or smaller than A_m-1 and when B_m is equal to or smaller than B_m-1, and therefore the vehicle refueling condition can be detected on the basis of differences between A_m and B_m-1 and between B_m and B_m-1.

15. A fuel volume measuring system for an automotive vehicle provided with a fuel tank, which comprises:

(a) a volume sensor disposed within the fuel tank and provided with three electrode plates for detecting the fuel volume within the fuel tank in dependence upon the change in fuel level, said three electrode plates generating the electrostatic capacity varied according to the change in the fuel level;

(b) a CR oscillator responsive to said volume sensor for outputting an oscillating signal the frequency of which varies in accordance with the electrostatic capacity generated by said volume sensor;

(c) a divider responsive to said CR oscillator for dividing the oscillation signal from said CR oscillator and outputting a fuel volume detection signal;

(d) a vehicle speed sensor for detecting vehicle speeds;

(e) a microcomputer including an input interface, central processing unit, a read-only memory, a random access memory, a clock generator, an output interface, etc. and responsive to said CR divider and said vehicle speed sensor, for averaging the fuel volume detection signal to obtain a simply averaged fuel volume data signal A_m, further weight-averaging the simply-averaged fuel volume data signal A_m to obtain a weight-averaged fuel volume data signal B_m when the vehicle speed is not zero, and calculating a fuel volume data signal Q_m on the basis of the weight-averaged fuel volume data signal B_m when the vehicle speed is not zero but on the basis of the simply-averaged fuel volume data signal A_m when the vehicle speed is zero; and

(f) an indicator responsive to said microcomputer for indicating a fuel volume on the basis of the calculated fuel volume data signal Q_m,

whereby the fuel volume data signal Q_m is calculated on the basis of the weight-averaged fuel volume data signal B_m for suppression of fluctuations of the fuel volume indication when the vehicle speed is not zero.

16. A fuel volume measuring system for an automotive vehicle as set forth in claim 15, wherein said microcomputer further comprises the functions of determining whether or not the absolute difference value between the current simply-averaged fuel volume data signal A_m and the preceding weight-averaged fuel volume data signal B_m-1 is equal to or greater than a predetermined value a and of eliminating the simply-averaged fuel volume data signal A_m when the absolute difference value between A_m and B_m-1 is equal to or greater than the predetermined value a beofre calculating the weight-averaged fuel volume data signal B_m on the basis of the simply-averaged fuel volume data signal A_m,

whereby the abnormal simply-averaged fuel volume data signal A_m can be eliminated before calculating the weight-averaged fuel volume data signal B_m.

17. A fuel volume measuring system for an automotive vehicle as set forth in claim 15, wherein said microcomputer further comprises the functions of determining whether or not the absolute difference value between the current simply-averaged fuel volume data signal A_m and the preceding weight-averaged fuel volume data signal B_m-1 is equal to or greater than a predetermined value a and of correcting the simply-averaged fuel volume data signal A_m, when the absolute difference value between A_m and B_m-1 is equal to or greater than the value a, by subtracting a predetermined value b from the preceding weight-averaged fuel volume data signal B_m-1 when the current simply-averaged fuel volume data signal A_m is smaller than the preceding weight-averaged fuel volume data signal B_m-1 and by adding the value b to the preceding weight-averaged fuel volume data signal B_m-1 when A_m is greater than B_m-1, before calculating the weight-averaged fuel volume data signal B_m,

whereby the abnormal simply-averaged fuel volume data signal A_m can be corrected by adding or subtracting a predetermined value to or from the preceding second averaged fuel volume data signal B_m-1.

18. A fuel volume measuring system for an automotive vehicle as set forth in claim 15, wherein said microcomputer further comprises the functions of determining whether or not the absolute difference value between the current simply-averaged fuel volume data signal A_m and the preceding weight-averaged fuel volume data signal B_m-1 is equal to or smaller than a allowable range c and of controlling the allowable range c by stepwise increasing the allowable range c by a predetermined value b until the absolute difference value between the two data signals A_m and B_m-1 becomes equal to or smaller than the corrected allowable range c when the absolute difference value between the two data signals A_m and B_m-1 is greater than the predetermined allowable range c and by stepwise decreasing the allowable range c by a predetermined value b until the corrected allowable range c becomes the original predetermined allowable range c, after calculating the weight-averaged fuel volume data signal B_m, when the absolute difference value between the two data signals A_m and B_m-1 becomes equal to or smaller than the corrected and increased allowable range c,

whereby the allowable range for the simply-averaged fuel volume data signal A_m can be controlled by adding or subtracting a predetermined value to or from the allowable range.

19. A fuel volume measuring system for an automotive vehicle as set forth in claim 15, wherein said microcomputer further comprises the functions of determining whether or not the absolute difference value between the current simply-averaged fuel volume data signal A_m and the preceding weight-averaged fuel volume data signal B_m-1 is equal to or smaller than a predetermined value c, of correcting the simply-averaged fuel volume data signal A_m, when the absolute difference value between A_m and B_m-1 is greater than the predetermined allowable range c, by adding or subtracting a predetermined value b to or from the preceding weight-averaged fuel volume data signal B_m-1, and of controlling the allowable range c by stepwise increasing the allowable range c by a predetermined value b until the absolute difference value between the two data signals A_m and B_m-1 becomes equal to or smaller than the corrected allowable range c, after calculating the weight-averaged fuel volume data signal B_m when the absolute difference value between the two data signals A_m and B_m-1 is greater than the predetermined allowable range c and by stepwise decreasing the increased allowable range c by a predetermined value b until the corrected allowable range c becomes the original predetermined allowable range c, after calculating the weight-averaged fuel volume data signal B_m when the absolute difference value between the two data signals A_m and B_m-1 becomes equal to or smaller than the corrected and increased allowable range c,

whereby an abnormal simply-averaged fuel volume data signal A_m can be corrected by adding or subtracting a predetermined value to or from the preceding second averaged data B_m-1 and additionally the allowable range for the simply-averaged fuel volume data signal A_m can be controlled by adding or subtracting a predetermined value to or from the allowable range.

20. A fuel volume measuring system for an automotive vehicle as set forth in claim 15, wherein said microcomputer further comprises the functions of comparing the current weight-averaged fuel volume data signal B_m with the preceding weight-averaged fuel volume data signal B_m-1 and of eliminating the current data signal B_m before calculating the fuel volume signal Q_m when the current weight-averaged fuel volume data signal B_m is greater than the preceding weight-averaged fuel volume data signal B_m-1,

whereby the abnormal weight-averaged fuel volume data signal B_m can be eliminated before calculating the fuel volume data signal Q_m.

21. A fuel volume measuring system for an automotive vehicle as set forth in claim 15, wherein said microcomputer further comprises the functions of comparing the current moving-averaged fuel volume data signal C_m with the preceding moving-averaged fuel volume data signal C_m-1 and of eliminating the current data C_m before calculating the fuel volume signal C_m when the current moving-averaged fuel volume data signal C_m is greater than the preceding moving-averaged fuel volume data signal C_m-1,

whereby the abnormal moving-averaged fuel volume data signal C_m can be eliminated before calculating the fuel volume signal Q_m.

22. A fuel volume measuring system for an automotive vehicle as set forth in claim 15, wherein said microcomputer further comprises the functions of comparing the current fuel volume signal Q_m with the preceding fuel volume signal Q_m-1 and of eliminating the current data signal Q_m before indicating the fuel volume when the current fuel volume signal Q_m is greater than the preceding fuel volume signal Q_m-1,

whereby the abnormal fuel volume signal Q_m can be eliminated before indicating the fuel volume.

23. A fuel volume measuring system for an automotive vehicle provided with a fuel tank, which comprises:

(a) a volume sensor disposed within the fuel tank and provided with three electrode plates for detecting the fuel volume within the fuel tank in dependence upon the change in fuel level, said three electrode plates generating the electrostatic capacity varied according to the change in the fuel level;

(b) a CR oscillator responsive to said volume sensor for outputting an oscillating signal the frequency of which varies in accordance with the electrostatic capacity generated by said volume sensor;

(c) a divider responsive to said CR oscillator for dividing the oscillation signal from said CR oscillator and outputting a fuel volume detection signal; and

(d) a microcomputer including an input interface, central processing unit, a read-only memory, a random access memory, a clock generator, an output interface, etc., and responsive to said CR oscillator, for averaging the fuel volume detection signal to obtain a simply-averaged fuel volume data signal A_m, further weight-averaging the simply-averaged fuel volume data signal A_m to obtain a weight-averaged fuel volume data signal B_m, subtracting at-least one preceding data signal S_m-1 indicative of fuel volume from at-least one current data signal S_m indicative of fuel volume to obtain at-least one difference between current fuel volume data and preceding fuel volume data, comparing the at-least one obtained difference with at-least one predetermined value, calculating a fuel volume Q_m on the basis of the weight-averaged fuel volume data signal B_m only when the at-least one difference between the current data signal and the preceding data signal is equal to or smaller than said predetermined value, and on the basis of the simply-averaged fuel volume data signal A_m when the at-least one difference between the current data signal and the preceding data signal is greater than the predetermined value,

whereby a vehicle refueling condition can be detected on the basis of the difference between S_m and S_m-1.

25. A fuel volume measuring system for an automotive vehicle as set forth in claim 23, wherein said at-least one of the preceding data signal S_m-1 indicative of fuel volume is the simply-averaged fuel volume data signal A_m-1.

26. A fuel volume measuring system for an automotive vehicle as set forth in claim 23, wherein said at-least one of the preceding data signal S_m-1 indicative of fuel volume is the weight-averaged fuel volume data signal B_m-1.

27. A fuel volume measuring system for an automotive vehicle as set forth in claim 23, wherein said at-least one of the preceding data signal S_m-1 indicative of fuel volume is a moving-averaged fuel volume data signal C_m-1.

28. A fuel volume measuring system for an automotive vehicle as set forth in claim 23, wherein said at-least one of the preceding data signal S_m-1 indicative of fuel volume is the fuel volume data signal Q_m-1.

29. A fuel volume measuring system for an automotive vehicle as set forth in claim 23, wherein said at-least one of the current data signal S_m indicative of fuel volume is the simply-averaged fuel volume data signal A_m.

30. A fuel volume measuring system for an automotive vehicle as set forth in claim 23, wherein said at-least one of the current data signal S_m indicative of fuel volume is the weight-averaged fuel volume data signal B_m.

31. A fuel volume measuring system for an automotive vehicle as set forth in claim 23, wherein said at least one of the current data signal S_m indicative of fuel volume is a moving-averaged fuel volume data signal C_m.

32. A fuel volume measuring system for an automotive vehicle as set forth in claim 23, wherein said at least one of the current data signal S_m indicative of fuel volume is the fuel volume signal Q_m.

33. A method of measuring fuel volume within a fuel tank for an automotive vehicle, which comprises the following steps of:

(a) detecting the fuel volume within the fuel tank repeatedly and outputting fuel volume detection signals corresponding thereto at regular time intervals;

(b) simply-averaging the fuel volume detection signals and outputting simply-averaged fuel volume data signals A_m ;

(c) detecting vehicle speed;

(d) if vehicle speed is zero, calculating the fuel volume data signal Q_m on the basis of the simply-averaged fuel volume data signal A_m ;

(e) if vehicle speed is not zero, weight-averaging the simply-averaged fuel volume data signal A_m, outputting a weight-averaged fuel volume data signal B_m and calculating the fuel volume data signal Q_m on the basis of the calculated weight-averaged fuel volume data signal B_m ; and

(f) indicating the fuel volume in accordance with the calculated fuel volume data signal Q_m,

whereby the fuel volume can be indicated on the basis of simply-averaged data signal A_m when vehicle speed is zero but of weight-averaged data signal B_m when vehicle speed is not zero.

34. A method of measuring fuel volume within a fuel tank for an automotive vehicle as set forth in claim 33, which further comprises the following step of:

(a) comparing the absolute difference value between the current simply-averaged fuel volume data signal A_m and the preceding weight-averaged fuel volume data signal B_m-1 with a predetermined value a;

(b) if the absolute difference value |A_m -B_m-1 | is equal to or greater than the predetermined value a, eliminating the simply-averaged fuel volume data signal A_m, and

(c) if the absolute difference value |A_m -B_m-1 | is smaller than the predetermined value a, weight-averaging the simply-averaged fuel volume data signal A_m before calculating the fuel volume data signal Q_m,

whereby an abnormal simply-averaged fuel volume data signal A_m can be eliminated.

35. A method of measuring fuel volume within a fuel tank for an automotive vehicle as set forth in claim 33, which further comprises the following steps of:

(a) comparing the absolute difference value between the current simply-averaged fuel volume data signal A_m and the preceding weight-averaged fuel volume data signal B_m-1 with a predetermined value a;

(b) if the absolute difference value |A_m -B_m-1 | is smaller than the predetermined value a, weight-averaging the simply-averaged fuel volume data signal A_m before calculating the fuel volume signal Q_m ;

(c) if the absolute difference value |A_m -B_m-1 | is equal to or greater than the predetermined value a,

(d) comparing the current simply-averaged fuel volume data signal A_m with the preceding weight-averaged fuel volume data signal B_m-1 ;

(e) if the current simply-averaged data signal A_m is equal to or greater than the preceding weight-averaged data signal B_m-1, correcting the current simply-averaged fuel volume data signal A_m by adding a predetermined value b to the preceding weight-averaged fuel volume data B_m-1 before weight-averaging the simply-averaged fuel volume data signal A_m ; and

(f) if the current simply-averaged data signal A_m is smaller than the preceding weight-averaged data signal B_m-1, correcting the current simply-averaged fuel volume data signal A_m by subtracting the predetermined value b from the preceding weight-averaged fuel volume data B_m-1, before weight-averaging the simply-averaged fuel volume data signal A_m ;

whereby an abnormal simply-averaged fuel volume data signal A_m can be corrected.

36. A method of measuring fuel volume within a fuel tank for an automotive vehicle as set forth in claim 33, which further comprises the following steps of:

(a) comparing the absolute difference value between the current simply-averaged fuel volume data signal A_m and the preceding weight-averaged fuel volume data signal B_m-1 with a predetermined allowable range c;

(b) if the absolute difference value |A_m -B_m-1 | is greater than the allowable range c, stepwise increasing the range c by a predetermined value b until the absolute difference value lies within the increased allowable range c before weight-averaging the simply-averaged fuel volume data signal A_m ; and

(c) if the absolute difference value |A_m -B_m-1 | is equal to or smaller than the allowable range c, weight averaging the simply-averaged fuel volume data signal A_m, and stepwise decreasing the increased allowable range c by the predetermined value b until the decreased allowable range c becomes the initial allowable range c before calculating fuel volume signal Q_m,

whereby the allowable range for an abnormal simply-averaged fuel volume data signal A_m can be increased or decreased.

37. A method of measuring fuel volume within a fuel tank for an automotive vehicle as set forth in claim 33, which further comprises the following steps of:

(a) comparing the absolute difference value between the current simply-averaged fuel volume data signal A_m and the preceding weight-averaged fuel volume data signal B_m-1 with a predetermined allowable range c;

(b) if the absolute difference value |A_m -B_m-1 | is greater than the allowable range c, correcting the current simply-averaged fuel volume data signal A_m by adding or subtracting a predetermined value to or from the preceding weight-averaged data signal B_m-1, weight-averaging the corrected simply-averaged data signal, and stepwise increasing the allowable range c by a predetermined value b until the absolute difference value lies within the increased allowable range c before calculating the fuel volume signal Q_m ; and

(c) if the absolute difference value |A_m -B_m-1 | is equal to or smaller tha allowable range c, weight-averaging the simply-averaged fuel volume data signal A_m, and stepwise decreasing the allowable range c by a predetermined value b until the decreased allowable range c becomes the initial allowable range c before calculating the fuel volume data signal Q_m,

whereby an abnormal simply-averaged fuel volume data signal A_m can be corrected and further the allowable range for an abnormal simply-averaged fuel volume data signal A_m can be increased or decreased.

38. A method of measuring fuel volume within a fuel tank for an automotive vehicle as set forth in claim 33, which further comprises the following steps of:

(a) comparing the current weight-averaged fuel volume data B_m with the preceding weight-averaged fuel volume data B_m-1, before calculating the fuel volume data signal Q_m ;

(b) if the current data B_m exceeds the preceding data B_m-1, eliminating the current data B_m before calculating the fuel volume data signal Q_m;

and

(c) if the current data B_m is equal to or smaller than the preceding data B_m-1, calculating the fuel volume signal Q_m on the basis of the compared current weight-averaged fuel volume data B_m,

whereby an abnormal fuel volume data signal B_m can be eliminated before calculating the fuel volume signal Q_m.

39. A method of measuring fuel volume within a fuel tank for an automotive vehicle as set forth in claim 33, which further comprises the following steps of:

(a) comparing the current fuel volume data signal Q_m with the preceding fuel volume data signal Q_m-1 before indicating the fuel volume;

(b) if the current signal Q_m is greater than the preceding signal Q_m-1, eliminating the current signal Q_m before indicating the fuel volume; and

(c) if the current signal Q_m is equal to or smaller than the preceding signal Q_m-1, indicating the fuel volume on the basis of the compared current fuel volume signal Q_m,

whereby an abnormal fuel volume data signal Q_m can be eliminated before indicating the fuel volume.

40. A method of measuring fuel volume as set forth in claim 37, which further comprises the following steps of:

(a) counting the number of times N that the difference between the current simply-averaged data signal A_m and the preceding weight-averaged data signal B_m-1 becomes greater than the predetermined value e;

(b) comparing the counted number of times N with a predetermined value f;

(c) if the counted number of times is equal to or smaller than the predetermined value f, calculating the fuel volume data signal Q_m on the basis of the calculated weight-averaged fuel volume data signal B_m ; and

(d) if the counted number of times N is greater than the predetermined value f, calculating the fuel volume data Q_m on the basis of the simply averaged fuel volume data signal A_m,

whereby the fuel volume can be indicated on the basis of the simply-averaged fuel volume data signal A_m when the fuel volume is increasing positively.

41. A method of measuring fuel volume within a fuel tank for an automotive vehicle, which comprises the following steps of:

(a) detecting the fuel volume within the fuel tank repeatedly and outputting fuel volume detection signals corresponding thereto at regular time intervals;

(b) simply-averaging the fuel volume detection signals and outputting a simply-averaged fuel volume data signal A_m ;

(c) weight-averaging the simply-averaged fuel volume data signal A_m and outputting a weight-averaged fuel volume data signal B_m ;

(d) comparing the current simply-averaged fuel volume data signal A_m with the preceding weight-averaged fuel volume data signal B_m-1 ;

(e) if the difference between the current simply-averaged data signal A_m and the preceding weight-averaged data signal B_m-1 is equal to or smaller than a predetermined value e, calculating the fuel volume signal Q_m on the basis of the calculated weight-averaged fuel volume data signal B_m ;

(f) if the difference between the current simply-averaged data signal A_m and the preceding weight-averaged data signal B_m-1 is greater than the predetermined value e, calculating the fuel volume signal Q_m on the basis of the calculated simply-averaged fuel volume data signal A_m ; and

(g) indicating the fuel volume in accordance with the calculated fuel volume data signal Q_m,

whereby the fuel volume can be indicated on the basis of the weight-averaged fuel volume data signal B_m when the fuel volume is decreasing but on the basis of the simply-averaged fuel volume data signal A_m when the fuel volume is increasing.

42. A method of measuring fuel volume within a fuel tank for an automotive vehicle, which comprises the following steps of:

(a) detecting the fuel volume within the fuel tank repeatedly and outputting fuel volume detection signals corresponding thereto at regular time intervals;

(b) simply-averaging the fuel volume detection signals and outputting simply-averaged fuel volume data signal A_m ;

(c) comparing the current simply-averaged fuel volume data signal A_m with the preceding simply-averaged fuel volume data signal A_m-1 ;

(d) if the current simply-averaged fuel volume data signal A_m is equal to or smaller than the preceding simply-averaged fuel volume data signal A_m-1, weight-averaging the simply-averaged fuel volume data signal A_m, outputting a weight-averaged fuel volume data signal B_m, and calculating the fuel volume data signal Q_m on the basis of the calculated weight-averaged fuel volume data signal B_m ;

(e) if the current simply-averaged fuel volume data signal A_m is greater than the preceding simply-averaged fuel volume data signal A_m-1, calculating the fuel volume signal Q_m on the basis of the calculated simply-averaged fuel volume data signal A_m ; and

(f) indicating the fuel volume in accordance with the calculated fuel volume data signal Q_m,

whereby the fuel volume can be indicated on the basis of the weight-averaged fuel volume data signal B_m when the fuel volume is decreasing, but on the basis of the simply-averaged fuel volume data signal A_m when the fuel volume is increasing.

43. A method of measuring fuel volume a set forth in claim 42, which further comprises the following steps of:

(a) counting the number of times that the current simply-averaged fuel volume data signal A_m is greater than the preceding simply-averaged fuel volume data signal A_m-1 ;

(b) comparing the counted number of times with a predetermined value f;

(c) if the counted number of times is equal to or smaller than the predetermined value f, calculating the fuel volume Q_m on the basis of the calculated weight-averaged fuel volume data signal B_m ; and

(d) if the counted number of times is greater than the predetermined value f, calculating the fuel volume Q_m on the basis of the simply averaged fuel volume data signal A_m,

whereby the fuel volume can be indicated on the basis of the simply-averaged fuel volume data signal A_m when the fuel volume is increasing positively.

44. A method of measuring fuel volume as set forth in claim 43, which further comprises the following steps of:

(a) when the counted number of times that the current simply-averaged fuel volume data signal A_m is greater than the preceding simply-averaged fuel volume data signal A_m-1 is greater than the predetermined value f, further comparing the current simply-averaged fuel volume data signal A_m with the preceding weight-averaged fuel volume data signal B_m-1 ;

(b) if the difference between the current simply-averaged data signal A_m and the preceding weight-averaged data signal B_m-1 is equal to or smaller than a predetermined value e, calculating the fuel volume data signal Q_m on the basis of the calculated weight-averaged fuel volume data signal B_m ; and

(c) if the difference between the current simply-averaged data signal A_m and the preceding weight-averaged data signal B_m-1 is greater than the predetermined value e, calculating the fuel volume signal Q_m on the basis of the calculated simply-averaged fuel volume data signal A_m,

whereby the fuel volume can be indicated on the basis of the simply-averaged fuel volume data signal A_m when the fuel volume is increasing more positively.

45. A method of measuring fuel volume within a fuel tank for an automotive vehicle, which comprises the following steps of:

(a) detecting the fuel volume within the fuel tank repeatedly and outputting fuel volume detection signals corresponding thereto at regular time intervals;

(b) simply-averaging the fuel volume detection signals and outputting simply-averaged fuel volume data signal A_m ;

(c) weight-averaging the simply-averaged fuel volume data signal A_m and outputting a weight-averaged fuel volume data signal B_m ;

(d) comparing the current simply-averaged fuel volume data signal A_m with the preceding weight-averaged fuel volume data signal B_m-1 ;

(e) if the current simply-averaged fuel volume data signal A_m is equal to or smaller than the preceding weight-averaged fuel volume data B_m-1, calculating the fuel volume data signal Q_m on the basis of the weight-averaged fuel volume data signal B_m ;

(f) if the current data signal A_m is greater than the preceding data signal B_m-1, comparing the current simply-averaged fuel volume data signal A_m with the preceding simply-averaged fuel volume data signal A_m-1 ;

(g) if the current data signal A_m is equal to or smaller than the preceding data signal A_m-1, calculating the fuel volume data signal Q_m on the basis of the weight-averaged fuel volume data signal B_m ;

(h) if the current data signal A_m is greater than the preceding data signal A_m-1, counting the number of times that the current data signal A_m is greater than the preceding data signal A_m-1 ;

(i) comparing the counted times with a predetermined value f;

(j) if the counted number of times is equal to smaller than a predetermined value f, calculating the fuel volume data signal Q_m on the basis of the weight-averaged fuel volume data signal B_m ;

(k) if the counted number of times is greater than the predetermined value f, comparing the current simply-averaged fuel volume data signal A_m with the preceding weight-averaged fuel volume data signal B_m-1 ;

(l) if the difference between the current data signal A_m and the preceding data signal B_m-1 is equal to or smaller than a predetermined value e, calculating the fuel volume data signal Q_m on the basis of the weight-averaged fuel volume data signal B_m ;

(m) if the difference is greater than the predetermined value e, calculating the fuel volume data signal Q_m on the basis of the calculated simply-averaged fuel volume data signal A_m ; and

(n) indicating the fuel volume in accordance with the calculated fuel volume data signal Q_m,

whereby the fuel volume can be indicated on the basis of the simply-averaged fuel volume data signal A_m when the fuel volume is increasing more positively.

46. A method of measuring fuel volume within a fuel tank for an automotive vehicle, which comprises the following steps of:

(a) detecting the fuel volume within the fuel tank repeatedly and outputting fuel volume detection signals corresponding thereto at regular time intervals;

(b) simply-averaging the fuel volume detection signals and outputting a simply-averaged fuel volume data signal A_m ;

(c) comparing the current simply-averaged fuel volume data signal A_m with the preceding simply-averaged fuel volume data signal A_m-1 ;

(d) if the difference between the current data signal A_m and the preceding data signal A_m-1 is greater than a predetermined value, calculating the current fuel volume data signal Q_m on the basis of the simply-averaged fuel volume data signal A_m ;

(e) if the difference is equal to or smaller than the predetermined value, calculating the weight-averaged fuel volume data signal B_m on the basis of the simply-averaged fuel volume data signal A_m ;

(f) comparing the current weight-averaged fuel volume data signal B_m with the preceding weight-averaged fuel volume data signal B_m-1,

(g) if the current weight-averaged fuel volume data signal B_m is equal to or smaller than the preceding data signal B_m-1, calculating the current fuel volume data signal Q_m on the basis of the weight-averaged fuel volume data signal B_m ;

(h) if the current data signal B_m is greater than the preceding data signal B_m-1, eliminating the weight-averaged fuel volume data signal B_m before calculating the fuel volume data signal Q_m ; and

(i) indicating the fuel volume in accordance with the calculated fuel volume data signal Q_m,

whereby an abnormal weighted-averaged fuel volume data signal B_m can be eliminated.