Dynanometer engine performance analyzer system
First Claim
1. A method of automatically measuring the torque of an engine that has a rotating power shaft, the method employing an automatic data storage and calculating device, sensor means for sensing the rotation of said power shaft and torque sensor means for sensing the torque on said power shaft;
- the method comprising;
measuring the time that elapses in the intervals between each successive N full revolutions of the power shaft, where N is a predetermined whole number integer; and
calculating a corresponding engine speed value from the measured time;
sampling the power shaft torque, provided as an integrated torque value from the torque sensor means, for each N-revolution interval;
assigning the sampled integrated torque value to a predetermined RPM speed interval based on the engine speed value associated with said sampled torque value;
computing a statistical mean torque value by combining said sampled torque value with any previous torque values for the same RPM speed interval;
storing the statistical mean torque value and the number of samples for each of said RPM intervals; and
listing the stored statistical mean torque values for the associated RPM speed intervals.
1 Assignment
0 Petitions
Accused Products
Abstract
A dynamic engine performance analyzer system measures engine torque and power continuously from an absorption brake and produces a statistically corrected and deskewed value of torque and power for each of a number of RPM bands. Torque and power values are integrated during each N shaft revolutions as the engine is slowly accelerated through a range of interest. The data are accumulated such that for each 100 RPM wide band in the range, there is a statistical mean value produced of torque and of power. Each 100 RPM band element represents the mean or average of several separate data measurements. A deskewing operation compensates for the fact that the samples may not all be taken evenly throughout each 100 RPM average band during acceleration. The inertial effects of acceleration and deceleration are compensated by adjusting the torque and power values upwards during acceleration and downwards during deceleration. The engine analysis is quite rapid, and provides extremely reliable and accurate performance data which closely approaches the theoretical best possible according to statistical theory.
-
Citations
20 Claims
-
1. A method of automatically measuring the torque of an engine that has a rotating power shaft, the method employing an automatic data storage and calculating device, sensor means for sensing the rotation of said power shaft and torque sensor means for sensing the torque on said power shaft;
- the method comprising;
measuring the time that elapses in the intervals between each successive N full revolutions of the power shaft, where N is a predetermined whole number integer; and
calculating a corresponding engine speed value from the measured time;
sampling the power shaft torque, provided as an integrated torque value from the torque sensor means, for each N-revolution interval;assigning the sampled integrated torque value to a predetermined RPM speed interval based on the engine speed value associated with said sampled torque value; computing a statistical mean torque value by combining said sampled torque value with any previous torque values for the same RPM speed interval; storing the statistical mean torque value and the number of samples for each of said RPM intervals; and listing the stored statistical mean torque values for the associated RPM speed intervals. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
- the method comprising;
-
9. A method of automatically measuring the torque of an engine that has a rotating power shaft, the method employing an automatic data storage and calculating device, sensor means for sensing rotation of said shaft and torque sensor means for sensing the torque on said power shaft;
- said engine and said torque sensor means having a given rotational inertia, the method comprising;
continuously accelerating said engine at not less than a predetermined negative rate but not more than a predetermined maximum positive rate such that the engine is accelerated smoothly through an operating test range; sampling said torque sensor means and said rotation sensor means automatically as said engine is being accelerated through said test range to produce at least one torque value and at least one corresponding engine speed value for each of a plurality of RPM speed intervals of a given width; automatically adjusting the torque values by a factor which increases the torque value when the acceleration is positive and decreases the same when the acceleration is negative to compensate for the fact that the rotational inertia of the system that includes the engine and torque sensor means absorbs torque during acceleration and releases torque during deceleration; writing into a memory of said storage and calculating device a value based on the adjusted torque value for each said engine speed interval; and after accelerating the engine through said test range, printing, for each engine speed interval, a value corresponding to the at least one adjusted torque value associated therewith as stored in said memory.
- said engine and said torque sensor means having a given rotational inertia, the method comprising;
-
10. A method of automatically measuring the torque of an engine that has a rotating power shaft the method employing an automatic data storage and calculating device, sensor means for sensing the rotation of said power shaft and torque sensor means for sensing the torque on said power shaft;
- the method comprising;
measuring the time that elapses in the intervals between each successive N full revolutions of the power shaft, where N is a predetermined whole number integer, and calculating a corresponding engine speed value from the measured time; sampling the power shaft torque, provided as an integrated torque value from the torque sensor means, during each N-revolution interval; assigning each sampled torque value to a predetermined RPM speed interval based on the engine speed value associated with said sampled torque value; storing for each said RPM speed interval at least one value corresponding to the sampled torque values associated therewith; and listing the stored values for the associated RPM intervals. - View Dependent Claims (20)
- the method comprising;
-
11. A method of automatically measuring a performance factor for an engine that has a rotating power shaft where the performance factor is dependent upon the speed of the power shaft, the method employing an automatic data storage and calculating device, sensor means for sensing the rotation of the power shaft, and sensor means for sensing the magnitude of said
measuring the speed of rotation of said power shaft during predetermined intervals, based on the number of revolutions occurring in said interval and the length of time of said interval; -
sampling the performance factor, provided as a value from the performance factor sensor means, during each said interval; assigning the sampled performance factor value to a predetermined RPM speed band based on the engine power shaft speed during the associated interval; computing a statistical mean value of the performance factor by combining the sampled performance factor values taken for each given RPM speed band; computing, for each.[.,.]. RPM speed band a statistical mean RPM speed value for all of the samples associated with each said RPM speed band; storing, for each RPM speed band, the statistical average performance factor value, and the statistical mean .[.RP.]. .Iadd.RPM .Iaddend.speed value associated therewith; and deskewing the stored statistical means performance factor values on the basis of the stored engine speed values to correct for differences between the statistical mean engine speed value of a given RPM speed band and the center RPM value of that band. - View Dependent Claims (12, 16, 17)
-
-
13. Apparatus for automatically measuring a performance factor for an engine that has a rotating power shaft where the performance factor is dependent upon the speed of the engine power shaft, comprising sensor means for detecting the rotation of the power shaft, sensor means for detecting the magnitude of the performance factor of the power shaft at a given time, and an automatic data storage and calculating device coupled to each of said sensor means and configured so as to include means for measuring the speed of rotation of the power shaft by measuring the amount of time that elapses in an interval between each successive N full revolutions of the power shaft where N is a predetermined integer, means for sampling and holding the performance factor during each said interval as a value derived from the performance factor sensor means, means for adjusting the sampled performance factor upwards when the engine is undergoing acceleration and downwards when the engine is undergoing deceleration;
- means for assigning the adjusted sampled performance factors to predetermined RPM speed bands based on the engine power shaft speed during the associated intervals; and
means for listing for each said RPM speed band a performance factor value corresponding to the adjusted sampled performance factor values associated therewith. - View Dependent Claims (14, 15)
- means for assigning the adjusted sampled performance factors to predetermined RPM speed bands based on the engine power shaft speed during the associated intervals; and
-
18. A method of automatically measuring the torque of an engine that has a rotating power shaft, the method employing an automatic data storage and calculating device, rotation sensor means for sensing the rotation of said power shaft and torque sensor means for sensing the torque in the power shaft, the method comprising:
-
supplying to the data storage and calculating device engine speed values from said rotation sensor means to correspond to the rotation speed of said power shaft and power shaft torque values from said torque sensor means to correspond to the torque on the power shaft at the associated rotation speeds thereof; statistically averaging, for at least one predetermined range of engine speed values, the power shaft torque values associated with those engine speed values, to produce an average torque value for each said range; and visually presenting the average torque values for at least selected ones of said at least one range of engine speed values. .Iaddend. .Iadd. - View Dependent Claims (19)
-
Specification