Adaptive control system for an internal combustion engine
First Claim
1. An adaptive control system for a power producing engine having at least one engine control parameter affecting an engine output, said engine having a drive train combination having at least one resonant frequency, said control system comprising:
- (a) a perturbation generator for perturbing intermittently a particular said engine control parameter about a base line value in at least one perturbation mode in a given operating mode of said engine which includes said at least one resonant frequency;
(b) measuring means for measuring a slope of said engine output with respect to said particular control parameter caused by said perturbation generator; and
(c) control means, responsive to said slope, for controlling one said engine control parameter so as to obtain a desired value of said slope, wherein said perturbation generator operates in another perturbation mode in another operating mode of said engine to perturb said particular control parameter at a frequency greater than said at least one resonant frequency.
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Abstract
An adaptive control system and method for a multi-cylinder internal combustion engine is provided wherein a perturbation generator perturbs an engine control parameter of a cylinder about a base-line value, and a measuring means measures the slope of an engine output with respect to perturbations in the engine control parameter caused by the perturbation generator. A correction unit employs the measured slope to correct at least one engine control parameter of the engine so as to obtain a desired value of the slope measured by the measuring means. The corrected control parameter can be the same or different from the perturbed control parameter. The perturbation generator operates in a first perturbation mode in an upper speed range of the engine and in a second perturbation mode in a lower speed range of the engine. The slope measuring unit operates in different measurement modes corresponding to these perturbation modes.
44 Citations
46 Claims
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1. An adaptive control system for a power producing engine having at least one engine control parameter affecting an engine output, said engine having a drive train combination having at least one resonant frequency, said control system comprising:
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(a) a perturbation generator for perturbing intermittently a particular said engine control parameter about a base line value in at least one perturbation mode in a given operating mode of said engine which includes said at least one resonant frequency; (b) measuring means for measuring a slope of said engine output with respect to said particular control parameter caused by said perturbation generator; and (c) control means, responsive to said slope, for controlling one said engine control parameter so as to obtain a desired value of said slope, wherein said perturbation generator operates in another perturbation mode in another operating mode of said engine to perturb said particular control parameter at a frequency greater than said at least one resonant frequency. - View Dependent Claims (2, 3, 4, 6, 7, 8, 9)
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5. An adaptive control system for a power producing engine having at least one engine control parameter affecting an engine output, said engine having a drive train combination having at least one resonant frequency, said control system comprising:
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(a) a perturbation generator for perturbing intermittently a particular said engine control parameter about a base line value in at least one perturbation mode in a given operating mode of said engine which includes said at least one resonant frequency; (b) measuring means for measuring a slope of said engine output with respect to said particular control parameter caused by said perturbation generator; and (c) control means, responsive to said slope, for controlling one said engine control parameter so as to obtain a desired value of said slope, wherein said particular control parameter and said one control parameter are different.
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10. An adaptive control system for a multi-cylinder internal combustion engine having at least one engine control parameter affecting an engine output, said control system comprising:
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(a) cylinder combination selection means for establishing a plurality of combinations of cylinders of said engine and for selecting each combination in turn, each of said combinations of cylinders including at least one cylinder; (b) a perturbation generator for perturbing a particular said engine control parameter of each of said combinations of cylinders at the time it is selected by said cylinder combination selection means, said perturbation generator operating in a first perturbation mode in an upper speed range of said engine and in a second perturbation mode in a lower speed range of said engine; (c) measuring means for measuring a slope or differential of said engine output with respect to perturbations in said particular engine control parameter caused by said perturbation generator for each of said combinations in turn, said measuring means operating in a first measurement mode corresponding to said first perturbation mode and a second measurement mode corresponding to said second perturbation mode; and (d) correction means, responsive to said slope, for correcting at least one said control parameter for each of said combinations of cylinders of said engine so as to obtain a desired value of said slope. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. An adaptive control system for a multi-cylinder, fuel injected, spark ignition, internal combustion engine comprising a flywheel, a resilient shaft connected to said flywheel, a gear means connected to said resilient shaft and a crankshaft, said engine having an engine output affected by at least one control input, said control system comprising:
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(a) a position transducer for producing a series of reference pulses representing rotational positions of said crankshaft; (b) a control means, responsive to said position transducer, for providing output signals for controlling at least one said control input; (c) an engine speed calculation means, responsive to said position transducer, for providing an output signal indicating engine speed to said control means; (d) cylinder synchronization means, responsive to said position transducer, for determining which cylinder is undergoing a combustion stroke; (e) gear indication means for indicating which gear of said engine is presently engaged; (f) load demand transducer means for sensing a load demand parameter of said engine; (g) fire period calculation means, responsive to said position transducer, for calculating a period which elapses between pistons in consecutive cylinders of said engine being at a given angular position after top dead center; (h) a first memory means storing data representing a particular control input of said engine as a function of engine speed and load demand; (i) a first calculation means, responsive to (i) said engine speed calculation means, (ii) said load demand transducer and (iii) said first memory means, for calculating a basic value for said particular control input corresponding to prevailing engine speed and load demand; (j) a second memory means storing data representing a second control input of said engine as a function of engine speed and load demand; (k) a second calculation means, responsive (i) said engine speed calculation device, (ii) said load demand transducer, and (iii) said second memory means, for calculating a basic value for said second control input corresponding to prevailing engine speed and load demand; (l) perturbation means, responsive to (i) said gear indication means, (ii) said fire period calculation means, and (iii) said cylinder synchronization means, for operating in at least one perturbation mode in a given operating mode of said engine including a highest resonant frequency of a resonant system comprising said flywheel, said resilient shaft means and said gear means in an lower speed range of said engine perturbing said particular control input to each cylinder of said engine in synchronization with the time it is undergoing a combustion stroke at an intermittent frequency which is a function of outputs from said gear determination means and said fire period calculation means; (m) measuring means for sensing a slope in said engine output with respect to said particular control input resulting from perturbations caused by said perturbation means; (n) third memory means comprising individual correction memories for each individual cylinder; (o) selector means, responsive to said cylinder synchronization means, for selective connection to said individual correction memories; (p) third calculation means, responsive to said load demand transducer and said engine speed calculation device and connected to said selector means so as to selectively receive said correction values from said individual correction memories through said selector means, for calculating a correction value for said second control input for each individual cylinder immediately prior to its firing; and (q) a first summer means for summing said basic value for said second control input and said correction value for said second control input relating to each individual cylinder immediately prior to its firing to provide an output to said control device. - View Dependent Claims (23, 24, 25, 26, 27)
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28. A method of controlling a power producing engine having at least one engine control parameter affecting an engine output, said engine having a drive train combination having at least one resonant frequency, said method comprising:
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(a) perturbing intermittently a particular said control parameter about a base line value in at least one perturbation mode in a given operating mode of said engine which includes said resonant frequency; (b) measuring a slope of said engine output with respect to said particular control parameter; and (c) controlling one said control parameter so as to obtain a desired value of said slope, wherein step (a) includes perturbing said particular control parameter in another perturbation mode in another operating mode of said engine at a frequency greater than said resonant frequency. - View Dependent Claims (29, 30, 31, 32, 33, 34)
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35. A method of controlling a power producing engine having at least one engine control parameter affecting an engine output, said engine having a drive train combination having at least one resonant frequency, said method comprising:
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(a) perturbing intermittently a particular said control parameter about a base line value in at least one perturbation mode in a given operating mode of said engine which includes said resonant frequency; (b) measuring a slope of said engine output with respect to said particular control parameter; and (c) controlling one said control parameter so as to obtain a desired value of said slope, wherein said particular control parameter and said one control parameter are different.
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36. A method of controlling a multi-cylinder internal combustion engine having an engine output affected by at least one engine control parameter, said method comprising:
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(a) establishing a plurality of combinations of cylinders of said engine, each of said combinations of cylinders including at least one cylinder; (b) selecting each of said combinations in turn; (c) perturbing a particular said control parameter of each of said combinations of cylinders at the time it is selected in step (b) by applying a first perturbation to said particular control parameter, permitting a period to elapse without perturbing said particular control parameter, applying a second perturbation of opposite polarity to that of said first perturbation to said particular control parameter and permitting another period to elapse without perturbing said particular control parameter; (d) creating a series of measurement windows following each perturbation of said particular control parameter, each series of measurement windows occupying part of the interval between successive perturbations; (e) calculating the slope of said engine output with respect to said particular control parameter for each of said combinations in turn from the change in engine output between adjacent measurement windows; and (f) applying a correction based on said slope to at least one said control parameter associated with the currently selected cylinder combination. - View Dependent Claims (40, 41, 42, 43, 44, 45, 46)
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37. A method of controlling a multi-cylinder internal combustion engine having an engine output affected by at least one engine control parameter, said method comprising:
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(a) establishing a plurality of combinations of cylinders of said engine, each of said combinations of cylinders including at least one cylinder; (b) selecting each of said combinations in turn; (c) when said engine is in an upper speed range, perturbing a particular said control parameter of each of said combinations of cylinders at the time it is selected in step (b) by generating a periodic perturbation waveform and applying a first perturbation to said particular control parameter during a first part of each period of said perturbation waveform and a second perturbation of opposite polarity to that of said first perturbation during a second part of said perturbation waveform; (d) when said engine is in a lower speed range, perturbing said particular control parameter of each of said combinations of cylinders at the time it is selected in step (b) by applying a first perturbation to said particular control parameter, permitting a period to elapse without perturbing said particular control parameter, applying a second perturbation of opposite polarity to that of said first perturbation to said particular control parameter and permitting another period to elapse without perturbing said particular control parameter; (e) in said upper speed range, creating a first series of contiguous first and second measurement windows associated respectively with said first and second parts of the perturbation waveform, each measurement window lagging its respective part of the perturbation waveform by a predetermined phase shift; (f) in said lower speed range, creating a second series of measurement windows following each perturbation of said particular control parameter, each series of measurement windows occupying part of the interval between successive perturbations; (g) in both said upper and lower speed ranges, calculating the slope of engine output with respect to said particular control parameter for each of said combinations in turn from the change in engine speed between adjacent measurement windows; and (h) applying a correction based on said slope to at least one said engine control parameter associated with the currently selected cylinder combination. - View Dependent Claims (38, 39)
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Specification