US 4,208,925 A · Electronic transmission control and method therefor

The method of shifting a transmission having a plurality of gears progressively increasing in ratio from a minimum gear to a maximum gear, said method comprising:

(a) predetermining the upshift transmission speed point and the downshift transmission speed point for each of said gears,
(b) obtaining a sample of the instantaneous actual transmission speed,
(c) comparing said speed sample with at least one of the shift points of the actual gear in which said transmission is operating,
(d) determining if said speed sample is either above the upshift speed point or below the downshift speed point of said actual gear,
(e) if a determination is made in step (d) that said speed sample is above the upshift speed point of said actual gear, the further steps of:
(1) comparing said speed sample with the upshift speed points of gears progressively higher than said actual gear,
(2) finding the first of said progressively higher gears having an upshift speed point greater than said speed sample,
(3) shifting said transmission from said actual gear to the gear found in step (e)(2),
(f) if a determination is made in step (d) that said speed sample is less than the downshift speed point of said actual gear, the further steps of:
(1) comparing said speed sample with the downshift speed points of gears progressively lower than said actual gear,
(2) finding the first of said progressively lower gears having a downshift speed point lower than said speed sample,
(3) shifting said transmission from said actual gear to the gear found in step (f)(2).

9 more elements

The method of shifting a transmission having a plurality of gears progressively increasing in ratio from a minimum gear to a maximum gear, said method comprising:

(a) predetermining the upshift transmission speed point and the downshift transmission speed point for each of said gears,
(b) periodically obtaining samples of the instantaneous actual speed of said transmission,
(c) comparing the actual gear the transmission is in which said minimum and maximum gears,
(d) comparing one of said speed samples with at least one of the shift points of the actual gear in which said transmission is operating,
(e) determining if either of the following two conditions exists:
(1) the actual gear is lower than the maximum gear and said speed sample is above the upshift speed joint for the actual gear,
(2) the actual gear is above the minimum gear and said speed sample is below the downshift speed point for the actual gear,
and if so, carry out one of the steps (f) or (g),
(f) if a determination is made in step (e) that the condition (e)(1) exists, the further steps of:
(1) simultaneously comparing said speed sample with the upshift speed points of gears progressively higher than said actual gear, and comparing said progressively higher gears with said maximum gear,
(2) finding the first of said progressively higher gears which is either the same as the maximum gear or which has an upshift speed point greater than said speed sample,
(3) shifting said transmission from said actual gear to the gear found in step (f)(2),
(g) if a determination is made in step (e) that the condition (e)(2) exists, the further steps of:
(1) simultaneously comparing said speed sample with the downshift speed points of gears progressively lower than said actual gear, and comparing said progressively lower gears with said minimum gear,
(2) finding the first of said progressively lower gears which is either the same as said minimum gear or which has a downshift speed point lower than said speed sample,
(3) shifting said transmission from said actual gear to the gear found in step (g)(2).

13 more elements

The method of shifting a transmission having an automatic range comprising a plurality of gears progressively increasing from a minimum gear to a maximum gear, said transmission having a gear-selector cane for selecting a maximum operating gear, said method comprising:

(a) initially selecting a maximum operating gear in said range and operating said transmission in said automatic range in a gear above said minimum gear and no higher than said initially selected maximum operating gear,
(b) subsequently selecting a maximum operating gear in said range which is lower than the actual gear said transmission is operating in,
(c) predetermining the downshift speed points for each gear of said automatic range to the next lower gear of said range, and generating separate signals indicative of each of said speed points,
(d) generating signals each representative of said subsequently selected maximum operating gear, and said actual gear,
(e) periodically sampling the instantaneous actual speed of said transmission and generating speed sample signals indicative of the speed of each sample,
(f) comparing said actual gear signal with said subsequently selected maximum operating gear signals,
(g) comparing one of said speed sample signals with the downshift speed point signal for said actual gear,
(h) determining from the comparison of steps (f) and (g) whether the following conditions exist:
(1) the gear signals are indicative that said actual gear is higher than said subsequently selected maximum operating gear, and
(2) the speed signals are indicative that the actual transmission speed is lower than the downshift speed point for the actual gear,
(i) if in step (h) it is determined that the two conditions are not met, repeat steps (e), (f), (g) and (h) with subsequent speed sample signals until both conditions of step (h) are met,
(j) generating, after both conditions of the first or subsequent step (h) have been met, gear signals indicative of gears progressively lower than said actual gear,
(k) comparing said gear signals of said progressively lower gears with said subsequently selected maximum operating gear signal,
(l) comparing the speed sample signal used in the step (h) wherein all three conditions of step (h) were first met with the downshift speed point signals for said progressively lower gears,
(m) determining from the comparison of steps (k) and (l) which is the first of said progressively lower gears wherein either one of the following two conditions exists:
(1) the gear signals are indicative that said lower gear is the same as said subsequently selected maximum operating gear,
(2) the speed signals are indicative that the actual transmission speed is above the downshift speed point of said lower gear,
(n) shifting said transmission from said actual gear to said first of said progressively lower gears wherein one of the conditions of step (m) exists,
(o) repeating steps (d)-(n) as often as necessary until said transmission is shifted to the gear selected in step (b).

16 more elements

The method of shifting a transmission having an automatic range comprising a plurality of gears progressively increasing from a minimum gear to a maximum gear, said transmission having a gear-selector cane for selecting a maximum operating gear, said method comprising:

(a) initially selecting a maximum operating gear in said range and operating said transmission in said automatic range in a gear above said minimum gear and no higher than said initially selected maximum operating gear,
(b) subsequently selecting a maximum operating gear lower than the actual gear said transmission is operating in,
(c) predetermining the downshift speed points for each gear of said automatic range to the next lower gear of said range, and generating separate signals indicative of each of said speed points,
(d) generating signals representative of said minimum gear, said subsequently selected maximum operating gear, and said actual gear,
(e) periodically sampling the instantaneous actual speed of said transmission and generating speed sample signals indicative of the speed of each sample,
(f) comparing said actual gear signal with said subsequently selected maximum and minimum gear signals,
(g) comparing one of said speed sample signals with the downshift speed point signal for said actual gear,
(h) determining from the comparison of steps (f) and (g) whether the following conditions exist:
(1) the gear signals are indicative that said actual gear is higher than said subsequently selected maximum operating gear, and
(2) the gear signals are indicative that said actual gear is higher than said minimum gear, and
(3) the speed signals are indicative that the actual transmission speed is lower than the downshift speed point for the actual gear,
(i) if in step (h) it is determined that not all three of the conditions are met, repeat steps (e), (f), (g) and (h) with subsequent speed sample signals until all three conditions of step (h) are met,
(j) generating, after all three conditions of the first or subsequent step (h) have been met, gear signals indicative of gears progressively lower than said actual gear,
(k) comparing said gear signals of said progressively lower gears with said subsequently selected maximum and minimum gear signals,
(l) comparing the speed sample signal used in the step (h) wherein all three conditions of step (h) were first met with the downshift speed point signals for said progressively lower gears,
(m) determining from the comparison of steps (k) and (l) which is the first of said progressively lower gears wherein any one of the following conditions exists:
(1) the gear signals are indicative that said lower gear is the same as said subsequently selected maximum operating gear,
(2) the gear signals are indicative that said lower gear is the same as said minimum gear,
(3) the speed signals are indicative that the actual transmission speed is above the downshift speed point of said lower gear,
(n) shifting said transmission from said actual gear to said first of said progressively lower gears wherein one of the conditions of step (m) exists,
(o) repeating steps (d)-(n) as often as necessary until said transmission is shifted to the gear selected in step (b).

18 more elements

In a method of controlling the shifting of a transmission having a plurality of gears in an automatic range progressively increasing in ratio from a minimum gear to a maximum gear, said transmission having a gear-selector cane associated therewith for selecting the maximum operating gear in said range, the steps of:

(a) periodically sampling the instantaneous actual speed of said transmission and determining the transmission speed each time such speed is sampled,
(b) each time the transmission speed is sampled, and with respect to the minimum gear, the selected maximum operating gear and the actual gear the transmission is in at such time:
(1) determining whether the actual gear is higher than said maximum operating gear selected by said cane, and,
(a) if so, determining whether the transmission speed is below the predetermined downshift speed point for the actual gear, and,
(1) if so, determining the lowest gear to which said transmission may be shifted,
(2) if not, repeat steps (d)-(g) at the next time said transmission speed is sampled,
(b) if not,
(2) determining whether the actual gear is below said selected maximum operating gear and the transmission speed is above the predetermined upshift speed point for the actual gear, and,
(a) if so, determining the highest gear to which said transmission may be shifted,
(b) if not,
(3) determining whether the actual gear is above said minimum gear and the transmission speed is below the predetermined downshift speed point for the actual gear, and,
(a) if so, determining the lowest gear to which said transmission may be shifted,
(b) if not, repeat step (b) at the next time said transmission speed is sampled.

10 more elements

In a method of controlling the shifting of a transmission having a plurality of gears in an automatic range progressively increasing in ratio from a minimum gear to a maximum gear, said transmission having a gear-selector cane associated therewith for selecting the maximum operating gear in said range, the steps of:

(a) predetermining the upshift and downshift transmission speed points for each of said gears and providing for the generation of separate signals indicative of each of said speed points,
(b) generating separate signals indicative of said minimum gear, said maximum operating gear and the actual gear which said transmission is in,
(c) periodically sampling the instantaneous actual speed of said transmission and generating a speed signal indicative of the transmission speed each time such speed is sampled,
(d) comparing said actual gear signal and said minimum gear signal each time the transmission speed is sampled,
(e) comparing said actual gear signal and said maximum operating gear signal each time the transmission speed is sampled,
(f) comparing said transmission speed signal with at least one of the speed point signals for said actual gear each time the transmission speed is sampled,
(g) each time the transmission speed is sampled, and from said comparisons of said gear signals and speed signals existing at such time:
(1) determining whether the actual gear is higher than said maximum operating gear selected by said cane, and,
(a) if so, determining whether the transmission speed is below the downshift speed point for the actual gear, and,
(1) if so, determining the lowest gear to which said transmission may be shifted,
(2) if not, repeat steps (d)-(g) at the next time said transmission speed is sampled,
(b) if not,
(2) determining whether the actual gear is below said selected maximum operating gear and the transmission speed is above the upshift speed point for the actual gear, and,
(a) if so, determining the highest gear to which said transmission may be shifted,
(b) if not,
(3) determining whether the actual gear is above said minimum gear and the transmission speed is below the downshift speed point for the actual gear, and,
(a) if so, determining the lowest gear to which said transmission may be shifted,
(b) if not, repeat steps (d)-(g) at the next time said transmission speed is sampled.

15 more elements

The method of shifting a transmission having a plurality of gears in an automatic range progressively increasing in ratio from a minimum gear to a maximum gear, said transmission having a gear-selector cane associated therewith for selecting a maximum operting gear in said range, said method comprising:

(a) predetermining the upshift and downshift transmission speed points for each of said gears and providing for the generation of separate signals indicative of each of said speed points,
(b) generating separate signals indicative of said minimum gear and said maximum operating gear,
(c) generating a signal indicative of the actual gear that said transmission is in,
(d) periodically sampling the instantaneous actual speed of said transmission and generating a speed sample signal indicative of each speed sample,
(e) comparing said actual gear signal with said minimum and maximum operating gear signals,
(f) comparing one of said speed sample signals with at least one of the shift speed point signals for said actual gear,
(g) determining from the comparisons of steps (e) and (f) if either of the following two conditions exist:
(1) the gear signals are indicative that the actual gear is lower than the maximum operating gear and the speed signals are indicative that the transmission speed is above the upshift speed point for the actual gear,
(2) the gear signals are indicative that the actual gear is higher than the minimum gear and the speed signals are indicative that the transmission speed is below the downshift speed point for the actual gear, and, if so, carry out one of the steps (h) or (i),
(h) if a determination is made in step (g) that the condition (g)(1 ) exists, the further steps of:
(1) generating gear signals indicative of gears progressively higher than said actual gear and comparing said gear signals with the maximum gear signal, and comparing the same said speed sample signal with the upshift speed point signals for such progressively higher gears,
(2) finding the first of said progressively higher gears wherein either a gear signal comparison is indicative that said higher gear is the same as said maximum operating gear, or a speed signal comparison is indicative that the upshift speed point of said higher gear is higher than said transmission speed, said higher gear found being the desired gear to which said transmission should be shifted,
(3) shifting said transmission from said actual gear to said desired gear found in step (h)(2),
(i) if a determination is made in step (g) that the condition (g)(2) exists, the further steps of:
(1) generating gear signals indicative of gears progressively lower than said actual gear and comparing said signals with the minimum gear signal, and comparing the same speed sample signal with the downshift speed point signals for said progressively lower gears,
(2) finding the first of said progressively lower gears wherein either a gear signal comparison is indicative that said lower gear is the same as said minimum gear, or a speed signal comparison is indicative that the downshift speed point of said lower gear is lower than said transmission speed, said lower gear found being the desired gear to which said transmission should be shifted,
(3) shifting said transmission from said actual gear to said desired gear found in step (i)(2).

14 more elements

A control for a system including an engine and a transmission coupled to the output of said engine, said transmission having a plurality of gears in an automatic range which progressively increase in ratio from a preselected minimum automatic gear, said transmission having associated therewith an operator-controllable gear-selecting cane for selecting any of the gears of said transmission in said range, said control comprising:

means for generating a plurality of speed point signals, each indicative of the predetermined upshift or downshift transmission speed point for each of said gears of said automatic range,
means for generating separate signals indicative of said minimum gear, said maximum operating gear and the actual gear which said transmission is in,
means for periodically sampling the instantaneous speed of said transmission and for generating an actual speed signal indicative of the transmission speed each time such speed is sampled,
first comparator means for comparing said actual gear signal and said minimum gear signal each time the transmission speed is sampled,
second comparator means for comparing said actual gear signal and said maximum operating gear signal each time the transmission speed is sampled,
third comparator means for comparing said speed signal with at least one of the speed point signals for said actual gear each time the transmission is sampled,
gear-calculating means operable each time the transmission speed is sampled, and responsive to said first, second and third comparator means, said gear-calculating means including:
a first portion for determining whether the actual speed is above the upshift speed point for said actual gear when said actual gear is below said selected maximum operating gear, and, if so, for calculating the highest gear to which the transmission may be shifted, such highest gear being one immediately above a gear which is both lower than said maximum operating gear and has an upshift speed point lower than said actual speed, said highest gear being either said maximum operating gear or having an upshift speed point greater than said actual speed,
a second portion for determining whether the actual speed is below the downshift speed point for said actual gear when said actual gear is above said minimum gear, and, if so, for calculating the lowest gear to which the transmission may be shifted, such lowest gear being one immediately below a gear which is above said minimum gear and has a downshift speed point higher than said actual speed, said lowest gear being either said minimum gear or having a downshift speed point lower than said actual speed.

6 more elements

A control for a system including an engine and a transmission coupled to the output of said engine, said transmission having a plurality of gears in an automatic range which progressively increase in ratio from a preselected minimum automatic gear, said transmission having associated therewith an operator-controllable gear-selecting cane for selecting any of the gears of said transmission, said control comprising:

means for generating an actual gear signal uniquely indicative of the actual gear existing in said transmission and for maintaining said signal until such time as said transmission is shifted from such gear,
means for generating a cane signal uniquely indicative of the gear selected by said gear-selecting cane and for maintaining said signal until such time as the gear selection is changed,
means for establishing a series of successive operating cycles for said control,
means for generating an actual speed signal once for each cycle of operation and for maintaining said signal during the cycle for which it is generated, each such speed signal being indicative of the actual transmission speed when such speed signal is generated,
means for producing gear test signals indicative of said actual gear and of gears progressively higher than said actual gear,
a first comparator means for comparing and determining the relationship of selected of said gear test signals to said cane signal,
means responsive to said gear test signals for producing predetermined upshift speed point signals for each one of said gear test signals,
a second comparator means for comparing and determining the relationship of produced speed point signals to an actual speed signal,
an upshift test means operable during a cycle of operations and responsive to said first and second comparator means for (1) determining that an upshift condition exists when said first comparator means determines that said actual gear is below the gear selected by said cane and said second comparator means determines that the actual speed is greater than the upshift speed point for said actual gear, and for (2) determining the desired and lowest gear above said actual gear which either said first comparator means determines is the same as the gear selected by said cane or said second comparator means determines to have an upshift speed point above said actual speed, and for (3) generating a new gear signal during said cycle of operation when said desired gear has been determined.

6 more elements

A control for a system including an engine and a transmission coupled to the output of said engine, said transmission having a plurality of gears in an automatic range which progressively increase in ratio from a preselected minimum automatic gear to a maximum gear, said control comprising:

means for generating an actual gear signal uniquely indicative of the actual gear existing in said transmission and for maintaining said signal until such time as said transmission is shifted from such gear,
means for generating and maintaining a minimum gear signal uniquely indicative of said minimum gear of said automatic gear,
means for establishing a series of successive operating cycles for said control,
means for generating an actual speed signal once for each cycle of operation and for maintaining said signal during the cycle for which it is generated, each such speed signal being indicative of the actual transmission speed when such speed signal is generated,
means for producing gear test signals indicative of said actual gear and of gears progressively lower than said actual gear,
a first comparator means for comparing and determining the relationship of selected of said gear test signals to said minimum gear signal,
means responsive to said gear test signals for producing predetermined downshift speed point signals for each one of said gear test signals,
a second comparator means for comparing and determining the relationship of produced speed point signals to an actual speed signal,
a downshift test means operable during a cycle of operations and responsive to said first and second comparator means for (1) determining that a downshift condition exists when said first comparator means determines that said actual gear is above said minimum gear and said second comparator means determines that the actual speed is below the downshift speed point for said actual gear, and for (2) determining the desired and highest gear below said actual gear which either said first comparator means determines is the same as said minimum gear or said second comparator means determines to have a downshift speed point below said actual speed, and for (3) generating a new gear signal during said cycle of operation when said desired gear has been determined.

6 more elements

A control for a system including an engine and a transmission coupled to the output of said engine, said transmission having a plurality of gears in an automatic range which progressively increase in ratio from a preselected minimum automatic gear, said transmission having associated therewith an operator-controllable gear-selecting cane for selecting any of the gears of said transmission in said range, said control comprising:

means for generating an actual gear signal uniquely indicative of the actual gear existing in said transmission and for maintaining said signal until such time as said transmission is shifted from such gear,
means for generating a cane signal uniquely indicative of the gear selected by said gear-selecring cane and for maintaining said signal until such time as the gear selection is changed,
means for generating and maintaining a minimum gear signal uniquely indicative of said minimum gear of said automatic gear,
means for establishing a series of successive operating cycles for said control,
means for generating an actual speed signal once for each cycle of operation and for maintaining said signal during the cycle for which it is generated, each such speed signal being indicative of the actual transmission speed when such speed signal is generated,
means for producing gear test signals indicative of said actual gear and of gears progressively higher and lower than said actual gear,
a first comparator means for comparing and determining the relationship of selected of said gear test signals to said cane signal,
a second comparator means for comparing and determining the relationship of selected of said gear test signals to said minimum gear signal,
means responsive to said gear test signals for producing predetermined upshift and downshift speed point signals for each one of said gear test signals,
a third comparator means for comparing and determining the relationship of produced speed point signals to an actual speed signal,
an automatic upshift test means operable during a cycle of operations and responsive to said first and third comparator means for (1) determining that an upshift condition exists when said first comparator means determines that said actual gear is below the gear selected by said cane and said third comparator means determines that the actual speed is greater than the upshift speed point for said actual gear, and for (2) determining the desired and lowest gear above said actual gear which either said first comparator means determines is the same as the gear selected by said cane or said third comparator means determines to have an upshift speed point above said actual speed, and for (3) generating a new gear signal during said cycle of operation when said desired gear has been determined,
an automatic downshift test means operable during a cycle of operations and responsive to said second and third comparator means for (1) determining that a downshift condition exists when said second comparator means determines that said actual gear is above said minimum gear and said third comparator means determines that the actual speed is below the downshift speed point for said actual gear, and for (2) determining the desired and highest gear below said actual gear which either said second comparator means determines is the same as said minimum gear or said third comparator means determines to have a downshift speed point below said actual speed, and for (3) generating a new gear signal during said cycle of operation when said desired gear has been determined.

9 more elements

A control for a system including an engine and a transmission coupled to the output of said engine, said transmission having a plurality of gears in an automatic range which progressively increase in ratio from a preselected minimum automatic gear, said transmission having associated therewith an operator-controllable gear-selecting cane for selecting any of the gears of said transmission, said control comprising:

means for generating an actual gear signal uniquely indicative of the actual gear existing in said transmission and for maintaining said signal until such time as said transmission is shifted from such gear,
means for generating a cane signal uniquely indicative of the gear selected by said gear-selecting cane and for maintaining said signal until such time as the gear selection is changed,
means for generating and maintaining a minimum gear signal uniquely indicative of said minimum gear of said automatic gear,
means for establishing a series of successive operating cycles for said control,
means for generating an actual speed signal once for each cycle of operation and for maintaining said signal during the cycle for which it is generated, each such speed signal being indicative of the actual transmission speed when such speed signal is generated,
gear signal stepping means for producing a gear-indicative signal at the output thereof and operative when energized to incrementally increase or decrease said gear-indicative signal to indicate progressively higher or lower gears, respectively,
a first comparator means for comparing and determining the relationship between said gear-indicative signal of said stepping means and said cane signal,
a second comparator means for comparing and determining the relationship between said gear-indicative signal of said stepping means and said minimum gear signal,
means responsive to the gear-indicative signals of said stepping means for producing predetermined upshift and downshift speed point signals for each gear indicated by such gear-indicating signals,
a third comparator means for comparing and determining the relation between a produced speed point signal and one of said actual speed signals,
means operable in each cycle of operation of said control for initially setting said stepping means to produce a gear-indicative signal which is indicative of said actual gear,
an automatic upshift test means operable during a cycle of operation of said control for (1) determining the existence of an upshift shift condition and energizing said stepping means to increase said gear-indicative signal by one each time during a cycle of operation that said first comparator determines that the gear then indicated by said stepping means is lower than the gear selected by said cane and said third comparator means determines that said actual speed is above the upshift speed point for said gear then indicated by said stepping means, and (2) for generating a new gear signal during the same cycle of operation and when said stepping means has been increased at least once and either said first comparator determines that the gear then indicated by said stepping means is the same as the gear selected by said cane, or said third comparator determines that said actual speed is less than the upshift speed point for said gear then indicated by said stepping means,
an automatic downshift test means operable during a cycle of operation of said control for (1) determining the existence of a downshift shift condition and energizing said stepping means to decrease said gear-indicative signal by one each time during a cycle of operation that said second comparator determines that the gear then indicated by said stepping means is greater than said minimum gear and said third comparator means determining that said actual speed is below the downshift speed point for said gear then indicated by said stepping means, and (2) for generating a new gear signal during the same cycle of operation and when said stepping means has been increased at least once and either said second comparator determines that the gear then indicated by said stepping means is the same as said minimum gear, or said third comparator determines that said actual speed is greater than the downshift speed point for said gear then indicated by said stepping means.

10 more elements

Electronic transmission control and method therefor

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Electronic transmission control and method therefor

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Abstract

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