Electronic control for motor vehicle transmission

• US 4,734,861 A
• Filed: 07/11/1986
• Issued: 03/29/1988
• Est. Priority Date: 08/27/1984
• Status: Expired due to Fees

• Current Assignee: Twin Disc Incorporated
• Original Assignee: Twin Disc Incorporated
• Inventors: Bertolasi, Robert B., Zwicky, Richard A., Blank, Paul C.
• Primary Examiner(s): Lall, Parshotam S.
• Application Number:
  US06/883,864
• Time in Patent Office: 627 Days
• Field of Search: 364/424.1, 364/569, 192/0.052, 192/0.075, 192/0.076, 74/866
• US Class Current: 701/67
• CPC Class Codes: B60W 2050/0045 using databus protocols
• CPC Class Codes: F16H 59/00 Control inputs to control units of change-speed-, or reversing-gearings for conveying rotary motion
• CPC Class Codes: F16H 61/0006 Electronic control units for transmission control, e.g. connectors, casings or circuit boards
• CPC Class Codes: F16H 61/0206 Layout of electro-hydraulic control circuits, e.g. arrangement of valves for control of actuators selecting and moving final output members, e.g. shift forks F16H61/2807
• CPC Class Codes: F16H 61/12 Detecting malfunction or potential malfunction, e.g. fail safe in control of hydrostatic gearing F16H61/4192; Circumventing or fixing failures
• CPC Class Codes: F16H 61/20 Preventing gear creeping ; Transmission control during standstill, e.g. hill hold control
• CPC Class Codes: H05K 1/144 Stacked arrangements of planar printed circuit boards

Abstract

An electronic control for the automatic transmission of a motor vehicle receives input signal in digital, analog, and pulsed form from signal generating devices responsive to operating conditions in the apparatus, processes them in accordance with a stored program and provides output signals to operate various tranducers. The electronic control is embodied in a stack of customized circuit boards. Each board is connected to a control bus (for information exchange between boards) and to an I/O signal bus (for information exchange between the apparatus and the electronic control). A connector board is connected to an electric power supply, to the signal generating devices, to the transducers and to visual display devices. A CPU (central processing unit) board protects against data loss in low/off power conditions. An input signal board employs high-speed logic circuits for measuring time length between leading edges of pulsed input signals to ascertain magnitude and rate of change of the rotational speed of certain components and actuates clutch solenoids accordingly. An output signal board embodies improved transducer-drive circuits for the clutch solenoids.

Claims

1. In combination:

a first component operable at various speeds;

signal generating means responsive to the speed of said first component for providing an input signal comprising a series of pulsed signals which are variable in frequency and pulse width and whose frequency is related to said speed, each pulsed signal having a leading edge;

a transducer having means operable in response to an output signal to effect operation of a second component;

and an electric controller for receiving said input signal and for providing said output signal and comprising;

a counter for measuring the length of the time interval between the leading edges of an incoming pulsed signal and the preceding pulsed signal, means for resetting said counter in response to each incoming pulsed signal, and means responsive to detection of a time interval of predetermined length between said incoming pulsed signal and said preceding pulsed signal to determine frequency and to provide said output signal to effect operation of said transducer and said second component.

6. A combination according to claims 1 or 2 or 3 or 4 or 5 wherein said electronic controller determines the magnitude and rate of change of magnitude of said time interval.

7. A combination according to claim 6 wherein said electronic controller includes first memory means in which a program can be stored, second memory means in which said electrical input signals can be stored, and a central processing unit for processing said electrical input signals in accordance with said program and for providing said electrical output signals to said transducers.

2. In combination in a power transmission system for a motor vehicle:

a drive shaft rotatable at various speeds;

signal generating means responsive to the speed of said drive shaft for providing an electrical input signal comprising a series of pulsed electrical signals which are variable in frequency and pulse width and whose frequency is related to said speed, each pulsed signal having a leading edge;

a solenoid operable in response to an electrical output signal to effect operation of a clutch connectable to said drive shaft;

and an electronic controller for receiving said input signal and for providing said output signal and comprising;

a counter for measuring the length of the time interval between the leading edges of an incoming pulsed signal and the preceding pulsed signal, means for resetting said counter in response to each incoming pulsed signal, and means responsive to detection of a time interval of predetermined length between said incoming signal and said preceding pulsed signal to determine frequency and to provide said electrical output signal to said solenoid to operate said clutch.

3. In combination:

apparatus comprising a first component operable at various speeds and a second component which is to be actuated when said first component reaches a predetermined speed;

and control means for said apparatus comprising;

signal generating means responsive to the speed of said first component for providing an input signal, said input signal comprising a series of pulsed signals which are variable in frequency and pulse width and whose frequency is related to speed, each pulsed signal having a leading edge;

a transducer having means operable in response to an output signal to actuate said second component;

and an electric controller for receiving said input signal and for providing said output signal and comprising;

a counter for measuring the length of the time interval between the leading edges of an incoming pulsed signal and the preceding pulsed signal, means for resetting said counter in response to each incoming pulsed signal, and means responsive to detection of a time interval of predetermined length between said incoming pulsed signal and said preceding pulsed signal to determine frequency and to provide said output signal to effect operation of said transducer and said second component.

4. In combination in a power transmission system for a motor vehicle:

transmission apparatus comprising a drive shaft rotatable at various speed and a solenoid-operated clutch which is to be actuated when said drive shaft reaches a predetermined speed;

and control means for said transmission apparatus comprising;

signal generating means responsive to the speed of said drive shaft for providing an electrical input signal, said input signal comprising a series of pulsed electrical signals which are variable in frequency and pulse width and whose frequency is related to speed, each pulsed signal having a leading edge;

a solenoid operable in response to an electrical output signal to actuate said solenoid-operated clutch;

and an electronic controller for receiving said input signal and for providing said electrical output signal and comprising;

a counter for measuring the length of the time interval between the leading edges of an incoming pulsed signal and the preceding pulsed signal, means for resetting said counter in response to each incoming pulsed signal, and means responsive to detection of a time interval of predetermined length between said incoming signal and said preceding pulsed signal to determine frequency and to provide said electrical output signal to said solenoid to operate said clutch.

5. In combination:

apparatus comprising a plurality of first components capable of changes in condition and a plurality of second components which are to be actuated when said first components undergo predetermined changes in condition,

said first components including a rotatable component operable at various speed,

said second components including a clutch component which is to be actuated when said rotatable component reaches a predetermined speed;

and control means for said apparatus comprising;

a plurality of signal generating means responsive to changes in condition of said first components to provide electrical input signals,

said signal generating means comprising a first signal generating device providing digital signals indicative of a change in condition of an associated first component, a second signal generating device providing analog signals indicative of the magnitude of a change in condition of an associated first component, and a third signal generating device providing a series of pulsed signals which are variable in frequency and pulse width and in which the time interval between the leading edge of a pair of signals is indicative of the magnitude and rate of change in magnitude in the rotational speed of said rotatable components;

and an electronic controller for receiving said input signals from said signal generating devices and for providing output signals to operate said transducers to effect actation of said second components,

said electronic controller comprising;

a counter for measuring the length of the time interval between the leading edges of an incoming pulsed signal and the preceding pulsed signal, from said third signal generating device, means for resetting said counter in response to each incoming pulsed signal, and means responsive to detection of a time interval of predetermined length between said incoming signal and said preceding pulsed signal to determine frequency and to provide said output signal to operate the transducer associated with said clutch component.