Engine throttle valve control system for automotive vehicle

Claim 2

In a method of controlling an internal combustion engine for a wheeled automotive vehicle the steps comprising: sensing a power indicative parameter which varies with a demand for engine power; storing a set of control maps in a memory; arranging each of said maps to produce an engine control value the magnitude of which increase in response to the magnitude and rate of change of said power indicative parameter; designing said maps to exhibit control characteristics wherein the magnitude of the engine control signal for a given magnitude of said power indicative parameter, increases from map to map; sensing wheel slip; upgrading the maps by changing the currently used one to one which increases the response characteristics in response to: the amount of wheel slip being below a first predetermined value; and downgrading the maps in response to the wheel slip exceeding said first predetermined value, said downgrading being accomplished by changing the currently used one to one which is one rank below that which was used a predetermined time period prior the wheel slip exceeding said first predetermined value.

Claim 3

A method as claimed in claim 1 further comprising the steps of: monitoring a second parameter which varies with the engine speed of said engine; and modifying the length of said predetermined time period in response to the magnitude of said engine speed indicative parameter in manner wherein the length of said predetermined time period is reduced with increasing engine speed.

Claim 4

A method as claimed in claim 1 further comprising the steps of: monitoring a third parameter which varies with the transmission gear ratio of a transmission associated with said engine; and modifying the length of said predetermined time period in response to gear ratio of said transmission in a manner wherein the length of said predetermined time period is reduced with increasing engine speed.

Claim 5

A method as claimed in claim 1, wherein said upgrading upgrading step is induced in response to the value of said control signal produced by the instant control map being at its maximum permissible level for the instant magnitude of said power indicative parameter.

Claim 6

A method as claimed in claim 1, wherein said step of upgrading further requires that the rate of change of the magnitude of said power indicative parameter in a direction which requires increased engine output, is greater than zero.

Claim 7

A method as claimed in claim 1 further comprising the steps of: changing the maps in a direction which reduces and downgrades the response characteristics in the event that the wheel slip is below a second predetermined value.

Claim 8

A method as claimed in claim 8 further comprising the step of arranging the map change which downgrades the same in response to the slip exceeding the second predetermined value to occur after the change which downgrades in response to the slip exceeding said first predetermined value.

Claim 9

A method as claimed in claim 1, wherein said wheel slip is determined by: determining value of a vehicle operation parameter which varies with the vehicle speed; determing the wheel speed of the driven wheels of vehicle; and comparing the wheel speed and vehicle speed indicative values to determine the value of the difference therebetween.

Claim 10

A method as claimed in claim 8 further comprising the steps of: determining a predetermined vehicle speed limit; using the difference obtained in said comparing step when the vehicle speed is below said predetermined vehicle speed limit; using value derived by dividing the difference obtained in said comparing step with the wheel speed of said driven wheels.

Claim 11

A method as claimed in claim 1 further comprising the steps of: using the rate at which the power demand indicative parameter is changing to determine the change in engine control signal; and limiting the value of the control signal to a value defined between the upper an lower limits of the instant control map.

Claim 12

A method as claimed in claim 10, wherein said power demand signal change rate is determined by cyclically noting the value of the demand signal and using the difference between the instant value and the previously recorded value and the difference between the previously recorded value and the value recorded before that.

Claim 13

A control system of an automotive vehicle having and engine and a transmission, said engine having an induction conduit through which air flows to said engine and a throttle valve disposed in said induction conduit for controlling the power output of said engine, said control system comprising: means for sensing a power indicative parameter which varies with a demand for engine power; a memory in which a set of control maps are stored, said maps being arranged so that each produces an engine control value the magnitude of which increases in response to the magnitude and rate of change of said power indicative parameter, said maps being designed to exhibit control characteristics wherein the magnitude of the engine control signal for a given magnitude of said power indicative parameter, increases from map to map; means for sensing wheel slip; control means for: upgrading the maps by changing the currently used one to one which increases the response characteristics in response to the amount of wheel slip being below a first predetermined value; and downgrading the maps in response to the wheel slip exceeding said first predetermined value, said downgrading being accomplished by changing the currently used one to one which is one rank below that which was used a predetermined period prior the wheel slip exceeding said first predetermined value.

Claim 14

A control system of an automotive vehicle having and engine and a transmission, said engine having an induction conduit through which air flows to said engine and a throttle valve disposed in said induction conduit for controlling the power output of said engine, said control system comprising: means for sensing a power indicative parameter which varies with a demand for engine power; a memory in which a set of control maps are stored, said maps being arranged so that each produces an engine control value the magnitude of which increases in response to the magnitude and rate of change of said power indicative parameter, said maps being designed to exhibit control characteristics wherein the magnitude of the engine control signal for a given magnitude of said power indicative parameter, increases from map to map; means for sensing wheel slip; control means for: upgrading the maps by changing the currently used one to one which increases the response characteristics in response to the amount of wheel slip being below a first predetermined value; and downgrading the maps in response to the wheel slip exceeding said first predetermined value, said downgrading being accomplished by changing the currently used one to one which is one rank below that which was used a predetermined period prior the wheel slip exceeding said first predetermined value.

Claim 15

A control system as claimed in claim 12 further comprising: means for monitoring a second parameter which varies with the engine speed of said engine; and wherein said control means further includes circuitry for modifying the length of said predetermined time period in response to the magnitude of said engine speed indicative parameter in manner wherein the length of said predetermined time period is reduced with increasing engine speed.

Claim 16

A control system as claimed in claim 12 further comprising: means for monitoring gear ratio of the transmission; and wherein said control means further includes circuitry for modifying the length of said predetermined time period in response to gear ratio of said transmission in a manner wherein the length of said predetermined time period is reduced with increasing engine speed.

Claim 17

A control system as claimed in claim 12, wherein said control means is arranged to induce map upgrading in response to the value of said control signal produced by the instant control map assuming its maximum permissible level for the instant magnitude of said power indicative parameter.

Claim 18

A control system as claimed in claim 12, wherein said control means is arranged to induce map upgrading when the rate of change of the magnitude of said power indicative parameter in a direction which requires increased engine output, is greater than zero.

Claim 19

A control system as claimed in claim 12 wherein said control means is further further arranged to induce changing the maps in a direction which reduces and downgrades the response characteristics in the event that the wheel slip is below a second predetermined value.

Claim 20

A control system as claimed in claim 17 further comprising the step of arranging the map change which downgrades the same in response to the slip exceeding the second predetermined value to occur after the change which downgrades in response to the slip exceeding said first predetermined value.

Claim 21

A control system as claimed in claim 12 wherein said control means further includes an arrangement for: determining a predetermined vehicle speed limit; using the difference obtained in said comparing step when the vehicle speed is below said predetermined vehicle speed limit; using value derived by dividing the difference obtained in said comparing step with the wheel speed of said driven wheels.

Claim 22

A control system as claimed in claim 12 wherein said control means further includes an arrangement for: using the rate at which the power demand indicative parameter is changing to determine the change in engine control signal; and limiting the value of the control signal to a value defined between the upper and lower limits of the instant control map.

Claim 23

In a method of controlling an internal combustion engine for a wheeled automotive vehicle, said engine being controlled by throttle valve means which is exclusively operated by an electronically generated engine control signal, the steps comprising: sensing a parameter which varies with a demand for engine power; storing a set of control maps in a memory; arranging each of said maps to produce an engine control signal the magnitude of which increases in response to the magnitude and rate of change of said parameter, said maps being designed to exhibit control characteristics wherein the magnitude of the engine control signal for a given magnitude of said parameter, increases from map to map; sensing wheel slip; upgrading the maps by changing the currently used one to one which reduces the response characteristics when: the amount of wheel slip is below said first predetermined value, and the control signal being produced by the instant control map is at its maximum permissible level for the instant magnitude of said parameter; downgrading the maps by changing the currently used one to which is at least one rank below the one which was used a predetermined period of time prior the occurance of wheel slip, when the wheel slip exceeds a first predetermined value; and using said engine control signal to control said throttle valve means.

Claim 24

In a method of controlling an internal combustion engine for a wheeled automotive vehicle, said engine being controlled by throttle valve means which is exclusively operated by an electronically generated engine control signal, the steps comprising: sensing a parameter which varies with a demand for engine power; storing a set of control maps in a memory; arranging each of said maps to produce an engine control signal the magnitude of which increases in response to the magnitude and rate of change of said parameter, said maps being designed to exhibit control characteristics wherein the magnitude of the engine control signal for a given magnitude of said parameter, increases from map to map; sensing wheel slip; upgrading the maps by changing the currently used one to one which reduces the response characteristics when: the amount of wheel slip is below said first predetermined value, and the control signal being produced by the instant control map is at its maximum permissible level for the instant magnitude of said parameter; downgrading the maps by changing the currently used one to which is at least one rank below the one which was used a predetermined period of time prior the occurance of wheel slip, when the wheel slip exceeds a first predetermined value; and using said engine control signal to control said throttle valve means.

Claim 25

A control system for an internal combustion engine for a wheeled automotive vehicle comprising: throttle valve means for controlling the amount of power produced by said engine, said throttle valve means being exclusively controlled by an engine control signal; means for sensing a parameter which varies with a demand for engine power; control map means for producing said engine control signal in a manner wherein the magnitude of said engine control signal increases in response to the magnitude and rate of change of said parameter, said control map means including a memory in which a plurality control maps are stored, said maps being designed to exhibit control characteristics wherein the magnitude of the engine control signal for a given magnitude of said parameter, increases from map to map; means for sensing wheel slip; and control means for: upgrading the maps by changing the currently used one to one which reduces the response characteristics when: the amount of wheel slip is below said first predetermined value, and the control signal being produced by the instant control map is at its maximum permissible level for the instant magnitude of said parameter; downgrading the maps when the wheel slip exceeds said predetermined value by changing the currently used one below that which was used a predetermined time period prior the exceeding of said first predetermined value; and generating said engine control signal based on the engine control value derived using said first set of maps.

Claim 26

A control system for an internal combustion engine for a wheeled automotive vehicle comprising: throttle valve means for controlling the amount of power produced by said engine, said throttle valve means being exclusively controlled by an engine control signal; means for sensing a parameter which varies with a demand for engine power; control map means for producing said engine control signal in a manner wherein the magnitude of said engine control signal increases in response to the magnitude and rate of change of said parameter, said control map means including a memory in which a plurality control maps are stored, said maps being designed to exhibit control characteristics wherein the magnitude of the engine control signal for a given magnitude of said parameter, increases from map to map; means for sensing wheel slip; and control means for: upgrading the maps by changing the currently used one to one which reduces the response characteristics when: the amount of wheel slip is below said first predetermined value, and the control signal being produced by the instant control map is at its maximum permissible level for the instant magnitude of said parameter; downgrading the maps when the wheel slip exceeds said predetermined value by changing the currently used one below that which was used a predetermined time period prior the exceeding of said first predetermined value; and generating said engine control signal based on the engine control value derived using said first set of maps.

Claim 27

In a wheeled vehicle a driven wheel; a first wheel speed sensor for detecting the rotational speed of said driven wheel; an undriven wheel; a second wheel speed sensor for detecting the rotational speed of said undriven wheel; a manually operable accelerator; a third sensor for detecting the position of said accelerator; an engine; an induction conduit through which air passes to said engine; a single throttle valve disposed in said induction conduit for controlling the amount of air which is permitted to pass therethrough; a servo motor unit operatively connected to said throttle valve, said servo motor being arranged to exclusively control the position of said throttle valve; a control circuit, said control circuit being responsive to the outputs of said first, second and third sensors, said control circuit being operatively connected to said servo motor unit and arranged to produce a throttle valve control signal for controlling said servo motor unit, said throttle valve control signal being indicative of the degree to which said throttle valve should be opened, said control circuit comprising: memory means for storing a plurality of engine control maps, said maps being recorded in terms of throttle valve opening and absolute accelerator movement, said maps being arranged to determine the angle to which the throttle valve should be opened for a given accelerator movement; wheel slip detection means for determining the amount of wheel slip which is occuring based on the outputs of said first and second sensors; and selection means for selecting which of said plurality of maps should be used, said selection means being responsive to the amount of wheel slip which is detected, said selection means being arranged so that upon a wheel slip in excess of a predetermined limit is detected a map which was used a predermined period of time ago is determined and utilized to determine which map is to be used under the instant circumstances.

Claim 28

In a wheeled vehicle a driven wheel; a first wheel speed sensor for detecting the rotational speed of said driven wheel; an undriven wheel; a second wheel speed sensor for detecting the rotational speed of said undriven wheel; a manually operable accelerator; a third sensor for detecting the position of said accelerator; an engine; an induction conduit through which air passes to said engine; a single throttle valve disposed in said induction conduit for controlling the amount of air which is permitted to pass therethrough; a servo motor unit operatively connected to said throttle valve, said servo motor being arranged to exclusively control the position of said throttle valve; a control circuit, said control circuit being responsive to the outputs of said first, second and third sensors, said control circuit being operatively connected to said servo motor unit and arranged to produce a throttle valve control signal for controlling said servo motor unit, said throttle valve control signal being indicative of the degree to which said throttle valve should be opened, said control circuit comprising: memory means for storing a plurality of engine control maps, said maps being recorded in terms of throttle valve opening and absolute accelerator movement, said maps being arranged to determine the angle to which the throttle valve should be opened for a given accelerator movement; wheel slip detection means for determining the amount of wheel slip which is occuring based on the outputs of said first and second sensors; and selection means for selecting which of said plurality of maps should be used, said selection means being responsive to the amount of wheel slip which is detected, said selection means being arranged so that upon a wheel slip in excess of a predetermined limit is detected a map which was used a predermined period of time ago is determined and utilized to determine which map is to be used under the instant circumstances.