Exhaust gas recirculation (EGR) internal combustion engine roughness control system

Claim 2

An exhaust gas recirculation valve control system for controlling position of the exhaust recirculation valve of an internal combustion engine having a rotatable member rotatable at speed varying with the speed of the engine, said exhaust gas recirculation valve control system comprising: a. speed sensor means responsively connected to the engine to provide a speed signal varying with the speed of tHe rotatable member; b. differentiator means operatively connected to said speed sensor means for differentiating said speed signal and providing a derivative signal varying with a derivative of said speed signal; c. rectifier means operatively connected to said differentiator means for rectifying said derivative signal and providing a rectified output signal indicating the magnitude of the speed changes; d. comparator means operatively connected with said rectifier means for providing a comparison signal having a first magnitude when said rectified output signal is above a predetermined magnitude and a second magnitude when said rectified output signal is below said predetermined magnitude; e. integrator means operatively connected to said comparator means for generating a control signal having a magnitude varying at a first predetermined rate when the magnitude of said comparison signal is one of said first and second magnitudes and at a second predetermined rate when the magnitude of said comparison signal is the other of said first and second predetermined magnitudes; and f. control means operatively connected to said integrator means and to said exhaust gas recirculation valve operative to control the position of said exhaust gas recirculation valve in accordance with the magnitude of said control signal.

Claim 3

The exhaust gas recirculation valve control system of claim 1 wherein said rectifier means comprise a full wave rectifier, said first predetermined rate causes said magnitude of said control signal to increase, and said second predetermined rate causes the magnitude of said control signal to decrease.

Claim 4

An exhaust gas recirculation valve control system for controlling the position of an exhaust gas recirculation valve of an internal combustion engine having a rotatable member rotatable at a speed varying with the speed of the engine, said exhaust gas recirculation valve control system comprising: a. speed sensor means responsively connected to the engine to provide a speed signal varying with the speed of the rotatable member; b. differentiator means operatively connected to said speed sensor for differentiating said speed signal and providing a roughness signal varying with a derivative of said speed signal; c. integrator means operatively connected to said differentiator means for integrating said roughness signal to provide a predetermined correction signal; and d. control means operatively connected to said integrator means and to said exhaust gas recirculation valve operative to control the position of said exhaust gas recirculation valve in accordance with said predetermined correction signal.

Claim 5

An exhaust gas recirculation valve control system for controlling the position of an exhaust gas recirculation valve of an internal combustion engine having a rotatable member rotatable at a speed varying with the speed of the engine, said exhaust gas recirculation valve control system comprising: a. speed sensor means responsively connected to the engine to provide a speed signal varying with the speed of the rotatable member; b. differentiator means operatively connected to said speed sensor for differentiating said speed signal and providing a roughness signal varying with a derivative of said speed signal; c. integrator means operatively connected to said differentiator means for integrating said roughness signal to provide a predetermined correction signal; and d. control means operatively connected to said integrator means and to said exhaust gas recirculation valve operative to control the position of said exhaust gas recirculation valve in accordance with said predetermined correction signal.

Claim 6

A closed loop exhaust gas recirculation flow control system for controlling the magnitude of another engine performance related parameter of an internal combustion engine while also controlling the exhaust recirculation flow, the engine having engine air fuel passage means for mixing and delivering a fuel flow with an operator controllable air flow to an engine inlet, the engine also having engine exhaust means for exhausting engine combustion products, said exhaust gas recirculation flow control system comprising: a. valve controlled exhaust gas recirculation conduit means operatively connecting the engine air fuel passage means and the engine exhaust means responsive to a recirculation flow control signal to vary a recirculation flow of engine combustion products from the engine exhaust means to the engine air fuel passage means; and b. recirculation flow control signal generation means responsive to said engine performance related parameter operative to generate said recirculation flow control signal in accordance with the magnitude of said engine performance related parameter and to communicate said recirculation flow control signal to said valve controlled exhaust gas recirculation conduit means so as to vary said recirculation flow intermediate a first continuous recirculation flow and a second conTinuous recirculation flow said first recirculation flow being less than said second recirculation flow and said valve controlled exhaust gas recirculation conduit means increasing said recirculation flow from said first continuous recirculation flow to said second continuous recirculation flow as said recirculation flow control signal decreases, said increasing recirculation flow reducing the NOx constituents in the engine combustion products while also increasing the magnitude of said engine performance related parameter.

Claim 7

A closed loop exhaust gas recirculation flow control system for controlling the magnitude of another engine performance related parameter of an internal combustion engine while also controlling the exhaust recirculation flow, the engine having engine air fuel passage means for mixing and delivering a fuel flow with an operator controllable air flow to an engine inlet, the engine also having engine exhaust means for exhausting engine combustion products, said exhaust gas recirculation flow control system comprising: a. valve controlled exhaust gas recirculation conduit means operatively connecting the engine air fuel passage means and the engine exhaust means responsive to a recirculation flow control signal to vary a recirculation flow of engine combustion products from the engine exhaust means to the engine air fuel passage means; and b. recirculation flow control signal generation means responsive to said engine performance related parameter operative to generate said recirculation flow control signal in accordance with the magnitude of said engine performance related parameter and to communicate said recirculation flow control signal to said valve controlled exhaust gas recirculation conduit means so as to vary said recirculation flow intermediate a first continuous recirculation flow and a second conTinuous recirculation flow said first recirculation flow being less than said second recirculation flow and said valve controlled exhaust gas recirculation conduit means increasing said recirculation flow from said first continuous recirculation flow to said second continuous recirculation flow as said recirculation flow control signal decreases, said increasing recirculation flow reducing the NOx constituents in the engine combustion products while also increasing the magnitude of said engine performance related parameter.

Claim 8

An engine exhaust gas recirculation flow control system for controlling the magnitude of an engine performance related parameter varying inversely with the NOx constituents in the engine combustion products of an internal combustion engine, the engine having air fuel passage means for mixing and delivering a fuel flow with an operator controllable air flow to an engine inlet, the engine also having engine exhaust means for exhausting engine combustion products, said exhaust gas recirculation flow control system comprising: a. valve controlled exhaust gas recirculation conduit means operatively connecting the air fuel passage means and the engine exhaust means responsive to a recirculation flow control signal to controllably vary the recirculation flow of engine combustion products between the air fuel delivery means and the engine exhaust means, said valve controlled conduit means operative to normally effect a first recirculation flow for minimizing the NOx constituents in the engine combustion products when the magnitude of said engine parameter is less than a predetermined value and to otherwise reduce said recirculation flow towards a second recirculation flow when the magnitude of said engine parameter momentarily exceeds said predetermined value, whereby said magnitude of said engine parameter is decreased towards said predetermined value as said recirculation flow decreases from said first flow to said second flow; and b. recirculation flow control signal generation means for generating said recirculation flow control signal for said valve controlled exhaust gas recirculation conduit means in accordance with the difference between the magnitudes of said engine performance related parameter and said perdetermined value.

Claim 9

An engine exhaust gas recirculation flow control system for controlling the magnitude of an engine performance related parameter varying inversely with the NOx constituents in the engine combustion products of an internal combustion engine, the engine having air fuel passage means for mixing and delivering a fuel flow with an operator controllable air flow to an engine inlet, the engine also having engine exhaust means for exhausting engine combustion products, said exhaust gas recirculation flow control system comprising: a. valve controlled exhaust gas recirculation conduit means operatively connecting the air fuel passage means and the engine exhaust means responsive to a recirculation flow control signal to controllably vary the recirculation flow of engine combustion products between the air fuel delivery means and the engine exhaust means, said valve controlled conduit means operative to normally effect a first recirculation flow for minimizing the NOx constituents in the engine combustion products when the magnitude of said engine parameter is less than a predetermined value and to otherwise reduce said recirculation flow towards a second recirculation flow when the magnitude of said engine parameter momentarily exceeds said predetermined value, whereby said magnitude of said engine parameter is decreased towards said predetermined value as said recirculation flow decreases from said first flow to said second flow; and b. recirculation flow control signal generation means for generating said recirculation flow control signal for said valve controlled exhaust gas recirculation conduit means in accordance with the difference between the magnitudes of said engine performance related parameter and said perdetermined value.

Claim 10

A closed loop exhaust gas recirculation flow control system for varying inversely-related first and second engine-combustion-influenced recirculation-flow-related parameters of an intermittently firing internal combustion engine having air fuel passage means for mixing and delivering a fuel flow with an operator controllable air flow to an engine air/fuel inlet, and engine exhaust means for permitting a portion of the engine combustion products to flow from the engine to the atmosphere, said exhaust gas recirculation flow control system comprising: a. valve-controlled exhaust-gas-recirculation conduit means adapted to permit a controllable portion of the engine combustion products to move in an engine-performance-related recirculation flow from the engine exhaust means to the engine air/fuel inlet, said valve-controlled exhaust-gas-recirculation conduit means including exhaust-gas-recirculation passage means and exhaust-gas-recirculation valve means operatively associated therewith, said valve means responsive to a recirculation flow control signal to vary said recirculation flow intermediate a first flow for limiting said first parameter and a second flow less than said first flow for limiting said second parameter; and b. recirculation flow control signal generation means having an input responsively associated with said engine to detect changes in said second parameter and having its output operatively connected to said exhaust gas recirculation valve means to provide said recirculation flow control signal thereto, whereby said recirculation flow is controlled to normally control said first parameter as long as the magnitude of said second parameter is below a predetermined level and to otherwise control said second parameter when the magnitude of said second parameter is above said predetermined level.

Claim 11

A closed loop exhaust gas recirculation flow control system for varying inversely-related first and second engine-combustion-influenced recirculation-flow-related parameters of an intermittently firing internal combustion engine having air fuel passage means for mixing and delivering a fuel flow with an operator controllable air flow to an engine air/fuel inlet, and engine exhaust means for permitting a portion of the engine combustion products to flow from the engine to the atmosphere, said exhaust gas recirculation flow control system comprising: a. valve-controlled exhaust-gas-recirculation conduit means adapted to permit a controllable portion of the engine combustion products to move in an engine-performance-related recirculation flow from the engine exhaust means to the engine air/fuel inlet, said valve-controlled exhaust-gas-recirculation conduit means including exhaust-gas-recirculation passage means and exhaust-gas-recirculation valve means operatively associated therewith, said valve means responsive to a recirculation flow control signal to vary said recirculation flow intermediate a first flow for limiting said first parameter and a second flow less than said first flow for limiting said second parameter; and b. recirculation flow control signal generation means having an input responsively associated with said engine to detect changes in said second parameter and having its output operatively connected to said exhaust gas recirculation valve means to provide said recirculation flow control signal thereto, whereby said recirculation flow is controlled to normally control said first parameter as long as the magnitude of said second parameter is below a predetermined level and to otherwise control said second parameter when the magnitude of said second parameter is above said predetermined level.

Claim 12

A closed-loop recirculating-exhaust-gas control system for controlling an engine combustion related parameter of an intermittently firing internal combustion engine having air fuel passage means for mixing and delivering a fuel flow with an operator controllable air flow to an engine inlet and an exhaust passage for exhausting an exhaust flow of combustion products from an engine exhaust to the atmosphere, said closed-loop recirculating-exhaust-gas control system comprising: a. valve-controlled exhaust-gas-recirculation conduit means for recirculating a controllable recirculation flow of combustion products from the engine exhaust to the engine air/fuel inlet, said conduit means including an exhaust recirculation passage and exhaust gas recirculation valve means operatively connected thereto for controlling said recirculation flow therein in accordance with a recirculation flow control signal; and b. engine combustion-related-parameter sensor means for detecting changes in said engine combustion-related parameter and providing said recirculation flow control signal to said recirculation valve means to control said recirculation flow so as to regulate the magnitude of said changes in said engine combustion related parameter at a predetermined magnitude.

Claim 13

A closed-loop recirculating-exhaust-gas control system for controlling an engine combustion related parameter of an intermittently firing internal combustion engine having air fuel passage means for mixing and delivering a fuel flow with an operator controllable air flow to an engine inlet and an exhaust passage for exhausting an exhaust flow of combustion products from an engine exhaust to the atmosphere, said closed-loop recirculating-exhaust-gas control system comprising: a. valve-controlled exhaust-gas-recirculation conduit means for recirculating a controllable recirculation flow of combustion products from the engine exhaust to the engine air/fuel inlet, said conduit means including an exhaust recirculation passage and exhaust gas recirculation valve means operatively connected thereto for controlling said recirculation flow therein in accordance with a recirculation flow control signal; and b. engine combustion-related-parameter sensor means for detecting changes in said engine combustion-related parameter and providing said recirculation flow control signal to said recirculation valve means to control said recirculation flow so as to regulate the magnitude of said changes in said engine combustion related parameter at a predetermined magnitude.

Claim 14

In the exhaust-gas recirculation control system of claim 7 wherein said intermittently firing internal combustion engine includes a variable speed member the speed of which varies with the speed of the engine and wherein said engine combustion related sensor means provides a time varying signal dependent on the speed of said variable speed member.

Claim 15

The closed loop recirculating exhaust gas control system of claim 8 wherein said time varying signal varies with a derivative of the speed of said variable speed member.

Claim 16

An engine exhaust gas recirculation flow control system for controlling exhaust gas recirculation flow of an internal combustion engine, the engine having air fuel passage means for mixing and delivering a fuel flow with an operator-controllable air flow to an engine inlet, engine exhaust means for exhausting engine combustion products, and a rotatable member the momentary speed changes of which vary with the momentary speed changes of the engine to indicate the roughness of engine operation, said exhaust gas recirculation flow control system comprising: a. engine roughness sensing means responsive to the momentary speed changes of the rotatable member and operative to provide a roughness signal having a magnitude varying with the roughness of the engine; and b. valve controlled exhaust gas recirculation conduit means operatively connecting the engine air fuel passage means and the engine exhaust means and including exhaust gas recirculation valve means operatively connected to said engine roughness sensing means operative to normally permit a first recirculation flow of engine combustion products when the magnitude of said roughness signal is less than a predetermined magnitude and to otherwise cooperate with said engine roughness sensing means to reduce said recirculation flow from said first flow to a lower flow when the magnitude of said roughness signal exceeds said predetermined magnitude, said engine roughness sensing means and said exhaust gas recirculation valve means thereby cooperating to control said recirculation flow so as to regulate the magnitude of the momentary speed changes.

Claim 17

An engine exhaust gas recirculation flow control system for controlling exhaust gas recirculation flow of an internal combustion engine, the engine having air fuel passage means for mixing and delivering a fuel flow with an operator-controllable air flow to an engine inlet, engine exhaust means for exhausting engine combustion products, and a rotatable member the momentary speed changes of which vary with the momentary speed changes of the engine to indicate the roughness of engine operation, said exhaust gas recirculation flow control system comprising: a. engine roughness sensing means responsive to the momentary speed changes of the rotatable member and operative to provide a roughness signal having a magnitude varying with the roughness of the engine; and b. valve controlled exhaust gas recirculation conduit means operatively connecting the engine air fuel passage means and the engine exhaust means and including exhaust gas recirculation valve means operatively connected to said engine roughness sensing means operative to normally permit a first recirculation flow of engine combustion products when the magnitude of said roughness signal is less than a predetermined magnitude and to otherwise cooperate with said engine roughness sensing means to reduce said recirculation flow from said first flow to a lower flow when the magnitude of said roughness signal exceeds said predetermined magnitude, said engine roughness sensing means and said exhaust gas recirculation valve means thereby cooperating to control said recirculation flow so as to regulate the magnitude of the momentary speed changes.

Claim 18

A closed-loop recirculating-exhaust-gas control system for controlling an engine combustion related parameter of an intermittently firing internal combustion engine having an engine inlet and an engine exhaust, said closed loop system comprising: a. valve-controlled exhaust-gas-recirculation conduit means for communicating a controllable exhaust gas recirculation flow from the engine exhaust to the engine inlet and including variable positiOn exhaust gas recirculation valve means operative to vary said recirculation flow continuously between a first flow and a second flow in accordance with a recirculation flow control signal; b. engine combustion-related-parameter sensor means responsively associated with said engine to provide a sensor output signal varying with changes in said engine combustion-related parameter, said parameter being controllable by decreasing said recirculation flow as the magnitude of said parameter changes increases above a predetermined magnitude; and c. control means connected between said engine combustion related parameter sensor means and said variable position exhaust gas recirculation valve means operative to provide a recirculation flow control signal thereto for causing said recirculation valve means to normally permit a first recirculation flow when the magnitude of said engine combustion-related parameter changes is less than said predetermined magnitude and to otherwise cause said recirculation valve to reduce said recirculation flow towards said second recirculation flow as the value of said engine combustion-related parameter changes increases above said predetermined magnitude.

Claim 19

A closed-loop recirculating-exhaust-gas control system for controlling an engine combustion related parameter of an intermittently firing internal combustion engine having an engine inlet and an engine exhaust, said closed loop system comprising: a. valve-controlled exhaust-gas-recirculation conduit means for communicating a controllable exhaust gas recirculation flow from the engine exhaust to the engine inlet and including variable positiOn exhaust gas recirculation valve means operative to vary said recirculation flow continuously between a first flow and a second flow in accordance with a recirculation flow control signal; b. engine combustion-related-parameter sensor means responsively associated with said engine to provide a sensor output signal varying with changes in said engine combustion-related parameter, said parameter being controllable by decreasing said recirculation flow as the magnitude of said parameter changes increases above a predetermined magnitude; and c. control means connected between said engine combustion related parameter sensor means and said variable position exhaust gas recirculation valve means operative to provide a recirculation flow control signal thereto for causing said recirculation valve means to normally permit a first recirculation flow when the magnitude of said engine combustion-related parameter changes is less than said predetermined magnitude and to otherwise cause said recirculation valve to reduce said recirculation flow towards said second recirculation flow as the value of said engine combustion-related parameter changes increases above said predetermined magnitude.

Claim 20

In the closed loop exhaust gas recirculation control system of claim 11 wherein said intermittently firing internal combustion engine has a variable speed member the speed of which varies with the speed of the engine, wherein said changes of said engine combustion related parameter varies with changes in the speed of said variable speed member, and wherein said engine parameter sensor is responsive to changes in the speed of said variable speed member.

Claim 21

A closed-loop recirculating-exhaust-gas control system for controlling an engine combustion-related parameter controllable by varying the recirculation flow of engine combustion products from the engine exhaust of an intermittently firing internal combustion engine to the inlet thereof, the engine having a variable speed member varying with the speed of the engine, said closed-loop recirculating-gas-control system comprising: a. valve-controlled exhaust-gas-recirculation conduit means operative to control the recirculation flow of engine combustion products from the engine exhaust to the engine inlet and including an exhaust gas recirculation passage and exhaust gas recirculation valve means responsive to a recirculation flow control signal to vary the recirculation flow intermediate a first flow and a second flow; b. speed sensing means responsively associated with said variable speed member to provide a sensor output signal varying with the changes in said variable speed member caused by changes in an engine combustion related parameter; and c. control means operatively connecting said speed sensing means and said recirculation valve means for providing said recirculation flow signal varying with a derivative of said sensor output signal for controlling said recirculation flow to regulate the magnitude of said changes in said engine performance rated parameter at a predetermined value.

Claim 22

A closed-loop recirculating-exhaust-gas control system for controlling an engine combustion-related parameter controllable by varying the recirculation flow of engine combustion products from the engine exhaust of an intermittently firing internal combustion engine to the inlet thereof, the engine having a variable speed member varying with the speed of the engine, said closed-loop recirculating-gas-control system comprising: a. valve-controlled exhaust-gas-recirculation conduit means operative to control the recirculation flow of engine combustion products from the engine exhaust to the engine inlet and including an exhaust gas recirculation passage and exhaust gas recirculation valve means responsive to a recirculation flow control signal to vary the recirculation flow intermediate a first flow and a second flow; b. speed sensing means responsively associated with said variable speed member to provide a sensor output signal varying with the changes in said variable speed member caused by changes in an engine combustion related parameter; and c. control means operatively connecting said speed sensing means and said recirculation valve means for providing said recirculation flow signal varying with a derivative of said sensor output signal for controlling said recirculation flow to regulate the magnitude of said changes in said engine performance rated parameter at a predetermined value.

Claim 23

A closed-loop recirculating-exhaust-gas control system responsive to an engine combustion related parameter of an intermittently firing internal combustion engine, the engine having air induction means for communicating an operator controllable air flow to an engine inlet, fuel metering means for providing a controllable fuel flow to the engine inlet in accordance with the air flow, and an exhaust gas passage for exhausting an exhaust flow of combustion products from an engine outlet to the atmosphere, said closed-loop recirculating exhaust gas control system comprising: a. valve controlled exhaust gas recirculation means including an exhaust gas recirculation passage connected at its one end to communicate with the engine outlet and at its other end with the engine inlet and further including a variable position exhaust gas recirculation valve, said valve controlled conduit means responsive on application of a valve Control signal to said recirculation valve to vary a controllable recirculation flow of the combustion products from the engine outlet to the engine inlet; b. engine combustion related parameter sensor means operatively connected with the engine to provide a sensor signal varying with momentary changes in said engine combustion related parameter relative to a predetermined magnitude thereof; and c. recirculation valve power actuator means operatively connecting said sensor means and said recirculation valve responsive to said sensor signal to vary the position of said recirculation valve so as to control said recirculation flow to regulate said engine combustion related parameter at said predetermined magnitude.

Claim 24

A closed-loop recirculating-exhaust-gas control system responsive to an engine combustion related parameter of an intermittently firing internal combustion engine, the engine having air induction means for communicating an operator controllable air flow to an engine inlet, fuel metering means for providing a controllable fuel flow to the engine inlet in accordance with the air flow, and an exhaust gas passage for exhausting an exhaust flow of combustion products from an engine outlet to the atmosphere, said closed-loop recirculating exhaust gas control system comprising: a. valve controlled exhaust gas recirculation means including an exhaust gas recirculation passage connected at its one end to communicate with the engine outlet and at its other end with the engine inlet and further including a variable position exhaust gas recirculation valve, said valve controlled conduit means responsive on application of a valve Control signal to said recirculation valve to vary a controllable recirculation flow of the combustion products from the engine outlet to the engine inlet; b. engine combustion related parameter sensor means operatively connected with the engine to provide a sensor signal varying with momentary changes in said engine combustion related parameter relative to a predetermined magnitude thereof; and c. recirculation valve power actuator means operatively connecting said sensor means and said recirculation valve responsive to said sensor signal to vary the position of said recirculation valve so as to control said recirculation flow to regulate said engine combustion related parameter at said predetermined magnitude.

Claim 25

An engine gas recirculation flow control system for varying in accordance with changes in an engine speed dependent parameter the recirculation flow between the engine exhaust and the engine inlet of a portion of the engine combustion products normally being recirculated to minimize the proportion of NOx constituents in the engine combustion products, the engine having air fuel passage means with an operator controllable throttle valve therein for admitting a controllable air flow, fuel metering means for providing an air-flow dependent intermittently-injected fuel flow to the air fuel passage means, and engine exhaust means for exhausting engine combustion products, said exhaust gas recirculation flow control system comprising: a. exhaust gas recirculation passage means having an inlet end connected to communicate with said engine exhaust means and an outlet end connected to communicate with the air fuel passage means downstream of the throttle valve; b. a valve positioned in said exhaust gas recirculation passage intermediate said inlet end and said outlet end continuously moveable between a first position and a second position; c. valve positioning means operatively connected with said valve responsive to a recirculation flow control signal to effect movement of said valve to a position between said first and second positions; d. speed sensor means having an input and an output, said sensor input responsively associated with the engine to detect the magnitude of said engine speed dependent parameter and said sensor output providing a speed signal varying with the magnitude of said engine speed dependent parameter; e. differentiator means having an input and an output, said differentiator input being connected in electrical circuit with said sensor output and said differentiator output providing a derivative signal varying with a derivative of said sensor speed signal; f. full wave rectifier means having an input and an output, said rectifier input connected with said differentiator output and said rectifier output providing a rectified signal varying with the absolute magnitude of said differentiator derivative signal; and g. comparator means having first input, a second input, and an output, said first comparator input connected to a reference voltage, said second comparator input connected to said rectifier output, and said comparator output connected in electrical circuit with said valve actuator means and providing said recirculation flow control signal thereto when said rectified output signal exceeds a predetermined voltage determined by the magnitude of said reference voltage.

Claim 26

An engine gas recirculation flow control system for varying in accordance with changes in an engine speed dependent parameter the recirculation flow between the engine exhaust and the engine inlet of a portion of the engine combustion products normally being recirculated to minimize the proportion of NOx constituents in the engine combustion products, the engine having air fuel passage means with an operator controllable throttle valve therein for admitting a controllable air flow, fuel metering means for providing an air-flow dependent intermittently-injected fuel flow to the air fuel passage means, and engine exhaust means for exhausting engine combustion products, said exhaust gas recirculation flow control system comprising: a. exhaust gas recirculation passage means having an inlet end connected to communicate with said engine exhaust means and an outlet end connected to communicate with the air fuel passage means downstream of the throttle valve; b. a valve positioned in said exhaust gas recirculation passage intermediate said inlet end and said outlet end continuously moveable between a first position and a second position; c. valve positioning means operatively connected with said valve responsive to a recirculation flow control signal to effect movement of said valve to a position between said first and second positions; d. speed sensor means having an input and an output, said sensor input responsively associated with the engine to detect the magnitude of said engine speed dependent parameter and said sensor output providing a speed signal varying with the magnitude of said engine speed dependent parameter; e. differentiator means having an input and an output, said differentiator input being connected in electrical circuit with said sensor output and said differentiator output providing a derivative signal varying with a derivative of said sensor speed signal; f. full wave rectifier means having an input and an output, said rectifier input connected with said differentiator output and said rectifier output providing a rectified signal varying with the absolute magnitude of said differentiator derivative signal; and g. comparator means having first input, a second input, and an output, said first comparator input connected to a reference voltage, said second comparator input connected to said rectifier output, and said comparator output connected in electrical circuit with said valve actuator means and providing said recirculation flow control signal thereto when said rectified output signal exceeds a predetermined voltage determined by the magnitude of said reference voltage.

Claim 27

An engine control system for controlling an engine parameter of an internal combustion engine having the rotatable member the speed of which varies with the speed of the engine: a. sensing means operatively associated with said rotatable member for providing a speed signal varying with the speed thereof; b. differentiator means operatively connected to said speed sensing means for differentiating said speed signal and providing a roughness signal varying with a derivative of said speed signal; and c. parameter controller means operatively connected with said differentiator means for controlling said engIne parameter in accordance with said roughness signal, wherein said parameter controller means includes an exhaust gas recirculation valve operative to control the recirculation flow of exhaust gases from the engine exhaust to the engine inlet.

Claim 28

An engine control system for controlling an engine parameter of an internal combustion engine having the rotatable member the speed of which varies with the speed of the engine: a. sensing means operatively associated with said rotatable member for providing a speed signal varying with the speed thereof; b. differentiator means operatively connected to said speed sensing means for differentiating said speed signal and providing a roughness signal varying with a derivative of said speed signal; and c. parameter controller means operatively connected with said differentiator means for controlling said engIne parameter in accordance with said roughness signal, wherein said parameter controller means includes an exhaust gas recirculation valve operative to control the recirculation flow of exhaust gases from the engine exhaust to the engine inlet.

Claim 29

An exhaust recirculation valve control system for controlling the exhaust gas recirculation valve of an internal combustion engine having an exhaust gas recirculation flow control valve and a rotatable member rotatable at a speed varying with the speed of the engine, said exhaust gas recirculation valve control system comprising: a. speed sensor means responsively connected to the engine to provide a speed signal varying with the speed of the rotatable member; b. differentiator means operatively connected to said speed sensor for differentiating said speed signal and providing a roughness signal varying with a derivative of said speed signal; and c. control means operatively connected to said differentiator means and to said exhaust gas recirculation valve operative to convert said roughness signal into a predetermined correction signal and to control said exhaust gas recirculation valve in accordance with said predetermined correction signal.

Claim 30

An exhaust recirculation valve control system for controlling the exhaust gas recirculation valve of an internal combustion engine having an exhaust gas recirculation flow control valve and a rotatable member rotatable at a speed varying with the speed of the engine, said exhaust gas recirculation valve control system comprising: a. speed sensor means responsively connected to the engine to provide a speed signal varying with the speed of the rotatable member; b. differentiator means operatively connected to said speed sensor for differentiating said speed signal and providing a roughness signal varying with a derivative of said speed signal; and c. control means operatively connected to said differentiator means and to said exhaust gas recirculation valve operative to convert said roughness signal into a predetermined correction signal and to control said exhaust gas recirculation valve in accordance with said predetermined correction signal.

Claim 31

An exhaust gas recirculation valve control system for controlling the exhaust gas recirculation valve means of an internal combustion engine having a rotatable member rotatable at a speed varying with the speed of the engine, said exhaust gas recirculation valve control system comprising: a. speed sensor means respectively connected to the engine to provide a speed signal varying with the speed of the rotatable member; b. differentiator means operatively connected to said speed sensor means for differentiating said speed signal and providing a derivative signal varying with a derivative of said speed signal; c. rectifier means operatively connected to said differentiator means for rectifying said derivative signal and providing a rectified output signal indicating the magnitude of the engine speed changes; d. comparator means operatively connected with said rectifier means for providing a roughness signal varying with magnitudes of said rectified output signal above a predetermined magnitude; and e. control means operatively connected to said comparator means and to said exhaust gas recirculation valve means operative to convert said roughness signal into a predetermined correction signal and to control said exhaust gas recirculation valve in accordance with said predetermined correction signal.

Claim 32

An exhaust gas recirculation valve control system for controlling the exhaust gas recirculation valve means of an internal combustion engine having a rotatable member rotatable at a speed varying with the speed of the engine, said exhaust gas recirculation valve control system comprising: a. speed sensor means respectively connected to the engine to provide a speed signal varying with the speed of the rotatable member; b. differentiator means operatively connected to said speed sensor means for differentiating said speed signal and providing a derivative signal varying with a derivative of said speed signal; c. rectifier means operatively connected to said differentiator means for rectifying said derivative signal and providing a rectified output signal indicating the magnitude of the engine speed changes; d. comparator means operatively connected with said rectifier means for providing a roughness signal varying with magnitudes of said rectified output signal above a predetermined magnitude; and e. control means operatively connected to said comparator means and to said exhaust gas recirculation valve means operative to convert said roughness signal into a predetermined correction signal and to control said exhaust gas recirculation valve in accordance with said predetermined correction signal.

Claim 33

In the exhaust gas recirculation flow control system recited in claim 18, said derivative of said speed signal being the first derivative thereof for indicating engine accelerations and decelerations and said rectifier means comprising a full wave rectifier so that said rectified output signal varies with the absolute magnitudes of said engine accelerations and decelerations.

Claim 36

An exhaust gas recirculation control system for positioning an exhaust recirculation valve of an internal combustion engine intermediate an open position permitting maximum recirculation flow and a closed position permitting minimum recirculation flow, the engine having a rotatable member rotatable at speeds varying with the speed of the engine, said exhaust gas recirculation control system comprising: a. speed sensor means responsively connected to the engine to provide a speed signal varying with the speed of the rotatable member, said speed signal having low and high frequency components; b. differentiator means operatively connected to said speed sensor means for differentiating said speed signal and providing a roughness signal varying with a derivative of said high frequency component of said speed signal; c. first control means connecting said differentiator means and said exhaust recirculation valve operative to bias said fuel delivery valve towards said open position when said roughness signal is less than a predetermined roughness magnitude and towards said closed position when the magnitude of said roughness signal is greater than said predetermined roughness magnitude; and d. second control means operatively connected between said first control means and said differentiator means for modifying said speed change related signal when the magnitude of said low frequency components exceeds a predetermined low frequency magnitude.

Claim 37

An exhaust gas recirculation control system for positioning an exhaust recirculation valve of an internal combustion engine intermediate an open position permitting maximum recirculation flow and a closed position permitting minimum recirculation flow, the engine having a rotatable member rotatable at speeds varying with the speed of the engine, said exhaust gas recirculation control system comprising: a. speed sensor means responsively connected to the engine to provide a speed signal varying with the speed of the rotatable member, said speed signal having low and high frequency components; b. differentiator means operatively connected to said speed sensor means for differentiating said speed signal and providing a roughness signal varying with a derivative of said high frequency component of said speed signal; c. first control means connecting said differentiator means and said exhaust recirculation valve operative to bias said fuel delivery valve towards said open position when said roughness signal is less than a predetermined roughness magnitude and towards said closed position when the magnitude of said roughness signal is greater than said predetermined roughness magnitude; and d. second control means operatively connected between said first control means and said differentiator means for modifying said speed change related signal when the magnitude of said low frequency components exceeds a predetermined low frequency magnitude.

Claim 38

A roughness control system for controlling the roughness of an internal combustion engine having an exhaust recirculation valve controllable to vary the exhaust recirculation flow and a rotatable member the momentary speed changes of which vary with the momentary speed changes of the engine to indicate the roughness of engine operation, said roughness control system comprising: a. engine roughness sensing means responsively connected to the engine for sensing momentary speed changes of the rotatable member and providing a roughness signal having a magnitude varying with the sensed momentary speed changes; and b. control means operatively connecting the exhaust recirculation valve and the said engine roughness sensing means for controlling the exhaust recirculation flow so as to regulate the magnitude of said roughness signal at a predetermined magnitude.

Claim 39

A roughness control system for controlling the roughness of an internal combustion engine having an exhaust recirculation valve controllable to vary the exhaust recirculation flow and a rotatable member the momentary speed changes of which vary with the momentary speed changes of the engine to indicate the roughness of engine operation, said roughness control system comprising: a. engine roughness sensing means responsively connected to the engine for sensing momentary speed changes of the rotatable member and providing a roughness signal having a magnitude varying with the sensed momentary speed changes; and b. control means operatively connecting the exhaust recirculation valve and the said engine roughness sensing means for controlling the exhaust recirculation flow so as to regulate the magnitude of said roughness signal at a predetermined magnitude.

Claim 40

An exhaust gas recirculation control system for positioning an exhaust recirculation valve in an exhaust recirculation conduit of an internal combustion engine intermediate an open position for permitting maximum recirculation flow and a closed position for permitting minimum recirculation flow, the engine having a rotatable member the momentary speed changes of which vary with the momentary speed changes of the engine to indicate the roughness of engine operation, said exhaust recirculation control system comprising: a. engine roughness sensing means responsively connected to the engine for sensing momentary speed changes of the rotatable member and providing a roughness signal having a magnitude varying with the sensed momentary speed changes; and b. control means connecting the exhaust recirculation valve and said engine roughness sensing means operative to normally bias the exhaust recirculation valve towards the open position when the magnitude of said roughness signal is less than a predetermined magnitude and to bias the valve towards the closing position when the magnitude of said roughness signal is greater than said predetermined magnitude, whereby the exhaust recirculation flow is controlled so as to regulate the magnitude of said roughness signal at said predetermined magnitude.

Claim 41

An exhaust gas recirculation control system for positioning an exhaust recirculation valve in an exhaust recirculation conduit of an internal combustion engine intermediate an open position for permitting maximum recirculation flow and a closed position for permitting minimum recirculation flow, the engine having a rotatable member the momentary speed changes of which vary with the momentary speed changes of the engine to indicate the roughness of engine operation, said exhaust recirculation control system comprising: a. engine roughness sensing means responsively connected to the engine for sensing momentary speed changes of the rotatable member and providing a roughness signal having a magnitude varying with the sensed momentary speed changes; and b. control means connecting the exhaust recirculation valve and said engine roughness sensing means operative to normally bias the exhaust recirculation valve towards the open position when the magnitude of said roughness signal is less than a predetermined magnitude and to bias the valve towards the closing position when the magnitude of said roughness signal is greater than said predetermined magnitude, whereby the exhaust recirculation flow is controlled so as to regulate the magnitude of said roughness signal at said predetermined magnitude.