CN103939220B - For stoping the cylinder control system and method that resonant frequency operates - Google Patents

Abstract

A cylinder control system and method for preventing resonant frequency operation is disclosed. The system includes command generator module, compensation module and score module. A command generator module generates a first command value and performs one of activation and deactivation of an intake valve and an exhaust valve of a first cylinder of the engine based on the first command value. A compensation module generates a compensation value for a second cylinder of the engine based on a response of the model to the first command value. The fraction module determines a target value corresponding to a fraction of the total number of cylinders of the engine to be activated based on the torque request. The command generator module further: generates a second command value based on the compensation value and the difference between the target value and the first command value; and performs activation and deactivation of the intake valve and the exhaust valve of the second cylinder based on the second command value Use one.

Description

Cylinder control system and method for preventing resonant frequency operation

Cross References to Related Applications

This application claims the benefit of U.S. Provisional Application No. 61/755,131, filed January 22, 2013. The disclosure of the above application is incorporated herein by reference in its entirety.

This application is related to U.S. Patent Application Serial No. 13/798,451 filed March 13, 2013, U.S. Patent Application Serial No. 13/798,351 filed March 13, 2013, and U.S. Patent Application Serial No. 13 filed March 13, 2013 /798,586, filed March 13, 2013, U.S. Patent Application Serial No. 13/798,590, filed March 13, 2013, U.S. Patent Application Serial No. 13/798,536, filed March 13, 2013 U.S. Patent Application Serial No. 13/798,435, filed March 13, 2013, U.S. Patent Application Serial No. 13/798,471, filed March 13, 2013, U.S. Patent Application Serial No. 13/798,737, filed March 13, 2013 U.S. Patent Application Serial No. 13/798,701, filed March 13, 2013, U.S. Patent Application Serial No. 13/798,518, March 13, 2013, U.S. Patent Application Serial No. 13/799,129 , U.S. Patent Application Serial No. 13/798,540, filed March 13, 2013, U.S. Patent Application Serial No. 13/798,574, filed March 13, 2013, and Serial No. 13/799,181, filed March 13, 2013 U.S. Patent Application Serial No. 13/799,116, filed March 13, 2013, U.S. Patent Application Serial No. 13/798,624, filed March 13, 2013, Serial No. US Patent Application Serial No. 13/798,384, and US Patent Application Serial No. 13/798,775, filed March 13, 2013. The entire disclosure of the above application is incorporated herein by reference.

technical field

The present disclosure relates to internal combustion engines and, more particularly, to engine control systems and methods.

Background technique

The background description provided herein is for the purpose of generally presenting the context of the disclosure. The work of the presently mentioned inventors—to the extent described in this Background section—and aspects of that description that might not otherwise constitute prior art at the time of filing, are neither expressly nor impliedly admitted to be prior art to the present invention.

Internal combustion engines combust an air and fuel mixture within cylinders to drive pistons, which produces drive torque. In some types of engines, air flow into the engine may be regulated by a throttle valve. The throttle valve can be adjusted to increase or decrease the air flow into the engine by increasing or decreasing the area of the throttle valve. As the throttle valve area increases, the air flow into the engine increases. A fuel control system adjusts the rate at which fuel is injected to provide a desired air/fuel mixture to the cylinders and/or to achieve a desired torque output. Increasing the amount of air and fuel provided to the cylinders increases the torque output of the engine.

Under some conditions, one or more cylinders of the engine may be deactivated. Deactivation of the cylinder may include opening and closing of an intake valve of the deactivated cylinder and stopping fueling of the cylinder. One or more cylinders may be deactivated, for example, to reduce fuel consumption when the engine may produce the requested amount of torque despite the deactivation of the one or more cylinders.

Contents of the invention

The cylinder control system includes command generator module, compensation module and score module. A command generator module generates a first command value and performs one of activation and deactivation of an intake valve and an exhaust valve of a first cylinder of the engine based on the first command value. A compensation module generates a compensation value for a second cylinder of the engine based on a response of the model to the first command value. The fraction module determines a target value corresponding to a fraction of the total number of cylinders of the engine to be activated based on the torque request. The command generator module further: generates a second command value based on the compensation value and the difference between the target value and the first command value; and performs activation and deactivation of the intake valve and the exhaust valve of the second cylinder based on the second command value Use one.

A cylinder control method includes: generating a first command value; one of activating and deactivating an intake valve and an exhaust valve of a first cylinder of an engine based on the first command value; An offset value is generated for a second cylinder of the engine. The cylinder control method further includes: determining a target value based on the torque request, the target value corresponding to a fraction of the total number of cylinders of the engine to be started; generating a second command value based on the compensation value and a difference between the target value and the first command value and performing one of activation and deactivation of the intake valve and the exhaust valve of the second cylinder based on the second command value.

Scheme 1. A cylinder control system of a vehicle, comprising:

a command generator module that generates a first command value and performs one of activation and deactivation of an intake valve and an exhaust valve of a first cylinder of the engine based on the first command value;

a compensation module that generates a compensation value for a second cylinder of the engine based on the response of the model to the first command value; and

a fractional module that determines a target value based on the torque request, the target value corresponding to a fraction of the total number of cylinders of the engine to be started,

where the instruction generator module further:

generating a second command value based on the compensation value and the difference between the target value and the first command value; and

One of activation and deactivation of the intake and exhaust valves of the second cylinder is performed based on the second command value.

Item 2. The cylinder control system of item 1, wherein at least one feature of the model is configured based on a predetermined resonant frequency of the vehicle.

Embodiment 3. The cylinder control system of embodiment 1, wherein the compensation module determines a velocity value and an acceleration value based on a model response to the first command value, and generates a compensation value based on the velocity and acceleration values.

Scheme 4. The cylinder control system of scheme 3, wherein the compensation module determines a first resonance value based on a velocity value multiplied by a first predetermined gain and determines a second resonance based on an acceleration value multiplied by a second predetermined gain value, and a compensation value is determined based on the first and second resonance values.

Item 5. The cylinder control system of item 4, wherein the compensation module determines the compensation value based on a sum of the first resonance value and the second resonance value.

Scheme 6. The cylinder control system as described in Scheme 1, which further comprises:

an accumulation module that generates an accumulated difference based on a previous value of the accumulated difference and a difference between the target value and the first command value; and

a difference module that generates an adjustment value based on a second difference between the accumulated difference and the compensation value,

Wherein the instruction generator module generates the second instruction value based on the adjustment value.

Item 7. The cylinder control system of item 6, wherein the difference module determines the adjustment value based on an accumulated difference minus a compensation value.

Item 8. The cylinder control system of item 6, wherein the command generator module generates the second command value based on a comparison of the adjusted value to a predetermined value.

Scheme 9. The cylinder control system of Scheme 6, wherein the command generator module:

setting the second command value as the first value when the adjustment value is less than the predetermined value, and setting the second command value as the second value when the adjustment value is not less than the predetermined value;

deactivating the intake and exhaust valves of the second cylinder when the second command value is set to the first value; and

When the second command value is set to the second value, the intake valve and the exhaust valve of the second cylinder are activated.

Item 10. The cylinder control system of item 1, wherein the fraction module determines the target value further based on a predetermined maximum torque of the engine.

Solution 11. A cylinder control method for a vehicle comprising:

generating a first instruction value;

performing one of activation and deactivation of intake valves and exhaust valves of a first cylinder of the engine based on the first command value;

generating a compensation value for a second cylinder of the engine based on the response of the model to the first command value;

determining a target value based on the torque request, the target value corresponding to a fraction of the total number of cylinders of the engine to be started;

generating a second command value based on the compensation value and the difference between the target value and the first command value; and

One of activation and deactivation of the intake and exhaust valves of the second cylinder is performed based on the second command value.

Item 12. The cylinder control method of item 11, wherein at least one feature of the model is configured based on a predetermined resonant frequency of the vehicle.

Scheme 13. The cylinder control method as described in Scheme 11, further comprising:

determining a velocity value and an acceleration value based on a response of the model to the first command value; and

Compensation values are generated based on velocity and acceleration values.

Scheme 14. The cylinder control method as described in Scheme 13, which further comprises:

determining a first resonance value based on a product of a velocity value and a first predetermined gain;

determining a second resonance value based on a product of the acceleration value and a second predetermined gain; and

A compensation value is determined based on the first and second resonance values.

Scheme 15. The cylinder control method as described in Scheme 14, further comprising:

A compensation value is determined based on the sum of the first and second resonance values.

Scheme 16. The cylinder control method as described in Scheme 11, further comprising:

generating the cumulative difference based on a previous value of the cumulative difference and a difference between the target value and the first command value;

generating an adjustment value based on a second difference between the cumulative difference and the compensation value; and

A second command value is generated based on the adjustment value.

Scheme 17. The cylinder control method as described in Scheme 16, further comprising:

An adjustment value is determined based on the cumulative difference minus the compensation value.

Scheme 18. The cylinder control method as described in Scheme 16, further comprising:

A second command value is generated based on a comparison of the adjustment value with a predetermined value.

Item 19. The cylinder control method according to item 16, further comprising:

setting the second command value as the first value when the adjustment value is less than the predetermined value, and setting the second command value as the second value when the adjustment value is not less than the predetermined value;

deactivating the intake and exhaust valves of the second cylinder when the second command value is set to the first value; and

When the second command value is set to the second value, the intake valve and the exhaust valve of the second cylinder are activated.

Item 20. The cylinder control method of item 11, further comprising determining the target value based on a predetermined maximum torque of the engine.

Other areas of applicability of the present disclosure will become apparent from the detailed description provided below. It should be understood that the detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

Description of drawings

The disclosure will be more fully understood from the detailed description and accompanying drawings, in which:

FIG. 1 is a functional block diagram of an exemplary engine system according to the present disclosure;

FIG. 2 is a functional block diagram of an exemplary engine control system according to the present disclosure;

3 is a functional block diagram of an exemplary cylinder control module according to the present disclosure;

4A and 4B are graphs of the Fast Fourier Transform (FFT) of cylinder firing patterns;

5 is a functional block diagram of an exemplary cylinder control module according to the present disclosure; and

FIG. 6 is a flowchart depicting an example method of controlling cylinder activation and deactivation according to the present disclosure.

detailed description

Internal combustion engines combust an air and fuel mixture within cylinders to produce torque. Under some conditions, an engine control module (ECM) may deactivate one or more cylinders of the engine. The ECM may deactivate one or more cylinders, for example to reduce fuel consumption, while the engine may produce the requested amount of torque despite the deactivation of the one or more cylinders.

The ECM determines the target ignition fraction based on the requested torque amount. The target firing fraction may correspond to the fraction of cylinders that should be activated to achieve the requested amount of torque. The ECM generates firing commands for future (eg, next) cylinders in a predetermined cylinder firing order based on the target firing fraction. The ignition command may be a value indicating whether a future cylinder should be activated or deactivated. For example, the ECM may set the ignition command to 1 when the future cylinder should be activated, and set the ignition command to 0 when the future cylinder should be deactivated.

The ECM generates the firing command further based on generating the firing command for a cylinder preceding the cylinder in the firing order. More specifically, the ECM determines the difference between the target firing fraction and a previous firing command value that resulted for a previous (eg, last) cylinder in a predetermined firing order. The ECM adds the differences determined over time to produce an accumulated difference and generates ignition commands for future cylinders based on the accumulated difference.

However, in some cases, the frequency at which the cylinders are activated may approach or become equal to the vehicle's predetermined resonant frequency. The magnitude of the noise and/or vibration may increase as the frequency of actuating the cylinders approaches a predetermined resonant frequency.

The ECM of the present disclosure determines offset values for future cylinders based on a virtual (device) model's response to previous firing commands generated for previous cylinders. The virtual model is configured based on a predetermined resonance frequency of the vehicle. The ECM adjusts the cumulative difference based on the offset value and generates firing commands for future cylinders based on the adjusted cumulative difference. Adjusting the accumulated difference based on the offset value hinders the firing of future cylinders when the firing of future cylinders would increase the resonance energy (and increases noise and/or vibration), and reduces the resonance energy (and reduces noise and/or vibration) when the firing of future cylinders will increase the resonance energy and/or vibration), to facilitate ignition of future cylinders.

Referring now to FIG. 1 , a functional block diagram of an exemplary engine system 100 is presented. The engine system 100 of a vehicle includes an engine 102 that combusts an air/fuel mixture to generate torque based on driver input from a driver input module 104 . Air is drawn into the engine 102 through an air intake system 108 . The intake system 108 may include an intake manifold 110 and a throttle valve 112 . For example only, the damper valve 112 may include a butterfly valve having rotatable vanes. An engine control module (ECM) 114 controls a throttle actuator module 116 , and the throttle actuator module 116 regulates opening of the throttle valve 112 to control airflow into the intake manifold 110 .

Air from the intake manifold 110 is drawn into cylinders of the engine 102 . While the engine 102 includes multiple cylinders, for illustration purposes, a single representative cylinder 118 is shown. For example only, engine 102 may include 2, 3, 4, 5, 6, 8, 10, and/or 12 cylinders. In some cases, the ECM 114 may instruct the cylinder actuator module 120 to selectively deactivate some cylinders (as discussed further below), which may improve fuel efficiency.

Engine 102 may operate using a four stroke cycle. The four strokes described below will be referred to as intake stroke, compression stroke, combustion stroke and exhaust stroke. During each revolution of a crankshaft (not shown), two of four strokes occur within cylinder 118 . Therefore, two crankshaft revolutions are necessary for cylinder 118 to go through all four strokes. For a four-stroke engine, one engine cycle may correspond to two crankshaft revolutions.

Air from the intake manifold 110 is drawn into the cylinder 118 through an intake valve 122 during the intake stroke when the cylinder 118 is activated. The ECM 114 controls a fuel actuator module 124 that regulates fuel injection to achieve a desired air/fuel ratio. Fuel may be injected into the intake manifold 110 at a central location or at multiple locations, such as near the intake valve 122 of each cylinder. In various implementations (not shown), fuel may be injected directly into the cylinders or into mixing chambers/ports associated with the cylinders. The fuel actuator module 124 may disable fuel injection to deactivated cylinders.

The injected fuel mixes with air and creates an air/fuel mixture in cylinder 118 . During the compression stroke, a piston (not shown) within cylinder 118 compresses the air/fuel mixture. Engine 102 may be a compression-ignition engine, in which case compression causes ignition of the air/fuel mixture. Alternatively, engine 102 may be a spark-ignition engine, in which case spark actuator module 126 energizes spark plug 128 in cylinder 118 based on a signal from ECM 114 to ignite the air/fuel mixture. Some types of engines, such as homogeneous charge compression ignition (HCCI) engines, may implement both compression ignition and spark ignition. The timing of the spark can be specified relative to the time when the piston is at its uppermost position, known as top dead center (TDC).

The spark actuator module 126 may be controlled by a timing signal specifying how far before or after TDC to generate the spark. Because piston position is directly related to crankshaft rotation, operation of the spark actuator module 126 may be synchronized with crankshaft position. The spark actuator module 126 may stop providing spark to deactivated cylinders or provide spark to deactivated cylinders.

During the combustion stroke, combustion of the air/fuel mixture drives the piston downward, thereby driving the crankshaft. The combustion stroke may be defined as the time between when the piston reaches TDC and when the piston returns to the bottom-most position, which is called bottom dead center (BDC).

During the exhaust stroke, the piston begins moving up from BDC and expels the byproducts of combustion through an exhaust valve 130 . The byproducts of combustion are exhausted from the vehicle through an exhaust system 134 .

The intake valves 122 may be controlled by an intake camshaft 140 and the exhaust valves 130 may be controlled by an exhaust camshaft 142 . In various implementations, multiple intake camshafts (including intake camshaft 140 ) may control multiple intake valves (including intake valve 122 ) for cylinder 118 and/or may control multiple banks of cylinders (including cylinder 118) intake valve (including intake valve 122). Similarly, multiple exhaust camshafts (including exhaust camshaft 142 ) may control multiple exhaust valves for cylinder 118 and/or may control exhaust valves (including exhaust valve 130). While camshaft based valve actuation is shown and discussed, camless valve actuators may be implemented.

The cylinder actuator module 120 may deactivate the cylinder 118 by disabling opening of the intake valve 122 and/or the exhaust valve 130 . The time to open the intake valve 122 may be varied relative to piston TDC by an intake cam phaser 148 . The time to open the exhaust valve 130 may be varied relative to piston TDC by an exhaust cam phaser 150 . A phaser actuator module 158 may control the intake cam phaser 148 and the exhaust cam phaser 150 based on signals from the ECM 114 . When implemented, variable valve lift (not shown) may also be controlled by the phaser actuator module 158 . In various other implementations, the intake valve 122 and/or the exhaust valve 130 may be controlled by actuators other than camshafts, such as electromechanical actuators, electrohydraulic actuators, electromagnetic actuators, and the like.

Engine system 100 may include a boosting device that provides pressurized air to intake manifold 110 . For example, FIG. 1 shows a turbocharger including a turbine 160 - 1 driven by exhaust gas flowing through exhaust system 134 . The turbocharger also includes a compressor 160 - 2 driven by the turbine 160 - 1 and compressing air introduced into the throttle valve 112 . In various implementations, a supercharger (not shown), driven by the crankshaft, may compress air from the throttle valve 112 and deliver the compressed air to the intake manifold 110 .

Wastegate 162 may allow exhaust gas to bypass turbine 160 - 1 , thereby reducing turbocharger boost (intake compression). The ECM 114 may control the turbocharger via a boost actuator module 164 . The boost actuator module 164 may regulate turbocharger boost by controlling the position of the wastegate 162 . In various implementations, multiple turbochargers may be controlled by the boost actuator module 164 . The turbocharger may have a variable geometry that may be controlled by the boost actuator module 164 .

An intercooler (not shown) may dissipate some of the heat contained in the compressed charge air generated when the air is compressed. Although shown separately for purposes of illustration, the turbine 160-1 and compressor 160-2 may be mechanically coupled to each other such that the intake air is placed in close proximity to the hot exhaust gas. The compressed charge air may absorb heat from components of the exhaust system 134 .

Engine system 100 may include an exhaust gas recirculation (EGR) valve 170 that selectively redirects exhaust gas back into intake manifold 110 . EGR valve 170 may be located upstream of turbine 160-1 of the turbocharger. The EGR valve 170 may be controlled by an EGR actuator module 172 .

Crankshaft position may be measured using crankshaft position sensor 180 . The temperature of the engine coolant may be measured using an engine coolant temperature (ECT) sensor 182 . The ECT sensor 182 may be located within the engine 102 or elsewhere where coolant is circulated, such as a radiator (not shown).

Pressure within the intake manifold 110 may be measured using a manifold absolute pressure (MAP) sensor 184 . In various implementations, engine vacuum (which is the difference between ambient air pressure and the pressure within the intake manifold 110 ) may be measured. The mass flow rate of air flowing into the intake manifold 110 may be measured using a mass air flow (MAF) sensor 186 . In various implementations, the MAF sensor 186 may be located in a housing that also includes the throttle valve 112 .

The position of the throttle valve 112 may be measured using one or more throttle position sensors (TPS) 190 . The temperature of air drawn into the engine 102 may be measured using an intake air temperature (IAT) sensor 192 . Engine system 100 may also include one or more other sensors 193 . The ECM 114 may use signals from the sensors to make control decisions for the engine system 100 .

The ECM 114 may communicate with a transmission control module 194 to coordinate shifting in a transmission (not shown). For example, the ECM 114 may reduce engine torque during a shift. The engine 102 outputs torque through a crankshaft to a transmission (not shown). One or more connecting devices, such as a torque converter and/or one or more clutches, regulate torque transfer between the transmission input shaft and the crankshaft. Torque is transmitted between the transmission input shaft and the transmission output shaft through gears.

Torque is transferred between the transmission output shaft and the wheels of the vehicle through one or more differential gears, drive shafts, or the like. The engine 102 , transmission, differential gears, drive shafts, and other torque transmitting or generating components make up the vehicle's powertrain.

The ECM 114 may communicate with a hybrid control module 196 to coordinate operation of the engine 102 and an electric motor 198 . Electric motor 198 may also function as a generator and may be used to generate electrical energy for use by the vehicle electrical system and/or for storage in the battery. While only the electric motor 198 is shown and discussed, multiple electric motors may be implemented. In various implementations, the individual functions of the ECM 114 , the transmission control module 194 , and the hybrid control module 196 may be integrated into one or more modules.

Each system that changes an engine parameter may be referred to as an engine actuator. Each engine actuator has an associated actuator value. For example, the throttle actuator module 116 may be referred to as an engine actuator, and the throttle opening area may be referred to as an actuator value. In the example of FIG. 1 , the throttle actuator module 116 achieves the throttle opening area by adjusting the blade angle of the throttle valve 112 .

The spark actuator module 126 may also be referred to as an engine controller, and corresponding actuator values may be spark advance relative to cylinder TDC. Other engine actuators may include cylinder actuator module 120 , fuel actuator module 124 , phaser actuator module 158 , boost actuator module 164 , and EGR actuator module 172 . For these engine actuators, the actuator values may correspond to cylinder activation/deactivation sequence, fueling rate, intake and exhaust cam phaser angles, boost pressure, and EGR valve opening area, respectively. The ECM 114 may control actuator values such that the engine 102 produces a desired engine output torque.

Referring now to FIG. 2 , a functional block diagram of an exemplary engine control system is presented. The torque request module 204 may determine the torque request 208 based on one or more driver inputs 212 , such as accelerator pedal position, brake pedal position, cruise control input, and/or one or more other suitable driver inputs. The torque request module 204 may additionally or alternatively be based on one or more other torque requests, such as a torque request generated by the ECM 114 and/or from sources such as the transmission control module 194, the hybrid control module 196, the chassis control module, etc. torque requests received by other modules of the vehicle) to determine the torque request 208 .

One or more engine actuators may be controlled based on torque request 208 and/or one or more other parameters. For example, the throttle control module 216 may determine a target throttle opening 220 based on the torque request 208 . The throttle actuator module 116 may adjust opening of the throttle valve 112 based on the target throttle opening 220 .

A spark control module 224 may determine a target spark timing 228 based on the torque request 208 . The spark actuator module 126 may generate the spark based on the target spark timing 228 . The fuel control module 232 may determine one or more target fueling parameters 236 based on the torque request 208 . For example, the target fueling parameters 236 may include the fuel injection amount, the number of fuel injections to inject the amount, and the timing of each injection. The fuel actuator module 124 may inject fuel based on the target fueling parameters 236 .

The phaser control module 237 may determine a target intake cam phaser angle 238 and an exhaust cam phaser angle 239 based on the torque request 208 . The phaser actuator module 158 may adjust the intake cam phaser 148 and the exhaust cam phaser 150 based on the target intake cam phaser angle 238 and exhaust cam phaser angle 239 , respectively. A boost control module 240 may determine a target boost 242 based on the torque request 208 . The boost actuator module 164 may control the boost device to output boost based on the target boost 242 .

A cylinder control module 244 (see also FIG. 3 ) generates a firing command 248 for a next cylinder in a predetermined firing order of cylinders (“next cylinder”). The ignition command 248 indicates whether the next cylinder should be activated or deactivated. For example only, the cylinder control module 244 may set the ignition command 248 to a first state (eg, 1) when the next cylinder should be activated, and set the ignition command 248 to a second state when the next cylinder should be deactivated. Two states (for example, 0). While the ignition command 248 is and will be discussed relative to the next cylinder in the predetermined firing order, the ignition command 248 may be generated for a second cylinder immediately following the next cylinder in the predetermined firing order, A firing command is generated for a third cylinder immediately after the second cylinder in the predetermined firing sequence, or a firing command is generated for another cylinder after the next cylinder in the predetermined firing sequence.

When the ignition command 248 indicates that the next cylinder should be deactivated, the cylinder actuator module 120 deactivates the intake and exhaust valves of the next cylinder. When the ignition command 248 indicates that the next cylinder should be activated, the cylinder actuator module 120 allows opening and closing of the intake and exhaust valves of the next cylinder.

When the ignition command 248 indicates that the next cylinder should be deactivated, the fuel control module 232 stops fueling the next cylinder. When the ignition command 248 indicates that the next cylinder should be activated, the fuel control module 232 sets the target fueling parameter 236 to provide fuel to the next cylinder. The spark control module 224 may provide spark to the next cylinder when the ignition command 248 indicates that the next cylinder should be activated. The spark control module 224 may provide spark to the next cylinder or cease providing spark when the ignition command 248 indicates that the next cylinder should be deactivated. Cylinder deactivation differs from fuel delivery (e.g. deceleration fuel delivery) in that the intake and exhaust valves of the cylinder whose fueling was stopped during the fuel delivery remain open during the fuel delivery and closed, while the intake and exhaust valves of the cylinders remain closed while those cylinders are deactivated.

Referring now to FIG. 3 , a functional block diagram of an exemplary implementation of the cylinder control module 244 is presented. The fraction module 304 determines a target ignition fraction 308 based on the torque request 208 . The target firing fraction 308 may correspond to a fraction of the total number of cylinders of the engine 102 that should be activated to achieve the torque request 208 . The engine 102 may be capable of outputting a predetermined maximum torque when all cylinders of the engine 102 are activated (and zero cylinders are deactivated). The target ignition fraction 308 may be a value between 0.0 and 1.0, inclusive, and the score module 304 may set the target ignition fraction 308 equal to the torque request 208 divided by the predetermined maximum torque or based on the torque request 208 divided by The target ignition fraction 308 is set at a predetermined maximum torque.

The first delay module 312 receives the ignition command 248 , stores the ignition command 248 for one cylinder ignition event, and outputs a previous (eg, last) value of the ignition command 248 as a previous ignition command 316 . The previous firing command 316 may correspond to the firing command 248 for the cylinder immediately preceding the next cylinder in the predetermined firing order (“previous cylinder”). For example, the previous ignition command 316 may be 1 (first state) when the last cylinder is activated according to the ignition command 248 generated for the last cylinder, and when the upper cylinder is deactivated according to the ignition command 248 generated for the last cylinder. The previous ignition command 316 may be 0 (second state) for one cylinder. For example only, the first delay module 312 may include a one-unit first-in-first-out (FIFO) buffer.

The first difference module 320 determines the difference 324 based on the target firing fraction 308 and the previous firing command 316 . For example, the first difference module 320 may set the difference 324 equal to the target firing fraction 308 minus the previous firing instruction 316 or set the difference 324 based on the target firing fraction 308 minus the previous firing instruction 316 .

The accumulation module 328 adds the difference 324 and the sum of previous values of the difference 324 to produce an accumulated difference 332 . In other words, the accumulation module 328 adds the difference to a previous (eg, last) value of the accumulated difference 332 to generate the accumulated difference 332 . The accumulated difference 332 is input to a second difference module 336 .

The resonance compensation value 340 is also input to the second difference module 336 . The resonance compensation value 340 is discussed further below. The second difference module 336 adjusts the accumulated difference 332 based on the resonance compensation value 340 to generate an adjustment value. In other words, the second difference module 336 determines the adjustment value 344 based on the accumulated difference 332 and the resonance compensation value 340 . For example, the second difference module 336 may set the adjustment value 344 equal to or based on the cumulative difference 332 minus the resonance compensation value 340 from the cumulative difference 332 .

The command generator module 348 generates the ignition command 248 for the next cylinder based on the adjustment value 344 and the predetermined value. More specifically, the command generator module 348 may generate the ignition command 248 for the next cylinder based on a comparison of the adjustment value 344 to a predetermined value. For example only, the command generator module 348 may set the fire command 248 for the next cylinder to 1 (to command activation of the next cylinder) when the adjustment value 344 is greater than or equal to the predetermined value. The command generator module 348 may set the fire command 248 for the next cylinder to 0 (to command deactivation of the next cylinder) when the adjustment value 344 is less than the predetermined value. In implementations where the ignition command 248 is set to 1 to command activation of the next cylinder and the ignition command 248 is set to 0 to command deactivation of the next cylinder, the predetermined value may be equal to 1. The first delay module 312 , the first difference module 320 , the accumulation module 328 , the second difference module 336 and the instruction generator module 348 may collectively form what may be referred to as a sigma-delta discretizer.

The compensation module 360 generates the resonance compensation value 340 . A second delay module 364 receives the ignition command 248 , stores the ignition command 248 for one cylinder ignition event, and outputs a previous (eg, last) value of the ignition command 248 as a previous ignition command 368 . The previous firing command 368 may correspond to the firing command 248 for the previous cylinder in the predetermined firing order. For example, the previous ignition command 368 may be 1 (first state) when the last cylinder was activated according to the ignition command 248 generated for the last cylinder, and the previous cylinder was disabled when the ignition command 248 was generated for the last cylinder. The previous ignition command 368 may be 0 (second state) when the last cylinder is used. For example only, the second delay module 364 may include a one-unit first-in-first-out (FIFO) buffer. In various implementations, the second delay module 364 may be omitted and the previous ignition command 316 may be used.

The model module 372 generates velocity values 376 and acceleration values 380 based on the state of the (virtual) model and the model's response to the previous ignition command 368 . The state of the model at a given time may be based on the model's response to previous ignition commands. By way of example only, the model may be or be based on a spring mass damper model. The characteristics of the model are determined based on powertrain characteristics of the vehicle and a predetermined resonant frequency. The velocity value 376 may correspond to the (model) mass velocity in response to the previous ignition command 368 . Acceleration value 380 may correspond to mass acceleration in response to previous ignition command 368 .

In various implementations, the model module 372 may selectively update one or more features of the model based on one or more operating parameters. For example, the predetermined resonant frequency may multiply or vary with engine speed. Accordingly, the model module 372 may selectively update one or more features of the model based on engine speed. Model module 372 may determine velocity value 376 and acceleration value 380 at the same rate that command generator module 348 generates ignition command 248 . For example, in various implementations, the model module 372 may update the velocity value 376 and the acceleration value 380 and the command generator module 348 may update the ignition command 248 every cylinder event (eg, every predetermined amount of crankshaft rotation) that occurs. In other implementations, the model module 372 may update the velocity value 376 and the acceleration value 380 at a time-based rate, such as over every predetermined period (the predetermined period is set to be shorter than the minimum possible period between two cylinder events ).

The first gain module 384 multiplies the velocity value 376 by a first predetermined gain to generate a first resonance value 388 . The second gain module 392 multiplies the acceleration value 380 by a second predetermined gain to generate a second resonance value 396 . The first and second predetermined gains may be calibratable and may be set based on how aggressively the cumulative difference 332 should be adjusted to avoid (prevent) operation at the predetermined resonant frequency and to facilitate operation outside the predetermined resonant frequency.

The summer module 398 sets the resonance compensation value 340 equal to or based on the sum of the first resonance value 388 and the second resonance value 396 . The effect of using the resonance compensation value 340 is to facilitate the activation of the next cylinder when its activation would not add energy to the system, and reduce the likelihood of operating at the predetermined resonant frequency. Conversely, the resonance compensation value 340 prevents activation of the next cylinder when activation of the next cylinder would add energy to the system, and likewise reduces the likelihood of operating at the predetermined resonant frequency. The resonance compensation value 340 provides a notch (or band stop) filter-like effect on the generation of the ignition command 248 to avoid operation at the predetermined resonance frequency.

An example of the effect of using the resonance compensation value 340 for a predetermined resonance frequency can be seen by comparing FIGS. 4A and 4B. 4A includes a graph of an implementation in which the compensation module 360 and the second difference module 336 are omitted and the accumulated difference 332 is used as the adjustment value 344 . Trace 404 tracks a first fast Fourier transform (FFT) of adjustment value 344 , and trace 408 tracks a second FFT of ignition command 248 . Trace 412 traces the delivery function of the device in question. As shown at 416, the second FFT includes peaks close to the peaks in the transfer function.

FIG. 4B includes diagrams for an embodiment similar to FIG. 3 in which the compensation module 360 and the second difference module 336 are included. Trace 420 tracks the FFT of adjustment value 344 , and trace 424 tracks the FFT of ignition command 248 . As shown in FIG. 4B , adjusting the adjustment value 344 based on the resonance compensation value 340 adjusts the ignition command 248 to attenuate the peak.

Referring back to FIG. 3 , in various embodiments, more than one predetermined resonant frequency may be targeted to avoid. In these embodiments, the model characteristics may be calibrated based on the characteristics of the powertrain and two or more predetermined resonant frequencies.

Additionally or alternatively, as in the example of FIG. 5 , multiple compensation modules like compensation module 360 may be implemented. FIG. 5 includes a functional block diagram of another exemplary implementation of the cylinder control module 244 . Referring now to FIG. 5 , the model characteristics of the compensation module 360 are calibrated based on characteristics of the vehicle powertrain and the first predetermined resonant frequency.

The second compensation module 504 generates a second resonance compensation value 508 . The second compensation module 504 may be similar to or identical to the compensation module 360, except that the model of the second compensation module 504 and the first and second predetermined gain values used by the second compensation module 504 may be calibrated based on a second predetermined resonant frequency. same.

The summer module 512 sets the final resonance compensation value 516 equal to or based on the sum of the resonance compensation value 340 and the second resonance compensation value 508 . The second difference module 336 sets the adjustment value 344 based on the accumulated difference 332 minus the final resonance compensation value 516 or sets it equal to the accumulated difference 332 minus the final resonance compensation value 516 . Although an example with two compensation modules is provided, more than two compensation modules may be implemented, and the summer module 512 may set the final resonance compensation value 516 equal to the sum of the resonance compensation values produced by each compensation module or based on This sum is used to set the final resonance compensation value.

Referring now to FIG. 6 , a flowchart depicting an example method of controlling cylinder activation and deactivation is presented. Control begins at 604 where the score module 304 generates the target firing score 308 . For example only, the fraction module 304 may set the target ignition fraction 308 equal to or based on the torque request 208 divided by the predetermined maximum torque.

At 608 , the first difference module 320 generates the difference 324 and the compensation module 360 generates the resonance compensation value 340 . The first difference module 320 may set the difference 324 equal to or based on the difference 324 between the target firing fraction 308 and the previous firing command 316 . The compensation module 360 generates the resonance compensation value 340 based on the previous ignition command 368 . More specifically, the model module 372 generates a velocity value 376 and an acceleration value 380, a first gain module 384 generates a first resonance value 388 based on the velocity value 376 and a first predetermined gain, and a second gain module 392 generates a first resonance value 388 based on the acceleration value 380 and the first predetermined gain. Two predetermined gains result in a second resonance value 396 . The summer module 398 sets the resonance compensation value 340 equal to or based on the sum of the first resonance value 388 and the second resonance value 396 .

At 612 , the accumulation module 328 generates an accumulated difference 332 based on the difference 324 . The cumulative module 328 may set the cumulative difference 332 equal to the sum of the difference 324 and a previous value of the cumulative difference 332 or set the cumulative difference 332 based on the sum. At 616 , the second difference module 336 generates the adjustment value 344 . The second difference module 336 may set the adjustment value 344 equal to the cumulative difference 332 minus the resonance compensation value 340 or set the adjustment value 344 based on the cumulative difference 332 minus the resonance compensation value 340 .

At 620 , the instruction generator module 348 determines whether the modulation value 344 is less than 1 (a predetermined value). If no at 620 , at 624 the command generator module 348 may set the ignition command 248 for the next cylinder in the predetermined firing order to 1 (first state) to command activation of the next cylinder. At 628 , the next cylinder is activated and control ends. When the ignition command 248 indicates that the next cylinder should be activated, the cylinder actuator module 120 allows opening and closing of the intake and exhaust valves of the next cylinder. When the ignition command 248 indicates that the next cylinder should be activated, the fuel control module 232 sets the target fueling parameter 236 to provide fuel to the next cylinder. The spark control module 224 may provide spark to the next cylinder when the ignition command 248 indicates that the next cylinder should be activated.

If 620 is true (when the adjustment value 344 is not less than 1), then at 632 the command generator module 348 may set the ignition command 248 for the next cylinder in the predetermined firing order to 0 (second state) to command the next deactivation of one cylinder. At 636 , the next cylinder is deactivated and control ends. When the ignition command 248 indicates that the next cylinder should be deactivated, the cylinder actuator module 120 deactivates the intake and exhaust valves of the next cylinder. The fuel control module 232 stops fueling the next cylinder when the ignition command 248 indicates that the next cylinder should be deactivated. The spark control module 224 may provide spark to the next cylinder or cease providing spark when the ignition command 248 indicates that the next cylinder should be deactivated. Although control is shown and discussed as ending, FIG. 6 shows one control loop, and a control loop may be executed, for example, every predetermined amount of crankshaft rotation.

The above description is merely illustrative in nature and is not intended to limit the disclosure, its application, or uses in any way. The broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent upon a study of the drawings, the specification, and the following claims. For purposes of clarity, the same reference numbers will be used in the drawings to identify similar elements. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A or B or C) using a non-exclusive logical or. It should be understood that one or more steps within a method may be executed in different order (or concurrently) without altering the principles of the present disclosure.

As used herein, the term module may refer to a portion of or include the following: an application specific integrated circuit (ASIC); a discrete circuit; an integrated circuit; a combinational logic circuit; a field programmable gate array (FPGA); (shared, dedicated, or group); other suitable hardware components providing the described functionality; or a combination of some or all of the above, such as a system on a chip. The term module may include memory (shared, dedicated, or group) that stores code executed by a processor.

As used above, the term code may include software, firmware and/or microcode, and may refer to programs, routines, functions, classes and/or objects. As used above, the term shared means that some or all code from multiple modules may be executed using a single (shared) processor. Furthermore, some or all code from multiple modules may be stored by a single (shared) memory. As used above, the term group means that some or all code from a single module may be executed using a group of processors. Additionally, some or all code from a single module can be stored using memory groups.

The apparatuses and methods described herein may be implemented in part or in whole by one or more computer programs executed by one or more processors. The computer programs include processor-executable instructions stored on at least one non-transitory tangible computer readable medium. The computer programs may also include and/or rely on stored data. Non-limiting examples of non-transitory tangible computer readable media include nonvolatile memory, volatile memory, magnetic storage, and optical storage.

Claims (18)

1. a cylinder control system for vehicle, comprising:

Command generator module, it produces the first command value, and carry out the first cylinder of electromotor based on the first command value The startup of intake valve and exhaust valve with one of disable；

Compensating module, it produces the offset of the second cylinder for electromotor based on model to the response of the first command value； And

Mark module, it determines desired value based on torque requests, and desired value is corresponding to the cylinder total quantity of electromotor to be launched Mark,

Wherein command generator module is further:

The second command value is produced based on the difference between offset and desired value and the first command value；And

Carry out the intake valve of the second cylinder and the startup of exhaust valve based on the second command value and one of disable；

Described cylinder control system farther includes:

Accumulation module, the difference between its previous value based on accumulative difference and desired value and first command value produces accumulative poor； And

Difference module, its based between accumulative difference and offset second difference produce adjusted value,

Wherein command generator module produces the second command value based on adjusted value.

2. cylinder control system as claimed in claim 1, at least one feature of wherein said model is based on vehicle pre- Determine resonant frequency to configure.

3. cylinder control system as claimed in claim 1, wherein said compensating module based on model for the first command value Response determines velocity amplitude and accekeration, and produces offset based on speed and accekeration.

4. cylinder control system as claimed in claim 3, wherein said compensating module is based on velocity amplitude and the first predetermined gain Product determine the first resonance value, product based on accekeration and the second predetermined gain determines the second resonance value, and Offset is determined based on the first resonance value and the second resonance value.

5. cylinder control system as claimed in claim 4, wherein said compensating module is based on the first resonance value and the second resonance Value and determine offset.

6. cylinder control system as claimed in claim 1, wherein said difference module goes offset to determine based on accumulative subtractive Adjusted value.

7. cylinder control system as claimed in claim 1, wherein said command generator module is based on adjusted value and predetermined value Relatively produce the second command value.

8. cylinder control system as claimed in claim 1, wherein said command generator module:

When adjusted value is less than predetermined value, the second command value is set to the first value, and will when adjusted value is not less than predetermined value Second command value is set to the second value；

When the second command value is set to the first value, disable intake valve and the exhaust valve of the second cylinder；And

When the second command value is set to the second value, start intake valve and the exhaust valve of the second cylinder.

9. cylinder control system as claimed in claim 1, wherein said mark module is based further on making a reservation for of electromotor Big torque determines desired value.

10. for a cylinder control method for vehicle, comprising:

Produce the first command value；

Carry out the intake valve of the first cylinder of electromotor and the startup of exhaust valve based on the first command value and one of disable；

Based on model, the response of the first command value is produced the offset of the second cylinder for electromotor；

Determining desired value based on torque requests, desired value is corresponding to there being the mark of the cylinder total quantity of electromotor to be launched；

The second command value is produced based on the difference between offset and desired value and the first command value；And

Carry out the intake valve of the second cylinder and the startup of exhaust valve based on the second command value and one of disable；

Described cylinder control method farther includes:

Difference between previous value based on accumulative difference and desired value and the first command value produces accumulative poor；

Adjusted value is produced based on the second difference between accumulative difference and offset；And

The second command value is produced based on adjusted value.

11. cylinder control methods as claimed in claim 10, at least one feature of wherein said model is based on vehicle Predetermined resonance frequencies configures.

12. cylinder control methods as claimed in claim 10, it farther includes:

Based on model, velocity amplitude and accekeration are determined for the response of the first command value；And

Offset is produced based on speed and accekeration.

13. cylinder control methods as claimed in claim 12, it farther includes:

Product based on velocity amplitude and the first predetermined gain determines the first resonance value；

Product based on acceleration figure and the second predetermined gain determines the second resonance value；And

Offset is determined based on the first resonance value and the second resonance value.

14. cylinder control methods as claimed in claim 13, it farther includes:

Based on the first resonance value and the second resonance value and determine offset.

15. cylinder control methods as claimed in claim 10, it farther includes:

Offset is gone to determine adjusted value based on accumulative subtractive.

16. cylinder control methods as claimed in claim 10, it farther includes:

Based on adjusted value and predetermined value relatively produce the second command value.

17. cylinder control methods as claimed in claim 10, it farther includes:

When adjusted value is less than predetermined value, the second command value is set to the first value, and will when adjusted value is not less than predetermined value Second command value is set to the second value；

When the second command value is set to the first value, disable intake valve and the exhaust valve of the second cylinder；And

When the second command value is set to the second value, start intake valve and the exhaust valve of the second cylinder.

18. cylinder control methods as claimed in claim 10, it farther includes predetermined torque capacity based on electromotor Determine desired value.