DE102015103789B4 - Method for improving response time of an engine using model predictive control - Google Patents

Abstract

A method comprising:generating predicted parameters based on a model (324) of a subsystem and a set of possible target values (230, 232, 234, 236, 238, 240, 242, 244); generating costs for the set of possible target values (230, 232, 234, 236, 238, 240, 242, 244) based on the predicted parameters and at least one of weighting values (342) and reference values (340); adjusting the at least one of the weighting values (342) and the reference values (340) based on a target rate of change in an operating condition of the subsystem; selecting the set of possible target values (230, 232, 234, 236, 238, 240, 242, 244) from a plurality of sets of possible target values (230, 232, 234, 236, 238, 240, 242, 244) based on cost; andadjusting an actuator (116, 120, 124, 126, 158, 164, 172) of the subsystem based on at least one of the target values (230, 232, 234, 236, 238, 240, 242, 244).

Description

The present disclosure relates to internal combustion engines, and more particularly to a method of improving the response time of an engine using model predictive control.

Internal combustion engines burn an air and fuel mixture in cylinders to drive pistons, which produces drive torque. Air flow into the engine is regulated via a throttle valve. More specifically, the throttle valve adjusts the throttle area, which increases or decreases airflow into the engine. As the throttle 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 for the cylinders and/or to achieve a desired torque output. Increasing the amount of air and fuel delivered to the cylinders increases the torque output of the engine.

In spark-ignited engines, a spark initiates combustion of an air/fuel mixture that is delivered to the cylinders. In compression-ignition engines, compression in the cylinders burns the air/fuel mixture delivered to the cylinders. Ignition timing and air flow may be the primary mechanisms for adjusting the torque output of spark-ignition engines, while fuel flow may be the primary mechanism for adjusting the torque output of compression-ignition engines.

Engine control systems have been developed to control engine output torque to achieve a desired torque. However, conventional engine control systems do not control engine output torque as accurately as desired. Furthermore, conventional engine control systems do not provide rapid response to control signals or coordinate engine torque control across the various devices that affect engine output torque.

US 2005 0 131 620 A1 discloses a method for controlling a diesel engine subject to temporary changes in target outputs. The target output values indicate the output values required by the system. Steady state information is used to obtain optimal inputs to the system when the target outputs are essentially constant. A model of the system is used to predict the outputs of the system in response to possible new values for the system's inputs. The method combines the steady state information with the predicted response of the system to determine the inputs to the system that cause the system outputs to match the target outputs as closely as possible. For each candidate, the method calculates the difference between the steady-state inputs and a candidate, as well as the difference between the target outputs and the predicted outputs that would result from accepting that candidate, to determine an optimal candidate, which is then used to update the inputs in the system is used.

The object of the invention is to provide a method with which it is possible to provide a rapid response of an engine control system to control signals and to coordinate engine torque control via various devices that influence engine output torque.

The task is solved by the subject matter of claim 1. Advantageous developments of the invention are described in the subclaims.

An example system according to the principles of the present disclosure includes a model predictive control (MPC) module and an actuator module. The MPC module generates predicted parameters based on a model of a subsystem and a set of possible target values. The MPC module generates a cost for the set of possible target values based on the predicted parameters and at least one of the weight values and reference values. The MPC module sets the at least one of the weighting values and the reference values based on a target rate of change in an operating condition of the subsystem. The MPC module selects the set of possible target values from several sets of possible target values based on cost. The actuator module sets an actuator of the subsystem based on at least one of the target values.

• 1 ein Funktionsblockschaltbild eines beispielhaften Kraftmaschinensystems gemäß der vorliegenden Offenbarung ist;
• 2 ein Funktionsblockschaltbild eines beispielhaften Kraftmaschinensteuersystems gemäß der vorliegenden Offenbarung ist;
• 3 ein Funktionsblockschaltbild eines beispielhaften Zielerzeugungsmoduls gemäß der vorliegenden Offenbarung ist;
• 4 ein Flussdiagramm ist, das ein beispielhaftes Verfahren zum Steuern eines Drosselventils, einer Einlassventil- und einer Auslassventil-Phasenlageneinstellung, eines Ladedruckregelventils, eines Abgasrückführungs-Ventils (AGR-Ventils), einer Zündzeiteinstellung und Kraftstoffbeaufschlagung unter Verwendung einer Modellvorhersagesteuerung gemäß der vorliegenden Offenbarung zeigt; und
• 5 und 6 Graphen sind, die beispielhafte Sollkrümmerdrücke, beispielsweise Ist-Krümmerdrücke, und beispielhafte Referenzöffnungsflächen des Ladedruckregelventils gemäß der vorliegenden Offenbarung zeigen.

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

• 1 is a functional block diagram of an example engine system in accordance with the present disclosure;
• 2 is a functional block diagram of an example engine control system in accordance with the present disclosure;
• 3 is a functional block diagram of an example target generation module in accordance with the present disclosure;
• 4 is a flowchart depicting an example method for controlling a throttle valve, intake valve and exhaust valve phasing, a wastegate, an exhaust gas recirculation (EGR) valve, ignition timing, and fueling using model predictive control in accordance with the present disclosure; and
• 5 and 6 are graphs showing example target manifold pressures, such as actual manifold pressures, and example reference orifice areas of the wastegate according to the present disclosure.

An engine control module (ECM) controls the torque output of an engine. More specifically, the ECM determines target values based on a requested torque amount and controls actuators of the engine based on the target values. For example, the ECM controls the intake and exhaust camshaft phasers based on the target phaser angles, a throttle valve based on a target throttle opening area, an exhaust gas recirculation (EGR) valve based on a target EGR opening, and a Wastegate of a turbocharger based on a target wastegate duty cycle. The ECM also controls ignition timing based on the target ignition timing and controls fueling based on the target fueling parameters.

The ECM could individually determine the target values using multiple single-input-single-output (SISO) controllers such as proportional-integral-derivative (PID) controllers. However, the target values can be adjusted to maintain system stability at the expense of possible fuel consumption reductions when multiple SISO controllers are used. Additionally, the calibration and design of each SISO controller can be costly and time-consuming.

The ECM of the present disclosure generates the target values using a model predictive control module (MPC module). The MPC module identifies possible sets of target values. The MPC module determines predicted parameters for each of the possible sets based on the target values of the possible sets and a mathematical model of the engine. For example, the MPC module may determine a predicted engine torque and one or more other predicted parameters for each of the possible sets of target values.

The MPC module may also determine costs associated with the use of each of the possible rates. For example, the cost of a possible set that is predicted to more closely track an engine torque request may be lower than other possible sets that are not predicted to track the engine torque request as closely as possible. The MPC module can select the possible set that has the lowest cost and that meets various constraints for use in controlling the actuators. In various implementations, instead of or in addition to identifying possible sets of target values and determining the cost of each of the sets, the MPC module may generate an area that represents the cost of possible sets of target values. The MPC module can then identify the possible lowest cost rate based on the increase in the cost area.

The cost of a possible set of target values can be determined based on differences between the possible target values and respective reference values. For example, the cost may be determined based on a difference between a possible target throttle opening area and a reference throttle opening area. The reference values may be predetermined and may correspond to stable operation of the engine.

The cost of a possible set of target values may also be determined based on an overall amount of change in each of the possible target values over a prediction period. For example, the cost may be determined based on an overall amount of change in the possible target throttle opening area over the prediction period. Additionally, the differences between the possible target values and respective reference values and/or the total change amounts in the possible target values may be weighted to control the effect that each difference and/or each total change amount has on the costs. For example, weighting values can be applied to each difference and/or each total change amount.

Determining the cost of possible sets of target values in a manner as described above may limit the rate at which an engine operating condition may be changed. In turn, an operating condition of the engine cannot be changed as quickly as desired. Thus, the ECM of the present disclosure may adjust the reference values and/or the weighting values based on a target rate of change in an operating condition of the engine. For example, the ECM may set one or more of the weighting values to zero so that the corresponding reference values can be adjusted in a manner that achieves the target rate. In another example, the ECM may adjust one or more of the reference values based on a reference trajectory that achieves the desired rate. Although control methods have been described herein in the context of an engine, the same principles can be applied to control methods for other subsystems.

With reference now to 1 The engine system 100 includes an engine 102 that combusts an air/fuel mixture to generate driving torque for a vehicle. The amount of drive torque generated by engine 102 is based on driver input from a driver input module 104. Engine 102 may be a gasoline spark ignition internal combustion engine.

Air is drawn into an intake manifold 110 through a throttle valve 112. By way of example, the throttle valve 112 may be a valve flap that has a rotatable flap. An engine control module (ECM) 114 controls a throttle actuator module 116 that regulates opening of the throttle valve 112 to control the amount of air drawn into the intake manifold 110.

Air from the intake manifold 110 is drawn into the cylinders of the engine 102. While the engine 102 may include multiple cylinders, a single representative cylinder 118 is shown for illustrative purposes. By way of example, the engine 102 may have 2, 3, 4, 5, 6, 8, 10 and/or 12 cylinders. The ECM 114 may instruct a cylinder actuator module 120 to selectively deactivate some of the cylinders, which may improve fuel economy under certain engine operating conditions.

The engine 102 may operate using a four-stroke cycle. The four strokes described below can be referred to as the intake stroke, the compression stroke, the power stroke and the exhaust stroke. During each revolution of a crankshaft (not shown), two of the four strokes occur in cylinder 118. Therefore, two crankshaft revolutions are necessary for cylinder 118 to experience all four of the cycles.

During the intake stroke, air is drawn from the intake manifold 110 into the cylinder 118 through an intake valve 122. The ECM 114 controls a fuel actuator module 124 that regulates fuel injection to achieve a target 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 of the cylinders. In various implementations (not shown), fuel may be injected directly into the cylinders or into mixing chambers associated with the cylinders. The fuel actuator module 124 may stop injecting fuel into cylinders that are deactivated.

The injected fuel mixes with air and creates an air/fuel mixture in the cylinder 118. During the compression stroke, a piston (not shown) in the cylinder 118 compresses the air/fuel mixture. An ignition actuator module 126 energizes a spark plug 128 in the cylinder 118 based on a signal from the ECM 114, igniting the air/fuel mixture. The spark timing can be specified relative to when the piston is at its top position, referred to as top dead center (TDC).

The ignition actuator module 126 can be controlled by an ignition timing signal that determines how far before or after TDC the spark should be generated. Since piston position is directly related to crankshaft rotation, operation of the ignition actuator module 126 may be synchronized with crankshaft angle. The production of sparks can be referred to as an ignition event. The ignition actuator module 126 may have the ability to vary the ignition timing of the spark for each ignition event. If the spark timing is changed between a last ignition event and the next ignition event, the ignition actuator module 126 may vary the spark timing for a next ignition event. The ignition actuator module 126 may stop providing spark to deactivated cylinders.

During the combustion stroke, combustion of the air/fuel mixture drives the piston away from TDC, thereby driving the crankshaft. The combustion stroke can be defined as the time period between the time the piston reaches TDC and the time the piston reaches bottom dead center (BDC). During the exhaust stroke, the piston begins to move away from the BDC, expelling the byproducts of combustion through an exhaust valve 130. The byproducts of combustion are expelled from the vehicle via an exhaust system 134. The exhaust system 134 includes a catalyst 136, such as a three-way catalytic converter (TWC). The catalyst 136 reacts with one or more components of the exhaust gas flowing through the catalyst 136. When the exhaust is fuel poor (oxygen rich), the catalytic converter stores 136 oxygen.

The intake valve 122 may be controlled by an intake camshaft 140 while the exhaust valve 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 the intake valves (including intake valve 122) of multiple cylinder banks of cylinders (including cylinder 118). 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) for multiple cylinder banks (including cylinder 118). In various other implementations, the intake valve 122 and/or the exhaust valve 130 may be controlled by devices other than camshafts, such as camless valve actuators. 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 timing at which the intake valve 122 is opened may be changed with respect to the piston TDC by an intake cam phaser 148. The timing at which the exhaust valve 130 is opened may be changed with respect to the 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. If variable valve lift is implemented (not shown), it may also be controlled by the phaser actuator module 158.

The engine system 100 may include a turbocharger that includes a hot turbine 160-1 that is powered by hot exhaust gases flowing through the exhaust system 134. The turbocharger also includes a cold air compressor 160-2, which is driven by the turbine 160-1. The compressor 160-2 compresses air that enters the throttle valve 112. In various implementations, a crankshaft-driven supercharger (not shown) may compress air from the throttle 112 and deliver the compressed air to the intake manifold 110.

An exhaust control valve 162 may allow exhaust to bypass the turbine 160-1, thereby reducing the boost pressure (the amount of intake air compression) provided by the turbocharger. The wastegate actuator module 164 may control the boost pressure of the turbocharger by controlling the opening of the wastegate 162. In various implementations, two or more turbochargers may be implemented and may be controlled by the boost actuator module 164.

An air cooler (not shown) may transfer heat from the compressed air charge to a cooling medium such as engine coolant or air. An air cooler that cools the compressed air charge using engine coolant may be referred to as an intercooler. An air cooler that cools the compressed air charge using air may be referred to as an intercooler. The compressed air charge can heat e.g. B. received via compression and/or from components of the exhaust system 134. Although the turbine 160-1 and the compressor 160-2 are separated for illustrative purposes As shown, they may be attached to each other, placing intake air in close proximity to hot exhaust.

The engine system 100 may include an exhaust gas recirculation (EGR) valve 170 that selectively directs exhaust gas back to the intake manifold 110. The EGR valve 170 may be positioned upstream of the turbocharger turbine 160-1. The EGR valve 170 may be controlled by an EGR actuator module 172 based on signals from the ECM 114.

An upstream oxygen sensor 176 measures an amount (e.g., concentration) of oxygen in the exhaust gas flowing into the catalytic converter 136. A downstream oxygen sensor 177 measures an amount (e.g., concentration) of oxygen in the exhaust gas downstream of the catalytic converter 136. The ECM 114 may use signals from the sensors and/or from one or more other sensors to make control decisions for the engine system 100.

Using a crankshaft position sensor 180, a position of the crankshaft can be measured. Based on the crankshaft position, a speed of the crankshaft (an engine speed) may be determined. Using an engine coolant temperature (ECT) sensor 182, a temperature of the engine coolant may be measured. The ECT sensor 182 may be located in the engine 102 or other locations where coolant is circulated, such as a radiator (not shown).

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

The throttle actuator module 116 may monitor the position of the throttle valve 112 using one or more throttle position sensors (TPS) 190. Using an intake air temperature (IAT) sensor 192, an ambient temperature of the air drawn into the engine 102 may be measured. Additionally, the engine system 100 may include one or more other sensors 193 such as an ambient humidity sensor, one or more knock sensors, a compressor outlet pressure sensor and/or a throttle inlet air pressure (TIPA) sensor, a wastegate position sensor, an EGR position sensor, and/or one or more other suitable sensors included. The TIAP sensor may measure the pressure downstream of the compressor 160-2 and upstream of the throttle valve 112. 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 gears in a transmission (not shown). For example, the ECM 114 may reduce engine torque during a gear shift. The ECM 114 may communicate with a hybrid control module 196 to coordinate operation of the engine 102 and an electric motor 198.

The electric motor 198 may also serve as a generator and may be used to generate electrical energy for use by vehicle electrical systems and/or for storage in a battery. In various implementations, various functions of the ECM 114, the transmission control module 194, and the hybrid control module 196 may be integrated into one or more modules.

Any system that varies an engine parameter may be referred to as an engine actuator. For example, the throttle actuator module 116 may adjust the opening of the throttle 116 to achieve a target throttle opening area. The ignition actuator module 126 controls the spark plugs to achieve a target spark timing relative to the piston TDC. The fuel actuator module 124 controls the fuel injectors to achieve target fueling parameters. The phaser actuator module 158 may control the intake cam phaser and the exhaust cam phaser 148 and 150 to achieve target intake cam phaser angles and target exhaust cam phases, respectively to achieve plate angle. The EGR actuator module 172 may control the EGR valve 170 to achieve a target EGR opening area. The wastegate actuator module 164 controls the wastegate 162 to achieve a target wastegate opening area. The cylinder actuator module 120 controls cylinder deactivation to achieve a target number of activated or deactivated cylinders.

The ECM 114 generates the target values for the engine actuators to cause the engine 102 to produce a target engine output torque. As discussed further below, the ECM 114 generates the target values for the engine actuators using model predictive control.

With reference now to 2 An example implementation of the ECM 114 includes a driving torque module 114. The driver torque module 202 determines a driver torque request 204 based on a driver input 206 from the driver input module 104. The driver input 206 may e.g. B. based on a position of an accelerator pedal and on a position of a brake pedal. Additionally, the driver input 206 may be based on a cruise controller, which may be an adaptive cruise control system that varies vehicle speed to maintain a predetermined following distance. The driver torque module 202 may store one or more accelerator pedal position characteristics to the target torque and may determine the driver torque request 204 based on a selected one of the characteristics. The driver torque module 202 may also apply one or more filters to limit the rate of changes to the driver torque request 204.

An axle torque arbitration module 208 arbitrates between the driver torque request 204 and other axle torque requests 210. The axle torque (torque at the wheels) may be generated by various sources, including an engine and/or an electric motor. For example, axle torque requests 210 may include a torque reduction requested by a traction control system when positive wheel slip is detected. Positive wheel slip occurs when axle torque overcomes friction between the wheels and the road surface and the wheels begin to slip against the road surface. Additionally, the axle torque requests 210 may include a torque increase request to counteract negative wheel slip, in which a tire of the vehicle slips in the other direction with respect to the road surface because the axle torque is negative.

Additionally, the axle torque requests 210 may include brake management requests and vehicle overspeed torque requests. Brake management requirements may reduce axle torque to ensure that axle torque does not exceed the ability of the brakes to hold the vehicle when the vehicle is stopped. Vehicle overspeed torque requests may reduce axle torque to prevent the vehicle from exceeding a predetermined speed. The axle torque requests 210 may also be generated by vehicle stability control systems.

The axle torque arbitration module 208 outputs an axle torque request 212 based on the results of an arbitration between the received axle torque requests 204 and 210. As described below, the axle torque request 212 from the axle torque arbitration module 208 may optionally be adjusted by other modules of the ECM 114 before being used to control the engine actuators.

The axle torque arbitration module 208 may output the axle torque request 212 to a propulsion torque arbitration module 214. In various implementations, the axle torque arbitration module 208 may output the axle torque request 212 to a hybrid optimization module 216. The hybrid optimization module 216 may determine how much torque should be generated by the engine 102 and how much torque should be generated by the electric motor 198. The hybrid optimization module 216 then outputs a modified axle torque request 218 to the drive torque arbitration module 214.

The drive torque arbitration module 214 converts the axle torque request 212 (or the modified axle torque request 218) from an axle torque domain (torque at the wheels) to a drive torque domain (torque at the crankshaft). The propulsion torque arbitration module 214 arbitrates between the (implemented) axle torque request 212 and other propulsion torque requests 220. The propulsion torque arbitration module 214 generates a propulsion torque request 222 as a result of the arbitration.

The propulsion torque requirements 220 can e.g. B. Torque reductions for engine overspeed protection, torque increases for stall prevention, and torque reductions requested by the transmission control module 194 to adapt to gear shifts. Additionally, propulsion torque requests 220 may result from a clutch fuel cutoff that reduces fuel output torque when the driver in a manual transmission vehicle depresses the clutch pedal to prevent engine speed from spinning up.

Additionally, the propulsion torque requests 220 may include an engine shutdown request that may be initiated when a critical failure is detected. For example, critical errors may include detection of vehicle theft, a jammed starter motor, electronic throttle control problems, and unexpected torque increases. In various implementations, if an engine shutdown request is present, arbitration selects the engine shutdown request as the winning request. If the engine shutdown request is present, the propulsion torque arbitration module 214 may output zero as the propulsion torque request 222.

In various implementations, an engine shutdown request may simply shut down the engine 102 separately from the arbitration process. The propulsion torque arbitration module 214 may continue to receive the engine shutdown request such that, for example, B. suitable data can be fed back to other torque request devices. For example, all other torque requesters may be informed that they have lost arbitration.

A torque reserve module 224 generates a torque reserve 226 to compensate for changes in engine operating conditions that may reduce engine output torque and/or to compensate for one or more loads. In one example, the engine air/fuel ratio and/or mass air flow may be varied directly, such as through diagnostic intrusive equivalent ratio testing and/or new engine flushing. Prior to beginning these processes, the torque reserve module 224 may create or increase the torque reserve 226 to quickly offset decreases in engine output torque that result from the air/fuel mixture becoming leaner during these processes.

The torque reserve module 224 may also create or increase the torque reserve 226 in anticipation of a future load, such as operation of the power steering pump or engagement of an air conditioning (A/C) compressor clutch. The torque reserve module 224 may create or increase the torque reserve 226 for A/C compressor clutch engagement when the driver initially requests air conditioning. Then, when the A/C compressor clutch engages, the torque reserve module 224 may reduce the torque reserve 226 by an amount equal to the estimated load on the A/C compressor clutch.

A target generation module 228 generates target values for the engine actuators based on the propulsion torque request 222, the torque reserve 226, and other parameters, as discussed further below. The target value generation module 228 generates the target values using model predictive control (MPC). The propulsion torque request 222 may be a braking torque. The braking torque may refer to a torque at the crankshaft under the current operating conditions.

The target values include a target wastegate opening area 230, a target throttle opening area 232, a target EGR opening area 234, a target intake cam phasing angle 236 and a target exhaust cam phasing angle 238. The target values also include a target ignition timing setting 240 , a target cylinder number 242 to be activated, and target fueling parameters 244. The wastegate actuator module 164 controls the wastegate 162 to achieve the target wastegate opening area 230. For example, a first translation module 248 may translate the target wastegate opening area 230 into a target duty cycle 250 to be applied to the wastegate 162, and the wastegate actuator module 164 may provide a signal to the wastegate 162 based on the target duty cycle 250 invest. In various implementations, the first translation module 248 may translate the target wastegate opening area 230 to a target wastegate position (not shown) and translate the target wastegate position to the target duty cycle 250.

The throttle actuator module 116 controls the throttle valve 112 to achieve the target throttle opening area 232. For example, a second translation module 252 may translate the target throttle opening area 232 into a target duty cycle 254 to be applied to the throttle valve 112, and the throttle actuator module 116 may apply a signal to the throttle valve 112 based on the target duty cycle 254. In various implementations, the second translation module 252 may translate the target throttle opening area 232 into a target throttle position (not shown) and translate the target throttle position into the target duty cycle 254.

The EGR actuator module 172 controls the EGR valve 170 to achieve the target EGR opening area 234. For example, a third translation module 256 may translate the target EGR opening area 234 into a target duty cycle 258 to be applied to the EGR valve 170, and the EGR actuator module 172 may generate a signal based on the target duty cycle 258 to the EGR valve 170. In various implementations, the third translation module 256 may translate the target EGR opening area 234 to a target EGR position (not shown) and the target EGR position to the target duty cycle 258.

The phaser actuator module 158 controls the intake cam phaser 148 to achieve the target intake cam phaser angle 236. Additionally, the phaser actuator module 158 controls the exhaust cam phaser 150 to achieve the target exhaust cam phaser angle 238. In various implementations, a fourth translation module (not shown) may be included and translates the target intake cam phasing angle and the target exhaust cam phasing angle 236 and 238 into a target intake duty cycle and a target exhaust duty cycle, respectively. The phaser actuator module 158 may apply the target intake duty cycle and the target exhaust duty cycle to the intake cam phaser and exhaust cam phaser 148 and 150, respectively. In various implementations, the target generation module 228 may determine a target valve overlap factor and a target effective displacement, and the phaser actuator module 158 may control the intake cam phaser and the exhaust cam phaser 148 and 150 to achieve the target overlap factor and the target effective displacement achieve.

The ignition actuator module 126 delivers 240 sparks based on the target ignition timing setting. The cylinder actuator module 120 selectively activates and deactivates the valves of cylinders based on the target cylinder number 242. In addition, the supply of fuel and spark to deactivated cylinders can be blocked. The target fueling parameters 244 may include, for example, a target number of fuel injections, a target fuel mass for each injection, and the target start timing for each injection. The fuel actuator module 124 controls fueling based on the target fueling parameters 244.

3 is a functional block diagram of an example implementation of the target value generation module 228. Now referring to the 2 and 3 The propulsion torque request 222 may be a braking torque as discussed above. A torque conversion module 304 converts the propulsion torque request 222 from a braking torque to a base torque. The torque request resulting from conversion to base torque is referred to as a base torque request 308.

Base torques may refer to crankshaft torque generated at a dynamometer during operation of the engine 102 while the engine 102 is warm and there are no torque loads on the engine 102 from accessories such as an alternator and the A/C compressor be imposed. The torque translation module 304 may provide the propulsion torque request 222, e.g. B. into the base torque request 308 using a map or a function that relates the braking torques to base torques. In various implementations, the torque translation module 304 may translate the propulsion torque request 222 into another suitable torque type, such as an indicated torque. An indicated torque may refer to a torque at the crankshaft attributable to work produced via combustion within the cylinders.

An MPC (model prediction) module 312 generates the target values 230-244 using MPC. The MPC module 312 may be a single module or may include multiple modules. For example, the MPC module 312 may include a sequence determination module 316. The sequence determination module 316 determines possible sequences of target values 230-244 that may be used together during N future control loops. Each of the possible sequences identified by the sequence determination module 316 includes a sequence of N values for each of the target values 230-244. With other Wor th, each possible sequence includes a sequence of N values for the target wastegate opening area 230, a sequence of N values for the target throttle opening area 232, a sequence of N values for the target EGR opening area 234, a sequence of N values for the target intake cam phasor angle 236 and a sequence of N values for the target exhaust cam phasor angle 238. Each possible sequence also includes a sequence of N values for the target ignition timing 240, the target cylinder number 242 and the target Fueling parameters 244. Each of the N values corresponds to one of the N future control loops. N is an integer greater than one.

A prediction module 323 determines the predicted response of the engine 102 to the possible sequences of target values 230-244 based on a mathematical model 324 of the engine 102, exogenous inputs 328, and feedback inputs 330, respectively. More specifically, the prediction module 323 generates a sequence of predicted engine 102 torques for the N control loops, a sequence of predicted MAPs for the N control loops, based on a possible sequence of the target values 266-270, the exogenous inputs 328 and the feedback inputs 330 using the model 324 , a sequence of predicted APCs for the N control loops, a sequence of predicted amounts of external dilution for the N control loops, a sequence of predicted amounts of internal dilution for the N control loops, a sequence of predicted combustion phasing values for the N control loops, a sequence of predicted combustion quality values for the N Control loops and a sequence of predicted effective displacement values for the N control loops.

The model 324 may have a calibrated function or map based on characteristics of the engine 102. The relationship between the engine 102 responses, the target values 230-244, the exogenous inputs 328, and the feedback inputs 330 may be nonlinear over the entire range of possible engine speeds and engine loads. However, model 324 may include a variety of linear models, each corresponding to an engine speed and load range. The prediction module 323 may select one of the models based on the current engine speed and load and use the selected model to predict the responses of the engine 102. For example, a first model may be used in an engine speed range of 1,000 revolutions per minute (rpm) to 2000 rpm and an engine load range of 100 Newton meters (Nm) to 150 Nm. A second model can be used in an engine speed range of 1,000 rpm to 2,000 rpm and an engine load range of 150 Nm to 200 Nm. A third model can be used in an engine speed range of 2,000 rpm to 3,000 rpm and an engine load range of 100 Nm to 150 Nm.

Dilution may refer to an amount of exhaust gas from a previous combustion event that is trapped within a cylinder for a combustion event. External dilution may refer to exhaust gas provided via the EGR valve 170 for a combustion event. Internal dilution (also referred to as residual dilution) may refer to exhaust gas remaining in a cylinder and/or exhaust gas driven back into the cylinder after the exhaust stroke of a combustion cycle. Effective displacement may refer to the volume of air drawn into cylinders of an engine as pistons in the cylinders move from TDC to BDC, less losses in air volume due to pistons driving air back into an intake manifold through intake valves of the cylinders .

Combustion phasing may refer to a crankshaft position at which a predetermined amount of injected fuel is burned within a cylinder compared to a predetermined crankshaft position for combustion of the predetermined amount of injected fuel. For example, combustion phasing may be expressed in terms of CA50 compared to a given CA50. CA50 can refer to a crankshaft angle (CA) at which 50 percent of a mass of injected fuel has burned within a cylinder. The predetermined CA50 may correspond to a CA50 at which a maximum amount of work is produced from the injected fuel and may be approximately 8.5 - approximately 10 degrees after TDC (top dead center) in various implementations. Although combustion phasing is discussed in terms of CA50 values, any suitable parameter indicating combustion phasing may be used. Additionally, although combustion quality is discussed as the coefficient of variation (COV) of indexed mean pressure (IMEP) values, another suitable parameter indicating combustion quality may be used.

The exogenous inputs 328 may include parameters that are not directly influenced by the engine actuators. For example, the exogenous inputs 328 may include engine speed, turbocharger inlet air pressure, IAT, and/or one or more other parameters. The feedback inputs 330 can e.g. B. an estimated torque output of the engine 102, an exhaust pressure downstream of the turbine 160-1 of the turbocharger, the IAT, an APC of the engine 102, an estimated internal dilution, an estimated external dilution, MAF, an air / fuel ratio of the engine 102, an Ignition timing adjustment, and/or one or more other suitable parameters included. The feedback inputs 330 may be measured using sensors (e.g., IAT sensor 192) and/or may be estimated based on one or more other parameters.

A cost module 332 determines a cost value for each of the possible sequences of target values 230-244 based on the predicted parameters determined for a possible sequence and the reference values 340. The cost module 332 may determine the cost value for each of the possible sequences based on relationships between the predicted parameters and the corresponding ones of the reference values 340. The relationships can be weighted to e.g. B. Control the effect that each of the relationships has on costs. In other words, the cost module 332 may apply weight values 342 to each of the relationships.

The cost module 332 may also determine the cost value for each of the possible sequences based on a total amount of change in each of the possible target values across the N control loops. For example, if N equals two and the possible target throttle opening area is increased by 50 square millimeters (mm ² ) in the first control loop and decreased by 50 mm ² in the second control loop, the total amount of change in the possible target throttle opening area is 100 mm ² . Thus, costs may increase as the total amount of change in a possible target value increases and vice versa. An example cost determination is discussed further below.

A selection module 344 selects one of the possible sequences of the target values 230-244 based on respective costs of the possible sequences. For example, the selection module 344 may select one of the lowest cost possible sequences while satisfying the actor constraints 348 and the output constraints 352.

In various implementations, compliance with the actor constraints 348 and the output constraints 352 may be considered when determining costs. For example, the cost module 332 may determine the cost value for each of the possible sequences based on relationships between the predicted parameters and the corresponding ones of the actor constraints 352 and the output constraints 348. As discussed further below, based on how the cost values are determined, the selection module 344 selects one of the possible sequences that best achieves the base air torque request 306, subject to the actuator constraints 348 and the output constraints 352, while achieving the APC minimized.

The selection module 344 can set the target values 230-244 to the first of the N values of the selected possible sequence. In other words, the selection module 344 may set the target wastegate opening area 230 to the first of the N values in the sequence of N values for the target wastegate opening area 230, may set the target throttle opening area 232 to the first of the N values in the Sequence of N values for the target throttle opening area 232, may set the target EGR opening area 234 to the first of the N values in the sequence of N values for the target EGR opening area 234, may set the target intake cam phaser angle 236 to the first of the N values in the sequence of N values for the target intake cam phasor angle 236 and may set the target exhaust cam phasor angle 238 to the first of the N values in the sequence of N values for the target exhaust cam phasor angle 238 set. The selection module 344 also sets the target ignition timing setting 240 to the first of the N values in the sequence of N values for the target ignition timing setting 240, the target cylinder number 242 to the first of the N values in the sequence of N values for the target Cylinder number 242 and the target fueling parameters 244 to the first of the N values in the sequence of N values for the target fueling parameters 244.

During a next control loop, the MPC module 312 identifies possible sequences, generates the predicted parameters for the possible sequences, determines the cost of each of the possible sequences, selects one of the possible sequences, and sets the target values 230-244 to first Set the target values 230-244 in the selected possible sequence. This process continues for each control loop.

An actuator limitation module 360 (see 2 ) sets the actuator restrictions 348 for each of the target values 230-244. In other words, the actuator restriction module 360 sets actuator restrictions for the throttle valve 112, actuator restrictions for the EGR valve 170, actuator restrictions for the wastegate 162, actuator restrictions for the intake cam phaser 148, and actuator restrictions for the exhaust cam phaser 150. The actuator limitation module 360 also sets actuator limitations for the ignition actuator module 126, actuator limitations for the cylinder actuator module 120, and actuator limitations for the fuel actuator module 124.

The actuator constraints 348 for each of the target values 230-244 may include a maximum value for an associated target value and a minimum value for that target value. In general, the actuator limitation module 360 may set the actuator limitations 348 to predetermined operating ranges for the associated engine actuators. Specifically, the actuator restriction module 360 may generally set the actuator restrictions 348 to predetermined operating ranges for the throttle valve 112, the EGR valve 170, the wastegate 162, the intake cam phaser 148, the exhaust cam phaser 150, the ignition actuator module 126, the cylinder actuator module 120, respectively .Adjust the fuel actuator module 124. Thus, the maximum value for a target value can be a maximum limit of a corresponding actuator and the minimum value for the target value can be a minimum limit of this actuator.

An output restriction module 364 (see 2 ) sets the output constraints 352 for the predicted torque output of the engine 102, the predicted MAP, the predicted APC, the predicted CA50, the predicted COV of IMEP, the predicted internal dilution, the predicted external dilution, and/or the predicted effective displacement. The output constraints 352 for each of the predicted values may include a maximum value for an associated predicted parameter and a minimum value for that predicted parameter. For example, the output constraints 352 may include a minimum torque, a maximum torque, a minimum MAP, a maximum MAP, a minimum APC, a maximum APC, a minimum CA50, a maximum CA50, a minimum COV of IMEP, a maximum COV of IMEP, have a minimum internal dilution, a maximum internal dilution and a minimum external dilution, a maximum external dilution, a minimum effective displacement and / or a maximum effective displacement.

The output restriction module 364 may generally set the output restrictions 352 to predetermined ranges for the associated predicted parameters. However, under some circumstances, the output restriction module 364 may vary one or more of the output restrictions 352. For example, the output restriction module 364 may retard the maximum CA50, such as when knocking occurs within the engine 102. In another example, the output limiting module 364 may increase the maximum COV of the IMEP under low load conditions, such as during engine idling, where a higher COV of the IMEP may be necessary to achieve a given torque requirement.

A setpoint module 368 (see 2 ) creates the reference values 340 for the target values 230-244. The reference values 340 include a reference for each of the target values 230-244. In other words, the reference values 340 include a reference wastegate opening area, a reference throttle opening area, a reference EGR opening area, a reference intake cam phasing angle, and a reference exhaust cam phasing angle. The reference values 340 also include a reference ignition timing, a reference number of cylinders, and reference fueling parameters. The reference values 340 may also include a reference for each of the exit restrictions 352. In other words, the reference values 340 may include a reference manifold absolute pressure (MAP), a reference air mass per cylinder (APC), an external reference dilution, an internal reference dilution, and a reference effective displacement.

The set point module 368 can also generate weighting values 342. The weight values 342 may include a weight value associated with relationships between: the predicted torque and the base torque request 308; the predicted APC and the minimum APC; the possible target values and the respective actuator restrictions 348; the other predicted parameters and the respective output constraints 352; the possible target values and the respective reference values 340; and the total amounts of change in the possible target values. The Setpoint module 368 may determine the reference values 340 and/or the weighting values 342 based on a desired rate of change in one or more operating conditions of the engine 102, as discussed in more detail below.

Instead of or in addition to generating sequences of possible target values and determining the cost of each of the sequences, the MPC module 312 may identify a sequence of possible target values with the lowest cost using convex optimization techniques. For example, the MPC module 312 may determine the target values 230-244 using a quadratic programming (QP) solver such as a Dantzig QP solver. In another example, the MPC module 312 may generate a surface of cost values for the possible sequences of target values 230-244 and identify a sequence of possible target values with the lowest cost based on the slope of the cost surface. The MPC module 312 may then test this sequence of possible target values to determine whether this sequence of possible target values meets the actuator constraints 348. If this is the case, the MPC module 312 may set the target values 230-244 to the first of the N values of this selected possible sequence, respectively, as discussed above.

If the actuator constraints 348 are not met, the MPC module 312 selects another sequence of possible target values with the next lowest cost and tests this sequence of possible target values for satisfaction of the actuator constraints 348. The process of selecting a sequence and testing the sequence for satisfaction Actor Constraints 348 can be referred to as an iteration. Multiple iterations can be performed during each control loop.

The MPC module 312 iterates until a lowest cost sequence that meets the actor constraints 348 is identified. In this way, the MPC module 312 selects the lowest cost sequence of possible target values while satisfying the actuator constraints 348 and the output constraints 352. If no sequence can be identified, the MPC module 312 may indicate that no solution is available.

The cost module 332 may determine the cost for the possible sequences of target values 230-244 based on relationships between: the predicted torque and base torque request 308, the predicted APC and the minimum APC; the possible target values and the respective actuator restrictions 348; the other predicted parameters and the respective output constraints 352; and the possible target values and the respective reference values 340. As discussed above, the relationships can be weighted to e.g. B. Control the effect that each of the relationships has on costs.

vorbehaltlich der Aktorbeschränkungen 348 und der Ausgabebeschränkungen 352 bestimmen. Kosten sind die Kosten für die mögliche Sequenz der Zielwerte 230-244, TPi ist das vorhergesagte Drehmoment der Kraftmaschine 102 für die i-te der N Steuerschleifen, BTRi ist die Basis-Drehmomentanforderung für die i-te der N Steuerschleifen und wT ist ein Gewichtungswert, der der Beziehung zwischen dem vorhergesagten Drehmoment und der Basis-Drehmomentanforderung zugeordnet ist. APCPi ist eine vorhergesagte APC für die i-te der N Steuerschleifen, MinAPC ist die minimale APC und wA ist der Gewichtungswert, der der Beziehung zwischen der vorhergesagten APC und der minimalen APC zugeordnet ist.By way of example, the cost module 332 may determine the cost for a possible sequence of target values 230-244 based on the following equation: $$COst={{\displaystyle {\sum }_{i=1}^{N}p{\epsilon }^2+\Vert wT\ast \left(T{P}_i-\text{BT}{R}_i\right)\Vert }}^2+{\Vert wA\ast \left(APC{P}_i-\text{MinAPC}\right)\Vert }^2,$$

subject to the actor restrictions 348 and the output restrictions 352. Cost is the cost for the possible sequence of target values 230-244, TPi is the predicted engine 102 torque for the ith of the N control loops, BTRi is the base torque request for the ith of the N control loops, and wT is a weighting value , which is associated with the relationship between the predicted torque and the base torque request. APCPi is a predicted APC for the ith of the N control loops, MinAPC is the minimum APC, and wA is the weight value associated with the relationship between the predicted APC and the minimum APC.

vorbehaltlich der Aktorbeschränkungen 348 und der Ausgabebeschränkungen 352. PTTOi ist eine mögliche Zieldrosselklappenöffnung für die i-te der N Steuerschleifen, TORefi ist die Referenzdrosselklappenöffnung für die i-te der N Steuerschleifen und wTO ist ein Gewichtungswert, der der Beziehung zwischen den möglichen Zieldrosselklappenöffnungen und den Referenzdrosselklappenöffnungen zugeordnet ist. ΔTO ist ein Gesamtbetrag der Änderung in den möglichen Zieldrosselklappenöffnungen über die N Steuerschleifen und wΔTO ist ein Gewichtungswert, der den Gesamtbetrag der Änderung in den möglichen Drosselklappenöffnungen zugeordnet ist.The above equation can be expanded to: $$\begin{array}{l}COst={{\displaystyle {\sum }_{i=1}^{N}p{\epsilon }^2+\Vert wT\ast \left(T{P}_i-\text{BT}{R}_i\right)\Vert }}^2+{\Vert wA\ast \left(APC{P}_i-\text{MinAPC}\right)\Vert }^2+\\ {\Vert wTO\ast \left(PTT{O}_i-\text{TORefi}\right)\Vert }^2+{\Vert \text{w}\Delta \text{TO}\ast \Delta \text{TO}\Vert }^2+\\ {\Vert wWG\ast \left(PTWGOi-WGORefi\right)\Vert }^2+{\Vert \text{w}\Delta \text{WG}\ast \Delta \text{WG}\Vert }^2+\Vert wEGR\ast (PTEGRi-\\ {EGRRefi)\Vert }^2+{\Vert \text{w}\Delta \text{EGR}\ast \Delta \text{EGR}\Vert }^2+{\Vert wICP\ast \left(PTICPi-ICRRefi\right)\Vert }^2+\Vert \text{w}\Delta \text{ICP}\ast \\ {\Delta \text{ICP}\Vert }^2+\Vert wECP\ast {\left(PTECPi-ECPRefi\right)}^2\Vert +{\Vert \text{w}\Delta \text{ECP}\ast \Delta \text{ECP}\Vert }^2+\Vert wS\ast \\ {\left(PSi-SRefi\right)\Vert }^2+{\Vert \text{w}\Delta \text{S}\ast \Delta \text{S}\Vert }^2+{\Vert wN\ast \left(PNi-NRefi\right)\Vert }^2+{\Vert \text{w}\Delta \text{N}\ast \Delta \text{N}\Vert }^2+\\ {\Vert wF\ast \left(PFi-FRefi\right)\Vert }^2+{\Vert \text{w}\Delta \text{F}\ast \Delta \text{F}\Vert }^2\end{array}$$

subject to the actuator constraints 348 and the output constraints 352. PTTOi is a possible target throttle opening for the ith of the N control loops, TORefi is the reference throttle opening for the ith of the N control loops, and wTO is a weighting value corresponding to the relationship between the possible target throttle openings and the Reference throttle valve openings are assigned. ΔTO is a total amount of change in the possible target throttle openings across the N control loops and wΔTO is a weight value associated with the total amount of change in the possible throttle openings.

PTWGOi is a possible target wastegate opening for the ith of the N control loops, WGORefi is the reference wastegate opening for the ith of the N control loops, and wWG is a weight value associated with the relationship between the possible target wastegate openings and the reference wastegate openings. ΔWG is a total amount of change in possible wastegate openings across the N control loops and wΔWG is a weighting value associated with the total amount of change in possible wastegate openings.

PTEGRi is a possible target EGR opening for the ith of the N control loops, EGRRef is the reference EGR opening for the ith of the N control loops, and wEGR is a weight value corresponding to the relationship between the possible target EGR Openings and the reference EGR openings are assigned. ΔEGR is a total amount of change in possible target EGR openings across the final control loops and wΔEGR is a weight value associated with the total amount of change in possible EGR openings.

PTICPi is a possible target intake cam phaser angle for the ith of the N control loops, ICPref is the reference intake cam phaser angle for the ith of the N control loops, and wICP is a weight value associated with the relationship between the possible target intake cam phaser angle and the reference intake cam phaser angles. ΔIPC is a total amount of change in the possible target intake cam phaser angles over the N control loops and wΔICP is a weighting value associated with the total amount of change in the possible target intake cam phaser angles.

PTECPi is a possible target exhaust cam phaser angle for the ith of the N control loops, ECPRef is the reference exhaust cam phaser angle for the ith of the N control loops, and wECP is a weighting value associated with the relationship between the possible target exhaust cam phaser angle and the reference exhaust cam phaser angles. ΔECP is a total amount of change in the possible target exhaust cam phaser angles over the N control loops and wΔECP is a weighting value associated with the total amount of change in the possible target exhaust cam phaser angles.

PSi is a possible target firing timing setting for the i-th of the N control loops, SRef is the reference firing setting for the i-th of the N control loops, and wS is a weighting value associated with the relationship between the possible target firing settings and the reference firing settings. ΔS is a total amount of change in the possible target firing settings across the N control loops and wΔS is a weighting value associated with the total amount of change in the possible target firing timing settings.

PNi is a possible number of cylinders for the i-th of the N control loops, NRef is the reference number of cylinders for the i-th of the N control loops, and wN is a weighting value corresponding to the relationship between the possible number of cylinders and the reference number of cylinders assigned. ΔN is a total amount of change in the possible number of cylinders over the N control loops and wΔN is a weighting value associated with the total amount of change in the possible number of cylinders.

PFi is a possible fueling for the ith of the N control loops, FRef is the reference fueling for the ith of the N control loops, and wF is a weighting value associated with the relationship between the possible fueling and the reference fueling. ΔF is a total amount of change in potential fueling across the N control loops, and wΔF is a weighting value associated with the total amount of change in potential fueling.

p is a weight value associated with satisfying the output constraints 352. ε is a variable that the cost module 332 can adjust based on whether the output constraints 352 are met. For example, the cost module 332 may increase ε when a predetermined parameter is greater or less than the corresponding minimum or maximum value (e.g., at least by a predetermined amount). If all output constraints 352 are met, the cost module 332 may set to zero. ρ can be greater than the weighting value wT, the weighting value wA and the other weighting values (wTO, wΔTO, wWG, wΔWG, wEGR, wΔEGR, wICP, wΔICP, wECP, wΔECP, wS, wΔS, wN, wΔN, wf, wΔF), so that the costs determined for a possible sequence become large if one or more of the exit constraints 352 are not met. This may prevent selection of a possible sequence if one or more of the output constraints 352 are not met.

The weighting value wT can be greater than the weighting value wA and the weighting values wTO wΔTO, wWG, wΔWG, wEGR, wΔEGR, wICP, wΔICP, wECP, wΔECP, wS, wΔS, wN, wΔN, wf and wΔF. In this way, as will be discussed below, the relationship between the predicted engine torque and the base air torque request 308 has a greater impact on the cost and thus on the selection of one of the possible sequences. As the difference between the predicted engine torque and the base air torque request 308 increases, the cost increases, and vice versa.

The weighting value wA can be smaller than the weighting value wT and larger than the weighting values wTO wΔTO, WWG, wΔWG, wEGR, wΔEGR, wICP, wΔICP, WECP, wΔECP, WS, wΔS, wN, wΔN wf and wΔF. In this way, the relationship between the predicted APC and the predetermined minimum APC has a large effect, but less than the relationship between the predicted engine torque and the base air torque request 308, on cost. As the difference between the predicted APC and the given minimum APC increases, the cost increases, and vice versa. The predetermined minimum APC can be zero so that the cost increases and the predicted APC increases and vice versa.

Therefore, determining the cost based on the difference between the predicted APC and the specified minimum APC helps ensure that the APC is minimized. Since fueling is controlled based on actual APC, reducing APC reduces fuel consumption to achieve a target air/fuel mixture. While the selection module 344 may select the one of the possible sequences with the lowest cost, the selection module 344 may select the one of the possible sequences that best achieves the base air torque requirement 308 while minimizing APC.

The weighting values wTO, wΔTO, wWG, wΔWG, wEGR, wΔEGR, wICP, wΔICP, wECP, wΔECP, wS, wΔS, wN, wΔN, wF and wΔF can be smaller than any of the other weighting values. In this way, the target values 266-270 can be adjusted near or at the reference values 340 during stationary operation. However, the MPC module 312 may adjust the target values 266-270 away from the reference values 340 during transient operation to achieve the base air torque request 308 while minimizing APC and satisfying the actuator constraints 348 and the output constraints 352.

As indicated above, the set point module 368 may determine the reference values 340 and/or the weighting values 342 based on the desired rate of change in one or more operating conditions of the engine 102. For example, the set point module 368 can use the reference values 340 and/or determine the weighting values 342 based on the desired rate of change of the torque output of the engine 102. Thus, the set point module 368 may determine the reference values 340 and/or the weighting values 342 based on the rate of change of the propulsion torque request 222 and/or the base torque request 308.

Determining the cost of the possible sequences of target values 230-244 based on one of the equations described above may limit the rate at which an operating condition of the engine 102 can be changed. For example, determining the cost based on the references between the possible target values and the reference values 340 may limit the rate of change of an engine operating condition. In another example, determining the cost based on the total amounts of change in the possible target values may limit the rate of change of an engine operating condition.

Thus, when a desired rate of change in an engine operating condition corresponds to transient operation, the set point module 368 may set one or more of the weighting values 342 to zero. In turn, the corresponding one of the target values 230-244 may be adjusted in a manner that changes the engine operating condition at the desired rate. The set point module 368 may determine that the desired rate corresponds to transient operation when the desired rate is greater than a first rate. Conversely, the setpoint module 368 may determine that the target rate corresponds to stable operation if the target rate is less than or equal to the first rate. The first rate may be the rate at which the engine operating condition may be changed when the cost is determined based on one of the equations described above. The set point module 368 may determine the first rate based on a rate of change in a predicted parameter (e.g., predicted torque output). Alternatively, the first installment can be specified.

In one example, determining the cost based on the reference throttle opening area and the total amount of change in possible target throttle openings may limit the rate at which the torque output of the engine 102 may be changed. Thus, if the driver adjusts the accelerator pedal position to a wide open throttle, the weighting values associated with the reference throttle opening area and the total change amount of the possible target throttle openings may be set to zero. In turn, the target throttle opening area 232 may be adjusted in a manner that changes the torque output of the engine 102 at a desired rate.

In another example, a desired manifold pressure may increase rapidly when, for example, one or more cylinders of the engine 102 are deactivated. However, determining the cost based on the reference wastegate opening area and the total amount of change in the possible wastegate opening areas of a sequence may limit the rate at which the torque output of the engine 102 can be changed. Thus, when one or more cylinders of the engine 102 are deactivated, the weighting values associated with the reference wastegate opening area and the total amount of change in the wastegate opening area may be set to zero. In turn, the target wastegate opening area 230 may be adjusted in a manner that changes the manifold pressure at the desired rate.

When the desired rate of change in the engine operating condition corresponds to stable operation, the set point module 368 may adjust each of the reference values 340 from a first value to a second value in a stepped manner. However, if a desired rate of change of an engine operating condition corresponds to transient operation, the set point module 368 may adjust one or more of the reference values 340 in a manner that achieves the desired rate. For example, the set point module 368 may adjust the reference value in a manner that causes an initial overshoot or undershoot of the second value depending on whether the set point module 368 increases or decreases the reference value. In the event of an overshoot or undershoot of the second value, the set point module 368 may adjust the reference value from a first value to a corresponding one of the actuator constraints 348 and then adjust the reference value to a second value.

In one example, when the base air torque request 308 increases from 50 Nm to 300 Nm, the target throttle opening area 232 may be adjusted in a stepped manner from 100 mm ² to 500 mm ² using the equations described above. However, if the rate of change of the base air torque request 308 corresponds to transient operation, the reference throttle opening area may be adjusted in a manner that reflects the desired rate of change in the Engine torque output achieved. For example, the reference throttle opening area may be initially set from 100 mm ² to 1000 mm ² and then set to 500 mm ² . In turn, the target throttle opening area 232 may be adjusted in a manner that changes the torque output of the engine 102 at the desired rate.

In another example, as discussed above, a desired manifold pressure may increase rapidly when one or more cylinders of the engine 102 are deactivated. However, adjusting the reference wastegate opening area in a stepped manner from a first value to a second value may limit the rate at which the manifold pressure can be changed. Thus, when one or more cylinders of the engine 102 are deactivated, the reference wastegate opening area may be adjusted from the first value to a wastegate opening area corresponding to fully closed and then adjusted to a second value. In turn, the target wastegate opening area 230 may be adjusted in a manner that changes the manifold pressure at the desired rate.

Instead of or in addition to determining whether the target rate corresponds to transient operation, the set point module 368 may determine the reference values 340 based on a predetermined relationship between the target rate and the reference values 340. Further, the set point module 368 may adjust one or more of the reference values 340 from a first value corresponding to stable operation to a second value corresponding to stable operation based on a reference trajectory. The reference trajectory can have a plurality of reference values. The reference trajectory can be non-linear, predetermined and/or determined based on a predetermined relationship between the target rate and the reference trajectory. The reference trajectory may also be determined based on the second value corresponding to stable operation after the change in engine operating condition is complete. The predetermined relationships used to determine the reference values and/or the reference trajectory may be embodied in a lookup table and/or an equation and may be linear or nonlinear.

Likewise, instead of or in addition to comparing the target rate of change to the first rate, the set point module 368 may determine the weighting values 342 based on a predetermined relationship between the target rate and the weighting values 342. The predetermined relationship may be embodied in a lookup table and/or an equation and may be linear or nonlinear. Further, the weight values 342 may be set to predetermined values other than zero.

The set point module 368 may adjust the reference values 340 and/or the weighting values 342 dynamically based on a desired rate of change in one or more operating conditions of the engine 102. In other words, the set point module 368 may adjust the reference values 340 and/or the weighting values 342 in real time while the engine 102 is operating (i.e., without turning off the engine 102 or the ECM 114). Additionally, the reference values 340 and/or the weighting values 342 may or may not be different from one control loop to the next or from one control maneuver to the next.

Now referring to 4 begins an exemplary method for controlling the throttle valve 112, the intake cam phaser 148, the exhaust cam phaser 150, the exhaust wastegate 162 (and therefore the turbocharger), the EGR valve 170, the ignition timing, fueling, and the number of cylinders turned on/off , using the MPC (Model Predictive Control) at 402. At 404, the propulsion torque arbitration module 214 determines the propulsion torque request 222. At 406, the torque conversion module 304 converts the propulsion torque request 222 to the base torque request 308 or to any other suitable type of torque for use by the MPC module 312 around.

At 408, the setpoint module 368 determines the reference values 340 and the weighting values 342. As discussed above, the setpoint module 368 may determine the reference values 340 and/or the weighting values 342 based on a desired rate of change in an operating condition of the engine 102. For example, the setpoint module 368 may set one or more of the weighting values 342 to zero when the target rate corresponds to transient operation. In another example, the set point module 368 may adjust one or more of the reference values 340 based on a reference trajectory when the desired rate corresponds to transient operation.

At 410, the sequence determination module 316 determines possible sequences of the target values 230-244. At 412, the prediction module 323 determines the predicted parameters for each of the possible sequences of target values. The prediction module 323 determines the predicted parameters for the possible sequences based on the model 324 of the engine 102, the exogenous inputs 328, and the feedback inputs 330. Specifically, the prediction module 323 generates using the model 324 based on a possible sequence of the target values 230 -244, the exogenous inputs 328 and the feedback inputs 330, a sequence of N predicted engine 102 torques for the N control loops, a sequence of N predicted fuel efficiency values for the N control loops, and a sequence of N predicted NVH values for the N control loops.

oder auf der Grundlage der Gleichung: $$\begin{array}{l}Cost={{\displaystyle {\sum }_{i=1}^{N}p{\epsilon }^2+\Vert wT\ast \left(T{P}_i-\text{BT}{R}_i\right)\Vert }}^2+{\Vert wA\ast \left(APC{P}_i-\text{MinAPC}\right)\Vert }^2+\\ {\Vert wTO\ast \left(PTT{o}_i-\text{TORefi}\right)\Vert }^2+{\Vert \text{w}\Delta \text{PTTO}\ast \Delta \text{PTTO}\Vert }^2+\Vert wWG\ast (PTWGOi-\\ {WGORefi)\Vert }^2+{\Vert \text{w}\Delta \text{PTWG}\ast \Delta \text{PTWG}\Vert }^2+{\Vert wEGR\ast \left(PTEGRi-EGRRefi\right)\Vert }^2+\\ {\Vert \text{w}\Delta \text{PTEGR}\ast \Delta \text{PTEGR}\Vert }^2+{\Vert wIP\ast \left(PTICPi-ICPRefi\right)\Vert }^2+{\Vert \text{w}\Delta \text{PTICP}\ast \Delta \text{PTICP}\Vert }^2+\\ {\Vert wEP\ast \left(PTECPi-ECPRefi\right)\Vert }^2+{\Vert \text{w}\Delta \text{PTECP}\ast \Delta \text{PTECP}\Vert }^2+\Vert wS\ast (PSi-\\ {SRefi)\Vert }^2+{\Vert \text{w}\Delta \text{PS}\ast \Delta \text{PS}\Vert }^2+{\Vert wN\ast \left(PNi-NRefi\right)\Vert }^2+{\Vert \text{w}\Delta \text{PN}\ast \Delta \text{PN}\Vert }^2+\\ {\Vert wF\ast \left(PFi-FRefi\right)\Vert }^2+{\Vert \text{w}\Delta \text{PF}\ast \Delta \text{PF}\Vert }^2\end{array}$$

vorbehaltlich der Aktorbeschränkungen 348 und der Ausgabebeschränkungen 352, bestimmen, wie es oben besprochen wurde.At 414, the cost module 332 determines the costs of each possible sequence. By way of example, the cost module 332 can calculate the costs for a possible sequence of target values 230-244 based on the equation: $$COst={{\displaystyle {\sum }_{i=1}^{N}p{\epsilon }^2+\Vert wT\ast \left(T{P}_i-\text{BT}{R}_i\right)\Vert }}^2+{\Vert wA\ast \left(APC{P}_i-\text{MinAPC}\right)\Vert }^2,$$

or based on the equation: $$\begin{array}{l}COst={{\displaystyle {\sum }_{i=1}^{N}p{\epsilon }^2+\Vert wT\ast \left(T{P}_i-\text{BT}{R}_i\right)\Vert }}^2+{\Vert wA\ast \left(APC{P}_i-\text{MinAPC}\right)\Vert }^2+\\ {\Vert wTO\ast \left(PTT{O}_i-\text{TORefi}\right)\Vert }^2+{\Vert \text{w}\Delta \text{PTTO}\ast \Delta \text{PTTO}\Vert }^2+\Vert wWG\ast (PTWGOi-\\ {WGORefi)\Vert }^2+{\Vert \text{w}\Delta \text{PTWG}\ast \Delta \text{PTWG}\Vert }^2+{\Vert wEGR\ast \left(PTEGRi-EGRRefi\right)\Vert }^2+\\ {\Vert \text{w}\Delta \text{PTEGR}\ast \Delta \text{PTEGR}\Vert }^2+{\Vert wIP\ast \left(PTICPi-ICPRefi\right)\Vert }^2+{\Vert \text{w}\Delta \text{PTICP}\ast \Delta \text{PTICP}\Vert }^2+\\ {\Vert wEP\ast \left(PTECPi-ECPRefi\right)\Vert }^2+{\Vert \text{w}\Delta \text{PTECP}\ast \Delta \text{PTECP}\Vert }^2+\Vert wS\ast (PSi-\\ {SRefi)\Vert }^2+{\Vert \text{w}\Delta \text{P.S}\ast \Delta \text{P.S}\Vert }^2+{\Vert wN\ast \left(PNi-NRefi\right)\Vert }^2+{\Vert \text{w}\Delta \text{PM}\ast \Delta \text{PM}\Vert }^2+\\ {\Vert wF\ast \left(PFi-FRefi\right)\Vert }^2+{\Vert \text{w}\Delta \text{PF}\ast \Delta \text{PF}\Vert }^2\end{array}$$

subject to the actor constraints 348 and the output constraints 352, determine as discussed above.

At 416, the selection module 344 selects one of the possible sequences of the target values 230-244 based on the cost of the possible sequences. For example, the selection module 344 may select one of the lowest cost possible sequences. The selection module 344 may therefore select one of the possible sequences that best achieves the base torque request 308 and the target exhaust enthalpy while minimizing fuel consumption and particulate emissions. Instead of or in addition to determining possible sequences of target values 230-244 at 410 and determining the cost of each of the sequences at 414, the MPC module 312 may identify a lowest cost sequence of possible target values using convex optimization techniques, as discussed above.

At 418, the MPC module 312 determines whether the selected one of the possible sequences meets the actor constraints 348. If the selected one of the possible sequences meets the actor constraints 348, the method continues at 420. Otherwise, the method continues at 422 where the MPC module 312 selects the next lowest cost one of the possible sequences. The procedure then returns to 418. In this way, the lowest cost sequence that meets the actor constraints 348 is used.

At 420, the first implementation module 248 converts the target wastegate opening area 230 into the target duty cycle 250 to be applied to the wastegate 162, the second implementation module 252 converts the target throttle opening area 232 into the target duty cycle 254, which should be applied to the throttle valve 112. Additionally, at 428, the third translation module 256 translates the target EGR opening area 234 into the target duty cycle 258 to be applied to the EGR valve 170. In addition, the fourth implementation module may translate the target intake cam phasing angle and the target exhaust cam phasing angle 236 and 238 into the target intake duty cycle and the target exhaust duty cycle, which is to be applied to the intake cam phaser or to the exhaust cam phaser 148 or 150.

At 424, the throttle actuator module 116 controls the throttle valve 112 to achieve the target throttle opening area 232 and the phaser actuator module 158 controls the intake cam phaser and exhaust cam phaser 148 and 150 to achieve the target intake cam phaser angle and target To achieve exhaust cam phaser angles 236 or 238. For example, the throttle actuator module 116 may apply a signal with the target duty cycle 254 to the throttle valve 112 to achieve the target throttle opening area 232.

Additionally, the EGR actuator module 172 controls the EGR valve 170 at 424 to achieve the target EGR opening area 234 and the wastegate actuator module 164 controls the wastegate 162 to achieve the target wastegate opening area 230. For example, the EGR actuator module 172 may apply a signal with the target duty cycle 258 to the EGR valve 170 to achieve the target EGR opening area 234, and the boost actuator module 164 may apply a signal with the target duty cycle 250 to that Apply wastegate 162 to achieve the target wastegate opening area 230. Additionally, at 424, the ignition actuator module 126 controls ignition timing based on the target ignition timing setting 240, the cylinder actuator module 120 controls cylinder activation and deactivation based on the target cylinder number 242, and the fuel actuator module 124 controls fueling based on the target fueling parameters 244. The procedure can end at 426. Alternatively, you can 4 illustrate a control loop, and the control loops may execute at a predetermined rate.

Now referring to 5 are a target manifold pressure 502, an actual manifold pressure 504 and a reference wastegate opening area 506 plotted with respect to an x-axis that represents the time 508. At 510, the desired manifold pressure 502 increases from a first pressure 512 to a second pressure 514 in a stepped manner. In response, the set point module 368 reduces the reference wastegate opening area 506 in a stepped manner from a first area 516 to a second area 518. The cost module 332 determines the cost of possible sequences of the target values 230-244 based on the equations described above, and the selection module 344 selects the one of the possible sequences that has the lowest cost. Thus, the rate at which the actual manifold pressure 504 increases from the first pressure 512 to the second pressure 514 may be less than the rate at which the desired manifold pressure 502 increases from the first pressure 512 to the second pressure 514.

Now referring to 6 are a target manifold pressure 602, an actual manifold pressure 604 and a reference wastegate opening area 606 plotted with respect to an x-axis that represents the time 608. At 610, the desired manifold pressure 502 increases from a first pressure 612 to a second pressure 614 in a stepped manner. In response, the set point module 368 reduces the reference wastegate opening area 506 from a first area 616 to a second area 618 based on a reference trajectory 620. The reference trajectory 620 is determined based on the rate of change of the desired manifold pressure 602. Thus, the rate at which the actual manifold pressure 604 increases from the first pressure 612 to the second pressure 614 is nearly equal to the rate at which the desired manifold pressure 602 increases from the first pressure 612 to the second pressure 614.

The term module can refer to an application specific integrated circuit (ASIC); to a digital, analog or mixed analog/digital discrete circuit; to a digital, analog or mixed analog/digital integrated circuit; to a combinational logic circuit; to a field programmable logic array (FPGA); to a processor (shared, dedicated, or group) that executes code; to memory (shared, dedicated or group) that stores code executed by a processor; to other suitable hardware components that provide the described functionality; or relate to, be part of, or contain a combination of some or all of the above, such as in a single-chip system.

The term code, as used above, may include software, firmware and/or microcode and may refer to programs, routines, functions, classes and/or objects. The term shared processor includes a single processor that executes some or all of the code from multiple modules. The term group processor includes a processor that executes some or all of the code from one or more modules together with additional processors. The term shared memory includes a single memory that stores some or all of the code from multiple modules. The term group memory includes a memory that is a part or stores all code from one or more modules together with additional memories. The term storage can be a subset of the term computer-readable medium. The term computer-readable medium does not include transient electrical and electromagnetic signals propagating through a medium and can therefore be considered concrete and non-transitory. Non-limiting examples of a non-transitory tangible computer-readable medium include non-volatile memory, volatile memory, magnetic storage, and optical storage.

Claims (10)

Method comprising: generating predicted parameters based on a model (324) of a subsystem and a set of possible target values (230, 232, 234, 236, 238, 240, 242, 244); generating costs for the set of possible target values (230, 232, 234, 236, 238, 240, 242, 244) based on the predicted parameters and at least one of weight values (342) and reference values (340); adjusting the at least one of the weighting values (342) and the reference values (340) based on a desired rate of change in an operating condition of the subsystem; selecting the set of possible target values (230, 232, 234, 236, 238, 240, 242, 244) from a plurality of sets of possible target values (230, 232, 234, 236, 238, 240, 242, 244) based on the cost; and Setting an actuator (116, 120, 124, 126, 158, 164, 172) of the subsystem based on at least one of the target values (230, 232, 234, 236, 238, 240, 242, 244). Procedure according to Claim 1 , further comprising setting at least one of the weighting values (342) to zero if the target rate of change is greater than a first rate. Procedure according to Claim 2 , wherein the weighting values (342) have a first weighting value (342) which is assigned to a difference between one of the possible target values (230, 232, 234, 236, 238, 240, 242, 244) and one of the reference values (340). , the method further comprising setting the first weight value (342) to zero if the target rate of change is greater than the first rate. Procedure according to Claim 2 , wherein the weighting values (342) have a first weighting value (342) which is assigned to the total amount of change in one of the possible target values (230, 232, 234, 236, 238, 240, 242, 244) over N control loops, and N is an integer greater than one, the method further comprising setting the first weight value (342) to zero if the desired rate of change is greater than the first rate. Procedure according to Claim 2 , further comprising determining the first rate based on a rate of change in at least one of the predicted parameters. Procedure according to Claim 1 , further comprising: determining a reference trajectory (620) based on the desired rate of change; and adjusting at least one of the reference values (340) based on the reference trajectory (620). Procedure according to Claim 1 , further with setting at least one of the reference values (340) to at least one of a maximum limit of the actuator (116, 120, 124, 126, 158, 164, 172) and a minimum limit of the actuator (116, 120, 124, 126, 158, 164, 172) if the target rate of change is greater than a first rate. Procedure according to Claim 1 , wherein the subsystem is an engine (102) and the operating condition is a desired torque output of the engine (102). Procedure according to Claim 8 , wherein the weighting values (342) have a first weighting value (342) associated with a difference between a target throttle opening area (232) and a reference throttle opening area, the method further comprising setting the first weighting value (342) to zero if the target -Rate of change is greater than a first rate. Procedure according to Claim 8 , wherein the reference values (340) have a reference throttle opening area, the method further comprising: determining a reference trajectory (620) based on the desired rate of change; and adjusting the reference throttle opening area based on the reference trajectory.

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