DE102021100235A1 - CONTROL SYSTEM AND PROCEDURE FOR HYBRID VEHICLES - Google Patents

Abstract

Aspects of the present invention relate to a method and control system for controlling an engine and an electric traction motor of a vehicle, the control system comprising one or more regulators, the control system configured to: obtain an engine speed setpoint; determine a rate of change in the engine speed setpoint; and to control the electric traction motor and / or the motor to provide a torque as a function of the motor speed setpoint and as a function of the rate of change.

Description

TECHNICAL AREA

The present disclosure relates to a hybrid vehicle control system and method. In particular, but not exclusively, it relates to a hybrid vehicle control system and method for controlling activation of an engine.

BACKGROUND

In a typical hybrid electric vehicle, one or more electric traction motors are used to contribute at least some tractive effort output torque ("torque" herein) to reduce or eliminate the use of an internal combustion engine ("engine" herein), and thus fuel consumption reduce emissions. If the torque demand is high or the traction battery charge is low, a contribution from the motor may be required.

In some situations the engine has to be run at a certain speed. A controller can determine a torque required to change the engine speed toward the desired speed target. The controller can control the motor in such a way that the determined torque is provided.

SUMMARY OF THE INVENTION

It is an object of the present invention to overcome one or more disadvantages of the prior art.

Aspects and embodiments of the invention provide a control system, vehicle, method and computer software according to the appended claims.

According to one aspect of the invention, there is provided a control system for controlling an engine and a traction electric motor of a vehicle, the control system comprising one or more regulators, the control system configured to: obtain an engine speed setpoint; determine a rate of change in the engine speed setpoint; and to control the electric traction motor and / or the motor to provide a torque depending on the motor speed setpoint and depending on the rate of change.

One advantage is a more responsive and quieter vehicle. This is because the controller is better able to reduce the error (difference) between the engine speed and a moving setpoint (engine speed setpoint).

The control system may be configured to determine a forward torque by multiplying the rate of change of the engine speed setpoint by a constant, the torque provided being a function of the forward torque. One advantage is that the motor speed is changed at a greater rate to compensate for the moving set point. The term “feedforward control” as used here refers to the measurement and consideration of a disturbance (e.g. a moving setpoint) before it has time to influence a system.

The control system may be configured to receive feedback indicative of the engine speed, the torque provided being dependent on a difference between the feedback engine speed and the engine speed setpoint. One advantage is improved responsiveness. The feedback minimizes the error from the setpoint, and the dependence on the rate of change compensates for the movement of the setpoint.

The torque provided can depend on the difference, which is processed with a proportional-integral (PI) or proportional-integral-derivative (PID) controller. One advantage is that the performance of the PI / PID controller is improved with moving setpoints. The forward torque reduces the dependency on the integrator term, which would otherwise build up sharply in response to a changing setpoint. Winding up the integrator causes the setpoint to overshoot. Therefore, the overshoot and the settling time are reduced.

The control system can be configured to apply a low pass filter to the speed setpoint before determining a required torque to control the electric traction motor and / or the motor. One advantage is improved stability, since the sensitivity of the derivative (determined rate of change) is reduced to discontinuities.

The specification of the engine speed can depend on the requirement to synchronize the engine speed with an input speed of the vehicle transmission. One advantage is that the synchronization can be carried out more quickly by using this method.

In some examples, the received engine speed setpoint is associated with a request to convert the engine from a first mode to a second mode, wherein the engine is in first mode is in a deactivated state and a torque path is disconnected between a first set of vehicle wheels and both the motor and the electric traction motor, and wherein in the second mode the motor is in an activated state and the torque path is connected. The control system may be configured to provide an indication when the engine speed has reached the engine speed setpoint to effect the connection of the torque path. One advantage is that the engine can be activated and quickly deliver the driver's torque demand before the torque path is connected. Possible use cases are: the first mode is an electric vehicle mode and the second mode is a hybrid electric vehicle mode; or the first mode is a sliding mode and the second mode is a non-sliding mode; or the first mode is a terrain-dependent mode and the second mode is another terrain-dependent mode.

In the electric vehicle mode, a second electric traction motor can be operable to apply a pulling torque to a second set of vehicle wheels. One advantage is that the vehicle can drive in electric vehicle mode when the (first) electric traction motor can only provide torque to vehicle wheels when the motor torque path is connected, e.g. B. when the first electric traction motor is a belt-integrated starter generator and / or an engine-accessory engine-generator or a crankshaft-integrated motor generator.

In the hybrid electric vehicle operating mode, the second electric traction motor can be operated in such a way that it exerts a torque on the second set of vehicle wheels (HL, HR). In one example, the first set of vehicle wheels includes front wheels and the second set of vehicle wheels (HL, HR) includes rear wheels, or the first set of vehicle wheels includes rear wheels and the second set of vehicle wheels includes front wheels. One advantage is that the vehicle has a multi-axis drive, e.g. B. a four-wheel drive can realize.

In some examples, the second electric traction motor is operable to provide pulling torque to change vehicle speed during at least a portion of a transition from electric vehicle mode to hybrid electric vehicle mode and wherein the engine speed setpoint is dependent on vehicle speed. One advantage is that the vehicle can be accelerated and braked during the transition. However, this functionality can result in a rapidly changing engine speed setpoint. Therefore, the control method described here compensates for the rate of change of the engine speed target value.

According to another aspect of the invention, there is provided a vehicle that includes the control system, the motor, and the electric traction motor.

According to a further aspect of the invention, a method for controlling a motor and an electric traction motor of a vehicle is provided, the method comprising: determining a motor speed setpoint; Determining a rate of change of the engine speed setpoint; and controlling the electric traction motor and / or the motor to provide a torque as a function of the motor speed setpoint and as a function of the rate of change.

According to a further aspect of the invention, computer software is provided which, when executed, is set up to execute one or more of the methods described herein.

According to a further aspect of the invention, there is provided a non-transitory computer-readable medium comprising computer-readable instructions which, when executed by a processor, cause one or more of the methods described herein to be performed.

According to a further aspect of the invention, a control system is provided which is configured to carry out one or more of the methods described herein.

The one or more controllers as described herein may collectively comprise: at least one electronic processor having an electrical input for receiving information associated with the engine speed setpoint; and at least one electronic storage device electrically coupled to the at least one electronic processor and having instructions stored therein; and wherein the at least one electronic processor is configured to access the at least one memory device and execute the instructions thereon to cause the control system to control the motor and / or the electric traction motor based on the information.

Within the scope of this application, it is expressly intended that the various aspects, embodiments, examples and alternatives set forth in the preceding paragraphs, in the claims and / or in the following description and the drawings, and in particular the individual features thereof, independently or can be used in any combination. This means that all embodiments and / or features of an embodiment can be combined with one another in any desired manner and / or combination, provided that these features are not incompatible with one another. Applicant reserves the right to amend any originally filed claim or to file a new claim accordingly, including the right to amend an originally filed claim to be dependent on another claim and / or to incorporate a feature of another claim, although it was not originally claimed that way.

Figure list

• 1 zeigt ein Beispiel für ein Fahrzeug;
• 2 zeigt ein Beispiel für ein System;
• 3A veranschaulicht ein Beispiel für ein Steuersystem und 3B veranschaulicht ein Beispiel für ein nicht-transitorisches computerlesbares Speichermedium;
• 4 illustriert ein Beispiel eines Zustandsdiagramms zum Umschalten zwischen zwei Modi;
• 5 veranschaulicht ein Beispiel für ein Verfahren; und
• 6A illustriert ein Beispiel eines Graphen mit Geschwindigkeits- und Zeitachsen; 6B

One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

• 1 shows an example of a vehicle;
• 2 shows an example of a system;
• 3A illustrates an example of a control system and 3B Figure 11 illustrates an example of a non-transitory computer readable storage medium;
• 4th illustrates an example of a state diagram for switching between two modes;
• 5 Figure 11 illustrates an example of a method; and
• 6A illustrates an example of a graph with speed and time axes; 6B

DETAILED DESCRIPTION

1 shows an example of a vehicle 10 in which embodiments of the invention can be implemented. In some, but not necessarily all examples, the vehicle is 10 a passenger car, which is also referred to as a passenger car or an automobile. In other examples, embodiments of the invention may be used for other applications such as e.g. B. Industrial vehicles are implemented.

The vehicle 10 can be a hybrid electric vehicle (HEV). When the vehicle 10 is a HEV, the vehicle can 10 be a full HEV or a mild HEV. Mild HEVs do not have an all-electric propulsion mode, but the electric traction motor can be configured to provide assistance such as driving. B. the gain of the output torque of the engine. Full HEVs have an all-electric propulsion mode.

When the vehicle 10 is a HEV, the vehicle can 10 configured for operation as a parallel HEV. Parallel HEVs include a torque path between the engine and at least one vehicle wheel and a torque path between an electric traction motor and at least one vehicle wheel. The torque path (s) can be through a torque path connector, such as a. B. a clutch can be decoupled. Parallel HEVs are different from serial HEVs because with serial HEVs, the purpose of the engine is to generate electrical energy and there is no torque path between the engine and the vehicle wheels.

In 2 is a system 20th for a parallel HEV 10 shown. The system 20th defines, at least in part, a powertrain of the HEV.

The system 20th includes a tax system 208 . The tax system 208 includes one or more controllers. The tax system 208 may include one or more of the following: a hybrid powertrain control module; an engine control unit; a transmission control unit; a traction battery management system; and / or the like.

The system 20th includes an engine 202 . The motor 202 is an internal combustion engine. In the engine shown 202 it is an internal combustion engine. The engine shown 202 includes three combustion chambers, but a different number of combustion chambers may be provided in other examples.

The motor 202 is functional with the control system 208 coupled with it the tax system 208 the output torque of the motor 202 can control. The output torque of the motor 202 can be controlled by controlling one or more of the following: air-fuel ratio; Ignition timing; Stroke of the poppet valve; Timing the poppet valve; Throttle opening position; Fuel pressure; Turbocharger boost pressure; and / or the like, depending on the type of engine 202 .

The system 20th includes an optional pinion starter 206 to start the engine 202 .

The system 20th includes a vehicle transmission assembly 204 to absorb the output torque from the engine 202 . The vehicle transmission assembly 204 may include an automatic vehicle transmission, a manual vehicle transmission, or a semi-automatic vehicle transmission. The vehicle transmission assembly 204 may have one or more friction clutches and / or a torque converter between the engine 202 and a gear train.

The system 20th may include a differential (not shown) for receiving output torque from the gear train. The differential can be used as a transaxle in the vehicle transmission assembly 204 be integrated or provided separately.

The motor 202 is mechanical via a torque path 220 connected or connectable to a first set of vehicle wheels (VL, VFR). The torque path 220 extends from an output of the engine 202 to the vehicle transmission assembly 204 , then to axles / drive shafts and then to the first set of vehicle wheels (VL, VR). In an overrun and / or friction braking situation of the vehicle, the torque from the first set of vehicle wheels (VL, VR) to the engine 202 flow. The torque flow towards the first set of vehicle wheels (VL, VR) is positive torque and the torque flow from the first set of vehicle wheels (VL, VR) is negative torque.

The illustrated first set of vehicle wheels (VL, VR) includes front wheels and the axles are front transverse axles. Hence the system 20th for front wheel drive by the engine 202 configured. In another example, the first set of vehicle wheels (VL, VR) includes rear wheels. The illustrated first set of vehicle wheels (VL, VR) is a pair of vehicle wheels, but a different number of vehicle wheels could be provided in other examples.

In the system shown 20th there is no longitudinal (center) drive shaft to make room for hybrid vehicle components. Hence the engine 202 Cannot be connected to a second set of rear wheels (rear wheels HL, HR in the illustration). The motor 202 can be installed across to save space. In an alternative example, the engine 202 Be configured to drive the front and rear wheels.

A torque path connector 218 such as B. a clutch is inside and / or outside a bell housing of the vehicle transmission assembly 204 intended. The coupling 218 is configured to use the torque path 220 between the engine 202 and connects and disconnects the first set of vehicle wheels (VL, VR). The system 20th can be configured so that it is the clutch 218 operated automatically without user intervention.

The system 20th includes a first electric traction motor 216 . The first electric drive motor 216 can be an AC induction motor or a permanent magnet motor or other type of motor. The first electric drive motor 216 is located on the motor side of the clutch 218 .

The first electric drive motor 216 can be mechanically connected to the motor via a belt or chain 202 be coupled. For example, the first electric traction motor 216 be a belt-integrated starter generator. The illustration shows the first electric drive motor 216 at an accessory drive end of the engine 202 , opposite a vehicle transmission end of the engine 202 . In an alternative example, the first is an electric traction motor 216 a crankshaft integrated motor generator located at a vehicle transmission end of the engine 202 is located.

The first electric drive motor 216 is configured to have positive torque and negative torque on a crankshaft of the engine 202 exercises to provide functions such as: Boosting the output torque of the engine 202 ; Deactivating (switching off) the motor 202 at a stop or while idling; Activate (start) the motor 202 ; and regenerative braking in a regeneration mode. In a hybrid electric vehicle mode, the engine can 202 and the first electric traction motor 216 both deliver positive torque at the same time to increase the output torque. The first electric drive motor 216 may not be able to drive all-electric for a long time.

However, if the torque path 220 between the engine 202 and the first set of vehicle wheels (VL, VR) is interrupted, a torque path is also established 220 between the first electric traction motor 216 and the first set of vehicle wheels (VL, VR) interrupted.

In 2 is a second electric drive motor 212 which is configured to enable at least one electric vehicle mode that includes pure electric driving. In some, but not necessarily all examples, is a maximum rated torque of the second electric traction motor 212 greater than a maximum nominal torque of the first electric traction motor 216 .

Even if the torque path 220 between the engine 202 and the first set of vehicle wheels (VL, VR) through the clutch 218 is interrupted, the vehicle can 10 be driven in electric vehicle mode because the second electric drive motor 212 is connected to at least one vehicle wheel.

The illustrated second electric traction motor 212 is configured to apply torque to the illustrated second set of vehicle wheels (HL, HR). The second set of vehicle wheels (HL, HR) includes vehicle wheels that do not belong to the first set of vehicle wheels (VL, VR). The illustrated second set of vehicle wheels (HL, HR) includes rear wheels, and the second electric travel motor 212 can be operated in such a way that it delivers a torque to the rear wheels HL, HR via rear transverse axes. Hence the vehicle 10 rear-wheel drive in electric vehicle mode. In an alternative example, the second set of vehicle wheels includes at least one vehicle wheel of the first set of vehicle wheels.

The tax system 208 can be configured to use the torque path 220 between the engine 202 and interrupts the first set of vehicle wheels (VL, VR) in the electric vehicle mode to reduce parasitic pumping energy losses. For example, the clutch 218 be opened. In the example of 2 this means that the first electric traction motor 216 is also decoupled from the first set of vehicle wheels (VL, VR).

Another advantage of the second electric drive motor 212 is that the second electric traction motor 212 can also be configured so that it can be operated in a hybrid electric vehicle mode to enable all-wheel drive operation despite the lack of a central drive shaft.

To store electrical energy for the electric traction motors, the system includes 20th a traction battery 200 . The traction battery 200 provides a nominal voltage that is required by electrical power consumers such as electric traction motors. If the electric traction motors run at different voltages, DC-DC converters (not shown) or the like can be provided in order to convert voltages.

The traction battery 200 can be a high voltage battery. High voltage traction batteries provide rated voltages in the hundreds of volts, as opposed to mild HEV traction batteries, which provide rated voltages in the tens of volts. The traction battery 200 can have a voltage and capacity that supports purely electric driving over longer distances. The traction battery 200 can have a capacity of several kilowatt hours to maximize range. The capacity can be in the range of a few tens of kilowatt hours or even over a hundred kilowatt hours.

Although the traction battery 200 shown as a unit could be the function of the traction battery 200 with a multitude of small traction batteries in different places on the vehicle 10 will be realized.

In some examples, the first electric traction motor 216 and the second electric traction motor 212 be configured to get electrical power from the same traction battery 200 Receive. By coupling the first (weak) electric drive motor 216 with a battery with a high capacity (ten to hundreds of kilowatt hours) the first electric traction motor 216 be able to provide the functionality of the methods described here for extended periods of time, not just for short periods of time. In another example, the electric traction motors 212 , 216 be paired with different traction batteries.

Finally, the illustrated system includes 20th Inverter. There are two inverters 210 , 214 shown, one for each electric traction motor. In other examples, one inverter or more than two inverters could be provided.

In an alternative implementation, the vehicle 10 different than in 2 be shown.

3A illustrates how the tax system 208 can be implemented. The tax system 208 from 3A illustrates a regulator 300 . In other examples, the control system 208 a variety of controls on board and / or outside the vehicle 10 include.

The regulator 300 from 3A includes at least one electronic processor 302 ; and at least one electronic storage device 304 electrically connected to the electronic processor 302 is coupled and in the instructions 306 (eg a computer program) are stored, wherein the at least one electronic storage device 304 and the instructions 306 are configured to work with the at least one electronic processor 302 cause one or more of the methods described herein to be performed.

3B illustrates a non-transitory computer readable storage medium 308 that the instructions 306 (Computer software) contains.

The tax system 208 can be configured to provide controller outputs to manipulate a variable (torque) in the direction of a setpoint. An example setpoint is at least one torque target. The at least one torque target may typically be based on a torque request, such as a torque request. B. the driver's torque request (e.g. accelerator pedal pressure, APD), a torque request for autonomous driving or a torque request for the cruise control. The at least one torque target can typically be proportional to the torque demand. The torque target may include an engine torque target for controlling the output torque of the engine. The torque target can be a Include a torque target for an electric traction motor for controlling the output torque of an electric traction motor.

Another example setpoint is an engine speed setpoint. The engine torque can be regulated to match the engine speed to the engine speed setpoint used at idle and in other scenarios. The torque of the first electric travel motor can be controlled in order to adapt the engine speed to the engine speed setpoint, since the first electric travel motor is mechanically coupled to the crankshaft of the engine.

A system 20th like the drivetrain of 2 can operate in a variety of modes. In one mode is the engine 202 deactivated and the torque path 220 between the engine 202 and the first set of vehicle wheels (VL, VR) is interrupted. In another mode the engine will 202 reactivated and the torque path 220 will be reconnected.

In a state diagram of the operating modes is shown. The state diagram shows a first mode 400 and a second mode 402 .

In the first mode 400 is the engine 202 in a deactivated state and the torque path 220 between the first set of vehicle wheels (VL, VR) and the engine 202 and the first electric traction motor 216 is interrupted. In one example, the effect of the combined deactivation and disconnection is that the engine speed drops towards zero. The deactivation refers to the fact that the engine 202 does not generate positive output torque or does not generate sufficient positive output torque for non-zero engine speed. The fuel injection can be adjusted to reduce fuel consumption.

In the second mode 402 is the engine 202 in an activated state and the torque path 220 is connected. When activated, fuel is burned in the engine's combustion chambers, causing the engine 202 a positive output torque to the torque path 220 supplies.

In some examples, the first is mode 400 the above-described electric vehicle mode and the second mode 402 is the hybrid electric vehicle mode.

The state diagram illustrates a first transition condition 404 for the transition from the first mode 400 to the second mode 402 . The state diagram illustrates a second transition condition 406 for the transition from the second mode 402 to the first mode 400 .

The first transition condition 404 may require at least one of the following conditions: manual user selection; a state of charge of the traction battery that falls below a threshold value; a torque request that rises above a threshold value (e.g. kickdown function); a temperature that is below a threshold (e.g., frosty weather); a change of the driving dynamics mode; a change of terrain response mode; and / or the like.

The second transition condition 406 may require at least one of the following conditions: manual user selection; a state of charge of the traction battery that rises above a threshold value; a torque demand that falls below a threshold; a temperature that is above a threshold; a change of the driving dynamics mode; a change of terrain response mode; and / or the like.

A vehicle dynamics mode refers to a mode that configures one or more of the following settings: a suspension setting; an accelerator response adjustment; a switch point setting; or a steering weight adjustment. An off-road mode refers to a mode that configures one or more of the following settings: a differential lock setting, a traction control setting. There may be overlaps between driving dynamics modes and terrain reaction modes. The settings can be preset or configurable.

Manual user selection can include the use of an input device of the man-machine interface. The input device may include an engine start button. The input device can comprise a driving dynamics mode selector switch. The input device can comprise a selector switch for the terrain reaction mode. In some examples, a terrain mode and / or a driving dynamics mode can be switched over automatically.

In some examples, the first is mode 400 a sliding mode and the second mode 402 a non-sliding mode. Sliding refers to the deactivation and shutdown of the engine 202 while driving the vehicle 10 without stopping to reduce fuel consumption and pumping losses. The first transition condition 404 may require a torque request above the threshold. The second transition condition 406 can set a torque request below the threshold for a time above the Threshold while the vehicle is moving 10 moves, for example. Sliding mode transitions can be made while the vehicle is in motion 10 does not brake. Transitions to the glide mode can be made while the vehicle is in motion 10 runs at considerable speeds, e.g. B. at more than 30 kilometers per hour.

In some, but not necessarily all examples, the vehicle includes 10 Terrain-dependent modes, such as the terrain-dependent modes described above. The first mode 400 is a terrain dependent mode and the second mode 402 is another terrain-dependent mode. Some terrain-dependent modes require the engine 202 connected and activated, e.g. B. Terrain-dependent modes.

• Ermitteln eines Motordrehzahlsollwerts (Block 502);
• Bestimmen einer Änderungsrate des Motordrehzahlsollwerts (Block 504); und
• Steuern des ersten elektrischen Fahrmotors 216 und/oder des Motors 202, um ein Drehmoment in Abhängigkeit von dem Motordrehzahlsollwert und in Abhängigkeit von der Änderungsrate bereitzustellen (Blöcke 506, 508).

In accordance with one aspect of the present invention, the control system is 208 configured to improve responsiveness in synchronizing engine speed to an engine speed setpoint by a method 500 that includes:

• Determining a motor speed setpoint (block 502 );
• Determine a rate of change of the engine speed setpoint (block 504 ); and
• Controlling the first electric traction motor 216 and / or the engine 202 to provide a torque as a function of the engine speed setpoint and as a function of the rate of change (blocks 506 , 508 ).

5 Figure 3 shows a flow chart for the method 500 according to an exemplary application for the transition from the first mode 400 (e.g. electric vehicle mode) to the second mode 402 (e.g. hybrid electric vehicle mode). The vehicle wheels may be in motion so a quick transition may be required to meet driver's expectations for responsiveness.

The tax system 208 can be configured to synchronize engine speed with vehicle wheel speed before engaging the clutch 218 engages to avoid a torque shock that jerks the vehicle occupants. The synchronization is complete when each side (e.g. lamella) of the clutch 218 the same speed as the other side (e.g. lamella) of the clutch 218 Has.

It is evident, however, that the blocks 502 , 504 , 506 and 508 of the procedure 500 Can also be applied to other applications where a variable motor speed setpoint is used. Examples are the engine idling and revving the engine 202 in an idle.

In block 502 includes the procedure 500 determining an engine speed setpoint. In some, but not necessarily all examples, the engine speed setpoint obtained is based on a request to transition from the first mode 400 to the second mode 402 .

The engine speed target in this example is used to synchronize the engine speed with the wheel speed of the vehicle and is therefore a different target than other speed targets, such as e.g. B. an engine idle speed target. For a vehicle moving at speeds above crawler, the engine speed setpoint is likely to be greater than an engine idle speed target. In the following blocks of the procedure 500 controls the tax system 208 at least the first electric drive motor 216 and / or the engine 202 to provide positive torque to increase engine speed toward the engine speed setpoint.

The wheel speed of the vehicle can increase or decrease during the mode transition, for example as a function of braking or the use of the second electric traction motor 212 . Therefore, the motor speed required for synchronization can vary. When the second electric traction motor 212 is operable during mode transition to provide output torque in response to torque demand, vehicle wheel speed may change during mode transition. Therefore, the engine speed target may change during mode transition.

In block 504 includes the procedure 500 determining the rate of change of the engine speed setpoint. The rate of change can be zero when the engine speed setpoint is constant. The determined rate of change can have a positive value other than zero when the vehicle wheels are accelerated. The determined rate of change can have a negative value other than zero if the vehicle is 10 decelerates. The determined rate of change can be proportional to the magnitude of the acceleration / deceleration.

The tax system 208 may be configured to apply a low pass filter to the engine speed setpoint prior to determining the rate of change of the engine speed setpoint. The low-pass filter smooths out any large discontinuity-like changes in the signal in order to improve the stability of the derived term "rate of change".

In block 506 includes the procedure 500 the determination of a required torque. The torque change required is the torque required to change the engine speed toward the engine speed setpoint.

The required torque depends on the motor speed setpoint received. For example, the control system 208 Be configured to receive feedback indicating engine speed. The required torque can depend on a difference (error) between the reported engine speed and the engine speed setpoint.

In one implementation, the error is processed with a PI / PID controller. The current value of the error is used to calculate the proportional torque. Past values of the error can be accumulated to calculate the integrator torque. A rate of change in the error is used to calculate the derived torque.

The required torque also depends on the determined rate of change of the speed setpoint. The rate of change of the engine speed setpoint can be used, for example, to calculate a forward torque. The forward torque is a torque that depends on the target dynamics and not on the current engine speed. Therefore, the required torque depends on the feedback control (e.g. via a PI / PID control scheme) and the feedforward control. Forward torque can be zero when the speed target is not moving. The forward torque compensates for the moving engine speed setpoint.

wobei τ das erforderliche Drehmoment ist, I ein Parameter ist, der die Motorträgheit angibt (äquivalent zur Masse), und α die Winkelbeschleunigung ist. Das Motorträgheitsmoment kann eine vorgegebene Konstante sein. Wenn die Motorträgheit nicht bekannt ist, kann eine andere Konstante verwendet werden. Die Winkelbeschleunigung basiert auf der Änderungsrate der Motordrehzahlvorgabe. Das Vorwärtsdrehmoment kann mit dem Solldrehmoment identisch sein.The forward torque value is configured to accelerate the engine / system inertia with an acceleration similar or equal to the engine speed setpoint. The value of the forward torque can be determined on the basis of Newton's second law for rotating bodies: $${\displaystyle \sum \tau }=\text{I.}\alpha$$

where τ is the required torque, I is a parameter indicating the motor inertia (equivalent to mass), and α is the angular acceleration. The motor moment of inertia can be a predetermined constant. If the motor inertia is not known, another constant can be used. The angular acceleration is based on the rate of change of the engine speed specification. The forward torque can be identical to the target torque.

The above proportional, integral, derivative and forward torques can be weighted with various pre-calibrated gains to achieve a desired level of responsiveness and smoothness and then summed to determine the final value of torque required.

The procedure 500 then go to block 508 in which the final value of the required torque is used to vary the engine speed in the direction of the engine speed setpoint. The motor 202 and / or the first electric traction motor 216 can be used to change the engine speed. In the present application (mode transition) the activation of the motor 202 and the reconnection of the torque path, the engine speed setpoint is likely to have a greater positive value than the current engine speed, so that the engine speed is increased. In other applications, the engine speed may need to be reduced.

In some examples, block includes 508 the control of the first electric drive motor 216 to provide at least a portion of the torque required to increase the engine speed toward the engine speed setpoint. Electric traction motors are more responsive than motors, which allows for faster synchronization. The engine speed begins with the assistance of the first electric drive motor 216 to increase, for example from a speed of zero.

When the engine 202 is initially below idle speed, the engine delivers 202 may initially not contribute to the required torque. The engine idle speed may be a predetermined value below 1000 RPM determined by the control system 208 is determined. The predetermined value (threshold value) can be fixed or vary based on recognized conditions (e.g. temperatures). In an alternative implementation, the engine speed can be controlled by a pinion starter 206 instead of the first electric drive motor 216 brought to the idle speed of the engine.

The tax system 208 can the engine 202 control so that it begins to contribute at least some of the required torque when it is determined that the engine 202 has reached engine idle speed. Therefore, for a period of time, the engine speed can both be controlled by the engine 202 as well as the first electric drive motor 216 can be increased at the same time. This reduces the time it takes to complete the mode transition.

In some, but not necessarily all examples, the first electric traction motor may 216 be controlled in the closed loop when the engine speed approaches the speed setpoint to achieve a locking torque, e.g. B. a negative torque to provide to prevent overshoot of the engine speed above the speed setpoint. This reduces the settling time, since electric traction motors respond faster than motors and can provide a larger amount of negative torque.

In block 510 includes the procedure 500 optionally the provision of an indication when the engine speed has reached the engine speed setpoint in order to connect the torque path 220 to cause. The display becomes a controller of an actuator of the torque path connector 218 (e.g. clutch), which is part of the control system 208 can be.

6A until 6D illustrate graphs of engine speed, proportional torque, integrator torque, and forward torque controlled according to the method 500 from 5 .

6A shows in the y-axis the amount of a manipulated variable (motor speed) that is generated according to the procedure 500 is regulated, as a solid curve 604 versus time in the x-axis. In 6A is also the magnitude of a target value (engine speed target value) by a chain-dashed line 600 shown. The setpoint increases as the vehicle accelerates. The dashed curve 602 is used for comparison purposes and illustrates the motor speed measured by a PI / PID controller without using the procedure 500 is regulated. The dashed line exceeds the target value, while the solid line does not (or to a lesser extent) overshoots the target value. The reasons for this are discussed below.

, and show the proportional torque, the integrator torque and the forward torque in their respective y-axes. Your x-axes are time axes that are with each other and with the time axis of cursing. The derived torque is not shown. The solid lines represent the proportional torque 614 , the integrator torque 624 and that according to the procedure 500 determined forward moment 632 The dashed lines represent the proportional torque 612 and the integrator torque 622 represent that for comparison purposes without applying the method 500 were determined.

The engine speed is set at time t0 600 determined. The engine speed setpoint changes in the period t0-t1 600 . The change shown is a linear increase, but it may vary depending on how the vehicle is driven 10 take any form. The engine speed setpoint stops at time t1 600 on to rise. From time t1, the engine speed setpoint shown remains 600 constant, but this is for illustrative purposes only.

The dashed lines of the 6A-6D illustrate the effect if the procedure 500 is not applied. The engine speed 602 initially remains behind the speed setpoint 600 back as the change in the speed setpoint 600 is not known to a standard PI / PID controller that only sees the error. The proportional torque 612 increases, and the integrator torque 622 increases sharply due to the wind-up, especially when the engine speed is at the engine speed setpoint 600 "Lags behind" (the engine speed setpoint 600 moves from the engine speed 602 away and not towards the engine speed). The engine speed setpoint stops at time t1 600 on to increase, but the integrator torque 622 continues to wind up due to the remaining error. The point in time t2 represents the point in time at which the engine speed 602 the engine speed target 600 achieved. After the time t2, the engine speed shoots up due to the high integrator torque 622 via the speed setpoint 600 out. The proportional torque 612 becomes negative, which is initially not sufficient to lower the motor speed until the integrator torque 622 has essentially subsided. The engine speed 602 therefore takes a long time to level off.

The solid lines of the 6A-6D illustrate the following the procedure 500 controlled torques 614 , 624 , 632 and the speed 604 . It becomes the pre-controlled torque described above 632 used. The shape of the pre-control torque curve 632 is proportional to the acceleration of the speed setpoint 600 . The initial rapid increase in forward torque 632 reduces the initial lag in engine speed 604 behind the engine speed setpoint 600 . The forward torque 632 therefore prevents the proportional torque 614 and the integrator torque 624 due to the change in the engine speed setpoint 600 achieve high values. Therefore, the tightening of the integrator torque is reduced, which causes the tendency of the PI / PID controller to overshoot the moving setpoint 600 prevented. Due to the reduced settling time, the completion of the synchronization can be indicated earlier and / or the torque shock is reduced.

For the purposes of this disclosure, it is to be understood that the controller (s) described herein 300 each a control unit or computing device with one or more electronic processors 302 can include. A vehicle 10 and / or a system thereof may comprise a single control unit or a single electronic regulator, or, alternatively, different functions of the regulator (s) may be embodied or housed in different control units or regulators. A set of instructions could be provided that, when executed, cause the controller (s) or control unit (s) to implement the control techniques (including the method (s) described) described herein. The set of instructions could be embedded in one or more electronic processors, or alternatively, the set of instructions could be provided as software to be executed by one or more electronic processors. For example, a first controller can be implemented in software executing on one or more electronic processors, and one or more other controllers can also be implemented in software executing on one or more electronic processors, optionally on the same one or more processors like the first regulator. However, it will be clear that other arrangements are also useful, and therefore the present disclosure is not intended to be limited to any particular arrangement. In any event, the instruction set described above may be embedded in a computer readable storage medium (e.g., a non-transitory computer readable storage medium) which may include any mechanism for storing information in a form that can be used by a machine or electronic processor / Computing device is readable including, without limitation: a magnetic storage medium (e.g., floppy disk); optical storage medium (e.g. CD-ROM); magneto-optical storage medium; Read Only Memory (ROM); Random Access Memory (RAM); erasable programmable memory (e.g. EPROM and EEPROM); Flash memory; or electrical or other types of media for storing such information / instructions.

It is appreciated that various changes and modifications can be made in the present invention without departing from the scope of the present application.

Any passage described as an “aspect of the invention” is a self-contained statement suitable for any current or future independent claim without the need for additional features.

In the 5 The blocks shown can include steps in a method and / or code sections in the computer program 306 represent. The representation of a particular order of the blocks does not necessarily mean that there is a required or preferred order for the blocks, and the order and arrangement of the blocks can be varied. In addition, some steps may be left out.

Although embodiments of the present invention have been described in the preceding paragraphs with reference to various examples, it should be understood that modifications can be made to the examples given without departing from the scope of the invention as claimed.

The features described in the preceding description can be used in combinations other than those expressly described.

Although functions have been described with reference to certain features, those functions may be performed by other features whether or not they are described.

Although features have been described with reference to particular embodiments, these features may also be present in other embodiments, whether or not they are described.

Although the foregoing description has sought to draw attention to those features of the invention that are believed to be of particular importance, it should be understood that applicant claims protection with respect to any patentable feature or combination of features referred to herein and / or shown in the drawings, whether or not special emphasis has been placed thereon.

Claims (10)

A control system for controlling an engine and an electric traction motor of a vehicle, the control system comprising one or more controllers, the control system configured to: obtain a setpoint for the engine speed; determine a rate of change in the engine speed setpoint; and control the electric traction motor and / or the motor to provide a torque as a function of the motor speed setpoint and as a function of the rate of change. Tax system according to Claim 1 configured to determine a forward torque comprising multiplying the rate of change of the engine speed setpoint by a constant, the torque provided being dependent on the forward torque. Tax system according to Claim 1 or 2 configured to receive feedback indicative of engine speed, the torque provided being dependent on a difference between the feedback engine speed and the engine speed setpoint; wherein the torque provided is optionally dependent on the difference which is processed using a proportional-integral or proportional-integral-derivative controller. The control system of any preceding claim configured to apply a low pass filter to the engine speed setpoint prior to determining a required torque for controlling the electric traction motor and / or the motor. The control system of any preceding claim, wherein the engine speed setpoint is dependent on a requirement to synchronize the engine speed with the input speed of the vehicle transmission. The control system according to any one of the preceding claims, wherein the received engine speed setpoint is dependent on a request to convert the engine from a first mode to a second mode, wherein in the first mode the engine is in a deactivated state and a torque path between a first set of vehicle wheels and both the engine and the electric traction motor is interrupted, and wherein in the second mode the motor is in an activated state and the torque path is connected; optionally the control system is configured to provide an indication when the engine speed has reached the engine speed setpoint to effect the connection of the torque path; optionally the first mode is an electric vehicle mode and the second mode is a hybrid electric vehicle mode; a second electric traction motor is optionally operable in the electric vehicle mode in order to deliver a pulling torque to a second set of vehicle wheels; optionally the second electric traction motor is operable to provide traction torque to change vehicle speed during at least a portion of a transition from electric vehicle mode to hybrid electric vehicle mode, and wherein the engine speed setpoint is dependent on vehicle speed; optionally in the hybrid electric vehicle operating mode, the second electric traction motor is operable to deliver a pulling torque to the second set of vehicle wheels; optionally the first set of vehicle wheels includes front wheels and the second set of vehicle wheels includes rear wheels, or wherein the first set of vehicle wheels includes rear wheels and the second set of vehicle wheels includes front wheels. The tax system according to Claim 6 wherein: the first mode is a sliding mode and the second mode is a non-sliding mode; or the first mode is a terrain-dependent mode and the second mode is another terrain-dependent mode. A vehicle having the control system, motor and electric traction motor according to any one of the preceding claims. A method of controlling an engine and an electric traction motor of a vehicle, the method comprising: Determining an engine speed setpoint; Determining a rate of change of the engine speed setpoint; and Controlling the electric traction motor and / or the motor to provide a torque as a function of the motor speed setpoint and as a function of the rate of change. Computer software that, when executed, is set up to perform a procedure Claim 9 perform.

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